iea bioenergy 32nd, 33rd, 34th and 35th update

International Energy AgencyBiomass and Bioenergy

IEA Bioenergy“This article was produced by the Implementing Agreementon Bioenergy, which forms part of a programme ofinternational energy technology collaboration undertakenunder the auspices of the International Energy Agency.”

U P D A T E 3 2

Opportunities and Barriers forSustainable International BioenergyTrade

This Technology Report from Task 40 was preparedfor ExCo58 in Sweden in October 2006 by M.Junginger (Main Editor), A. Faaij, P-P.Schouwenberg, C. Arthers, D. Bradley, G. Best, J.Heinimö, B. Hektor, P. Horstink, A. Grassi, K.Kwant, Ø. Leistad, E. Ling, M. Peksa,T. Ranta, F.Rosillo-Calle, Y. Ryckmans, M. Wagener, A. Walter,and J. Woods.

Abstract

Trade of biomass and bioenergy (biotrade) canprovide a stable and reliable situation for sustainableproduction of biomass fuels,become a source ofadditional income and increased employment (e.g.,for rural communities), and may contribute to thesustainable management of natural resources. Forimporters, biotrade may assist to fulfil greenhousegas emission reduction targets in a cost-effectivemanner, diversify their fuel mix, and lead to moresustainable energy production. Stimulated by therenewable energy policies in several countries, risingoil prices, and a wish for diversification of supply, inmost Task 40 Member Countries growth rates of 10-20% or more per year have been observed ininternational trade of biomass and bioenergy.

However, a multitude of different barriers currentlyexist, hampering the development of internationalbioenergy trade. These include economic, technical,logistical, ecological, social, cognitive, legal, andtrade barriers, lack of clear international accounting

rules and statistics, and issues regarding landavailability, deforestation, energy balances, potentialconflicts with food production, and local use versusinternational trade.

Background and Rationale

A reliable supply of and steady demand forbioenergy are vital for developing market activitiesin this area. Given the expectations for a highbioenergy demand on a global scale and by manynations, the pressure on the available biomassresources will increase. Without the development ofbiomass resources (e.g., through energy crops andbetter use of agro-forestry residues) and a wellfunctioning biomass market to assure a reliable,sustainable and lasting supply, those ambitions maynot be achieved. The development of internationalmarkets for bioenergy may become an essentialdriver to develop bioenergy potentials, which arecurrently under-utilised in many regions of theworld. This is true for residues and for dedicatedbiomass production (through energy crops ormultifunctional systems such as agro-forestry). Theopportunity to export biomass-derivedcommodities for the world’s energy market canprovide a reliable demand for rural communities,thus creating important socio-economicdevelopment incentives and market access. Trade inbiomass energy carriers (biotrade) may also enablea more efficient use of materials.

It is essential that this growth in biomass productionand trade proceeds in a sustainable manner. This isof special importance for biomass as sustainability isone of the main reasons for developing renewableenergy sources.

Objectives

Task 40 ‘Sustainable International Bioenergy Trade:Securing Supply and Demand’, started in 2004 andcurrently has 10 participating countries, plus theFAO as an affiliated international body. In addition,joint activities have been organised with otherinstitutions, e.g., the World Bank, EUBIONET II andother IEA Bioenergy Tasks. A key element of thework programme is monitoring the rapidly growinginternational bioenergy trade in solids, liquid fuels,and power while simultaneously evaluatingopportunities and barriers for the development of asound international market. From 2004 to 2006, Task40 has produced a number of reports and jointlyorganised a number of workshops (seewww.bioenergytrade.org). This report summarisesthe main results and the input from all Task 40participants,and addresses bioenergy trade from thepoint-of-view of these participants. It highlights themain issues currently hampering development of theinternational trade in biomass.

While this paper deals with bioenergy trade barriersand opportunities in general, a number ofdeliverables under the work programme of Task 40specifically emphasise the sustainability aspects ofbiomass supply and demand. In some of theparticipating countries the support measures forbioenergy are formally linked to sustainability andhence this issue receives particular attention.

Furthermore, bioenergy trade requires a goodunderstanding of supply and demand issues.Barriers to both supply and demand can hamperinternational trade but it is beyond the scope of thispaper to present an exhaustive overview of allbarriers related to biomass production, trade, anduse. Where appropriate, we have includedreferences for more information.

It is also important to note that the field ofinternational biotrade is developing rapidly, and thusfrequent reviews of barriers and opportunities maybe needed (e.g., bi-annually). The topics described inthis paper reflect the situation in 2006.

Opportunities

Many countries have both a large technicalagricultural and forestry residue potential and a largepotential for dedicated energy plantations formingthe base for efficient production of biofuels such aspellets (Bradley, 2006), or charcoal from energyplantations or ethanol from sugarcane (Walter et al.,2006). Given the availability of land and relativelylow costs of labour in many developing countries,biomass production costs can be low and offer anopportunity for exporting biomass-based energycarriers to developed countries. The export ofbiomass-derived fuels for the world’s energy marketscan provide a reliable demand for fuel from ruralcommunities, particularly in many developingcountries; this can create an important incentive andaccess to the market in many areas of the world.However, availability of resources per se is notenough as there are many other factors that need tobe taken into account, e.g., accessibility, quality, etc.

In the past decade such trade flows have beenincreasing rapidly. Many trade flows are betweenneighbouring countries, but increasingly, long-distance trade is also occurring. Examples are theexport of ethanol from Brazil to Japan and the EU,palm kernel shells (a residue of the palm oilproduction process) from Malaysia to theNetherlands,and wood pellets from Canada,EasternEurope, and Brazil to Sweden, Belgium, theNetherlands, and the UK.

These trade flows may offer multiple benefits forboth exporting and importing countries. Forexample, exporting countries may gain a source ofadditional income and an increase in employment.Also, sound biomass production can contribute tothe sustainable management of natural resources.Importing countries may be able to meet theirgreenhouse gas (GHG) emission reduction targetsand diversify their fuel mix and thus contribute togreater energy security, a major driving force in mostOECD/IEA countries. Today, bioenergy is cost-efficient, in some cases even in direct comparisonwith oil (e.g., for heating purposes).


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For market participants such as utilities, companiesproviding transportation fuels, as well as thoseinvolved in biomass production and supply (such asforestry companies), good understanding, clearcriteria, and identification of promising possibilitiesare of key interest. Investments in infrastructure andconversion capacity rely the on minimisation of riskof supply disruptions in volume, quality, and price.

Biomass energy in general, and internationalbiomass trade in particular, offers manyopportunities. These are described in detail in thevarious country reports published by Task 40 (e.g.,Bradley, 2006; Heinimö and Alakangas, 2006;Junginger et al., 2006; Walter et al., 2006; see alsowww.bioenergytrade.org for more country reports).They are not, however, the main concern of thisreport. For an overview of the global theoreticalpotential of biomass, see Smeets et al., 2004; for ageneral discussion of the potential of biomassenergy, see Turkenburg et al., 2000.

Inventory of Barriers

Based on Task 40 results,a literature review, andinterviews, a number of potential barrier categorieshave been identified. These barriers may vary greatlyin terms of scope, relevance for exporting andimporting countries, and how stakeholders perceivethem. A summary of the main barriers is givenbelow. At the same time, it must be emphasised that,depending on the situation, these barriers can also beopportunities, and thus some positive examples arealso included.

The categorisation of the barriers is to some extentarbitrary. Some of the issues discussed under thevarious headings are complex and encompasselements of several barriers, e.g., logistical barriersindirectly cause economic barriers.

Economic barriersOne of the principal barriers to the use of biomassenergy in general is the competition with fossil fuelon a direct production cost basis (i.e., excluding

externalities). For example, the market price in2004-2005 for biomass pellets in the Netherlandswas about Û7 to 7.5/GJ (van Sambeek et al., 2004),while the cost of coal in 2005 was about Û2/GJ. Onthe other hand, current production costs lie betweenUS$0.7/GJ (free on board in the Amazon) andUS$1.7/GJ (transported in the Southeast) in Brazil(Walter et al., 2006)1. Thus, the high prices seem tobe caused by a strongly increasing demand overrecent years, while cheap raw materials at favourableprices are no longer available in abundance andcannot support production increase at the same paceas the development of demand.

In order to promote bioenergy many developed andsome developing countries have stimulated thedevelopment and use of biomass for electricity, heatand transportation by the introduction of measuressuch as governmental RD&D programmes, tax cutsand exemptions, investment subsidies, feed-in tariffsfor renewable electricity, mandatory blending forbiofuels,or biofuel quotas. However, an often-heardcriticism from the industry is that these measuresmay not be sufficient (e.g., no mandatory target forthe EU-25 Biofuels Directive). In addition, they aremostly temporary and tend to change frequently.This discourages long-term investments, as they areconsidered too risky. On the other hand, thanks to theEU Biofuels Directive, the EU production ofbiofuels more than tripled within the past 2 years andcontinues to grow. Thus, the European Commissionargues that the policies adopted have attractedinvestment in new production facilities (K. Maniatis,pers. comm.).

Studies have indicated huge potential for biomasssupply from some regions, such as Canada andBrazil. The limiting factor in biomass supply often isnot the amount available, but the investment requiredto gather and pre-treat or densify the biomass tomake transportation economic. Capital forinvestment in these regions may be limited, orinvestment may be deemed too risky until marketsshow some long-term stability and growth. Optionsfor fully developing these resources include long-


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1. It is, however, not clear whether these prices include capital costs, and probably the raw material is available for free.


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term contracts for biomass at prices that ensureeconomic return for the local investor, or integratingsupply operations with demand, whereby biomassconsumers in one region invest in plant in thesupplying region.

Due to the often small size of bioenergy markets andthe fact that biomass by-products are a relatively newcommodity in many countries, markets can beimmature and unstable, as in the case of the woodpellet market. During the winter of 2005-2006, thismarket was very volatile due mostly to supplyshortages, caused by much higher demand fromEuropean households (who were replacing theirexpensive fossil fuels with wood pellets), higherdemand from power companies,and difficulties inthe supply of pellets due to a long period of coldweather. All these factors meant that suppliers didnot manage to meet the unforeseen demand. Theefforts of some market areas to solve the lack ofsupply were futile because some of the newproducing parties tended not to honour contracts butsold their shipments to the highest bidder (P-P.Schouwenberg, pers. comm.). This is one examplethat shows the immaturity of this market.

Unstable markets make it difficult to sign long-term,high-volume contracts as this is seen as too risky.Also, with no harmonised support policy (e.g., on aEU level), new national incentives (and associateddemand for bioenergy) may distort the market andshift supply to other countries within a shorttimeframe (Faber et al., 2005). Due to increasinginternational competition, Dutch traders expect agrowing demand for cheap biomass fuel streams inthe mid-term (5-10 years) in developed countries,but also in developing countries because of theexpected rise in local demand (Junginger et al.,2006).

Due to the small volumes, biomass fuel trade is sofar completely bilateral, i.e., direct agreementsbetween buyer and seller. A few biomass exchangewebsites have emerged over the past year, but tradedvolumes remain low.

In summary, while the strong increase in overallbiomass demand is a positive development in itself,the market is hampered at present by many factorssuch as its dependence on (short-term) policysupport measures and typical problems of emergingmarkets such as small bilateral volumes, a lack ofmarket transparency, etc.

Technical barriersA general problem of some biomass types is variablephysical properties (e.g., low density and bulkynature) and chemical properties, such as high ashand moisture content, and nitrogen, sulphur, orchlorine content. These properties make biomassdifficult and expensive to transport, and oftenunsuitable for direct use, say for co-firing with coalor natural gas power plants. Power producers aregenerally reluctant to experiment with new biomassfuel streams, e.g., bagasse or rice husks. Asshipments within these streams often fail to providethe required physical and chemical properties, powerproducers are afraid to damage their installations(designed for fossil fuels), especially the boilers.While technology is available to deal with the fuels(e.g., different types of fluidised bed boilers), it maytake several years or even decades before the oldcapacity is replaced (Heinimö and Alakangas, 2006).In the longer term, the limited ability to use differentfuels may lead to a restricted availability of biomassfuels (Junginger et al., 2006). This is a particularlyimportant issue as many European coal-fired powerplants need to be modernised or shut down in thenext 5 to 10 years.

Logistical barriersRelated to technical barriers are logistical barriers.One of these problems is a general lack oftechnically mature pre-treatment technologies forcompacting biomass at low cost to facilitatetransportation, although this is fortunatelyimproving. Densification technology has improvedsignificantly recently (e.g., for pellets) although thistechnology is only suitable for certain biomass types.Also, the final density per cubic metre is still far less

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than oil for example, given the nature of biomass.Pyrolysis or torrefaction may be a possible pre-treatment option, but still needs to be proven on acommercial scale. In the case of the import of liquidbiofuels (e.g., ethanol, vegetable oils, biodiesel), thisis not an issue, as the energy density of thesebiofuels is relatively high.

When setting up biomass fuel supply chains, forlarge-scale biomass systems, logistics play a pivotalpart. Various studies have shown that long-distanceinternational transport by ship is feasible in terms ofenergy use and transportation costs (Hamelinck,2004) but availability of suitable vessels andmeteorological conditions (e.g., winter time inScandinavia and Russia) need to be considered.

However, local transportation by truck in countriesinvolved in both exporting and importing of biomassmay be a high cost factor, which can influence theoverall energy balance and total biomass costs(Batidzirai et al., 2006; Hamelinck, 2004). Forexample, in Brazil, new sugarcane plantations areconsidered in the Centre-West, but the cost oftransport and lack of infrastructure can be a seriousconstraint. Harbour and terminal suitability tohandle large biomass streams can also hinder theimport and export of biomass to certain regions. Themost favourable situation is when the end user has afacility close to the harbour and so avoids additionaltransport by trucks.

The lack of significant volumes of biomass can alsohamper logistics. In order to achieve low costs, largevolumes need to be shipped on a regular basis. Onlyif this can be assured, will there be forthcominginvestment on the supply side (e.g., new biomasspellet factories) and this will reduce costssignificantly. The bulky nature of biomass fuels andthe relatively low value per unit would restrictavailability of suitable areas for handling these fuelsin busy ports. On the other hand, this bulky nature incombination with a high demand for specificbiomass streams means that the present capacity(including storage, handling equipment, etc.) ofsome harbours (e.g., Stockholm, Gothenburg,

Immingham, several harbours in the Baltic States) isfully utilised. A further increase in biomass handlingwould require specific investment.

International trade barriersAs with other traded goods, several forms of biomasscan face technical trade barriers. As some biomassforms have been traded only recently, so far notechnical specifications for biomass and no specificbiomass import regulations exist. This can be amajor hindrance to trading. For example, in the EUmost residues containing traces of starches areconsidered potential animal fodder, and thus subjectto EU import levies. For example, rice residuescontaining 0-35% starch are levied E44/ton (aboutE3.1/GJ) (Junginger et al., 2006). For denaturisedethanol of 80% and above, the import levy isE102/m3 (about E4.9/GJ), representing substantialadditional costs. Brazil is planning to increaseethanol production drastically over the next 8 years,and to start up biodiesel production from soy beans,palm oil, etc., although only a fraction of bothbiofuels will be exported and the rest will be useddomestically. Brazil could, in theory, export moreethanol than is scheduled so far. A major constraintis that countries with large markets (USA, Japan, andthe EU) are completely or partially closed due totrade barriers. The USA applies ad valorem duties of2.5% for imports from most-favoured-nations(MFN) and 20% for imports from other countries.Japan applies ad valorem duties of 27% - MFNtreatment. At present, these duties represent asignificant barrier to trade, influencing thecompetitiveness of foreign imports. It is important toensure that treatment takes into consideration thestatus of the exporting countries, to account for theirlevel of development and potential for export.Finally, it is important to bear in mind that sometechnical trade barriers can, in fact, be imposed toconstrain imports and to protect local producers.

Another issue connected with international trade istransport tarif fs. In recent years, general transporttariffs have increased quite significantly, e.g., woodpellets to the Netherlands were on average E1.75/GJ

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(on a total cost of E7-7.5/GJ) in 2004 (van Sambeeket al., 2004). This was caused partly by the highdemand for transportation from South-east Asia, butdemonstrates the dependence of biotrade on lowtransportation tariffs.

In addition, the risk of contamination of importedbiomass with pathogens or pests (e.g., insects, fungi)is another important limiting factor in internationaltrade. For example, undebarked untreatedroundwood and chips from outside Europe are (witha few exceptions) not allowed and are inspectedthoroughly for import into the EU (Heinimö andAlakangas, 2006). Similarly, agricultural residueswhich could be used both as fodder and biomass forenergy, may currently be denied entry if they do notmeet certain fodder requirements. However, it isimportant to bear in mind that these limitations arenot exclusive to bioenergy, and that they are in placeto protect public and animal health.

A potential future trade barrier may be thebiotechnology issue. Many countries (mainly in theEU) are highly opposed to import products wherebiotechnology was used (Cartagena Protocol onBiosafety). However, in short-rotation plantationsand energy crops, genetic modifications, e.g., forincreasing the yield or the water content, arebeneficial for bringing down production costs. Thismay, for example, be relevant for ethanol fromgenetically modified corn or sugarcane.

Ecological barriers2

Large-scale plantations dedicated to energy frombiomass may pose various ecological andenvironmental issues that cannot be ignored, e.g.,monocultures and associated potential loss ofbiodiversity, soil erosion, fresh water use, nutrientleaching, and pollution from chemicals(Lewandowski and Faaij, 2004; Smeets et. al., 2005).For example, the cultivation of soy beans in Braziland palm oil in Indonesia and Malaysia for food andfodder has been strongly criticised by variousenvironmental NGOs because of the negative socialand environmental effects,e.g., the violation of landproperty rights of small farmers, or the additional

pressure on land and on valuable ecosystems such asrain forests3. Use of soy bean oil and palm oil asfeedstock for biofuels would contribute to theseeffects. However, studies have shown that fordedicated perennial, woody, energy crop plantationsin general these problems can be less serious than forthe currently common crops for food or fodderproduction. If designed and managed wisely, biomassplantations can be multi-functional and generate localenvironmental benefits. For example, willowplantations in Sweden may be used for soil carbonaccumulation, increased soil fertility, reducednutrient leaching, shelter belts for the prevention ofsoil erosion, plantations for the removal of cadmiumfrom contaminated arable land (phytoextraction), andvegetation filters for the treatment of nutrient-rich,polluted water (Börjesson and Berndes, 2006). Short-rotation woody crops (SRC) in general require veryfew inputs of herbicides and pesticides. Rich et al.,(2001) reported SRC plantations were generallybetter for a wide variety of wildlife than existingadjacent farmland around the ARBRE project area(UK). When established on agricultural land theusual result is an increase in bio-diversity, i.e., nosignificant displacement of species and in some casesan actual increase of species occurred. SRC isgenerally regarded as environmentally friendly andmost environmental groups view the technologyfavourably. Also, in the UK large-scale SRCmonoculture is unlikely given the nature of landtenure. Rather, the most likely scenario may be alarge number of small plots scattered over large areas.

Social barriers2

Also linked to the potential large-scale energyplantations are the social implications, e.g., the effecton the quality of employment (which may increase,or decrease, depending on the level of mechanisation,local conditions, etc.), potential use of child labour,education, and access to health care (Lewandowskiand Faaij, 2004; Douglas et al., 2004). However, suchimplications will reflect prevailing situations andwould not, necessarily, be better or worse than forany other similar activity. One example is theagricultural sector in Brazil, where the level of social

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2. Some Task participants see this as a land use issue. Responsibility for land use (changes) lies with many more actors, and is clearly not the sole responsibilityof bioenergy trade alone. Also, the ecological and social barriers only have indirect influence on trade.

3. Furthermore, a well-known feedstock for ethanol production is sugarcane. In a recent report from Task 40 participants (Smeets et al., 2006) it was shownthat current ethanol production from sugarcane in Sao Paulo does not pose any major ecological problems, nor does it directly threaten the Amazon rain forests.

benefits and child labour are still important issues butthey have significantly improved over the period1992-2004. Macedo, (2005, see chapter 12), gives anaccount of the positive contributions of the sugarcaneand ethanol industry on job creation and income.Further examples of social benefits are highlighted byWoods and Hall (1994) for developing countries, andPerlack et. al., (1995), on woody biomass plantations.

Competition between and integration of biomassfor energy applications and for other end uses.Various types of biomass can be utilised for end-usesother than energy, e.g., as raw material for the pulpand paper industry, as raw material for the(chemical) industry (e.g., tall oil or ethanol), asanimal fodder (e.g., straw), or for humanconsumption (e.g., ethanol or palm oil). Thiscompetition can be directly for biomass, but is alsooften focused on land availability.

Throughout human history biomass in all its formshas been the most important source of all our basicneeds,often summarised as the six ‘Fs’: Food, Feed,Fuel, Feedstock, Fibre, and Fertiliser. Biomassproducts are also frequently a source of a seventh ‘F’- Finance. Until the early 19th century biomass wasthe main source of energy for industrial countriesand, indeed, it continues to provide the bulk ofenergy for many developing countries. Food versusfuel is a very old issue that is frequently brought updespite the fact that a large number of studies havedemonstrated that land availability is not the realproblem (Partners 4 Africa, 2005). Whiletheoretically large areas of (abandoned/degraded)crop land are available for biomass cultivation,biomass production costs on such land are generallyhigher due to lower yields and accessibilitydifficulties. Deforested areas may have moreproductive soil, but these sites are generallyconsidered unsustainable in the long term. Foodsecurity, i.e., production and access to food, wouldprobably not be affected by large energy plantationsif proper management and policies were put in place.However, in practice food availability is not theproblem, but the lack of purchasing power of the

poorer strata of the population. A new element totake into account is climatic change, whichintroduces a high degree of uncertainty.

As mentioned above, next to competition with food,there also may be competition with otherapplications, such as fodder. If there was a largeincrease in demand for energy, say from agriculturalresidues, scarcity of fodder products could occur,leading to price increases. In the Netherlands, thefodder industry sees the feed-in tariff for electricityfrom biomass as an indirect subsidy for agro-residues (Junginger et. al., 2006); on the other hand,the use of fodder is also subsidised. Similararguments have been voiced by the European pulpand paper industry, which fears the increasingcompetition from strong promotion and subsidies forrenewable energy sources in the EU. Increasingcompetition for wood will increase the price andlower the supply of the raw material for the forestindustry, decreasing the competitiveness of theEuropean pulp and paper industry (CEPI, 2006).Wood use for forest products usually gives greateradded value and creates more jobs than the direct useof wood products for energy production (CEPI,2003). Furthermore, there is a large potential marketfor bio-products and the use of woody feedstocks toreplace fossil-based feedstocks – an issue we do notfurther address here.

Methodological barriers – lack of clearinternational accounting rules.Before large-scale international trade of bioenergycan be implemented, clear rules and standards need tobe established, e.g., who is entitled to the CO2 credits.A related issue concerns the methodology that shouldbe used to evaluate the avoided emissions,considering the fuel life-cycle. As these avoidedemissions typically depend strongly on the chosenreference system, it is debatable whether the samemethodology could be applied to all biomass sources.

Another issue is the indirect import of biomass forenergy (processed biomass). Biomass trade can beconsidered as a direct trade of fuels and as indirect


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flows of raw materials that end up as fuels in energyproduction after the production process of the mainproduct. For example, in Finland, the biggestinternational biomass trade volume is indirect tradeof raw wood (including roundwood and pulp chips).Almost half of these imports end up as by-products(e.g., bark, sawdust, and black liquor) used forenergy production (Heinimö and Alakangas, 2006).

Legal (national) barriersInternational environmental laws may limit biomassfor energy. For example, in the Netherlands, four outof five major biomass power producers considerobtaining emission permits to be one of the majorobstacles to further deployment of various biomassstreams for electricity production. The main problemis that Dutch emission standards are not entirelyconsistent with EU emission standards. In severalcases in 2003 and 2004, permits given by localauthorities have been declared invalid by Dutchcourts (Junginger et al., 2006). While these barriersonly indirectly influence international bioenergytrade, they may cause a significant reduction ofpotential biomass import volumes.

Lack of information disseminationBoth the benefits of sustainable biomass energy ingeneral and specifically the need for internationalbiomass trade are still largely unknown to manystakeholders such as industrial parties, policymakers, NGOs, and the general public. More activedissemination of information by IEA Bioenergy,various UN institutions, national governments, andother organisations is required.

Broader Issues to be Considered in Relation toBiomass Trade

Energy balances and local use versusinternational tradeThe overall energy balance of biomass and biofuelsuse needs to be positive, although this is not alwaysclear cut. Energy balances have improvedconsiderably in the last decade as productivity hasincreased with lower inputs, as in the case of ethanolfrom sugar cane in Brazil (Macedo, 2005). Similarly,some oil crops such as palm oil, dende, and macaúbacan deliver biodiesel with relatively high energyoutput/input ratios (Horta Nogueira, 2005). Relatedto energy balances are GHG balances of biofuels4.As shown in a report published by the IEA (2004),the current production of ethanol from wheat andsugar beet or biodiesel from rape seed (as iscurrently the main practice within the EU) achieveslower GHG emission reductions (typically in therange of 20-60%) than ethanol from sugarcane (80-90%) (Quirin et. al., 2004). Development of suchfirst-generation biofuels with mediocre energy andGHG balances on a large-scale is often driven byadditional considerations such as fuel security, andemployment in the agricultural sector, but could beconsidered unsustainable by some in the longerterm5. For example, import of ethanol produced fromsugarcane would generally show better energy andGHG balances,but these balances are somewhatworsened by long-distance transport – especiallywhen including substantial transportation by truck.

Connected to this issue is the question whetherbiofuels should be used preferably locally or tradedinternationally. While many developing countrieshave a low energy consumption compared todeveloped countries, their energy demand isincreasing rapidly. Should biomass for energy beutilised locally or exported; should market forceshave the last say? For example, Finland currentlyexports to other EU countries large volumes ofpellets which could also be utilised domestically.The main drivers are higher incentives paid forelectricity from pellets in other European countries.


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4. GHG emissions are often coupled to energy inputs during the production of biofuels, e.g. diesel fuel for agricultural machinery. However, emissions of otherGHG gases such as methane or nitrous oxide during biomass cultivation also influence GHG balance, but not the energy balance of biofuels.

5. For example, in the Netherlands, a commission consisting of various stakeholders from government, industry, and NGOs decided that minimum sustainabilitycriteria for biomass should achieve 30% GHG emission reductions, though by 2011 this level should be increased to 50% (Cramer, et. al., 2006).

It can be expected that countries that have greaterdifficulties in meeting commitments (Kyoto, greenpolicies, etc.) will introduce stronger incentives.From an energy efficiency point of view, it would bemore rational to use the biomass primarily locally,and export only the excess6. However, the actualenergy balances and CO2 emission reductions alsodepend strongly on the reference energy systems inboth the exporting and importing countries.Furthermore, it should be borne in mind thatinternational competition will force domesticproducers to be more competitive.

For more information about Task 40, visitwww.bioenergytrade.org

References

Börjesson, P. and Berndes, G. 2006. The prospectsfor willow plantations for wastewater treatment inSweden. Biomass and Bioenergy, 30, p. 428–438.

Batidzirai, B., Faaij, A. and Smeets, E. 2006.Biomass and bioenergy supply from Mozambique,Energy for Sustainable Development, Volume X No.1, March, p. 54-81.

Bradley, D. 2006. Canada Biomass-BioenergyReport. IEA Bioenergy Task 40 Country Report forCanada, available at www.bioenergytrade.org

Confederation of European Paper Industries(CEPI). 2006. Competitiveness and Europe’s Pulp& Paper industry: The State of Play, Cepi, 6 p.Available at: http://www.cepi.org/files/StateofPlay-094156A.pdf

Confederation of European Paper Industries(CEPI). 2003. The European paper Industry’s viewsand action plan on climate change. Available ath t tp : / /www.cep i .o rg /con ten t /de fau l t .asp?pageid=10

Cramer, J., Wissema, E., Lammers, E., et. al.2006. Criteria for sustainable biomass productionNetherlands, Final report of the Project group‘Sustainable production of biomass’. EnergyTransition Task Force, July.

Douglas, J., Perk, H. and Wyn, L.T. 2004,FairBioTrade: Pulp or Fiction. A rapid appraisal ofthe social issues in the Malaysian palm oil industry.Solidaridad: Utrecht, The Netherlands. p. 43.

Faber, J., Bergsma, G. and Vroonhof, J. 2005.Bioenergy in Europe. Policy trends and issues, CE,Delft, the Netherlands, p. 64.

Hamelinck, C.N. 2004. Outlook for advancedbiofuels, in Copernicus Institute, Department ofScience, Technology and Society, UtrechtUniversity, Promotor: W.C. Turkenburg, Co-promoter: A.P.C. Faaij, Utrecht University, Utrecht,the Netherlands. p. 232.

Heinimö, J. and Alakangas, E. 2006. Solid andLiquid biofuels markets in Finland – a study oninternational biofuels trade. IEA Bioenergy Task 40and EUBIONET II – Country Report of Finland.

Horta Nogueira, L.A. 2005. Biodiesel in Brazil,Universidade Federal de Itajubá, Minas Gerais,Brasil. Presentation given at the IEA Bioenergy Task40 workshop on ‘Sustainable Bioenergy Trade’,Campinas, Brazil, December, available atwww.bioenergytrade.org

IEA. 2004. Biofuels for transport. An internationalperspective. International Energy Agency, Paris,France, p. 210.

Junginger, M., de Wit, M. and Faaij, A. 2006. IEABioenergy Task 40: Country report for theNetherlands – update. Copernicus Institute –Department of Science, Technology and Society,Utrecht, the Netherlands, p. 28.


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6. Some Task participants do not fully support this assumption. Also, they emphasise that we trade food products all over the world, and that rules for biomassshould not be too ambitious – environmental and other principles should be applied equally across sectors.

Lewandowski, I.M. and Faaij, A. 2004, Stepstowards the development of a certification system forsustainable bioenergy trade. Copernicus Institute,Department of Science, Technology and Society,Utrecht University: Utrecht, the Netherlands. p. 99.

Macedo, I. 2005. Sugar cane’s energy. Twelvestudies on Brazilian sugar cane agribusiness and itssustainability. UNICA, Sao Paulo Sugar CaneAgroindustry Union, 1st Edition, September, p. 237.

Partners 4 Africa. 2005. Policy Debate on GlobalBiofuels Development, Special Issue of RenewableEnergy for Development. Stockholm EnvironmentInstitute, available at www.partners4africa.org

Perlack, R.D., Wright, L.L., Huston, M.A., andSchramm, W.E. 1995, Biomass Fuel from WoodyCrops for Electric Power Generation, Prepared bythe Oak Ridge National Laboratory in Collaborationwith Winrock International, ORNL-6871,September.

Rich, T.J., Sage, R., Moore, N., Robertson, P.,Aegerter, J. and Bishop, J. 2001. ARBREMonitoring-Ecology of SRC Plantations (InterimReport), ETSU B/U1/00627/REP; London, UK.

Quirin, M., Gärtner, S.O., Pehnt, M., andReinhardt, G. 2004. CO2 mitigation throughbiofuels in the transport sector, status andperspectives, IFEU, Stuttgart, Germany, August.

Smeets, E.M.W., Junginger, M., Faaij, A.P.C.,Walter, A. and Dolzan, P. 2006. Sustainability ofBrazilian bio-ethanol. Copernicus Institute, UtrechtUniversity, Report NWS-E-2006-110, September, p.136, available at www.bioenergytrade.org

Smeets, E.M.W., Faaij, A.P.C. and Lewandowski,I.M. 2005. The impact sustainability criteria on thecosts and potentials of bioenergy production. Anexploration of the impact of the implementation ofsustainability criteria on the costs and potential ofbioenergy production applied for case studies inBrazil and Ukraine. Department of Science,Technology and Society, Copernicus Institute,Utrecht University, Utrecht, the Netherlands.

Smeets, E.M.W., Faaij, A.P.C. and Lewandowski,I.M. 2004, A quickscan of global bioenergypotentials to 2050- an analysis of the regionalavailability of biomass resources for export inrelation to the underlying factors. Department ofScience, Technology and Society, CopernicusInstitute, Utrecht University: Utrecht, theNetherlands. p. 121.

Turkenburg, W.C., Beurskens, J., Faaij, A.P.C.,Fraenkel, P., Fridleifsson, I., Lysen, E., Mills, D.,Moreira, J., Nilsson, L.J., Schaap, A. and Sinke, W.2000. Chapter 7: Renewable energy technologies. In:World Energy Assessment. Goldemberg, J. (chair),Washington D.C., UNDP. p. 220 - 272.

van Sambeek, E.J.W.,de Vries, H.J., Pfeiffer, E.A.,and Cleijne, H. 2004. Onrendable toppen duurzameelektriciteitsopties. Advies ten behoeve van devaststelling van de MEP-subsidies voor de periodejuli tot en met december 2006 en 2007. 2004,ECN/KEMA, Petten, the Netherlands. p. 38.

Walter, A., Dolzan, P. and Piacente, E. 2006.Biomass Energy and Bioenergy Trade: Historicdevelopments in Brasil and current Opportunities.IEA Bioenergy Task 40 Country report for Brazil,available at www.bioenergytrade.org

Woods, J. and Hall, D.O. 1994. Bioenergy fordevelopment - Technical and environmentaldimensions - FAO Environment and energy paper13. FAO - Food and Agriculture Organisation of theUnited Nations, Rome, Italy.


IEA Bioenergy



U P D A T E 3 3

Mechanical Biological Treatment of Municipal Solid Waste

This Technology Report from Task 36 was preparedfor ExCo58 in Sweden in October 2006 by NicoleJaitner and Jim Poll

Abstract

The IEA Bioenergy Agreement is set up to examineand develop bioenergy solutions. One potentialsource of energy is municipal wastes, and whilstmass burn energy from waste solutions exist, thereare many barriers to its implementation. Onealternative approach is to pre-sort waste usingcombinations of mechanical and biologicalprocesses (so call MBT processes) so that energyand additional recycling can be recovered, often atscales unattractive for mass burn systems andovercoming some of the barriers inherent with massburn energy from waste.

This report reviews mechanical biological treatmentprocesses. These typically split the residual wastestream into 3 fractions: a recyclable stream (glass,metals, etc.), a biological stream (for composting oranaerobic digestion), and a fuel stream for energyrecovery. There are about 50 such facilities inoperation in Europe mainly in Germany, Italy, andSpain. There is considerable interest in thesetechnologies throughout the world, but particularlyin Europe, as a means of achieving resource recovery(materials and energy) and landfill diversion.However, while the technology has its limitationsand is still developing it offers potential EfWsolutions in circumstances where other traditionalapproaches would be difficult to implement.

Introduction

One of the Topics in the Programme of Work beingundertaken by Task 36 in the 2004-2006 triennium isMechanical Biological Treatment (MBT) ofmunicipal solid waste (MSW). The aim of this workis to review the status of MBT systems and theirpotential for integrating energy recovery processes.

One of the drivers for this technology in Europe isthe Landfill Directive [1]. The Directive imposestargets on EU member states to reduce the amount ofbiodegradable waste going to landfill compared tothe waste generated in 1995 to: 75% by 16 July2006; 50% by 16 July 2009; and 35% by 16 July2016. An even stronger driver is the complete ban onorganic material entering landfills in countries suchas Sweden, Switzerland, Austria, and Germany.

Compliance with the EC and national directivesrequires increased deployment of recycling andrecovery operations for waste. One of the options isto segregate the biodegradable waste and treat it inone of a number of ways. The interest in MBT isincreasing as a potential option for achieving therequirements of the landfill directive.

In other parts of the world the key driver is theadditional resource efficiency achieved throughsorting and treatment to optimise the embeddedenergy recovery through maintaining the energycontained in materials and products that arerecycled, rather than combusted, for the recovery ofthe inherent energy [2].

The use of MBT also alleviates some of the publicantipathy for Energy from Waste (EfW) incinerationtechnologies [3]. MBT allows the recovery of energy

from municipal wastes with reduced problems ingaining permits to build such plants.

MBT Process and Products

MBT is a generic term that encompasses a widerange of technologies that aim to process waste by amixture of biological treatment and mechanicalseparation to achieve waste stabilisation, recyclingand energy recovery. The details of a range ofsystems are provided in system reviews e.g., thosecarried out by Juniper [4], UK Environment Agency[5, 6] and the Swedish Association of WasteManagement [7]. In MBT the biodegradable fractionis treated post sorting, whilst in BiologicalMechanical Treatment (BMT) the biologicaltreatment occurs first.

Mixed residual waste (i.e., waste remaining aftersource separation, or “grey” waste) is first sorted viaa series of mechanical treatment options thatseparate out recyclable materials (e.g., metal andglass) and fractions for biological treatment and orrefuse derived fuel. All systems have sortingprocesses that separate various fractions andmechanically degrade the organic fractions throughshredding, wetting, and tumbling, or through theaddition of steam. The main effect is to concentratethese fractions for further processing. The keydifference between various systems is the choiceadopted for processing the higher calorific valuematerials. Options include producing a substitute for

fossil fuels (refuse derived fuel - RDF), or removingthe higher calorific components such as plastics forlandfilling and processing the residue to producecompost. The main biological process can be carriedout either aerobically (composting) or anaerobically(digestion - AD). Whilst biologically these aredifferent processes, the final degraded solid productsare similar, with anaerobic digestion having theadded benefit of generating a gas with a highmethane content that can be used as a fuel.

BMT is a special case of MBT where the whole ofthe waste is treated biologically prior to sorting. Thisbiological treatment is principally to dry the wastethus making subsequent mechanical separation forRDF more effective. Waste is aerated withincomposting vessels; as temperature rises so themoisture is driven off. After one to two weeks thewaste is dried and undergoes mechanical separationto generate a fuel (RDF) fraction. The fuel is thenprepared for market. The reject waste is still high inorganics and can undergo further composting togenerate a poor quality compost for landfill cover,but typically this fraction is simply landfilled as themost readily degradable materials are lost in theinitial composting stage.

The main outputs from the various MBT/BMTprocesses are shown in the Table below. Thefractions of these outputs vary between the differentproprietary processes but generally, depending onthe feedstock, are within the ranges shown.


IEA Bioenergy

Main Outputs from MBT/BMT Processes Fractions

Recyclables: e.g., metals aggregate substitutes and plastics 4 - 14%

Organic/Compost: the organic rich fraction that is then composted 38 - 70%or digested to generate a compost product and biogas

Fuel (RDF): the fuel fraction that is either burnt on-site or sent for 0 - 75%combustion in a remote combustion facility

Rejects: the residues and rejects that have to be landfilled. 10 –25%

There are five main types of MBT process:

• Plants which stabilise waste prior to landfill

• Plants which produce a compost product

• Plants which produce a RDF product

• Plants which produce both a compost product anda RDF product

• Plants which incorporate anaerobic digestion togenerate biogas for electricity production

MBT processes also enable metals and othermaterials to be recovered for recycling.

Task 36 has compiled a database of MBT facilities[8]. The number of MBT plants has risen rapidlyfrom around 20 in 1990 to 65 in 2000 and over 170by 2005. Figure 1 shows the number of plants bycountry. Germany has the largest number of MBTplants, followed by Italy and Spain. The totalcapacity of these plants is over 15 million tonnes peryear, and the capacities range from under 10,000tonnes per year to 300,000 tonnes per year.

Typical examples of well established processes arethe Horstmann process which produces RDF andcompost products and/or stabilised waste forlandfilling, and the Eco-Deco process whichprincipally produces a RDF product. The totalcapacity of Eco-deco plants installed in Italy andSpain is over 750,000 t/yr, and the three plantsplanned for the UK (two are built) will have a totalcapacity of over 400,000 t/yr.

An anaerobic digestion (AD) process can be used torecover energy, and one example of this type ofprocess is the 3R-UR process at Eastern Creek,Sydney, Australia which has a current capacity of175,000 t/yr. An example of a developing technologyis the autoclave (steam treatment) process forproducing a RDF product which has not beencommercially demonstrated for MSW applicationsbut there are several demonstration facilities andprojects in planning.


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GermanyItaly

Spain UKFrance

Austria

The NetherlandsFinland

AustraliaUSA

China

BelgiumU.A.E.

Canada

Czech RepublicTurkey

JapanPoland

LuxembourgIsra

el

SwedenLibya

Figure 1: Number of plants in each country(based on data from the Task 36 MBT database)

Tonnesper

aunnum


IEA Bioenergy

The Challenges for MBTAlthough a significant number of MBT processeshave been developed, and a large number ofcommercial plants have been constructed, thepotential for future plants will depend on a numberof commercial and technical challenges, particularlythe availability of markets and/or uses for theproducts that MBT plants produce.

Three approaches for using MBT plants to recoverenergy are anaerobic digestion, the use of the RDFproduct as a secondary fuel in an industrial facility,and dedicated combustion facilities.

Anaerobic digestion: AD systems can recoversubstantial energy from the degradable fractions ofthe waste and are inherently biological in origin asthe plastics and fossil derived wastes do not degrade.The amount of energy that can be derived from thewaste is dependant on the feedstock composition andthe process configuration. However, depending onthe particulars of the process design and operation,gas yields are between 40 and 140 m3/t of inputwaste. This corresponds to electrical production ofbetween 100 and 360 kWh/tonne of waste. Withplant consumption being between 100 and 300kWh/t the export energy is between 0 and 200 kWh/tof electricity with additional heat energy availablewhich may find use in heating schemes

RDF as a secondary fuel: The use of RDF in anindustrial combustion facility as a replacement forother fuels may be constrained by waste specificlegislation (such as the Waste Incineration Directivein the EU). There are also a number of technicalissues. For example, RDF has a lower carbon contentthan coal requiring altered air injection patterns, andthe higher levels of alkali metals can result in higherlevels of fouling and corrosion. One common use forRDF is in cement kilns, but as the chlorine contentcan affect the quality of the cement product, thecement industry has set limits for the maximumchlorine content of the RDF product, and someplants have not been able to meet this limit.Furthermore, there is often some public opposition

to the use of RDF (and other fuels) as a waste fuel inany combustion facility. The calorific value of RDFvaries with processes from products that are similarto the input waste (but are dried or have some inertmaterials, e.g., glass, metals etc. removed) at 10-12MJ/kg, to highly refined plastics rich fuels with a CVup to 20 MJ/kg. The efficiency of combustion andenergy conversion will vary with the combustionplant with incinerators achieving electric efficienciesof around 20% but co-combustion in power plantswill give much higher efficiencies similar to thoseachieved on the primary fuel.

Dedicated combustion facilities: These can eitherburn the RDF directly, or further process it using agasification or pyrolysis technology. The technicalissues for direct combustion of RDF will be similar tothose for combustion in an industrial facility.Gasification technologies are well established forprocessing some biomass and waste materials such aswood, but there are currently few commerciallyoperating plants that treat municipal wastes. RDF ismore homogeneous than municipal waste as it hasgone through mechanical sorting and pre-treatmentprocess, and is easier to process, and there is also areadily available market for the electricity that wouldbe generated. However, the combined costs for theMBT plant and the thermal treatment facility meanthat this is likely to be a much less economicallyattractive option than conventional incinerationsystems, but still may be more appropriate to aparticular location due to the local political, legislative,or structural circumstances. It can also apply to areaswhere smaller satellite MBT facilities can support acentral combustion facility where higher efficienciescan be exploited through larger scale plant, improvedtechnology, or locating near a heat user.

The RDF produced by a MBT process will have tocompete with other “renewable” or “non-fossil”fuels such as tyres, biomass products, and energycrops. Potential users may view fuels with a highrenewable content as a more attractive fuel, but theRDF produced by many MBT processes will have ahigh plastic content diluting the renewable content,


and thus would complicate the accounting of CO2benefits or may not count as a renewable fuel undersome regulatory systems.

Research suggests that the RDF produced by steamtreatment (autoclave) processes will have a muchhigher biomass content (the RDF contains a muchlower percentage of plastic), and thus this type ofprocess, may be able to produce a more marketableRDF product. It should be noted that these processesare still in development and no full scale processesare operating on MSW and the initial promise ofthese system may not be fully realised.

The development of markets for these fuels is beingassisted by the development of standards for solidrecovered fuels (SRF) through the Europeanstandards organisation (CEN /TC342). Thedevelopment of these standards will allowdevelopers and operators to optimise their facilitiesfor the fuel qualities available with the confidencethat the fuel will not compromise operation of theirenergy production plant. However, the existence ofstandards will not of itself develop markets and otherfactors will be required to fully facilitate the sale ofRDF/SRF.

Where AD is a component of the MBT system thenthe biogas produced will contribute to the energybalance of the plant. The opportunities for gasutilisation have been extensively addressed by Task37 and include direct combustion in a boiler, engine,or turbine to generate steam or electricity orconversion to pipeline quality for injection to the gasnetwork or use as vehicle fuel [9].

MBT processes may also produce a compost productfrom the mixed residual waste input which is likelyto have higher levels of contamination (glass, metal,plastics) and lower nutrient levels than productsproduced from source separated feedstocks. Thus,whilst there may be opportunities to use thecompost/digestate produced by MBT processes as asoil improver, it will be very difficult for it tocompete with the compost produced from sourceseparated materials in many of the current marketsfor waste derived compost products. Most of the

compost being produced by MBT plants is currentlybeing landfilled or used as landfill cover, althoughsome is being used in Australia, Spain, and Israel.The use of compost from mixed residual wastedepends entirely on the legislation implemented inthe various countries.

MBT plants can also recover dry recyclable productsincluding ferrous and non-ferrous metals, glass, anda mixed polymer plastics product. These productswill have to compete with source separated products,and whilst the glass product may well be suitable foruse in aggregate substitute applications, markets forthe mixed polymer product are currently limited.

The original concept for MBT was to developprocesses that reduce the biodegradable content ofresidual waste, by stabilising it through the use of acomposting process so that it could be landfilledwith lower environmental impacts. This approach issupported by environmental pressure groups and aprinciple benefit of this approach is that the publicopposition associated with mass burn systems can beminimised. This allows the development of EfWsystems in locations where for example waste heatcould be fully utilised and where permittingprocesses may prevent traditional systems.

In Germany, the first MBT plants which wereinstalled were able to identify markets (cement kilnsand power stations) for their RDF product, but thelimited total size of these markets, together with theissues regarding potential use of the compostproduct, mean that the new plants which are beingconstructed in Germany in order to enable thelandfill Directive targets to be met are onlyproducing a stabilised product (with a organiccarbon content of less than 5%) which is thenlandfilled. Recent changes in German legislationhave also reduced the capacity in EfW facilities,which means that finding capacity to burnadditional RDF will be more difficult. It should benoted that there on-going substantial increases inwaste incineration capacity in Germany. Swedenand the Netherlands to cope with waste divertedfrom landfill.



The Future for MBTConventional EfW (incineration) will continue tohave a key role to play in treating residual wastes.MBT type processes may complement EfW systemsand offer a number of potential benefits but faceconsiderable challenges in realising these. Factorsthat make MBT attractive include the following:

• MBT plants may be financially viable when thereject fraction can be landfilled and landfillcharges are low.

• MBT plants have the potential to operateeconomically at smaller scale and thus have theability to process waste locally, producing a RDFproduct that can be burnt in more remotecombustion facilities.

• The RDF product should be more suitable for heatrecovery as well as electricity generation as thescale should better match the smaller demands forheat in areas without district heating networks.

• MBT integrated with anaerobic digestion offers thepotential for renewable energy recovery comparedto composting based systems.

However, a number of factors can make MBTunattractive:

• The overall amount of energy, as electricity, whichcan be recovered using a MBT process is likely tobe lower than that from using conventionalincineration. This is due to the energy used in theprocess and the residues sent to landfill and notburnt.

• Lack of markets for the RDF and compost productscan prove a barrier for the commercial viability ofthe MBT facility. Processes which might producehigher biomass content RDF product (such asautoclaving) are still being developed and mayprovide some competition for MBT in future.

• The poor public perception of any facilitycombusting waste derived fuels (including theRDF produced by MBT plants and industrialprocesses burning the RDF product) can be abarrier for getting permits to operate.

• Greater landfill capacity will be required forprocess rejects (and for any products which cannot be marketed or used).

Some MBT technologies are well established, andwhilst markets have been found for the RDFproducts that the initial plants produced, the currentmarket capacity is limited. A large potential marketfor RDF is use in power stations, but unless co-firingsolutions can be further developed successfully (bothcommercially and technically), the capacity forusing RDF products to generate electricity may wellbe restricted to either MBT plants which incorporatean AD facility or a dedicated thermal conversionfacility. There will be limited opportunities torecover heat at these plants as waste facilities areoften sited away from other industry and housingdue to concerns over odour and emissions.Additional development work could be conducted toproduce better quality compost products and developsuitable markets for them and to improve the qualityand range of other recyclates to enhance theconservation of embedded energy. Otherwise, thefuture role of MBT may well be just to treat smalllocal arisings of waste in order to recover recyclablesand stabilise the remaining waste prior to landfill,but this will depend on the availability of suitablelandfill capacity.

Task 36 participants visiting the OMRIN MBT plant in the

Netherlands. This plant features mechanical sorting and anaerobic

digestion as the biological treatment. The residual fraction is

partially land filled but mainly incinerated


References

1 European Commission. 1999. Council Directive1999/31/EC of 26 April 1999 on the landfill ofwaste, Official Journal of the European Union, L182, 16.7.1999, p. 1–19.

2 Australian Government ProductivityCommission. 2006. Waste Management,http://www.pc.gov.au/inquiry/waste/draftreport/waste.pdf

3 Hogg, D. 2006. Dirty Truths.http://www.foe.co.uk/resource/briefings/dirty_truths.pdf

4 Juniper Consulting. 2005. MBT: A guide forDecision Makers – Processes Policies andMarkets. http://www.juniper.co.uk/Publications/mbt_report.html

5 Environment Agency. Waste Technology DataCentre, http://www.environment-agency.gov.uk/wtd/679004/?version=1&lang=_e

6 DEFRA. 2005. Mechanical Biological Treatmentand Mechanical Heat Treatment of MunicipalSolid Waste. http://www.defra.gov.uk/environment/waste/wip/newtech/pdf/mechbiotreat.pdf

7 Wannholt, L. 1999. Biological treatment ofdomestic waste in closed plants in Europe - Plantvisit reports’. RVF Report 98:8. ISSN 1103-4092.RVF - The Swedish Association of WasteManagement and RVF Service AB, Malmö.321pp.

8 Wheeler, P. 2007. MBT facilities, a review ofsystem. In press.

9 IEA Bioenergy Task 37. 2006. Biogas Productionand Utilisation, http://www.iea-biogas.net/


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IEA Bioenergy

“This article was produced by the Implementing Agreementon Bioenergy, which forms part of a programme ofinternational energy technology collaboration undertakenunder the auspices of the International Energy Agency.”

U P D A T E 3 4

News from the Secretariat

The 59th meeting of the Executive Committee washeld in Golden, Colorado, USA on 25-27 April, withKyriakos Maniatis as Chairman and John Tustin asSecretary. The meeting was hosted by DOE/NREL.The Chairman expressed the appreciation of theExCo to Larry Russo for the excellent meeting andstudy tour arrangements. Some of the outcomes ofthe meeting are detailed below.

Changes in the Executive CommitteeNew Executive Committee Members are: Mr BirgerKerckow, Germany; Mr Sandile Tyatya, SouthAfrica and Mr Paul Grabowski, USA. New AlternateMembers are: Ms Birte Mesenburg, Germany andMr Kazuyuki Takada, Japan.

Election of Second Vice ChairmanTo strengthen the succession plan, the ExCo agreedit was desirable to elect a second Vice Chairman for2007. In a close ballot, Ir. Kees Kwant, the Memberfor the Netherlands, was elected.

Participation in the Implementing AgreementThe participation of Italy in the ImplementingAgreement ceased in December 2006. Korea andTurkey sent observers to ExCo59 and madepresentations on their national RD&D programmes.

Mr Nobuyuki Hara, Desk Officer for Bioenergy at IEAHQ

(left) with Dr Soon-Chul Park, from the Korean Institute of

Energy Research.

Technical Coordinator’s Work ProgrammeDr Adam Brown, the Technical Coordinator (TC),made a comprehensive presentation of his workprogramme for 2007. The main focus will be policyrelated deliverables (35%), Task coordination (20%)and responses to IEAHQ (15%). The TC has alreadybeen involved with IEAHQ by providing commentson ETE Briefs and two reports related to ‘renewableheating and cooling technologies’. He is keen todevelop a more proactive approach with IEAHQrather than just responding to requests. He willreview the scope for improved Task coordination inthe Agreement, working closely with the TaskLeaders. He said it was important to stay focussed onthe goal of producing policy-related deliverables. Atpresent there are US$451,000 of uncommitted fundsfor the triennium ending December 2009. It will beimportant to have a very strategic approach on howthese funds are applied.

The TC presented a proposal for ‘technologyreviews’. He said that, given the expert resourcesavailable to it, IEA Bioenergy is well placed to deliveran authoritative review of each of the main resourceand technology trajectories of bioenergy. They wouldbuild on the technology position papers which havealready been produced and could be of great value ininforming both influential IEAHQ publications andnational policies. The reviews could also help todevelop an appreciation of the technologies mostlikely to be able to contribute significantly tosustainable energy supply on a global scale. It wasagreed that this was an important multi-year, strategicdirection for the Implementing Agreement.

Strategic PublicationsThe paper ‘Potential Contribution of Bioenergy tothe World’s Future Energy Demand’ prepared byAndre Faaij and the Tasks was presented forapproval and will now proceed to publication.

The proposal for a paper titled ‘Lifecycle Analysis ofBiomass Fuels, Power, and Heat as Compared totheir Petroleum-based Counterparts and OtherRenewables’ was approved. Production will bemanaged by Task 38. The aim is to cover key LCAaspects of bioenergy and to compare the mostimportant bioenergy chains with their fossil andrenewable competitors. The final draft will beavailable by December 2007.

Another strategic proposal - a ‘Handbook of PelletProduction and Utilisation’ - was also approved.Production will be managed by Task 32. The scopeof the handbook will include international pelletmarkets as well as relevant international constraintsand applications.

Energy Technology EssentialsIEA Bioenergy now has the opportunity to publishmaterial in a new four page technical fact sheetseries called Energy Technology Essentials (ETE’s).Produced by IEAHQ, they are used at IEAMinisterial and other policy-type meetings. They

will provide an excellent mechanism forcommunicating IEA Bioenergy information to thehighest levels. At ExCo59, it was agreed that eachTask produce an ETE instead of a Task TechnologyReport as a ‘one-time-action’.

ExCo59 Workshop

A very successful workshop titled ‘The BiorefineryConcept’ was well attended by ExCo Members andTask Leaders. Presentations were:

• Commercialising biorefineries: the path forward -Larry Russo, DOE, USA

• Ensuring success through stage gate and beyond -Bob Wooley, NREL, USA

• Proving biochemical technologies at the pilot scalefor integrated biorefinery development - DanSchell, NREL, USA

• Biorefinery: from agriculture towards industrialapplications - Ed de Jong, WUR, The Netherlands

• Developing and proving thermochemicaltechnologies at the pilot scale for integratedbiorefinery development – Dave Dayton, NREL,USA

• The IBUS concept: integrated biomass utilisationsystems (co-production of electricity andbioethanol) - Børge Holm Christensen, InbiconA/S, Denmark

• Incorporating conversion R&D and demonstratingfor adaptation to an existing facility. Contrastbarriers and successes in US versus EUdeployment - Quang Nguyen, Abengoa Bioenergy,USA

• Incorporating conversion R&D and demonstratingfor adaptation in an existing facility - MichaelLadisch, Aventine Bioenergy, USA


IEA Bioenergy

• Upgrading of by-products from biodiesel and thesugar industry by bioconversion and chemicalcatalysis - Thomas Willke, Federal AgriculturalResearch Center (FAL), Germany

• Overcoming the challenges of commercialisingthermochemical R&D and pilot plant results -Prabhakar Nair, UOP, USA

• From R&D through piloting to commercialization:managing the process - Jim Spaeth, DOE, USA

• Biorefinery Development: the Iogen Story -Maurice Hladik, Iogen Corporation, Canada

The presentations and a summary and conclusionsfrom the Workshop are now available on the IEABioenergy website.

ExCo59 Study Tour

NRELIn conjunction with ExCo59, about 35 attendeesparticipated in an excellent study tour organised by

Larry Russo and his colleagues at the NationalRenewable Energy Laboratory (NREL). NREL isthe US Department of Energy’s main facility forrenewable energy research and established theNational Bioenergy Center in October 2000. TheCentre’s technologies are available for industryR&D to foster development of biomass conversiontechnology and biorefineries. The study tour was ofcore interest to the participants.

Dr Mike Himmel conducted a tour of the BiomassSurface Characterisation Laboratory (BSCL).Advanced imaging of plant material providesinsights into biomass recalcitrance, to helpresearchers unlock the embedded energy in plants.The philosophy is that by understanding thestructural barriers of biomass - especially biomasssurfaces - conversion processes can be taken to thenext stage. The BSCL has electron and opticalmicroscopes and other research tools, to probebiomass-to-energy processes at atomic andmolecular levels. Such highly sensitive instrumentsmust operate in a stringently controlled environment.

IEA BioenergyBiomass and Bioenergy

International Energy Agency

The study tour group outside the NREL Visitor Centre in Golden, USA.

IEA BioenergyBiomass and Bioenergy

International Energy Agency

Dr Calvin Feik described the ThermochemicalConversion Pilot Facilities to the group. He said theywere working on a wide variety of feedstocks,including agricultural residues and energy crops, withthe feedstock often being in pelletised form. They alsowork on feedstocks supplied by industry and carry outparametric testing for individual companies. TheThermochemical Process Development Unit (PDU)can be operated in either gasification or pyrolysis mode.The half-ton-per-day thermochemical PDU is based ona fluidised-bed reactor coupled with a thermal cracker.This configuration is very flexible and can handle arange of process conditions to reflect product gascompositions of interest to industrial partners.

Particulate removal, secondary catalytic conversion,and condensation equipment are also available. Themodular design of the facilities allows them to readilyaccommodate equipment supplied by researchpartners. Process mass balances are continuouslycomputed from online data. Products andintermediates can be analysed by several methods.

Raw synthesis gas and pyrolysis vapours can beupgraded using the fluidised-bed catalytic reformingreactor. The integration of power generationapplications with biomass gasification processes canbe evaluated, for example, by testing product gas usagein internal combustion engines or micro-turbines. Socan the production of fuels and chemicals in micro-catalytic reactors. These capabilities add up to a uniqueR&D facility for optimising and integratingthermochemical biomass conversion processes.

Dr Calvin Feik, speaking to the tour group at the NREL

Thermochemical Conversion Plant facility.

Dr Rick Elander conducted a tour of theBiochemical Conversion PDU which is the mostwidely used facility at NREL, as it allows testing anddevelopment of complete production processes. It isan integrated pilot plant for converting biomass (e.g.,corn stalks and cobs, sawdust and switchgrass) toethanol at a rate of 900 kg per day of dry biomassand has been operating for 12 years. It was designedto provide a user facility to accelerate thedevelopment of processes for the conversion of awide variety of lignocellulosic biomass types toethanol. The objective is to perform routinemaintenance and calibration activities to maintainthe facility in a state of operational readiness for bothinternal and external customers. Such activitysignificantly improves the operability of the pilotplant and enhances its capability to supply necessaryprocess performance data for customers.Fermentation trials can be performed with aerobic oranaerobic micro-organisms in batch, fed-batch, orcontinuous mode. The researchers are working toimprove the efficiency and economics of thebiochemical conversion process technologies byfocusing their efforts on improving pre-treatmenttechnology, breaking hemicellulose down tocomponent sugars, and developing more cost-effective cellulase enzymes for breaking cellulosedown to its component sugar.

Coors BreweryThe afternoon of the study tour was spent at CoorsBrewery in Golden, the world’s largest brewery on asingle site, which was selected for its high qualityrocky mountain water. The group was shown all thestages of beer making from steeping (preparing thebarley for germination), germination and kilning ofthe barley; milling, brewing, fermentation and theirunique sterile-fill process. There was time to tastethe products, but the highlight was a special visit tothe recently expanded ethanol plant.

Coors launched the ethanol operation in 1996 with aplant producing 1.6 million gallons of ethanol frombrewing wastes which are piped from the brewery.With increasing ethanol demand Coors expanded theplant in 2005. The plant now produces in excess of 4

million gallons per year of 200 proof ethanol. This isaccomplished through conventional processes whichinclude: a low temperature cook section; enzymaticconversion of starches to fermentable sugars; yeastfermentation (two 250,000 gallon fermenters);stripping of ethanol from the mash; distillation; andmolecular sieve dehydration of the alcohol. Coorsproduces 87,000 tons per year of brewer’s grains on adry-matter basis from the brewing process. These arecurrently sold as cattle feed in a wet and dry form.

Merrick, an engineering and architectural company,owns the plant and leases the land from Coors, whooperate the facility. Valero Energy Corp. blends theethanol produced into gasoline for its DiamondShamrock stations in Colorado.

Participants in the study tour at the Coors Brewery ethanol

facility.

Bioenergy in USA

Larry Russo, US Department of Energy, USA

Over the last two years, biomass has taken thespotlight as President Bush has laid out increasinglyaggressive goals for moving biofuels into themarketplace, to reduce the nation’s dependence onforeign sources of energy and reduce greenhousegas emissions from the transportation sector.President Bush has established a goal to reduceUSA gasoline usage by 20% in the next ten years -called ‘Twenty in Ten’.

USA will reach this ambitious goal by setting amandatory fuels standard to increase the supply ofrenewable and alternative fuels such as ethanol. Thisstandard will require 35 billion gallons (133 billionlitres) of renewable and alternative fuels in 2017which is nearly five times the legislated 2012 target.In 2017, this will displace 15% of projected annualgasoline consumption in USA.

In addition to expanding the use of renewable andalternative fuels, ‘Twenty in Ten’ also aims to reformand modernise corporate average fuel economystandards for cars and extend the current light truckstandard. In 2017, it is estimated that increased fuelefficiency will reduce projected annual gasoline useby up to 8.5 billion gallons (33 billion litres), anadditional 5% reduction in gasoline usage. Thesecombined efforts in alternative fuels and fuelefficiency will enable USA to meet the goal toreduce gasoline usage by 20% in the next ten years.

Critical to achieving the ‘Twenty in Ten’ goal are theDepartment of Energy (DOE), the NationalLaboratories and university and industry partnersworking together. Biomass research has been acornerstone of DOE’s renewable energy research,development and deployment efforts over the last 25years. Biomass, which includes agricultural andforestry residues, perennial grasses, woody energycrops, and post-consumer wastes, is unique amongthe renewable energy resources in that it can beconverted to carbon-based fuels and chemicals, inaddition to electric power.

Meeting these goals will require significant andrapid advancements in biomass feedstock andconversion technologies; availability of largevolumes of sustainable biomass feedstock;demonstration and deployment of large-scaleintegrated biofuels production facilities; and biofuelsinfrastructure development efforts. In addition, theexisting agricultural, forestry, and commercialsectors will be making the decisions to invest inbiomass systems - from shifting land use, to buildingcapital-intensive biorefineries, to establishing theinfrastructure and public vehicle fleet for ethanol


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distribution and end use - in the context of economicviability and the needs of the marketplace.

DOE’s national laboratory network is comprised ofmore than a dozen facilities including the NationalRenewable Energy Laboratory (NREL), Oak RidgeNational Laboratory, Idaho National Laboratory andPacific Northwest National Laboratory. These state-of-the-art R&D facilities provide the capability toperform cutting edge research which can beimplemented into commercial technology to achievethe USA’s aggressive bioenergy goals.

The ambitious USA goal of ‘Twenty in Ten’ isdriving R&D efforts at the DOE to expand themarket for biomass fuels. The efforts of the DOE andits laboratories such as NREL are helping tofacilitate a more rapid deployment of biofueltechnologies.

For more information on ‘Twenty in Ten’ visit:www.whitehouse.gov/infocus/energy/

For more information on biomass research at NREL,visit: www.nrel.gov/biomass/

Task 33: Thermal Gasification of Biomass

This summary article was supplied by Dr SureshBabu, Leader of Task 33.

Gas cleanup for biomass gasification A technical hurdle that almost all gasificationprocesses have to overcome is the development ofeconomical and environmentally sound gas cleanupand effluent recycle and disposal processes. Rawproduct gases contain particulates, tars, ammonia,alkalis, chlorides and other impurities, which have tobe almost completely removed before convertingsynthesis gas to fuels and chemicals.

In this context, Task 33 organised a workshop inDresden, Germany to review the developments in

raw gas cleanup. The research examples presented atthis workshop show significant progress with bothlow- and high-temperature gas cleaning. Thecommercial applicability of these developments willevolve as these technologies are demonstrated overextended test periods and upon validation of techno-economic benefits.

Gas cleanup research in USABoth conventional and advanced gas cleanup optionsare being pursued to remove tar, particulates andalkali metals from raw product gases. In addition tothese contaminants, light hydrocarbons should beminimised or eliminated to avoid the energy-intensive reforming process and reduce the overallprocess costs. The ultimate objective of tar reformerresearch at NREL in Golden, Colorado is to reducethe cost of synthesis gas production. In support ofthis objective, NREL is testing and evaluatingcatalytic steam reforming of tars produced duringgasification of biorefinery residues.

The Gas Technology Institute in Des Plaines,Illinois is using high temperature glass meltingtechnology to produce Olivine containing catalystsfor in-situ removal of tars in biomass gasification.These tests, conducted over a range of 750-900°C,showed that 80% of naphthalene was decomposedat the lower temperature and near completeconversion was observed at 900°C.

The Research Triangle Institute in North Carolinaand its research partners developed a fluidised bedreactor containing a novel tri-functional catalystthat decomposes tar and remove NH3 and sulphurcompounds from raw synthesis gas over atemperature range of 600-700°C.

Gas cleanup research in AustriaThe Technical University of Vienna, Austria hasconducted research on the comparative evaluation oftar removal using Olivine versus Nickel-Olivine.Using the FICFB demonstration gasifier at Güssing,it has been determined that Ni-Olivine reduces tarcontent by about 90%. Further investigations are in


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progress to ascertain the effect of Ni-Olivine on thedistribution and nature of tar components. Tests witha commercial monolithic Ni honeycomb catalystinstalled in a slip-stream at the Güssing gasificationplant, show that it is possible to achieve >99%removal of most of the major tar relatedcontaminants under raw gas conditions.

Ultra-clean gas cleanup research in GermanyITC in Karlsruhe has been conducting an exhaustivescreening of sorbents for removing trace constituentsof HCl and H2S from hot raw gases, in support ofcommercialising the Sustec SVZ process forbiofuels. The entrained high-temperature gascleaning process at 800°C does not produce any tars.Furthermore, the use of sorbents essentially removesall HCl and H2S and most of the organic sulphur.

High-temperature gas cleanup research in UKPorvair in Norfolk is investigating using catalyticallyactive metal foam in biomass gasification research.Metal foam is a promising substrate for gas cleanup,with a high catalytic surface area, low pressure drop,and good depth filtration properties. Porvair’spermeable media filters are made to withstand900°C. They have a porosity in the range of 3.1 x 10-11 m2 to 1.8 x 10-13 m2 which exhibits an efficiencyof 99.98% separation of particles > 0.3 micron, and95% separation of < 0.45 micron particles.

Gas cleanup research in The NetherlandsDahlman is commercialising OLGA, a multistageoil-based tar scrubbing system which operates abovethe water dew point. Pilot tests have shown that theprocess removes all tars and tar aerosols, as well asmost of the BTX compounds. The process iscurrently being tested with an updraft gasifier inMoissannes, France.

The Technical University of Eindhoven is exploringthe use of pulsed corona to decompose tar moleculesunder hot-gas conditions. Pulsed corona is anefficient source of electrons, radicals, and excitedmolecules. When energetic electrons collide with

gas molecules they produce radicals which arechemically very active and easily attach to or modifyother molecules that they come in contact with. Ingeneral, it has been observed that higher coronadensities are required under reducing conditionscompared to inert gas conditions.

Gas cleanup research in FinlandVTT in Espoo has conducted extensive slip-streamgas clean-up tests with nickel monolith. Reportingon the gas cleanup research at the Novel gasificationplant in Kokemaki, VTT reported that the gascleaning system works adequately to provide a cleanfuel gas for the downstream Jenbacher gas engines.The treated gas contains tars < 100 mg/Nm3,ammonia < 50 ppmv after catalytic removal andscrubber, and dust < 10 mg/Nm3 after gas filtration.

Gas cleanup research in SwitzerlandThe Pyroforce® Gasification system demonstratedin Switzerland first cools the raw gas toapproximately 160°C to prevent clogging bytar/soot. The cooled gas is passed through pre-coatedfilters to remove solids, acids, heavy metals andsticky tars. It is then cooled further in washingcolumns, to condense water along with heavy HCand partial absorption of ammonia. With thismethodology the biomass gasifier and the gas enginehave demonstrated satisfactory integrated operationover extended periods

For further information on the work of Task 33,contact Suresh Babu at [email protected]


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U P D A T E 3 5

Biomass Gasification for HydrogenProduction – Process Description andResearch Needs

This Technology Report from Task 33 was preparedby the Task Leader Suresh Babu for ExCo56 inDublin in October 2005.

Introduction

Renewable biomass and biomass-derived fuels couldbe readily gasified to produce high purity hydrogenor hydrogen-rich gas. Among the biomass energyconversion schemes, gasification produces a productgas, which could be used either to produce hydrogenor co-produce value-added by-products. As a readilyrenewable fuel, biomass may become a significantcomponent in the global sustainable energy mix ifthe use of fossil fuels is limited for any number ofreasons. In addition, biomass utilisation can expeditemitigation of greenhouse gas emissions and promoteintroduction of ‘green’ industries with associatedgrowth in rural economies. Hydrogen or hydrogen-rich gas produced from biomass could be readilyused in most of the present natural gas or petroleumderived hydrogen energy conversion systems andalso in advanced power generation devices such asfuel cells.

Process DescriptionsAt present, there are no commercial biomassgasification processes for hydrogen production. Ingeneral, except for direct air-blown gasification,enriched-air or oxygen-blown gasification, steamgasification, or any other indirectly heatedgasification process should be able to produce a

synthesis gas, which could be converted tohydrogen. From the wide variety of biomassgasification processes that are being developed,processes considered to be suitable for producingeither hydrogen or hydrogen-rich gases aredescribed in the following sections.

BIOSYN Gasification and Gas ConditioningTechnologies: The BIOSYN gasification process [1](Figure 1) was developed during the 1980s byBIOSYN Inc., a subsidiary of Nouveler Inc., adivision of Hydro-Quebec (Montréal, Quebec,Canada). The process is based on a bubblingfluidised bed gasifier containing a bed of silica oralumina capable of operating up to 1.6 MPa.Extensive oxygen-blown biomass gasification testswere conducted during 1984 to 1988, in a 10tonnes/hour (t/h) demonstration plant located at St-Juste de Bretennieres, Québec, Canada, to producesynthesis gas for methanol production. Air blownatmospheric gasification tests were also conductedfor evaluating cogeneration. In the following years, a50 kg/h BIOSYN process development unit has alsoproven the feasibility of gasifying primary sludges,RDF, rubber residues (containing 5 - 15% Kevlar),and granulated polyethylene and propylene residuesto produce hydrogen-rich synthesis gases.

The process accepts feed particle sizes up to 5 cm,feed bulk densities higher than 0.2 kg/l and feedmoisture content up to 20%. The thermal efficiencyfor biomass gasification varies from 70 to 80%. Theproduct gas containing mostly CO, CO2, and H2could be cleaned to remove carry over dust andcondensable tar and upgraded to produce high-purityhydrogen. With air as the gasifying agent the HHVof the fuel gas is about 6 MJ/Nm3. Enriched air, with

40% oxygen, can produce a fuel gas having a higherheating value (HHV) of about 12 MJ/Nm3 at half thegas yield. The raw gas cyclones remove 85 to 95% ofentrained particles.

The supporting R&D conducted during thedemonstration of the BIOSYN Process, includes gasscrubbing for efficient tar removal with reducedwater requirements, recycling the insoluble tars tothe gasifier, wet oxidation and adsorption ofdissolved organic compounds in the scrubbing water,and recycling carbon-rich ashes and carry overcarbon with adsorbed organic compounds to thegasifier. The R&D effort also included hot-gasfiltration of entrained dust using a static bed ofperlite particles and a moving sand bed filter, andcatalytic steam cracking of tar. Proprietary gas clean-up catalysts were developed to decompose 99% oftars and 97% of naphthalene compounds. The fullyintegrated BIOSYN Process, with hot-gas filtrationand high-temperature tar reforming, water-gas shiftconversion to convert CO to hydrogen and CO2, andCO2 removal to produce high-purity hydrogen, wasnever demonstrated. The BIOSYN Process is nowcommercialised by Enerkem Technologies Inc, asubsidiary of the Kemestrie Group, a spin-offcompany of the University of Sherbrooke. Recently,a commercial installation to gasify 2.2 t/h ofgranulated polypropylene residues was planned forconstruction in Spain. Environmental InternationalEngineering S.L., a Spanish-based development and

engineering group, in partnership with Enerkem,was planning to erect and commission the plant. Theelectricity output of the plant will be sold to the grid.

FERCO SilvaGas Process: The FERCO SilvaGasProcess [2] (Figure 2) employs the low-pressureBattelle (Columbus) gasification process whichconsists of two physically separate reactors; agasification reactor in which the biomass isconverted into a medium calorific value (MCV) gasand residual char at a temperature of 850 to 1000ºC,and a combustor that burns the residual char toprovide heat for gasification. Heat transfer betweenreactors is accomplished by circulating sandbetween the gasifier and combustor. Since thegasification reactions are supported by indirectheating, the primary product is a synthesis gas withmedium calorific value. A typical product gascomposition obtained in pilot plant tests, at steam tobiomass (wood chips) ratio of 0.45, is 21.2% H2,43.2% CO, 13.5% CO2, 15.8% CH4, and 5.5% C2+.The estimated HHV of this fuel gas is 17.75 MJ/Nm3. A 200 tonnes/day (t/d) capacity Battelledemonstration gasification plant was built at theMcNeil Power plant in Burlington, Vermont.Following plant shakedown and initial tests the planthas operated intermittently. At this plant, the fuel gaswas co-fired in the existing McNeil wood firedboiler. The process was developed by US DOEBiomass Power Program, FERCO, BattelleColumbus Laboratory, Burlington ElectricDepartment, Zurn Industries, OEC/Zurn, and NREL.


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The BIOSYN Options for Waste & BiomassGassification & Synthetic Gas Conditioning

Feedback

Biomass• forest residues• agri-residuesMSW (RDF)Non-recyclable plasticsSludges

Air

N2-richstream

O2-richstream

O2 enriching unit

BubblingFluid-Bed

Atmospheric orPressurized

Gasfilter

Solid Residuesfrom process

Recycling(in construction materials)

PurgeAqueous

Phase

DischargeTreatedWater

SkimmingWater

Treatment

AqueousPhase

RecycleAqueous

Phase

CleanSynthetic

Gas

EnergyProduction

Three-stageScrubbing

CatalyticTar Reforming

Hot GasFiltration

SyntheticGas

Option 1

Option 2

kWe

FlueGasses

kW1

Recycle Treated Water

Cyclones

Figure 2: SilvaGas Process

Figure 1: BIOSYN Process

MTCI Process: The MTCI gasification process(Figure 3) also employs indirect heating to promotesteam gasification of biomass to produce a MCVfuel gas. The gasifier combusts part of the fuel gas inpulsed combustion burners which promote heattransfer to the gasification section. Extensive pilotplant tests were conducted in a 20 t/d processdevelopment unit (PDU) at the MTCI laboratoriesnear Baltimore, Maryland. These tests also includedevaluation of black liquor gasification process.Based on the PDU tests a 50 t/d capacity black liquorgasification demonstration unit was built atWeyerhauser’s New Bern facility.

In the MTCI Process, the black liquor is steamreformed/gasified at an operating temperature ofabout 600ºC (~1,110ºF). The raw gas is upgradedthrough several steps of gas cleanup, resulting in asynthesis gas rich in hydrogen (>65% by volume)with a higher heating value (HHV) of approximately10.4 MJ/(dry)Nm3. In one of the pilot testcampaigns, cleaned synthesis gas was metered to asolid-oxide fuel cell operating at about 1000ºC(1830ºF), which produced a net 2.6 volts D.C., 62amps or an equivalent of 161 watts of electricity.

Figure 3: MTCI Process

The first MTCI black liquor gasification plant wascommissioned in September 2003, at the Norampacmill in Trenton, Ontario, Canada. The plant wasdesigned to handle 115 t/d back liquor (60% solids).The gasifier has operated for extended periods, buthas experienced some bed agglomeration problems.The second MTCI plant, with a capacity of 200 t/dsodium carbonate black liquor (with 60% solids),was launched in 2001 by Georgia Pacific, FluorDaniels, and Stone Chem, with support fromUSDOE. The five-year demonstration project islocated at the Georgia Pacific paper mill in BigIsland, Virginia. The project will cost approximately$87 million with about 50% cost contribution fromindustry. Plant commissioning was started in the fallof 2004, and to date the unit has operated at 50% ofdesign capacity. No agglomeration problems wereobserved at this demonstration plant.

Figure 4: RENUGAS Process

RENUGAS Process: The GTI/IGT RENUGAS®‚Process [4] (Figure 4) employs a 20 bar pressurisedbubbling fluidised bed. The process was extensively


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tested with a variety of biomass materials, includingbark-paper sludge mixtures, bagasse, and pelletisedalfalfa stems in a 12 t/d PDU at IGT test facilities inChicago. Subsequently USDOE selected theRENUGAS Process for scale-up and demonstration,using bagasse, at the HC&S sugar mill at Paia inHawaii. The project was terminated when the 100 t/ddemonstration plant had limited success in handlingthe low-density, shredded bagasse. A typical gascomposition obtained in the IGT PDU with bagasseat 2.2 MPa, and 850ºC is 19% H2, 26% CO, 37%CO2, 17% CH4, and 1% C2+. The heating value ofthis fuel gas is approximately 13 MJ/Nm3. Theproject participants included US DOE BiomassPower Program, IGT, Westinghouse ElectricCorporation, State of Hawaii, PICHTR, and HC&S.

Although, the pressurised air-blown RENUGASprocess was initially developed for IGCCapplications, by replacing air with oxygen, theprocess could produce synthesis gas that could beupgraded to high-purity hydrogen.

Carbona, which licensed the Renugas technologyfrom GTI, has constructed and tested a 15 MWthhigh-pressure (20 bar) Renugas pilot plant inTampere, Finland [5]. Around 1993, Carbonasuccessfully operated the pressurised gasifier forover 2000 hours with a variety of biomass wastesand has also evaluated hot-gas filtration for IGCCapplication. In October 2004, Carbona reported thatground has been broken for building a 5.4 MWecapacity low pressure, Renugas demonstrationproject in Skive, Denmark. The project will start itsoperation with pelletised wood.

In January 2005, GTI completed the shakedown of anew 24 t/d, adiabatic Flex Fuel Test Facility in DesPlaines, Illinois [5]. This facility is capable ofgasifying up to 30 t/d of biomass and at operatingpressures up to 25 bar.

Forced Internal Circulation Fluidised Bed(FICFB) Process: The two-stage, combinedfluidised bed gasifier and CFB combustion processdeveloped by the Technical University of Vienna(TUV), Austria (Figure 5) with Repotec has

demonstrated exceptional rapidity of success inscaling-up the laboratory scale unit to a commercialdemonstration plant Güssing, Burgenland [6]. Theprincipal novelty of the process is its ability toproduce a MCV fuel gas without the use of oxygen.The process employs a catalytically activecirculating fluidised bed of solids that can reduce tarin the raw gases. The raw product gases are cooledfor heat recovery and scrubbed with an organicliquid to remove most of the tar. The raw MCVproduct gas can be processed to produce hydrogen orhydrogen-rich gas. The condensate along with someof the scrubber solvent is recycled to the combustionzone for complete thermal decomposition of allcondensable organic compounds produced duringbiomass gasification. The clean gas is thenintroduced to an Jenbacher gas engine to generate agross ~2.0 MWe power and ~4.5 MWth heat. Thereported parasitic power consumption is ~0.2 MWe.The electrical efficiency of the Jenbacher gas engineis 36 to 37%. At the end of 2004, the gasifier hadlogged more than 14,000 hours and the totaloperating time with the integrated gasifier and gasengine was about 11,000 hours.

A typical dry, raw gas composition reported fromair-blown biomass gasification tests is given belowin % by volume: H2= 30-45, CO= 20-30, CO2= 15-25, CH4 = 8-12 vol.%, N2=1-5, (NH3= 500-1000ppm, H2S = 20-50 ppm, Tar= 0.5-1.5 g/Nm3,Particles= 10-20 g/Nm3).

Figure 5: FICFB Gasification Process


CHEMREC Process: In 1987, the development ofthe Chemrec Process (Figure 6) for black liquorgasification was started in Sweden [7,8]. The processwas bought by Kvaerner in 1990. In 2000 Kvaernersold their majority rights to the German industrialgroup Babcock Borsig Power (52%) and to theSwedish company Nykomb Synergetics (24%).Since 2002, Chemrec has been in search of seekingnew industrial partners because Babcock BorsigPower is in insolvency and its part in Chemrec hasbeen bought by Nykomb Synergetics.

The Chemrec process can be operated at slightlyabove atmospheric pressure for incremental blackliquor gasification in parallel with an existingrecovery boiler. The process when operated underpressurised system can replace the recovery boiler.The pressurised black liquor gasification combinedcycle mode (BLGCC) is more energy efficient thanthe recovery boiler and can generate approximatelydouble the amount of electric power than a modernrecovery boiler. The Chemrec gasification reactor issimilar to the Texaco gasifier (now owned by GE).Black liquor is injected with oxygen, into a high-pressure (~30 bar) and high temperature (~950ºC)reactor to gasify the cellulose, lignin componentsand smelt and reduce the inorganic salts. Thefavourable reaction kinetics in the gasifier due to thepresence of a catalyst (Na and K) results in lowmethane content gas compared to normalgasification of biomass. In the low-pressureChemrec process, black liquor is gasified with air.Atomisation and droplet size are very important togasifier performance; atomisation is achieved usingmedium pressure steam. The high-pressure Chemrecprocess is operated with oxygen. The black liquorinjection nozzles are designed to facilitate on-linecleaning. The reactor temperature is maintained atabout 950ºC in the lower part of the gasifier. An oilor gas fired burner at the top of gasifier is used toheat the gasifier for start-up and for hot stand-by.The chemical smelt is recovered from the gas streamat the base of the gasifier by quenching withcondensate. The product green liquor is pumped tothe mill system. A small quantity (a few percent) ofsulphur, as H2S, leaves with the product gas in the

low-pressure system while approx 60% of sulphurleaves with the product gas in the high-pressuresystem. In the pressurised system, the H2S isremoved by scrubbing employing standardH2S/COS removal technology. By proper selectionof the desulphurisation scrubbing process, theabsorption of CO2 can be reduced. With airgasification, the product is an LCV gas, whilepressurised oxygen blown gasification results in aMCV gas.

Figure 6: The Chemrec Process

Chemrec has provided the following data on gasifierperformance, for the low and high pressure (30 bar)gasification cases. The gas compositions are fromtwo slightly different black liquor feed stocks.

The Swedish Government is providing $25 million(50% matching funds) to develop and verify theperformance of the Chemrec pressurised process intwo steps. Chemrec has constructed a 20 t/d dry solids(3 MWth), oxygen-blown development plant in Piteå,Sweden. After about one year of testing the processwill be scaled up to a 300 t/d dry solids capacity andbuilt as a complete BLGCC plant. The Kappa



Kraftliner mill in Piteå has expressed a desire to providethe host site for the plant. This effort, which began in2001, will continue through 2006. Upon successfuloperation in the 20 t/d development plant, US pulp andpaper industry and US DOE may consider building acommercial BLGCC demonstration based on theChemrec technology in USA .

As shown, the gas composition from the pressurisedChemrec process is well suited for further treatmentto produce synthesis gas which then can beconverted into automotive fuels such as methanol,DME, FTD or hydrogen.

The operation of a 300 t/d dry solids capacity, low-pressure Chemrec gasifier in New Bern(Weyerhaeuser Mill) was started in 1996 andstopped in January 2000 when a crack was detectedin the reactor vessel. The plant was taken out ofoperation and extensive investigations were carriedout to understand and come up with a new design toavoid further structural problems. The plantconstruction was modified and the Weyerhaeusergasifier has resumed operation in 2003. The newgasifier refractory is expected to last for about twoyears while the previous lining operatedsatisfactorily for a little over one year.


Table 1: Gasifier Performance Predictions for Operation with Air and Oxygen

Low Pressure High PressureAir Blown Oxygen-blown

Assumptions:

Reactor Temp, °C 950 950

Reactor Pressure, bar 2 30

Air feed, t/tds 2.2

O2 feed, t/tds —- 0.34

Oxidant temp, °C 100 135

Gas Composition (vol. %):

CH4 0.2 1.1

CO 6.0 29.5

CO2 12.5 14.6

COS - 0.04

H2 8.6 31.1

H2O 26.3 22.2

H2S 0.2 1.5

NH3 0.01 0.00

N2 + Ar 46.2 0.18

Higher heating value:

(MJ/m3, dry, at 15oC) 2.6 10

Typical black liquor properties are: C 37.2%, H 3.6%, O 34.4%, S 3.7%, N 0, Na18.6%, K 2.5%, HHV: 14.36 MJ/kg, dry

SVZ Schwarze Pumpe GmbH: SVZ [9] hasconverted some of the existing former East Germanera, FDV Process coal gasifiers in Schwarze Pumpe,Germany to convert biomass, coals, and wastes intoclean fuel gas and synthesis gas (Figures 7a, 7b, 7c).The plant gasifies a wide variety of waste materialsalong with low-rank coals in an updraft moving bedgasifier. The waste materials include demolitionwood, used plastics, sewage sludge, auto-fluff MSW,contaminated waste oil, paint and varnish sludge,mixed solvents, tars, and on-site process wastestreams. The waste materials are blended with coalat a ratio of 4:1. SVZ has developed an effective feedhandling system which employs thermal pre-treatment to convert heterogeneous feed materials toproduce a nearly uniform in shape and bulk densitygasifier feedstock.

The oxygen-blown, 25 bar-pressurised, 14 t/h FDVprocess, similar to Lurgi’s moving bed coalgasification process, converts the mixed feedstocksto MCV fuel gas or synthesis gas. The raw gas issubjected to conventional (Rectisol) gas cleaning toseparate contaminants from the product gas.

The SVZ facility has also built a 25 bar pressurised,35 t/h capacity British Gas Slagging Lurgigasification system for converting mixed feed stocksto MCV fuel gas or synthesis gas. As is the case withthe FDV Process, the raw gas is subjected toconventional gas cleaning to produce a clean productgas and liquid and solids containing waste slurrystream.

The third oxygen-blown, refractory lined gasifier isthe FSV 15 t/h entrained flow gasifier, similar to theTEXACO process, which serves the role of a‘bottoming’ gasifier that effectively treats thehydrocarbons containing waste streams from gasprocessing into a contaminant-free synthesis gas andmineral slag. If required, a supplementary fuel, i.e.natural gas is used to maintain the reactortemperature in the range of 1600 to 1800ºC. Thisprocess is today owned by Lurgi and called the MultiPurpose Gasifier.

Figure 7A: Pressurised Moving Bed Gasifier with Revolving Grate

Figure 7B: Pressurised Moving Bed Gasifierwith Liquid Slag Discharge


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Figure 7C: SVZ Schwarze Pumpe EntrainedFlow Gasifier with Slag Discharge

The SVZ plant is a first-of-a-kind integratedgasification, methanol and combined-cycleelectricity production plant that convertscontaminated and difficult to handle waste materialsto clean, value-added products. The high gasificationtemperatures of up to 1800°C are high enough tototally decompose contaminants in the product gasor gas scrubbing effluent streams. The vitrified slag,the only gasifier waste product, safely encapsulatesany residual pollutants and can be used asconstruction material.

In July 2002, SVZ was sold to ORESTO, asubsidiary of Nord GB Gesellschaft fürBeteiligungen mbH, Hamburg.

CHRISGAS Project: Between 1993 and 1999,Sydkraft Ab adopted the Ahlstrom/FW CFBgasification process to develop and demonstrate thefirst pressurised Bioflow biomass gasification IGCCprocess for CHP (9 MWth and 6 MWe) applicationin Värnamo, Sweden [7]. This demonstration, widely

recognised for its technical success, operated thepressurised CFB gasifier for about 8500 hours. Theintegrated operation of the pressurised gasifier withhot-gas clean-up and power generation in a close-coupled Alstom’s (now part of Siemens) Typhoongas turbine was demonstrated for over 3600 hours.Although, the facility has been mothballed forseveral years, it will be reactivated as the centrepiece for demonstrating the CHRISGAS project, amulti-national consortia technology developmenteffort. The project’s mission is to developpressurised, oxygen-blown gasification of biomassand wastes to produce synthesis gas and itssubsequent conversion to transportation liquidfuels.9 The results from the CHRISGAS projectshould be also useful for evaluating the productionof hydrogen from biomass.

The CHRISGAS project is coordinated by VäxjöUniversity at the Växjö Värnamo Biomass GasificationCentre (VVBGC). The Project team includes, AGA-Linde, Catator, KS Ducente, Royal Institute ofTechnology (KTH), S.E.P. Scandinavian EnergyProject, TPS Termiska Processer, (Valutec),VäxjöEnergi, TK Energi, DK, Valutec, FI, FZ Jülich, DE,Linde, Pall Schumacher, University of Bologna, IT,Technical University Delft, NL, and CIEMAT, ES. Theproject budget is more than Euro18 million.

Research Needs

The following sections highlight research needs fordeveloping and commercialising biomass gasifiersfor hydrogen production.

Feed PreparationUnlike fossil fuels, biomass is dispersed and lacksthe infrastructure to ensure sustained supply of low-cost quality controlled gasification feedstock.Biomass has certain physical characteristics, such aslow bulk density and its fibrous nature that presentsmany challenges in collection and transportation to acentral gasification plant. Although the feedpreparation and feed handling systems for woodybiomass are well developed for low-pressure


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systems, reliable feeders for other types of biomassfor pressurised gasifiers require further development.

Low-cost pelletisation of low-density herbaceousfeedstocks would widen the range of renewable feedmaterials that are available for biomass gasification.Pellets are easy and economical to transport andtheir relatively uniform shape and bulk densitywould render them easy to handle, store and feedpressurised systems.

Biomass GasificationThe present gasification systems are generallydesigned and operated to produce fuel gas for heatand power. The processes described above alsoproduce a fuel gas with little or no inert N2, i.e.,produce a synthesis gas containing primarily CO,H2, CO2, H2O(g), and some gaseous hydrocarbonsand condensable hydrocarbons. Fundamentalresearch is needed to improve product selectivity, toproduce essentially high-purity H2. The role ofcatalytic and non-catalytic bed additives on rawproduct gas yield and thermodynamic limitationsshould be investigated. Nearly total carbonconversion to produce high-purity H2 would requireminimal gas cleaning and separation to produce pureH2. It is conceivable that direct-H2 yield could beimproved by varying certain aspects of gasificationreactor designs and operating conditions.Gasification reactors should also be designed toincorporate the capability to thermally decomposeorganic condensates and ammonia that would beproduced from systems employing conventionallow-temperature gas cleaning and quenching.

Robust and sturdy low-cost, high-temperature heattransfer materials, which can operate up to 1100ºC(~2000ºF) would help develop indirectly heatedreactor designs that would prevent products ofcombustion from contaminating steam or ‘recycledproduct gas.’

Small-scale, low-cost air enrichment is anothertechnology that will be beneficial to producehydrogen production from biomass.

Raw Gas Handling and Clean-upSignificant progress has been made over the past 10years towards developing a better understanding ofbiomass gas handling and conditioning processes andtechnologies for use in biomass gasification foradvanced power production. However, there is needfor further R&D in this process step for removal orelimination of particulates (from attrition of gasifiersolids and secondary vapour-phase carbonaceousmaterials), alkali compounds, tar, chlorides, andammonia. High-temperature gas processing,including reforming of hydrocarbons and water-gasshift to convert CO to H2 should be investigated,particularly for raw product gases with all itscontaminants produced in biomass gasification. Inorder to improve the overall thermal efficiency and toretain process simplicity, it is desirable to conduct gascleaning at raw gas temperatures or at temperatureswhich may require some gas cooling but does notrequire any reheating of raw cleaning gases. Gascooling and design of appropriate heat exchangershave become the focus of the recent Essent/AMERand ARBRE biomass gasification demonstrationprojects, for co-firing and power generationapplications. In the development of high-efficiencygasification systems, it may be necessary that most ifnot all of these gas handling and gas clean-up R&Dshould be conducted at elevated pressures that matchwith the end-use for product H2.

Gas cleaning R&D should also investigate CO2removal at high temperatures, although it may not berequired for biomass gasifiers that may be developedfor molten carbonate fuel cells. Physical and ionicseparation membranes that can separate H2 at hightemperatures would be useful to produce high-purityH2, while CO or gaseous hydrocarbons are beingchemically converted to H2.

Gas cleaning in general will have a major impact onthe environmental impact of biomass gasifiers.Incomplete gas cleaning would shift the contaminantremoval problem to some other location downstreamfrom the gasifier, requiring expensive treatment ofall process effluents.


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Interface Issues and System IntegrationAs is the case with other energy conversion schemes,there could be several unique issues that need to beaddressed for integrating hydrogen producingbiomass gasification systems with selected end useapplications. Obviously a central hydrogenproducing biomass gasifier or gasifiers feeding to acentral hydrogen storage and distribution systemmay face simpler problems compared to hydrogenproducing biomass gasifiers that are closely coupledto selected chemical or energy conversion systems.Examples of the latter include issues related tocoupling gasifiers with high-temperature fuel cells.

System Definition and Market AssessmentWhenever ‘biomass gasification to hydrogen’becomes commercial, it would be necessary todetermine the range of capacity of conceptualcommercial plants. These specifications would bedependent to a great extent on the application, thecost and availability of feedstock. Upon definingthe basic plant specifications, it would be possibleto determine the process economics, theiradvantage over conventional alternatives, andhence the market potential for biomass gasifiers forspecific applications.

Information Dissemination and PolicyTo promote the successful development andcommercialisation of biomass gasifiers for hydrogenproduction and utilisation, timely dissemination ofinformation is absolutely essential. Given thecompetition from conventional sources of hydrogen,public education and information are definitelyrequired to craft, deploy, and implement policies thatare conducive to commercialising hydrogenproducing biomass gasification systems. It is crucialto document the performance of the new biomassgasification systems, to highlight success stories butalso in showing solutions to problems that may arise.The deployment of hydrogen producing biomassgasification systems for high-efficiency and selectedvalue-added applications will benefit from policiesthat encourage the use of renewable fuels.

References

1 International Energy Association 1997, ‘State of theArt of Biomass Gasification, Prepared by EuropeanConcerted Action, Analysis and Coordination of theActivities Concerning Gasification of Biomass’,AIR3-CT94-2284 and IEA Bioenergy, BiomassUtilisation, Task XIII, Thermal Gasification ofBiomass Activity, Canadian Country Report

2 Paisley, M.A., and Overend, R.P., 2002, ‘TheSylvaGas Process from Future Energy Resources –A Commercialisation Success’, 12th EuropeanBiomass Conference, June 17-21, 2002,Amsterdam, The Netherlands;w w w . f e r c o e n t e r p r i s e s . c o m /downloads/Amsterdam%20020619.pdf

3 Momtaz N. Mansour, Ravi R. Chandran and LeeRockvam, The Evolution of and Advances inSteam Reforming of Black Liquor, Manufacturingand Technology Conversion International, Inc.,www.tri-inc.net/EvolutionSR.pdf

4 Spliethoff, H. 2001, ‘Status of BiomassGasification for Power Production’, IFRFCombustion Journal, Article No. 200109

5 Contact: Suresh P. Babu, Gas TechnologyInstitute, 1700 South Mount Prospect Road, DesPlaines, IL 60018, USA, E-mail:[email protected]

6 Rauch, et.al, 2004, ‘Steam Gasification ofBiomass at CHP Plant in Guessing - Status of theDemonstration Plant,’ Second World Conferenceand Technology Exhibition, Biomass for Energy,Industry and Climate Protection, May 10-14,Rome, Italy. www.gastechnology.org/iea

7 International Energy Association 1997, ‘State of theArt of Biomass Gasification, Prepared by EuropeanConcerted Action, Analysis and Coordination of theActivities Concerning Gasification of Biomass’,AIR3-CT94-2284 and IEA Bioenergy, BiomassUtilisation, Task XIII, Thermal Gasification ofBiomass Activity, Sweden Country Report


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8 Consonni, S., Larson, E.D., Kreutz, T.G., andBerglin, N. 1998. Black Liquor-Gasifier/GasTurbine Cogeneration. ASME J. Engng. for GasTurbines & Power, Vol. 120, pp.442-449.

9 CHRISGAS 2004. www.chrisgas.com


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iea bioenergy 32nd, 33rd, 34th and 35th update

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