79e4150d6054be6034

Journal of Cleaner Production 11 (2003) 5159www.cleanerproduction.net

Application of life cycle assessment to the Portuguese pulp andpaper industry

E. Lopes, A. Dias, L. Arroja , I. Capela, F. PereiraDepartment of Environment and Planning, University of Aveiro, 3810 Aveiro, Portugal

Received 15 July 2000; received in revised form 20 August 2001; accepted 18 January 2002

Abstract

In this paper, the Life Cycle Assessment (LCA) methodology is applied to Portuguese printing and writing paper in order tocompare the environmental impact of the use of two kinds of fuels (heavy fuel oil and natural gas) in the pulp and paper productionprocesses. The results of inventory analysis and impact assessment show that the pulp and paper production processes play animportant role in almost all of the analysed parameters, which do not always result in an important contribution to the correspondingimpact categories. The substitution of heavy fuel oil by natural gas in the pulp and paper production processes seems to be environ-mentally positive. 2002 Elsevier Science Ltd. All rights reserved.

Keywords: LCA; Pulp; Paper; Eucalyptus globulus; Natural gas; Heavy fuel oil

1. Introduction

The concept of sustainability is becoming increasinglyimportant in the Portuguese pulp and paper industry,which is one of the most important economic activitiesin Portugal. In order to improve its environmental per-formance, this industry has made important investments,not only in the production process itself, but also in theflue gases and liquid effluents treatment systems. Besidesthis concern regarding pollution prevention, one of theissues of most relevance in the context of sustainabilityis the consumption of energy. Traditionally, Portuguesemills have used fuel oil as a fossil fuel in the chemicalrecovery system in pulp production and for on-siteenergy production in paper manufacturing. However, anew source of primary energy is now becoming availablefor the Portuguese industry with the recent installationof a national grid of natural gas. The utilisation of thisalternative fossil fuel instead of fuel oil constitutes aninteresting option from both the environmental and econ-omic point of view. This is particularly true in paperproduction where energy production in a combined cycle

Corresponding author. Tel.: +351 234 370 200; fax: +351 234429 290.

E-mail address: [email protected] (L. Arroja).

0959-6526/02/$ - see front matter 2002 Elsevier Science Ltd. All rights reserved.PII: S0959- 65 26 (02)00 00 5- 7

seems appealing for reasons related to energy rationalis-ation issues. More than being aware of the consequencesof natural gas utilisation in the mills, it is important toevaluate the global impact of this process modificationthrough the whole paper life cycle. Life Cycle Assess-ment (LCA) is thus the most appropriate tool to achievethis purpose, allowing a global overview of this activity.In this study, LCA methodology was applied to Portug-uese production of printing and writing paper in orderto evaluate its environmental performance and also tomake a comparative environmental assessment of fueloil and natural gas, respectively, as energy sources inthe manufacturing process.

2. Methodology

This study was performed using a methodologicalframework based on ISO (International Organization forStandardization) recommendations [14]. According toISO, LCA is divided into four phases: goal and scopedefinition, inventory analysis, impact assessment andinterpretation.

The goal and scope definition is extremely importantsince the study will be carried out according to the state-ments made in this phase. The goal must refer theintended application and audience, and the reasons for

52 E. Lopes et al. / Journal of Cleaner Production 11 (2003) 5159

conducting the study. In the scope definition, the follow-ing items, among others, should be described: systemunder study, functional unit (FU), system boundaries,allocation procedures, impact assessment methodologies,data quality requirements and assumptions.

The inventory analysis involves data collection on rawmaterials and energy consumption, emissions to air,water and soil and solid waste generation.

The impact assessment phase assigns inventory resultsto impact categories and quantifies the system potentialcontribution to different environmental impacts.

Finally, in the interpretation phase, the inventoryanalysis and impact assessment results are discussed andthe significant environmental issues are identified toreach conclusions and recommendations consistent withthe goal and scope requirements.

2.1. Goal and scope definition

2.1.1. PurposeThe purpose of this study is the identification and

assessment of the environmental impacts associated withthe production, use and final disposal of printing andwriting paper produced in Portugal from Eucalyptus glo-bulus and consumed in Portugal.

The two main reasons for conducting this study are:

to determine the contribution of different (groups of)processes to the printing and writing paper life cycleenvironmental impact;

to compare the potential environmental impacts oftwo different fossil fuel sources (natural gas andheavy fuel oil) used in the eucalyptus pulp productionprocess and for on-site energy production in paperproduction.

2.1.2. Product descriptionThe product under study is printing and writing paper.

The raw materials used in the production of paper areeucalyptus pulp, softwood pulp produced in Scandinaviaand precipitated calcium carbonate (PCC).

2.1.3. Product system description and boundariesThe system under study produces eucalyptus pulp and

printing and writing paper using the typical technologycurrently available in Portuguese mills. The softwoodpulp production uses typical Scandinavian modern tech-nology.

The system boundaries, schematically represented inFig. 1, include the following subsystems:

Eucalyptus globulus forest, softwood forest, softwood pulp production, Eucalyptus globulus pulp production, printing and writing paper production,

Fig. 1. System boundaries.

final disposal (recycling, landfilling and composting), chemical production, transport, electric energy production, fuel production (including extraction).

Excluded from the system boundaries are:

the production and maintenance of capital goods(buildings, machinery, etc.),

the production of plants used in forest plantation, the inputs and outputs that represent less than 1% of

the printing and writing paper mass, the paper utilisation phase.

2.1.4. Functional unitThe primary purpose of the functional unit (FU) is to

provide a reference unit to which the inventory data arenormalised. In this study, the FU was defined as 1 tonneof white printing and writing paper, with a standardweight of 80 g/m2, produced from Portuguese Eucalyp-tus globulus kraft pulp and consumed in Portugal.

2.1.5. AllocationThe allocation procedures were applied following ISO

recommendations [2]:

whenever possible, allocation was avoided by unitprocess division or system boundaries expansion,

where allocation could not be avoided, the outputsand inputs of the system were partitioned among itsdifferent products or functions in a way that reflectsphysical relationships among them,

when physical relationships could not be established,the inputs and outputs were allocated between theproducts and functions in a way that reflects otherrelationships among them (for example mass or econ-omic relationships).

53E. Lopes et al. / Journal of Cleaner Production 11 (2003) 5159

2.1.6. Impact assessment methodologyThe impact assessment conducted in this study con-

siders the following impact categories:

global warming (GW), using the IPCC global warm-ing potentials for 100 years [5];

acidification (A), using the acidification potentialsdefined by Hauschild and Wenzel, 1997 [6];

eutrophication (E), using the weighting factors for themaximum-scenario defined in [5];

non-renewable resource depletion (NRRD), using thereserve-to-use ratios taken from [5];

photochemical oxidant formation (POF), using thephotochemical ozone creation potentials defined byHeijungs et al., 1992 [5].

2.1.7. Data quality requirementsWhenever possible and feasible, inventory data were

provided by the pulp and paper industry and by otherinvolved bodies, and checked by mass and energy bal-ances. The remaining data were taken from the literatureand specialised databases.

2.2. Inventory analysis

Inventory data were collected for the purpose ofcharacterisation of the identified subsystems in the paperlife cycle.

2.2.1. Eucalyptus forestThe production of eucalyptus includes forest instal-

lation, forest growth and wood harvesting. The plant pro-duction was excluded from this study, since the environ-mental burdens associated with this stage wereconsidered irrelevant. Forest installation and growthcomprises path opening, land preparation, soil prep-aration, deep fertilisation, plantation, pest control, soilmobilisation and soil fertilisation. Wood harvestingincludes felling, debarking, cutting, off-road hauling andtruck loading.

The mass and energy consumptions are typical datagathered from Portuguese harvested eucalyptus forests[7]. The air emissions associated with fuel consumptionin the mechanical operations were calculated using emis-sion factors for diesel and petrol [8].

2.2.2. Softwood forestThis subsystem includes pine growth and pine har-

vesting, 75% of which is done by regeneration fellingand 25% by thinning. Inventory data are average Finnishdata from 1989 (wood growth) and 1995 (woodharvesting) taken from KCL-EcoData database [9].

2.2.3. Softwood pulp productionSoftwood pulp is used as a raw material in printing

and writing paper production and it is imported from

Scandinavia. Data on the production of softwood pulpinclude the pulping process, ECF bleaching with oxygendelignification and reduced chlorine dioxide consump-tion, pulp drying, activated sludge plant, sludge combus-tion, energy generation from bark and concentrated blackliquor (liquor from wood cooking) and mill condensationpower plant. These data were taken from KCL-EcoDatadatabase [9] and refer to 1997 typical Finnish technologyfor the production of market softwood kraft pulp.

Since the softwood pulp production process defined inthis study produces surplus electricity, the environmentalburdens associated with the production of the sameamount of electricity in the Finnish grid were subtractedfrom the inputs and outputs of this subsystem.

2.2.4. Eucalyptus globulus pulp productionTo perform this study, two scenarios were defined:

actual scenario (AS): eucalyptus pulp and paper inte-grated production using heavy fuel oil

natural gas scenario (NGS): eucalyptus pulp andpaper integrated production using natural gas.

The production of eucalyptus pulp includes the wood-yard, wood cooking, brownstock washing and screening,ECF (elemental chlorine free) pulp bleaching usingchlorine dioxide produced on site, chlorine dioxide pro-duction, chemical recovery, energy generation from barkand concentrated black liquor, wastewater treatment inan activated sludge plant and solid waste landfilling. Thelime kiln is a part of the chemical recovery system andits role is to recover lime to be recycled. Besides theheavy fuel oil or natural gas, the lime kiln burns non-condensable gases from the cooking and black liquorevaporation plants.

In order to quantify only the inputs and outputs ofintegrated pulp production, allocation procedures wereapplied to this process:

none of the existing Portuguese pulp mills is 100%integrated, since they also produce surplus marketpulp for export. To avoid allocation, the existing sys-tems were disaggregated and the environmental bur-dens associated with the drying section of the pulpmill were excluded from the study;

the surplus electricity production in the eucalyptuspulp manufacturing was taken into account, consider-ing its alternative production in the Portuguese grid.

2.2.5. Printing and writing paper productionThe printing and writing paper production includes

eucalyptus pulp transfer, softwood pulp bales pulping,pulp refining, cleaning and screening, broke recovery,paper machine, finishing, wastewater treatment in anactivated sludge plant and on site energy production. Inthe actual scenario, energy requirements are satisfied by


electricity and steam produced on-site in a heavy fueloil boiler, plus electricity from the national grid. In thenatural gas scenario, energy requirements are entirelysatisfied by electricity and steam generated in a com-bined cycle system (gas turbine, gas boiler and steamturbine), with the surplus electricity produced exportedto the national grid.

Actual inventory data for the current scenario wereprovided by the Portuguese pulp and paper industry, andwere checked by mass and energy balances. With respectto the natural gas scenario, the inventory data were takenfrom studies carried out by the Portuguese industry.

2.2.6. Final disposalCurrently, final disposal alternatives in Portugal for

printing and writing wastepaper are recycling (11%),landfilling (84%) and composting (5%).

2.2.6.1. Recycling The inventory data refer to typicalPortuguese data for the production of packaging papers(testliner and fluting) since most of the recovered usedpaper is integrated in the production of these kinds ofpapers. The recycling technology includes pulping,screening, refining, washing, drying and finishing. Thissubsystem also includes primary treatment of wastewaterand on-site energy production in a heavy fuel oil boilerand in a diesel engine.

In the characterisation of this subsystem some allo-cation procedures had to be applied since recycling ful-fils an additional function: the production of a new pro-duct (testliner and fluting). Allocation was avoided byexpanding the system boundaries in order to includekraftliner production (testliner and fluting equivalentproduct made of virgin fibre). The inputs and outputs ofthe kraftliner production [10] were subtracted from theinventory of the recycling subsystem. The basic assump-tion is that the use of secondary fibre displaces the useof virgin fibre.

2.2.6.2. Landfilling 70% of the landfill sites con-sidered in this final disposal alternative include systemsfor leachate control, collection and treatment, and 30%represent uncontrolled tipping, the latter meaning thatlandfill sites are not lined with an impermeable layer orlayers, and do not include systems for leachate control,collection and treatment. In both cases the landfill gasis neither burnt nor used for energy recovery. Inventorydata were based on data from literature [11] allocated tothe paper fraction of municipal solid waste (MSW) ona causality basis. When leachate treatment occurs, liquidemissions were calculated considering Portuguese waste-water discharge legislation.

2.2.6.3. Composting Input and output data correspondto the European average technology [11]. Allocation tothe paper fraction of MSW was done on a causality

basis. Besides being an alternative for final disposal ofwastepaper, composting also produces a valuable pro-duct (compost) displacing the usage of chemical fertiliz-ers. Therefore some credit should be given to this pro-cess, but the lack of quantitative data concerning thereduction in chemical fertilizer application precluded theassessment of that credit in this study.

2.2.7. Chemical productionThe environmental burdens associated with the pro-

duction of chemicals used as feedstocks in several subsy-stems throughout the paper life cycle were included inthis study in order to comply with the cut-off criteria.In addition, the production of hydrogen peroxide andsodium chlorate was included because, according to theliterature, [12] they are energy-intensive processes.Inventory data were collected from the literature [8,13].

2.2.8. TransportsThis subsystem includes the circulation, between sub-

systems, of wood, softwood pulp, paper, wastepaper,chemicals and fuels by 16 tonne, 28 tonne and garbagetrucks, ocean ships and electric trains. The travelled dis-tances were provided by the involved bodies and theemission factors were obtained from the literature [8].

2.2.9. Electric energy productionSome subsystems purchase electricity from the

national grid, while others have a surplus of electricityproduction. Taking into account the subsystems geo-graphic boundaries the following electricity productiongrids were characterised: Portugal, Spain, France,Belgium, Finland and UCPTE (Union for the Connectionof Production and Transportation of Electricity). Inven-tory data regarding these models were obtained in theliterature [8]; besides electricity production, they includefuel extraction, processing and transportation(precombustion).

2.2.10. Fuel productionThis subsystem comprises the precombustion of the

consumed fuels in the other paper life cycle stages. Thefuels considered are heavy fuel oil, light fuel oil, dieseloil and natural gas. Inventory data were taken from theliterature [14].

2.3. Impact assessment

In the first step of the impact assessment phase(classification) the inventory results are assigned to dif-ferent impact categories, based on the expected types ofimpact on the environment. Table 1 shows the inventoryparameters considered in this study and the impact categ-ories selected for analysis.

In the next step of impact assessment(characterisation), the total potential contribution from


Table1Impact categories and corresponding parameters

Impact category Parameters

Global warming, 100 years (GW) Non-renewable CO2, CH4, N2OAcidification (A) SO2, NOx, HCl, NH3, HF, H2SEutrophication (E) NOx air, NH3 air, N water, NO3 water, NH4+ water, P water, PO43 water, COD waterNon-renewable resource depletion (NRRD) Crude oil, Natural gas, CoalPhotochemical oxidant formation (POF) CH4, Halogenated hydrocarbons, Aromatic hydrocarbons

all inputs and outputs to the different impact categoriesis calculated using weighting factors [5,6].

The impact assessment stage may also include nor-malisation, grouping and weighting of the impact categ-ories leading to a single environmental score. Sinceaccording to ISO standards [3] these are optionalelements, they were not performed in this study.

3. Results

3.1. Inventory analysis results

It is possible to make a first interpretation at the inven-tory analysis level based on individual parameters. Theinventory results consist of an exhaustive list of para-meters, but in this paper only the parameters commonlydiscussed from an environmental point of view are ana-lysed: non-renewable and renewable energy consump-tion, non-renewable carbon dioxide (CO2), nitrogenoxides (NOx), sulfur dioxide (SO2), chemical oxygendemand (COD) and adsorbable organic halogens (AOX).Figs. 24 show the energy consumption, the air emis-sions and the water emissions at the different stages ofthe paper life cycle, for the actual scenario and for thenatural gas scenario. It is important to note that only the

Fig. 2. Inventory results: energy consumption.

CO2 originated during the combustion of non-renewablefuels (non-renewable CO2) was considered, since one ofthe assumptions of this study is that the CO2 releasedfrom renewable sources (renewable CO2) is balanced byCO2 absorption in the forest.

3.1.1. Energy consumptionThe two parameters selected for analysis are renew-

able and non-renewable energy. Renewable energy isenergy that is contained in the renewable fuels and/orresources (water, wood, bark and black liquor) con-sumed across the paper life cycle for energy production.Non-renewable energy refers to the energy content ofthe fossil fuels consumed in the whole system.

The eucalyptus pulp production process is the mostimportant consumer of renewable energy since all theenergy produced in this subsystem is based on renewablefuels (bark and black liquor). As shown in Fig. 2, finaldisposal has a negative contribution to this parameter,which reflects the credits given to the recycling processin the inventory analysis.

When the fuel source changes from heavy fuel oil tonatural gas there is a slight decrease in this parameter(renewable energy consumption) exclusively due to thecontribution of the electric energy production subsystemthat, as a result of the surplus electricity production in


Fig. 3. Inventory results: air emissions.

Fig. 4. Inventory results: water emissions.

the paper production process, becomes negative. Thismeans that the renewable energy consumption avoidedby the exportation of electricity to the national gridexceeds the renewable energy associated with the elec-tricity consumption in the other stages of the paperlife cycle.

When it comes to non-renewable energy consumption,the most important contributor is on-site energy pro-duction in the printing and writing paper production inboth scenarios. This contribution increases significantlywhen natural gas replaces heavy fuel oil since, in termsof energy, the amount of natural gas consumed duringpaper production is higher than the one of heavy fuel oilin the present scenario. This increase, however, does notresult in an increase in the systems total contribution tonon-renewable energy consumption because of the sur-plus electricity generated in the paper production processin the natural gas scenario.

3.1.2. Air emissionsComparing the non-renewable CO2 emissions and

non-renewable energy consumption in Figs. 2 and 3, itis possible to see that these two parameters haveapproximately the same profile. Thus, the major sourceof non-renewable CO2 emissions is on-site energy pro-duction in the paper production process. The substitutionof heavy fuel oil by natural gas leads to a reduction ofapproximately 50% in total emissions.

Most of NOx emissions are generated by transport,and among these mainly by the transportation of euca-lyptus wood from the forest to the pulp mill (Fig. 3). Theeucalyptus pulp production is the second most importantcontribution to this parameter due to black liquor com-bustion. The paper production also has a significant con-tribution to NOx emissions in the heavy fuel oil scenariodue to on-site energy production, which is remarkablyreduced to 0.5% in the natural gas scenario. With the


replacement of heavy fuel oil by natural gas, a reductionof more than 40% is reached in the total emissions ofNOx mainly caused by a decrease in these emissions inthe paper production together with the avoided NOxemissions in electricity production.

As far as the SO2 emissions are concerned, the mainsource in the present scenario is on-site energy pro-duction during the paper production (Fig. 3). The euca-lyptus pulp production and the electric energy productionalso have an important contribution. It is important topoint out that the contribution of electric energy pro-duction is mainly related with the production of elec-tricity for the paper production process. Changing thefuel source to natural gas, SO2 emissions are reduced bymore than 98%, since the SO2 emissions avoided bythe production of electricity in the paper production pro-cess almost equal the total SO2 emissions generatedthroughout the paper life cycle. In this scenario the paperproduction contribution becomes meaningless and themajor source is final disposal, followed by chemical andeucalyptus pulp production.

3.1.3. Water emissionsThe eucalyptus pulp production is the most important

source of COD emissions in both scenarios, followed bythe paper production and the softwood pulp production,as can be seen in Fig. 4. The total contribution of theother subsystems is negligible.

AOX emissions appear mostly in the pulp productionprocesses, due to the chlorine dioxide consumption inthe bleaching process. The eucalyptus pulp productioncontributes with more than 80% to this parameter, andthe softwood pulp production contributes with almost20%.

As expected, the different fuel sources do not affectthe results of these parameters.

3.2. Impact assessment results

The results of the impact assessment phase for theactual scenario and for the natural gas scenario areshown in Fig. 5.

3.2.1. Global warmingMost of global warming potential results from the

final disposal of printing and writing wastepaper. Thisimportant contribution is mainly originated by methane(CH4) emissions that occur during wastepaper landfil-ling. Although the systems total CO2 emissions areeight (natural gas scenario) to 15 (heavy fuel oilscenario) times greater than total CH4 emissions, the lat-ter assumes a more important role in this impact categorysince its global warming potential is 24.5 times greaterthan the one of CO2, according to Table 1. The secondmost important contributor to this potential impact is on-site energy production in paper production, exclusively

due to CO2 emissions. The replacement of heavy fueloil by natural gas originates a reduction in the systemsglobal warming potential of about 20%, as a result ofthe decreased CO2 emissions in the natural gas scenarioas explained in the interpretation of the inventory analy-sis results.

3.2.2. AcidificationIn the present scenario, paper production is the most

important contributor to the overall acidification poten-tial, which is mainly due to SO2 emissions from on-siteenergy production. Transport, eucalyptus pulp pro-duction and electric energy production are importantcontributors as well. In the transport subsystem the con-tribution to acidification is dominated by NOx emissionswhile in the two other subsystems, SO2 emissions aremainly responsible. In the natural gas scenario areduction of almost 75% of the overall acidificationpotential is observed. This happens mostly as a result ofthe paper production contribution reduction to nearlyzero, and of the avoided emissions by the surplus elec-tricity production in paper manufacturing. In addition,the acidification potentials of the eucalyptus pulp andfuels production subsystems undergo slight decreases,which also contribute to the overall reduction.

3.2.3. EutrophicationThe largest contribution to the overall eutrophication

potential comes from the eucalyptus pulp production,mainly as a result of its COD emissions. Transport andpaper production are also relevant subsystems contribu-ting to this impact category. In the transport subsystemthis is mainly due to NOx emissions while in the paperproduction subsystem COD emissions are dominant. Theoverall eutrophication potential is reduced by more than20% with the replacement of heavy fuel oil by naturalgas, due to a decrease in the paper production contri-bution (caused by a decrease in NOx emissions from on-site energy production) and from the avoided emis-sions by the surplus electricity production in papermanufacturing. The eutrophication potentials of theeucalyptus pulp and fuel production subsystems undergoslight decreases, which contributes to the overallreduction as well.

3.2.4. Non-renewable resource depletionPaper production is the subsystem contributing most

to non-renewable resource depletion. The reason for thisis that the paper production subsystem consumes exclus-ively non-renewable fuels (heavy fuel oil or natural gas,according to the different scenarios) for on-site steamand electricity production. The second most importantcontribution to this impact category is that of transport,because it comes from the consumption of diesel oil andheavy fuel oil by the several modes of conveyancethroughout the paper life cycle. The overall potential to


Fig. 5. Impact assessment results.

this impact category is reduced by more than 45% in thenatural gas scenario, mainly due to the surplus of elec-tricity generated in the paper production process. Inaddition, the contributions of the eucalyptus pulp andpaper productions are smaller in the natural gas scenario.

3.2.5. Photochemical oxidant formationThe final disposal of wastepaper contributes almost

100% to the overall photochemical oxidant formationpotential due to the CH4 emissions from wastepaperlandfilling. Thus, there are no significant differences inthe photochemical oxidant formation potential betweenthe two alternative scenarios.

4. Conclusions

Based on the inventory analysis and impact assess-ment results, the following conclusions can be drawnconcerning the contribution of the different processes tothe printing and writing paper life cycle environmentalimpact, which was one the reasons stated for carryingout this study:

the printing and writing paper production is the mostimportant contributor to non-renewable CO2 emis-sions due to on-site energy production, which doesnot correspond, however, to a major contribution tothe overall global warming potential. Actually, in Por-tugal this impact category is dominated by CH4 emis-sions from wastepaper landfilling. On-site energy pro-duction in the paper production subsystem is themajor source of SO2 emissions, which makes it themost significant contributor to the acidification impactcategory. This subsystem is also the main consumerof non-renewable energy and, as a result, it is respon-sible for the most important share of the global system

potential impact concerning non-renewable resourcedepletion.

although the eucalyptus pulp production is the largestconsumer of energy throughout the paper life cycle,its contribution to air emissions is not predominant,because almost 95% of the energy consumed in theeucalyptus pulp production process is renewableenergy from bark and black liquor combustion.Consequently, this subsystem has the highest renew-able energy consumption in the paper life cycle. Theeucalyptus pulp production is also an important con-tributor to acidification since it is one of the majorsources of SO2 emissions, and furthermore dominatesthe results for water emissions (COD and AOX), thusbeing responsible for a great part of the overalleutrophication potential.

the final disposal stage assumes a predominant role inglobal warming and photochemical oxidant formationimpact categories, as a result of the CH4 emissionsin landfilling.

transport is the main source of NOx emissions,resulting in an important contribution to the eutroph-ication and acidification impact categories.

the contribution of the remaining stages of the paperlife cycle to the impact categories is not relevant.

The replacement of heavy fuel oil by natural gas inthe eucalyptus pulp and paper production processesappears to be environmentally positive, provided that acogeneration unit is installed to produce energy in thepaper making process. In this way, this process, which inthe present scenario is a net energy consumer, becomesa net exporter to the national electricity grid, with thecorresponding avoided emissions. This modificationsignificantly reduces the total emissions of CO2, SO2 andNOx, leading to a smaller potential contribution from theglobal system to global warming, acidification and


eutrophication. Changing the fuel source to natural gasalso decreases the non-renewable resource depletion bymore than 45%.

Acknowledgements

This study has been performed in association with theproject Life Cycle Assessment (LCA) Environmen-tal Impact Assessment of the Activity: From Eucalypt toPaper (3/3.2/PAPEL/2323/95) which is financed by theFCT Fundacao para a Ciencia e Tecnologia and bythe program PRAXIS XXI. The authors would also liketo thank Emporsil, Portucel Industrial, Soporcel andRAIZ for their collaboration in providing first handinformation and inventory data.

References

[1] International Organization for Standardization (ISO), Environ-mental management Life cycle assessment Principles andframework. ISO 14040, 1997.

[2] International Organization for Standardization (ISO), Environ-mental management Life cycle assessment Goal and scopedefinition and inventory analysis. ISO 14041, 1998.

[3] International Organization for Standardization (ISO), Environ-

mental management Life cycle assessment Life cycleimpact assessment. ISO 14042, 2000.

[4] International Organization for Standardization (ISO), Environ-mental management Life cycle assessment Life cycleinterpretation. ISO 14043, 2000.

[5] Lindfors LG. Nordic Guidelines on Life-Cycle Assessment. Nord1995:20. Copenhagen, Denmark: Nordic Council of Ministers,1995.

[6] Jensen A et al. Life Cycle Assessment (LCA): a guide toapproaches experiences and information sources. Copenhagen,Denmark: European Environment Agency, 1997.

[7] Emporsil and Soporcel, Technical report: management of Euca-lyptus globulus forest (in Portuguese).

[8] Habersatter K et al. Inventaires ecologiques relatifs aux embal-lages. Berne, Switzerland: Swiss Federal Office of Environment,Forests and Landscape no 250, 1998.

[9] KCL-ECO, EcoData. Registered Trademarks of the Finnish Pulpand Paper Research Institute, Espoo, Finland, 1999.

[10] FEFCO, Groupement Ondule and Kraft Institute, European Data-base for Corrugated Board Life Cycle Studies, 1997.

[11] White P, Franke M, Hindle P. Integrated solid waste manage-ment: a lifecycle inventory. Cornwall, UK: Blackie Academic &Professional, 1995.

[12] Stromberg L et al., Guidelines on Life Cycle Inventory Analysisof Pulp and Paper. NORDPAP DP 2/30, SCAN FORSK-RAP-PORT 669, 1997.

[13] Virtanen Y, Nilsson S. Environmental Impacts of Waste PaperRecycling. London, UK: International Institute for Applied Sys-tems Analysis, 1993.

[14] Habersatter K et al. Ecobalance of Packaging Materials State of1990. Berne, Switzerland: Swiss Federal Office of Environment,Forests and Landscape no 132, 1991.

Application of life cycle assessment to the Portuguese pulp and paper industryIntroductionMethodologyGoal and scope definitionPurposeProduct descriptionProduct system description and boundariesFunctional unitAllocationImpact assessment methodologyData quality requirements

Inventory analysisEucalyptus forestSoftwood forestSoftwood pulp productionEucalyptus globulus pulp productionPrinting and writing paper productionFinal disposalRecyclingLandfillingComposting

Chemical productionTransportsElectric energy productionFuel production

Impact assessment

ResultsInventory analysis resultsEnergy consumptionAir emissionsWater emissions

Impact assessment resultsGlobal warmingAcidificationEutrophicationNon-renewable resource depletionPhotochemical oxidant formation

ConclusionsAcknowledgementsReferences

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