Fuel Processing Technology 133 (2015) 35–42

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Fuel Processing Technology

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Small addition effect of agave biomass ashes in cement mortars

J.R. González-López ⁎, J.F. Ramos-Lara 1, A. Zaldivar-Cadena 1, L. Chávez-Guerrero 1,R.X. Magallanes-Rivera 1, O. Burciaga-Díaz 1

Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León 66450, México

⁎ Corresponding author. Tel.: +52 8183294000x7252.E-mail addresses: rhodio@hotmail.com (J.R. González-L

(J.F. Ramos-Lara), azaldiva70@hotmail.com (A. Zaldivar-Cad(L. Chávez-Guerrero), rxmagallanes@gmail.com (R.X. Magaoswaldo.burciaga@gmail.com (O. Burciaga-Díaz).

1 Tel.: +52 8183294000x7252.

http://dx.doi.org/10.1016/j.fuproc.2014.12.0410378-3820/© 2015 Elsevier B.V. All rights reserved.

a b s t r a c t

a r t i c l e i n f o

Article history:Received 10 October 2014Received in revised form 24 December 2014Accepted 26 December 2014Available online xxxx

Keywords:AgaveSubproductCharacterizationBiomass

The use of industrial waste for the production of biomass is a topic that has gained increasing interest. This is dueto the need to use plants that do not affect the food supplywhen used for power generation from biomass. Agavesalmiana residuesmeet these characteristics. It has now been proposed as a possible source of bioenergy produc-tion because of its growth characteristics. Therefore, in this research, the effect of combustion temperature of theA. salmiana as it could happen in the energy production was studied. In addition, the characteristics of these res-idues were analyzed to serve as a basis for possible future applications in construction materials. Results indicatethat the ashes are mainly CaCO3 when calcined at below 700 °C, and CaO above this temperature. The apparentparticle size was between 25 and 32 μm. However, it is observed that it consists of much smaller particles of ap-proximately 300 nm. This reduction in size is related to decomposition at higher temperatures and is reflected inthe increase of the specific area up to 70%. The compression strength at early ages was up to 90% higher than areference, when 5% cement replacement mixes were performed.

© 2015 Elsevier B.V. All rights reserved.

1. Introduction

Agroindustry is a sector that mainly serves the needs of food supply,both animal and human consumption. It has been recently observedthat there is a great potential for some of these industries, such assugar, wood, and others to share part of their crops to the productionof biomass for power generation [1–3]. As a result, studies of how toturn these plants into energy sources have constantly been done toincrease power energy efficiency. However, once the plants have beenburned to produce energy, the product of such combustion is a residuewith variable content of organic and inorganic material; these residuesare the biomass ashes (BA) and in most of cases those residues do nothave a defined application; thus, confinement is regularly practiced.BA contains different features and their properties must be establishedto determine the possible uses or final disposal. Currently, a uniqueclassification to relate the properties and/or applications of BA doesnot exist. However, several researches have been conducted to classifyBA depending on their chemical composition and mineral phase to anextensive number of different reported BA [4]. This classification

ópez), ralf_89s@hotmail.comena), guerreoleo@hotmail.comllanes-Rivera),

considered carbonaceous content, organic phases, inorganic materialcomposition and fluids contained in them, and possible uses wereestablished from themain chemical element groups that are often asso-ciated [5].

Currently, between 8 and 12% of energy is produced through bio-mass direct burning. The result of the widespread use of energy pro-duction from biomass will be the increase of the residues which areknown as biomass bottom ashes. This form of energy productionwill continue growing and the amount of waste would be even com-parable to the fly ash that is currently produced by burning fossilfuels [6]. This makes it urgent to establish the possible uses thatthese BA might have.

BA properties would depend on the characteristics of the plantsused as biomass; temperature and time process; and the procedurefor its final disposal. Thus, it is necessary to emphasize the needto analyze in the most elaborate way, a methodology for BA charac-terization, which considers chemical composition, mineral phases,size, and morphology of the BA to elucidate their potential usesor the characteristics under which they shall be confined. Thechemical composition of the BA is based on the content of themain components, having regularly as main elements: O, C, H, Nin the organic material; and Si, Ca, K and Mg in the inorganic mate-rial [4,7].

Among the plants that are potential sources for generating biomasswith high power generation potential, is the Agave salmiana. Further-more, the conditions where these plants grow are mostly arid regions;therefore vast land that is uncultivable now could be planted. So, agreat potential for future energy production has been found [8,9].

36 J.R. González-López et al. / Fuel Processing Technology 133 (2015) 35–42

Nowadays, most of the grown agave is intended for themezcal produc-tion industry, which is an alcoholic beverage produced in Mexico. Anadvantage of using this plant as a possible rawmaterial for power gen-eration is that it does not compete withworldwide food production andit can be grown on currently unused arid land. Arid and semi-arid areasare expanding more because of climatic changes, and it has been foundthat plants of the genus agave can grow in placeswhere the total annualrainfall (TAR) is as low as 427 mm. However, this affects their annualproductivity in 10 Mgha−1 and increasing to 34 Mgha−1 when theTAR is 848mm. Thus, it can be said that the conditions of higher produc-tivity for theproduction of these plants are not fully established [10] andthe energy demandwill develop this sector and consequently thewastegeneration previously mentioned. Then, because of the large amount ofwaste generated from biomass, some researchers have proposed tointegrate high volumes of biomass residues in products such as paper,activated carbon and agglomerates, focusing mainly on the use ofbagasse and not to the ash resulting from its burning as biomass.Agroresidues that have gone through this same process are olive andsugarcane, which are mostly consumed to produce food, and morerecently for biofuel. The extensive use of sugarcane has led to character-ize itswaste and to use it in buildingmaterials. Researchers have report-ed thepossible use of different sugarcanewastes: for themanufacture offibers, in fiber-reinforced compositematerials [11]; and ashes in ceram-ic matrices, such as refractory materials [12]; or the effect of the sugar-cane BA addition as supplementary material in cement[13,14] as analternative for construction in countries with emerging economies.The reactivity of the ash is limited because it contains organic residues,since the commonly used calcination temperature is not high enough toreduce the content of organics [15].

For all the aforementioned, studies have been conducted on thebiomass waste decomposition conditions that would help to determinetheir actual use, either as a mineral filler [16], material for cementreplacement [17,18], or as building materials [19–22]. In general, theagroindustrial waste of sugarcane production, has been through a pro-cess of assimilation of their capabilities and limitations to increase itsuse [23]. Nowadays, applications are real, and this is the same processthat other agroindustrial residues, as rice husks, have been through[24,25]. Studies related to the waste of agave industry are currentlyfocused on the characterization and use of the fibers of agave, and toits potential use in applications of environmental engineering, eitheras a source of calcium or chemical removal [24–29]. Thus, the calcina-tion conditions for its use as fuel and how these residues can be usedwithin different industries, must be appropriately set, considering thatagavewill be a biomass for energy productionwidely used in the future.

2. Material and methods

The plant leaves used in this workwere obtained fromMexico in theregion located at 100°23′46.793″W25°21′53.218″Nwhich correspondsto a semi-arid region. In this area, the plant is used for the production ofmezcal and it corresponds to the A. salmiana specie. This plant has a lifecycle of about 6 years and it can reach a size from 2 to 6mdepending onspecies. These plants were obtained bymanual labor and the removal ofmaterial was not concentrated in the heart (piñas) of the plant, but inthe leaves.

As it was mentioned above, BA has been proposed to be used poten-tially in building materials. However, the way agave biomass ashes(ABA) are used is rarely studied in the literature, so, according to studiesconsulted, a detailed description of the components of ABA will berequired to determine their possible use. The first parameter to deter-mine the feasibility of using ABA is to know their chemical composition,because the ashes of biomass are normally distinguished for havingcarbonaceous material, highly crystalline materials, and a higher alkalicontent than coal ashes [30]. Some researchers have reported thatthese BA classifications are first determined by their main chemicalgroup. The chemical composition of ABA depends on the type of plant

species, soil and the conditions under which they were calcined, andstored [1,31]. In this study, the combustion of dry A. salmiana bagassewas conducted at different temperatures, and the resulting ashes werecharacterized by thermogravimetric analysis (TGA), visual inspection,chemical composition, X-ray diffractometry, particle size distribution,morphology, and loss on ignition (LOI). Trying to use agroindustrialwaste in building material applications suggests that a very importantfactor for their interaction in cement matrices is LOI content, i.e. theamount of organics it contains [4]. But, there is no agreement of howto determine the LOI in the BA ashes. The composition of the BA varies,and some of the components can be decomposed at high temperatures,so the analysis of the loss on ignition is complex because it is not onlyrelated to the carbon-based organic material, but with the decomposi-tion of carbonates, sulfates, phosphates and other elements. In thisstudy, recommendations of ASTMC311 standardwere used to LOImea-surement. The resulting ABA from the ashing process proposed was notsubjected to a washing process; this to observe if the material obtainedwould have a direct potential use in cement matrix.

The compressive resistance is an ideal parameter to analyzewhetherthe additions of these residues are feasible to be into the cementitiousmatrix. As it has been mentioned, there is a consensus that the produc-tion of energy from biomass will have an important participation in thesector, so that the residues obtainedwill be of concern in their final dis-position. Previous experiences with other BA have proven to be feasiblein the replacement and/or addition within the cementitious matrix, so,using a similar methodology will help to investigate this possibility. Inthis research, the compressive strength effect of the addition of ashesburnt at different temperatures was evaluated to determine the conve-nience of burning the ashes at high temperatures.

The procedures used to fabricate specimens and to evaluate theaddition of ABA in mortars were based on ASTM C311 standard, whichindicates the requirements to evaluate a fly ash and natural pozzolansthat could be used in Portland cement concrete. Strictly speaking,biomass ashes are not classified according to the ASTM C618 standard,which exclude this type of ashes due to their chemical composition.Compressive strength tests in mortars were carried out accordingto ASTM C109 and the proportioning mixtures used are shown inTable 1, which was designed to evaluate the cement replacement byABA for each of the different combustion temperatures, and for a mix-ture reference made only with Portland cement. ABA dry densities arealso reported for each combustion temperature according to ASTMC188. After the 28 days of curing, samples were dried at 60 °C to con-stant weight. Then, they were immersed in water and constant weightwasmeasured according to ASTM C642 to determine water absorption.From results in Table 1, it was observed that the effect of adding ABA isnot very significant, and the values are very similar to the mortar refer-ence. Water absorption is related to durability; thus, from the results itcould be said that the capillary absorption effectwill be similar in all testmortars. The amount of replacementwas 5%mass, instead of 20% as rec-ommended by ASTM C618 standard; because the mortar consistencymeasured by ASTM C1437 remarkably decreased as shown in Table 1,the consistency reduction is related to the ABA particle size and theirchemical and mineralogical composition. The cement used was anordinary Portland cement according to ASTM C150 and aggregateused was standard silica sand, according to ASTM C778. The sandcementitious ratio was 1:2.75 and a water/cement ratio of 0.484.

3. Experimental procedure

3.1. Bagasse collection and preparation

Agave leaves were removed directly from the plant and subsequentlyits initial weight was determined. Once they were weighed, they weresubjected to a drying process during 120 h and the results show thatthe dry sample (dry bagasse) is about 12% of the plant weight. The dryingprocess removes water that could interfere in the combustion process.

Table 1Proportioning of mixtures used for compression testing of agave ashes calcined at different temperatures.

Sample OPC (g) ABA (g) Sand (g) H2O (ml) w/b ABA density (g/cm3) Mortar consistency (mm) Mortar H2O absorption (%)

Reference 500 0 1375 242 0.484 – 195 2.07ABA 500 475 25 1375 242 0.484 2.64 168 2.31ABA 600 475 25 1375 242 0.484 2.70 172 1.96ABA 700 475 25 1375 242 0.484 2.65 166 2.31ABA 800 475 25 1375 242 0.484 2.65 162 2.05ABA 900 475 25 1375 242 0.484 2.67 156 1.82

37J.R. González-López et al. / Fuel Processing Technology 133 (2015) 35–42

3.2. Ashing process

During the fermentation of the agave bagasse, alcohol is obtainedand the rest of the organic material is discarded or it can be used asfuel, although currently most of these residues are just burned outdoorsbecause of the lack of adequate facilities to recycle them. The residueremaining from burning bagasse is an ashwith highly variable character-istics and depending on these features are the applications for which itcan be used. For this work, the combustion of the dry agave bagassewas performed in a muffle at 500, 600, 700, 800 and 900 °C during 3 h.The temperature of ash generation is intimately related to the chemicaland mineralogical species reported [32,33], so this study aims todetermine how these chemical species evolve and to estimate how itsperformance could be based on to their chemical composition. ABA wassubjected to different tests in order to determine the most feasibletemperature for its possible use in the building materials applications asa cement replacement.

Exposure to different calcination temperatures resulted in the decom-position of agave ash, which gave different color depending on the tem-perature to which it was exposed; see Fig. 1. Samples were identified asAA and after this identification the test temperature used is presented.Above 500 °C all the carbonaceous material is expected to be graduallyeliminated and the inorganic content is expected to remain [4]. On theother hand, in order to remove harmful durability compounds, such asK and Cl salts, temperatures exceeding 1200 °C may be necessary.

4. Results and discussion

The first step was drying the samples in an air convection oven dur-ing 120 h at 60 °C in order to focus on the dry solid waste. Subsequently,the dried samples were calcined using a direct burning as a source ofpartial combustion to incinerate them, as it would have been done toburn the residue in the field. The partial combustion process wasperformed during 10 min approximately, and its objective was toreduce the volume of organicmaterial. However, large amount of carbo-naceous residues were observed, so the carbon matter combustion willbe completed with the combustion ashing process. Once the dry leaves

Fig. 1. Coloring waste resulting from the agave bagasse burning. It can be o

were partially burned, theywere placed in amuffle at several controlledtemperatures (500–900 °C) to perform the combustion processes.

The result of burning dry bagasse reduced the samplemasses between85 and 90% of the drymass, so that, the total quantity of ash is about 2 kgper 100 kg of plant. Therefore, if 10% of the currently unused arid andsemi-arid lands were used to plant A. salmiana or one of its variationsto generate biomass, the amount of ash at an annual average rate of20Mgha−1, would be around 140 million tons per year. So, this expecta-tive supports the necessity to have fully characterized this residue andcompare it to other similar residues.

4.1. Chemical analysis

In this work, all procedures were performed under laboratory con-trolled conditions, avoiding contamination of the samples; and in smallquantities to ensure the homogeneity of the resulting ABA. The chemicalcomposition of homogenized samples was obtained by XRF and they arereported as oxides in Table 2. ABAmainly contain CaO in more than 64%wt for all samples; this is because these plants are composedprimarily byoxalates and carbonates. Other elements found in large quantities areMgO and K2O, so it will be important to determine whether theseelements affect the performance once the waste is integrated into acementitiousmatrix [34]. TheMgO content is affected by the combustiontemperature used; even at 900 °C the content of MgO disappears due todecomposition of the compounds that have been reported in otherstudies. On the contrary, the content of K2O is approximately constantover the entire range of combustion [32]. These elements are normallyassociated with the growth conditions of the plants and their alkalinenature. The system found is therefore CaO +MgO + K2O.

ABA chemical composition differs from most of the previouslystudied BA; however, the main group of composition elements is similarto some BA previously reported. According to the classification proposedby Vassilev et al. [4,5], it is an alkaline ash mainly composed of CaO andMgO. These characteristics may be suitable for applications in construc-tion materials; however, the high content of MgO, K2O and SO3 shouldbe considered. Other trace elements that were found are P2O5, SiO2,Fe2O3 and SrO. The sum of all these is about 5% for ABA burned a temper-ature below 800 °C; and 2.5% for 900 °C. Therefore, their effect should be

bserved that the ash tone changes when calcined from 500 to 900 °C.

Table 2Chemical composition of the ABA in terms of ashing temperature.

%wt.

AA500 AA600 AA700 AA800 AA900

MgO 16.133 16.182 7.945 6.401 –

SiO2 1.452 1.451 1.416 1.468 1.341P2O5 3.674 3.452 2.558 1.845 –

SO3 0.762 0.777 0.721 0.702 –

K2O 12.664 12.68 13.452 12.477 15.046CaO 64.639 64.601 71.708 76.861 82.113Fe2O3 0.239 0.198 0.157 0.541 0.845SrO 0.111 0.110 1.153 0.143 0.167

Table 3Loss on ignition for each calcination condition.

Sample ID LOI (%)

AA 500 28.50AA 600 26.00AA 700 23.76AA 800 –

AA 900 –

38 J.R. González-López et al. / Fuel Processing Technology 133 (2015) 35–42

considered in future researches related to the effect on the durability ofthese ashes.

4.2. Thermal gravimetric analysis (TGA)

Agave decomposition depends on combustion ashing temperatures;the decomposition of agave is reported in the thermogravimetric analy-sis of Fig. 2, having used a sample of 10.93 mg with a heating tempera-ture ramp of 10 °C in air atmosphere. The graphic can be divided indifferent zones: loss of moisture for up to 150 °C; and decomposition oforganic products between, 185 and 347 °C; above this temperature, thecarbonaceous compounds will begin to decompose. The graphic showsthat burning at a temperature lower than 500 °C will leave a largeramount of organic waste than burning above 500 °C, which leaves anash with a more homogeneous appearance and in which some thermalchanges were seen above 700 °C. The amount of ash obtained afterthese calcination processes was about 7%, so handling a range between500 and 900 °C will give an idea of what properties can be obtainedfrom this ash depending on their physicochemical properties, withoutexposing the ABA at such unnecessary high temperature that wouldmelt them.

4.3. Loss on ignition

In this paper, the methodology of subjecting the samples to 750 °C ±50 °C was applied during 2 h. Samples calcined at each of the tests

Fig. 2. Thermogram o

temperatureswere placed in a crucible at 750±50 °Cduring 2 h to deter-mine the LOI. The results are shown in Table 3. From these, it was foundthat the lower the calcination temperature, the higher the loss on ignition.Therefore, the amount of organic waste in the ash could be up to 20%higher at the lower temperature, in relation to the maximum ashingtemperature tested. The LOI values were not reported when the ashingtemperature was higher than the LOI test temperature. From theseresults, it can be seen that the LOI of ABA previously burned, probablyonly leading mainly to the decomposition of the CaO-based compounds.However, a study using a different methodology by the law of LOI couldindicate what really is decomposing.

4.4. X-ray diffractometry

Agave plant decomposition, after ashing temperatures, left an ashresidue of approximately 1.6% compared to the leaves' weight. Theresidues obtained by burning dried material show that they are mainlycomposed of calcium carbonate, potassium phosphate oxide and mag-nesite; see Fig. 3. However, carbonates, CaCO3 and Mg (CO3) began todecompose at a temperature between 500 and 700 °C. Because of that,a reduction in intensity for the peaks of this phase was observed inthe counts until the CaO becomes the largest mineralogical phase inthe ash when it is burned at 900 °C. All these compounds have beenreported in other studies that confirm the alkaline nature of the ABA,and that they are composed of highly crystalline material and commonmineral phases. The content of ABA mineral phases is different fromother reported, such as BA sugar cane and wood waste, which couldhave pozzolanic characteristics [35]. Temperature affects the typeof compounds that may exist due to different phenomena such as

f agave bagasse.

Fig. 3. Diffractograms of agave bagasse ash at different calcination temperatures. Q—calcium carbonate CaCO3, C—lime CaO, P—potassium phosphate oxide KPO3, andM—magnesite Mg (CO3).

39J.R. González-López et al. / Fuel Processing Technology 133 (2015) 35–42

oxidation, decarbonation, evaporation or fusion and, results agree withthe obtained from XRF chemical composition.

4.5. Scanning electron microscope (SEM).

4.5.1. Morphology and apparent particle sizeThe size and morphology of the BA particles are also critical variables

in determining a possible application in building materials. ABA couldbe considered as semi-reactive compounds with some applications asbinders [36].WhenABAwereprepared for SEMobservation, they showeda tendency to agglomerate, probably because of their size. This tendencymade it difficult to determine their individual particles. Immediatelybefore the SEM observation, the samples were subjected to agitation ina dispersion of isopropyl alcohol ultrasonically during 30 min, andsubsequently they were deposited onto the slide. Fig. 4 shows thatagitate ultrasonically the samples dispersed in the solution is insufficientto completely separate the particles, as they tend to agglomerate intolumps of about 25 mμ.

The ashing process should affect the decomposition characteristics.Thus, this decomposition is expected to result in a refinement of theparticle size, whichwas not possible to observe due to the agglomeration.This decrease in particle size can be demonstrated by the higher specificarea reported in Fig. 5. The calcined samples were analyzed by gasphysisorption i.e. BET fineness, using a sample of 4mg. The values report-ed in the tests indicate that the specific area is increased depending on thecombustion temperature. The maximum values were increased to reach

Fig. 4. Agglomerates of CaCO3 in calcined ash at 600 °C.

14.0 m2/g at a temperature of 800 °C and then they were subsequentlyslightly reduced. These changes can be associatedwith the decompositionof the original compounds or decarbonation process. As the temperatureincreases there is a separation of particles, and at a higher temperaturethan 800 °C there is an apparent agglomeration due to exposure to thistemperature.

Agglomerations observed at lowmagnifications by SEM, correspondapproximately to the determined average size by Laser DiffractionParticle size, where at different ashing temperatures, the apparentparticle size was between 25 and 32 μm (see Fig. 4). In consequence,the apparent particle size is the result of this agglomeration. However,when observing at higher magnifications it was found that theseagglomerations are composed of individual particles with sizes rangingfrom about 0.300 μm and up to 2.400 μm, as it can be seen in Fig. 6.

The use of compounds of this nature can be consistent within acement matrix hydrated phases. A way to evaluate the affinity of ABAwith an ordinary Portland cement matrix OPC is replacing the cementwith ABA and testing compressive strength development. However,these tests are limited to the immediate response, so, other consider-ations regarding the workability and durability must be addressed.

4.6. Compressive strength of mixtures with ABA additions

The results of performing additions of the ashes in an OPC matrixand testing them in compression are shown in Fig. 7. From ABA chemi-cal composition, it can be determined that the potential of pozzolanicreaction is low because the contents of compounds forming CSH gelare not significant (low content of SiO2) [35,37]. Therefore, the behaviorreported in studies in which the ashes mainly contain SiO2 and reactpozzolanically, is not expected [38]. However, other types of mecha-nisms can be developed from the compounds of ABA; calcite is currentlyused as filler in composite cements. Some researchers have observedthat adding calcite in low percentages can promote the reaction atearly ages of C3A and accelerate hydration of C3S [39–41]. The reactivityof these additions depends on the particle size. When preparing themixtures, water demand should be taken into account, because thesurface area of these additions is very large, and it could cause complica-tions to the workability of the sample.

The effect of adding ABA in the OPCmatrix is very noticeable at earlyages where compressive strength at 7 days was 90% higher for the ABAburned at 500, 600 and700 °C thanOPCmortar reference, as is shown inFig. 7. The ABA burned at 800 °C developed a resistance at 7 days 10%lower than the reference days. Thismay be related to the decompositionof carbonates and alkali presence in the ABA. At 900 °C the behaviorwassimilar to that at temperatures between 500 and 700 °C, even thoughthe main compound of the ABA 900 is lime which can act as nucleation

Fig. 5. Specific surface area and average particle size of calcined ash residues.

Fig. 6. Images of reference and waste calcined at 500 °C, top left and right respectively; 600 °C middle right; 700 °Cmiddle left; and, 800 °C and 900 °C bottom left and right respectively.

40 J.R. González-López et al. / Fuel Processing Technology 133 (2015) 35–42

Fig. 7. Strength development and standard deviations for reference and test samples.

41J.R. González-López et al. / Fuel Processing Technology 133 (2015) 35–42

site or portlandite source. Another possibility is that due to the fineparticle size of ABA 900 and to the high reactivity of CaO that composethem, this could be easily carbonated and that is why the behavior issimilar to that reported in the ashes burned at lower temperatures.For test formulations, 28 day strength development was about 10%higher, around 55 MPa a 28 d in comparison to 7 d age, whereas, thereferencemixture exceeded 60MPa at the same age. From these results,it can be determined that the samples calcined at a lower temperaturehave a similar behavior to the samples calcined at a higher temperature.Therefore, 500 °C could be used as an ideal temperature for treating thisresidue when added to an OPC cementitious matrix. However, themechanisms which determine the effect of compounds at differenttemperatures should be clearly established and the effects of high alkaliscontent should be investigated in both, fresh state, and durability of theintended applications.

5. Conclusions

The A. salmiana use has been reported as a sustainable alternative forenergy production that does not affect resources for human consumption.Hence, it was considered to have a detailed study of residue resultingfrom the use of this plant as biomass. From the studies made in thiswork the following is concluded:

• From the ashing process, the amount of ashes generated from thedried plant is about 7%; therefore, if the tendencies reported in somestudies are used to estimate ABA, they could be comparable to thosereported in power coal generation industries. The loss on ignition inthis type of BA should be cautiously interpreted, because of the highcontent of carbonates, sulfates, and phosphates. However, it must beensured that the amount of carbonaceous organic material is low.

• The calcination temperature affects the ash compounds, havingmain-ly CaCO3 at temperatures below 800 °C and CaO at temperaturesabove this value, besides Mg(CO3) and, KPO3 compounds. The chem-ical composition of ABA, according to the classification given by otherauthors, will be semi-reactive andwould have possible applications as

cementitious in building materials. However, the effect of highcontent of alkalis should be studied.

• The apparent particle size on average is between 25 and 32 μm forall ashing temperatures. However, when observing in the scanningelectron microscope, the agglomerates are found to be formed byparticles as small as 300 nm and the disintegration of the largerparticles depends on the temperature. Because of this, the specificarea increases from 6.82 m2/g to 14.00 m2/g, and from 500 to800 °C. It should be studied a mechanism to separate these parti-cles, or to determine whether the difference in surface area affectsthe performance of the possible applications, or if the apparentparticle size is the one that controls their behavior.

• The compressive strength of samples with additions of 5% in mass,showed a strength development at 7 days 90% higher than OPCreference. This strength development could be a consequence ofthe semi-reactive characteristics of the ash components. However,the subsequent strength development was only 10% at 28 days.

• The results suggest that the best ashing temperature is 500 °C becauseapparently the prevailing mechanism is the same for higher temper-atures. The ABA alkali content was high, so further studies should befocused on its effect in the construction material durability.

References

[1] S.C. Davis, H. Griffiths, J. Holtum, A.L. Saavedra, S.P. Long, The evaluation of feed-stocks in GCBB continues with a special issue on agave for bioenergy, GCB Bioenergy3 (1) (2011) 1–3, http://dx.doi.org/10.1111/j.1757-1707.2010.01085.x.

[2] T.O. West, Introduction: integrative approaches for estimating current and futurefeedstock availability, GCB Bioenergy 2 (5) (2010) 215–216, http://dx.doi.org/10.1111/j.1757-1707.2010.01057.x.

[3] S.V. Loo, J. Koppejan, Handbook of Biomass Combustion and Co-firing, Twente Uni-versity Press, The Netherlands, 2003.

[4] S.V. Vassilev, D. Baxter, L.K. Andersen, C.G. Vassileva, An overviewof the compositionand application of biomass ash. Part 1. Phase–mineral and chemical composition andclassification, Fuel 105 (2013) 40–76, http://dx.doi.org/10.1016/j.fuel.2012.09.041.

[5] S.V. Vassilev, D. Baxter, L.K. Andersen, C.G. Vassileva, An overview of the composi-tion and application of biomass ash.: Part 2. Potential utilisation, technological andecological advantages and challenges, Fuel 105 (2013) 19–39, http://dx.doi.org/10.1016/j.fuel.2012.10.001.

42 J.R. González-López et al. / Fuel Processing Technology 133 (2015) 35–42

[6] M.J.R. Hinojosa, A.P. Galvín, F. Agrela, M. Perianes, A. Barbudo, Potential use of bio-mass bottom ash as alternative construction material: Conflictive chemical parame-ters according to technical regulations, Fuel 128 (2014) 248–259, http://dx.doi.org/10.1016/j.fuel.2014.03.017.

[7] R. Rajamma, R.J. Ball, L.A.C. Tarelho, G.C. Allen, J.A. Labrincha, V.M. Ferreira, Characterisa-tion and use of biomass fly ash in cement-basedmaterials, Journal of HazardousMate-rials 172 (2–3) (2009) 1049–1060, http://dx.doi.org/10.1016/j.jhazmat.2009.07.109.

[8] L.L. Escamilla-Treviño, Potential of Plants from the Genus Agave as Bioenergy Crops,BioEnergy Research 5 (1) (2012) 1–9, http://dx.doi.org/10.1007/s12155-011-9159-x.

[9] L. Chávez-Guerrero, J. Flores, B.I. Kharissov, Recycling of ash frommezcal industry: arenewable source of lime, Chemosphere 81 (5) (2010) 633–638, http://dx.doi.org/10.1016/j.chemosphere.2010.08.042.

[10] S.C. Davis, F.G. Dohleman, S.P. Long, The global potential for Agave as a biofuelfeedstock, GCB Bioenergy 3 (1) (2011) 68–78, http://dx.doi.org/10.1111/j.1757-1707.2010.01077.x.

[11] S.N. Monteiro, R.J.S. Rodriquez, M.V.D. Souza, J.R.M. D'Almedia, Sugar cane bagassewaste as reinforcement in low cost composites, Advanced Performance Materials5183–5191 (1998).

[12] A.E. Souza, S.R. Teixeira, G.T.A. Santos, F.B. Costa, E. Longo, Reuse of sugarcanebagasse ash (SCBA) to produce ceramic materials, Journal of EnvironmentalManagement 92 (2011) 2774–2780.

[13] J.F.M. Hernández, B. Middendorf, M. Gehrke, H. Budelmann, Use of wastes of thesugar industry as pozzolana in lime-pozzolana binder: study of the reaction, Cementand Concrete Research 28 (11) (1998) 1525–1536.

[14] G.C. Cordeiro, R.D. Toledo Filho, E.M.R. Fairbairn, Effect of calcination temperature onthepozzolanic activity of sugar cane bagasse ash, Construction and BuildingMaterials23 (2009) 3301–3303.

[15] N. Chusilp, C. Jaturapitakkul, K. Kiattikomol, Effects of LOI of ground bagasse ashon the compressive strength and sulfate resistance of mortars, Constructionand Building Materials 23 (12) (2009) 3523–3531, http://dx.doi.org/10.1016/j.conbuildmat.2009.06.046.

[16] G.C. Cordeiro, R.D. Toledo Filho, L.M. Tavares, E.M.R. Fairbairn, Pozzolanic activityand filler effect of sugar cane bagasse ash in Portland cement and lime mortars,Cement and Concrete Composites 30 (5) (2008) 410–418, http://dx.doi.org/10.1016/j.cemconcomp.2008.01.001.

[17] M. Frias, E. Villar-Cocina, E. Valencia-Morales, Characterization of sugar cane strawwaste as pozzolanic material for construction: calcining temperature and kineticparameters, Waste Management (New York, N.Y.) 27 (2007) 533–538.

[18] E.V. Morales, E. Villar-Cocina, M. Frías, S.F. Santos, H. Savastano Jr., Effects of calcin-ing conditions on the microstructure of sugar cane waste ashes (SCWA): influencein the pozzolanic activation, Cement and Concrete Composites 31 (2009) 22–28.

[19] B. Carrasco-Hurtado, F.A. Corpas-Iglesias, N. Cruz-Pérez, J. Terrados-Cepeda, L.Pérez-Villarejo, Addition of bottom ash from biomass in calcium silicate mason-ry units for use as construction material with thermal insulating properties,Construction and Building Materials 52 (2014) 155–165, http://dx.doi.org/10.1016/j.conbuildmat.2013.11.018.

[20] B. Carrasco, N. Cruz, J. Terrados, F.A. Corpas, L. Pérez, An evaluation of bottom ashfrom plant biomass as a replacement for cement in building blocks, Fuel 118(2014) 272–280, http://dx.doi.org/10.1016/j.fuel.2013.10.077.

[21] C. Leiva, L.F. Vilches, J. Vale, C. Fernández-Pereira, Fire resistance of biomass ashpanels used for internal partitions in buildings, Fire Safety Journal 44 (4) (2009)622–628, http://dx.doi.org/10.1016/j.firesaf.2008.12.005.

[22] M. Cabrera, A.P. Galvin, F. Agrela, M.D. Carvajal, J. Ayuso, Characterisation andtechnical feasibility of using biomass bottom ash for civil infrastructures, Con-struction and Building Materials 58 (2014) 234–244, http://dx.doi.org/10.1016/j.conbuildmat.2014.01.087.

[23] Y.R. Loh, D. Sujan, M.E. Rahman, C.A. Das, Sugarcane bagasse—the future compositematerial: a literature review, Resources, Conservation and Recycling 75 (2013)14–22, http://dx.doi.org/10.1016/j.resconrec.2013.03.002.

[24] K. Ganesan, K. Rajagopal, K. Thangavel, Evaluation of bagasse ash as supplementarycementitious material, Cement and Concrete Composites 29 (6) (2007) 515–524,http://dx.doi.org/10.1016/j.cemconcomp.2007.03.001.

[25] L. Chávez-Guerrero, R. Rangel-Méndez, E.Muñoz-Sandoval, D.A Cullen, D.J. Smith, H.Terrones, M. Terrones, Production and detailed characterization of bean husk-basedcarbon: efficient cadmium (II) removal from aqueous solutions, Water Research 42(13) (2008) 3473–3479, http://dx.doi.org/10.1016/j.watres.2008.04.022.

[26] K.G. Satyanarayana, T.H.S. Flores-Sahagun, L.P. Dos Santos, J. Dos Santos, I. Mazzaro,A. Mikowski, Characterization of blue agave bagasse fibers of Mexico, CompositesPart A: Applied Science and Manufacturing 45 (2013) 153–161.

[27] C. Juárez, A. Durán, P. Valdez, G. Fajardo, Performance of “Agave lechuguilla” naturalfiber in portland cement composites exposed to severe environment conditions,Building and Environment 42 (2007) 1151–1157.

[28] M.S. Alonso, S.L. Rigal, Characterization and valoration of agave tequilana weberbagasse of the tequila industry, Revista Chapingo Serie Horticultura (1997) 31–39.

[29] C. Nieto-Delgado, J.R. Rangel-Méndez, Production of activated carbon from organicby-products from the alcoholic beverage industry: surface area and hardness opti-mization by using the response surface methodology, Industrial Crops and Products34 (3) (2011) 1528–1537, http://dx.doi.org/10.1016/j.indcrop.2011.05.014.

[30] A.A. Tortosa Masiá, B.J.P. Buhre, R.P. Gupta, T.F. Wall, Characterising ash of biomassand waste, Fuel Processing Technology 88 (11–12) (2007) 1071–1081, http://dx.doi.org/10.1016/j.fuproc.2007.06.011.

[31] Y. Niu,W. Du, H. Tan,W. Xu, Y. Liu, Y. Xiong, S. Hui, Further study on biomass ash char-acteristics at elevated ashing temperatures: the evolution of K, Cl, S and the ash fusioncharacteristics, Bioresource Technology 129 (2013) 642–645, http://dx.doi.org/10.1016/j.biortech.2012.12.065.

[32] Q.H. Li, Y.G. Zhang, A.H. Meng, L. Li, G.X. Li, Study on ash fusion temperature usingoriginal and simulated biomass ashes, Fuel Processing Technology 107 (2013)107–112, http://dx.doi.org/10.1016/j.fuproc.2012.08.012.

[33] S. Wang, A Miller, E. Llamazos, F. Fonseca, L. Baxter, Biomass fly ash in concrete:mixture proportioning and mechanical properties, Fuel 87 (3) (2008) 365–371,http://dx.doi.org/10.1016/j.fuel.2007.05.026.

[34] T.C. Esteves, V.M. Ferreira, J.A. Labrincha, R. Rajamma, A.S. Silva, D. Soares, Use ofbiomass fly ash for mitigation of alkali–silica reaction of cement mortars, Construc-tion and Building Materials 26 (1) (2012) 687–693, http://dx.doi.org/10.1016/j.conbuildmat.2011.06.075.

[35] V.G. Papadakis, S. Tsimas, Supplementary cementing materials in concrete Part I:efficiency and design, Cement and Concrete Research 32 (2002) 1525–1532.

[36] J. Cuenca, J. Rodríguez, M. Martín-Morales, Z. Sánchez-Roldán, M. Zamorano,Effects of olive residue biomass fly ash as filler in self-compacting concrete,Construction and Building Materials 40 (2013) 702–709, http://dx.doi.org/10.1016/j.conbuildmat.2012.09.101.

[37] S.V. Vassilev, C.G. Vassileva, A new approach for the classification of coal fly ashesbased on their origin, composition, properties, and behaviour, Fuel 86 (10–11)(2007) 1490–1512, http://dx.doi.org/10.1016/j.fuel.2006.11.020.

[38] S. Wang, L. Baxter, Comprehensive study of biomass fly ash in concrete: strength,microscopy, kinetics and durability, Fuel Processing Technology 88 (11–12)(2007) 1165–1170, http://dx.doi.org/10.1016/j.fuproc.2007.06.016.

[39] D.P. Bentz, Activation energies of high-volume fly ash ternary blends: hydration andsetting, Cement and Concrete Composites 53 (2014) 214–223, http://dx.doi.org/10.1016/j.cemconcomp.2014.06.018.

[40] D.P. Bentz, T. Sato, I. de la Varga, W.J. Weiss, Fine limestone additions to regulatesetting in high volume fly ash mixtures, Cement and Concrete Composites 34 (1)(2012) 11–17, http://dx.doi.org/10.1016/j.cemconcomp.2011.09.004.

[41] F.U.A. Shaikh, S.W.M. Supit, Mechanical and durability properties of high volumefly ash (HVFA) concrete containing calcium carbonate (CaCO3) nanoparticles,Construction and Building Materials 70 (2014) 309–321, http://dx.doi.org/10.1016/j.conbuildmat.2014.07.099.