Abstract
Development of biofuels such as lignocellulosic ethanol represents a sustainable alternative in the transport sector. Wheat straw is a promising feedstock for bioethanol production in Europe due to its large production and high carbohydrates content. In a process to produce cellulosic ethanol, previous to the enzymatic hydrolysis to obtain fermentable sugars and the subsequent fermentation, a pretreatment step to break down the recalcitrance of lignocellulose fiber is essential. In this work, a range of steam explosion pretreatment conditions were evaluated according to different parameters: sugars recovery, degradation products generation, and enzymatic hydrolysis yields. Moreover, the enzymatic hydrolysis process was also studied at high substrate loadings, since operating at high solids loading is crucial for large scale development of ethanol production. Pretreatment at 200°C - 10 min resulted in higher enzymatic hydrolysis yield (91.7%) and overall glucose yields (35.4 g glucose/100 g wheat straw) but also higher production of toxic compound. In turn, the characteristics of the pretreated wheat straw at lower severity (Log R0=3.65) correspond to 190°C and 10 min, with minimal sugars degradation and toxics formation indicated a great potential for maximizing total sugars production by using optimal enzyme combinations including accessory enzymes in the enzymatic hydrolysis step.
References
[1] Kim S., Dale B.E., Global potential bioethanol production from wasted crops and crop residues, Biomass Bioenerg., 2004, 26, 361-375. 10.1016/j.biombioe.2003.08.002Search in Google Scholar
[2] Tomás-Pejó E., Alvira P., Ballesteros M., Negro M.J., Pretreatment technologies for lignocellulose-to-bioethanol conversion, In: Pandey A., Larroche C., Ricke S.C., Dussap C.G., Gnansounou E., (Eds.), Biofuels: Alternative feedstocks and conversion processes, Academic Press, Amsterdam, 2011. Search in Google Scholar
[3] Avellar B.K., Glasser W.G., Steam assisted biomass fractionation I. Process considerations and economic evaluation, Biomass Bioenerg., 1998, 14, 205-218. 10.1016/S0961-9534(97)10043-5Search in Google Scholar
[4] Oliveira, F.M.V., Pinheiro, I.O., Souto-Maior, A.M., Martin, C., Gonçalves A.R., Rocha G.J.M., Industrial-scale steam explosion pretreatment of sugarcane straw for enzymatic hydrolysis of cellulose for production of second generation ethanol and value-added products, Bioresour. Technol., 2013, 130, 168-173. 10.1016/j.biortech.2012.12.030Search in Google Scholar
[5] Sharma S., Kumar R., Gaur R, Agrawal R., Gupta R.P., Tuli D.K., Das B, Pilot scale study on steam explosion and mass balance for higher sugar recovery from rice straw, Bioresour.Technol. , 2015, 175, 350-357. 10.1016/j.biortech.2014.10.112Search in Google Scholar
[6] Sun Y., Cheng J., Hydrolysis of lignocellulosic materials for ethanol production: a review, Bioresour. Technol., 2002, 83, 1-11. 10.1016/S0960-8524(01)00212-7Search in Google Scholar
[7] Jurado M., Prieto A., Martínez-Alcalá A., Martínez A.T., Martínez M.J., Laccase detoxification of steam-exploded wheat straw for second generation bioethanol, Bioresour. Technol., 2009, 100, 6378-6384 10.1016/j.biortech.2009.07.049Search in Google Scholar
[8] Palmqvist E., Hahn-Hägerdal B., Fermentation of lignocellulosic hydrolysates II: inhibitors and mechanism of inhibition, Bioresour. Technol., 2000, 74, 25-33. 10.1016/S0960-8524(99)00161-3Search in Google Scholar
[9] Overend R.P., Chornet E., Fractionation of lignocellulosics by steam-aqueous pretreatments, Phil. Trans. R. Soc. Lond., 1987, 321, 523-536. 10.1098/rsta.1987.0029Search in Google Scholar
[10] Alvira P., Negro M.J., Ballesteros M., Effect of endoxylanase and alpha-arabinofuranosidase supplementation on the enzymatic hydrolysis of steam exploded wheat straw, Bioresour. Technol., 2011, 102, 4552-4558. 10.1016/j.biortech.2010.12.112Search in Google Scholar PubMed
[11] Alvira P., Tomás-Pejó E., Negro M.J., Ballesteros M., Strategies of xylanase supplementation for an efficient saccharification and cofermentation process from pretreated wheat straw, Biotechnol. Prog., 2011, 27, 944-950. 10.1002/btpr.623Search in Google Scholar PubMed
[12] García-Aparicio M., Ballesteros M., Manzanares P., Ballesteros I., González A., Negro M.J., Xylanase contribution to the efficiency of cellulose enzymatic hydrolysis of barley straw, Appl. Biochem. Biotechnol., 2007, 137-140, 353-365. 10.1007/s12010-007-9064-0Search in Google Scholar
[13] Ohgren K., Bura R., Saddler J., Zacchi G., Effect of hemicellulose and lignin removal on enzymatic hydrolysis of steam pretreated corn stover, Bioresour. Technol., 2007, 98, 2503-2510. 10.1016/j.biortech.2006.09.003Search in Google Scholar
[14] Marcos M., García-Cubero M.T., González-Benito G., Coca M., Bódalo S., Lucas S., Optimization of the enzymatic hydrolysis conditions of steam-exploded wheat straw for maximum glucose and xylose recovery, J. Chem. Technol. Biotechnol., 2013, 88, 237-246. 10.1002/jctb.3820Search in Google Scholar
[15] Oliva J.M., Sáez F., Ballesteros I., González A., Negro M.J., Manzanares P., et al., Effect of lignocellulosic degradation compounds from steam explosion pretreatment on ethanol fermentation by thermotolerant yeast Kluyveromyces marxianus, Appl. Biochem. Biotechnol., 2003, 105, 141-154. 10.1385/ABAB:105:1-3:141Search in Google Scholar
[16] Romani A., Garrote G., Ballesteros I., Ballesteros M., Second generation bioethanol from steam exploded Eucalyptus globulus wood, Fuel, 2013, 111, 66-74. 10.1016/j.fuel.2013.04.076Search in Google Scholar
[17] Ballesteros I., Ballesteros M., Cara C., Sáez F., Castro E., Manzanares P., et al., Effect of water extraction on sugars recovery from steam exploded olive tree pruning, Bioresour. Technol., 2011, 102, 6611-6616. 10.1016/j.biortech.2011.03.077Search in Google Scholar
[18] Chu Q., Yang D., Li X., Ma B., Yu S., Yong Q., An integrated process to enhance ethanol production from stream-exploded corn stover, Fuel, 2013, 107, 823-827 10.1016/j.fuel.2013.02.002Search in Google Scholar
[19] Horn S.J., Nguyen Q.D., Westereng B., Nilsel P.J., Eijsink V.G.H., Screening of steam explosion conditions for glucose production from non-impregnated wheat straw, Biomass Bioenerg., 2011, 35, 4879-4886. 10.1016/j.biombioe.2011.10.013Search in Google Scholar
[20] Ballesteros I., Negro M., Oliva J.M., Cabañas A., Manzanares P., Ballesteros M., Ethanol production from steam-explosion pretreated wheat straw, Appl. Biochem. Biotechnol., 2006, 130, 496-508. 10.1385/ABAB:130:1:496Search in Google Scholar
[21] García-Aparicio M.P., Oliva J.M, Manzanares P., Ballesteros M., Ballesteros I., González A., et al., Second generation ethanol production from exploded barley straw by Kluyveromyces marxianus CETC 10875, Fuel, 2011, 90, 1624-1630. 10.1016/j.fuel.2010.10.052Search in Google Scholar
[22] Amores I., Ballesteros I., Manzanares P., Sáez F., Michelena G., Ballesteros M., Ethanol production from sugarcane bagasse pretreated by steam explosion, Electronic Journal of Energy & Environment 2011, 1, 25-36. 10.7770/ejee-V1N1-art519Search in Google Scholar
[23] Manzanares P., Ballesteros I., Negro M.J., Oliva J.M., González A., Ballesteros M., Biological conversion of forage sorghum biomass to ethanol by steam explosion pretreatment and simultaneous hydrolysis and fermentation at high solid content, Biomass Conv. Bioref., 2012, 2, 123-132. 10.1007/s13399-012-0040-8Search in Google Scholar
[24] Barta Z., Oliva J.M., Ballesteros I., Dienes D., Ballesteros M., Réczey K., Refining hemp hurds into fermentable sugars or ethanol, Chem. Biochem. Eng., 2010, 24, 331–339. Search in Google Scholar
[25] Ballesteros I., Oliva J.M., Sáez F., Negro M.J., Manzanares P., Ballesteros M., Enzymic hydrolysis of steam exploded herbaceous agricultural waste (Brassica carinata) at different particle sizes, Process Biochem., 2002, 38, 187-192. 10.1016/S0032-9592(02)00070-5Search in Google Scholar
[26] Ghose T.K., Measurement of Cellulase Activities, Pure Appl. Chem., 1987, 59, 257-268. 10.1351/pac198759020257Search in Google Scholar
[27] Bailey M.J., Biely P., Poutanen K., Interlaboratory testing of methods for assay of xylanase activity, J. Biotechnol., 1991, 23, 257-270. 10.1016/0168-1656(92)90074-JSearch in Google Scholar
[28] Sluiter J.B., Ruiz R.O., Scarlata C.J., Sluiter A.D., Templeton D.W., Compositional analysis of lignocellulosic feedstocks. 1. review and description of methods, J. Agric. Food Chem., 2010, 58, 9043-9053. 10.1021/jf1008023Search in Google Scholar
[29] Alvira P., Moreno A.D., Ibarra D., Sáez F., Ballesteros M., Improving the fermentation performance of Saccharomyces cerevisiae by laccases during ethanol production from steamexploded wheat straw at high substrate loadings, Biotechnol Prog., 2013, 29, 74-82. 10.1002/btpr.1666Search in Google Scholar
[30] Alvira P., Tomás-Pejó E., Ballesteros M., Negro M.J., Pretreatment technologies for an efficient bioethanol production process based on enzymatic hydrolysis: A review, Bioresour. Technol., 2010, 101, 4851-4861. 10.1016/j.biortech.2009.11.093Search in Google Scholar
[31] Montané D., Farriol X., Salvadó J., Jollez P., Chornet E., Application of steam explosion to the fractionation and rapid vapor-phase alkaline pulping of wheat straw, Biomass Bioenerg. 1998, 14, 261-276 10.1016/S0961-9534(97)10045-9Search in Google Scholar
[32] Sun R.C., Sun X.F., Wang S.Q., Zhu W., Wang X.Y., Ester and ether linkages between hydroxycinnamic acids and lignins from wheat, rice, rye, and barley straws, maize stems, and fast-growing poplar wood, Ind. Crops Prod., 2002, 15, 179-188. 10.1016/S0926-6690(01)00112-1Search in Google Scholar
[33] García-Aparicio M., Ballesteros I., González A., Oliva J.M., Ballesteros M., et al., Effect of inhibitors released during steam-explosion pretreatment of barley straw on enzymatic hydrolysis, Appl. Biochem. Biotechnol., 2006, 129, 278-288. 10.1385/ABAB:129:1:278Search in Google Scholar
[34] Oliva J.M., Ballesteros I., Negro M.J., Manzanares P., Cabañas A., Ballesteros M., Effect of binary combinations of selected toxic compounds on growth and fermentation of Kluyveromyces marxianus, Biotechnol. Prog., 2004, 20, 715-720. 10.1021/bp034317pSearch in Google Scholar
[35] Palmarola-Adrados B., Galbe M., Zacchi G., Combined steam pretreatment and enzymatic hydrolysis of starch-free wheat fibers, Appl. Biochem. Biotechnol., 2004, 113, 989-1002. 10.1007/978-1-59259-837-3_80Search in Google Scholar
[36] Banerjee S., Mudliar S., Sen R., Giri B., Satpute D., Chakrabarti T., et al., Commercializing lignocellulosic bioethanol: Technology bottlenecks and possible remedies, Biofuels Bioprod. Bioref., 2010, 4, 77-93. 10.1002/bbb.188Search in Google Scholar
[37] Mohagheghi A., Tucker M., Grohmann K., Wyman C., High solids simultaneous saccharification and fermentation of pretreated wheat straw to ethanol, Appl. Biochem. Biotechnol., 1992, 33, 67-82. 10.1007/BF02950778Search in Google Scholar
[38] Rosgaard L., Andric P., Dam-Johansen K., Pedersen S., Meyer A.S., Effects of substrate loading on enzymatic hydrolysis and viscosity of pretreated barley straw, Appl. Biochem. Biotechnol., 2007, 143, 27-40. 10.1007/s12010-007-0028-1Search in Google Scholar
[39] Taherzadeh M.J., Karimi, K., Fermentation inhibitors in ethanol processes and different strategies to reduce their effects. In: Pandey A., Larroche C., Ricke S.C., Dussap C.G., Gnansounou E., (Eds.), Biofuels: Alternative feedstocks and conversion processes, Academic Press, Amsterdam, 2011. Search in Google Scholar
[40] Moreno, A.D., Tomás-Pejó, E., Ibarra, D., Ballesteros, M., Olsson, L., Fed-batch SSCF using steam-exploded wheat straw at high dry matter consistencies and a xylose-fermenting Saccharomyces cerevisiae strain: Effect of laccase supplementation, Biotechnol. Biofuels, 2013, 6 (1), 160. 10.1186/1754-6834-6-160Search in Google Scholar
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