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Wouter J. J. Huijgen - One of the best experts on this subject based on the ideXlab platform.
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Characteristics of wheat straw lignins from ethanol-based Organosolv treatment
Industrial Crops and Products, 2014Co-Authors: Wouter J. J. Huijgen, Galina Telysheva, Alexandr Arshanitsa, R.j.a. Gosselink, P J De WildAbstract:Abstract Non-purified lignins resulting from ethanol-based Organosolv fractionation of wheat straw were characterized for the presence of impurities (carbohydrates and ash), functional groups (hydroxyl, carboxyl and methoxyl), phenyl-propanoid structural moieties, molar mass distribution and thermal behavior. In accordance with its herbaceous nature, the syringyl/guaiacyl-ratio of the wheat straw lignins was substantially lower than of Alcell lignin. In addition, the content of p -hydroxyphenyl and carboxyl groups is substantially higher for the wheat straw lignins. The non-purified Organosolv lignins had a high purity with 0.4–5.2% carbohydrate impurities, both originating from lignin to carbohydrate complexes and residual Organosolv liquor. The use of H 2 SO 4 in the Organosolv process improved the lignin yield, but at low acid doses increased the carbohydrate impurities. For applications where a low amount of carbohydrates is important, lignin from a high-temperature autocatalytic Organosolv process was found to be preferred. The highest content of total hydroxyl groups was determined when lignins were produced using 30 mM H 2 SO 4 as catalyst or 50% w/w aqueous ethanol as solvent for the Organosolv process. Aliphatic hydroxyl groups, the most predominant type of hydroxyl groups present originating for a substantial part from residual carbohydrates, were found to decrease with reaction time and ethanol proportion of the Organosolv solvent. The correlations between Organosolv process conditions and lignin characteristics determined can facilitate the use of Organosolv lignins in value-added applications such as in polymers and resins and as a feedstock for bio-based aromatics.
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Fractionation of wheat straw by prehydrolysis, Organosolv delignification and enzymatic hydrolysis for production of sugars and lignin.
Bioresource Technology, 2012Co-Authors: Wouter J. J. Huijgen, A. T. Smit, P J De WildAbstract:Abstract Wheat straw was fractionated using a three-step biorefining approach: (1) aqueous pretreatment for hemicellulose prehydrolysis into sugars, (2) Organosolv delignification, and (3) enzymatic cellulose hydrolysis into glucose. Prehydrolysis was applied to avoid degradation of hemicellulose sugars during Organosolv delignification. Maximum xylose yield obtained was 67% or 0.17 kg/kg straw (prehydrolysis: 175 °C, 30 min, 20 mM H2SO4) compared to 4% in case of Organosolv without prehydrolysis (Organosolv: 200 °C, 60 min, 60% w/w aqueous ethanol). Prehydrolysis was found to reduce the lignin yield by Organosolv delignification due to the formation of ‘pseudo-lignin’ and lignin recondensation during prehydrolysis. This reduction could partly be compensated by increasing the temperature of the Organosolv delignification step. Prehydrolysis substantially improved the enzymatic cellulose digestibility from 49% after Organosolv without prehydrolysis to 80% (20 FPU/g substrate). Increasing the Organosolv delignification temperature to 220 °C resulted in a maximum enzymatic glucose yield of 93% or 0.36 kg/kg straw.
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catalytic Organosolv fractionation of willow wood and wheat straw as pretreatment for enzymatic cellulose hydrolysis
Journal of Chemical Technology & Biotechnology, 2011Co-Authors: Wouter J. J. Huijgen, A. T. Smit, J H ReithAbstract:BACKGROUND: Ethanol-based Organosolv fractionation of lignocellulosic biomass is an effective pretreatment technology for enzymatic cellulose hydrolysis to produce sugars and lignin within a biorefinery. This study focuses on the catalytic effect of H2SO4, HCl, and MgCl2 on Organosolv pretreatment of willow wood and wheat straw. RESULTS: The use of catalysts improved fractionation of both feedstocks. The maximum enzymatic cellulose digestibility obtained was 87% for willow wood (using 0.01 mol L−1 H2SO4 as catalyst) and 99% for wheat straw (0.02 mol L−1 HCl). Non-catalytic Organosolv fractionation at identical conditions resulted in 74% (willow wood) and 44% (wheat straw) glucose yield by enzymatic hydrolysis. Application of catalysts in Organosolv pretreatment was particularly effective for wheat straw. The influence of the acid catalysts was found to be primarily due to their effect on the pH of the Organosolv liquor. Acid catalysts particularly promoted xylan hydrolysis. MgCl2 was less effective than the acid catalysts, but it seemed to more selectively improve delignification of willow wood. CONCLUSION: Application of catalysts in Organosolv pretreatment of willow wood and wheat straw was found to substantially improve fractionation and enzymatic digestibility. The use of catalysts can contribute to achieving maximum utilization of lignocellulosic biomass in Organosolv-based biorefineries. Copyright © 2011 Society of Chemical Industry
P J De Wild - One of the best experts on this subject based on the ideXlab platform.
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Characteristics of wheat straw lignins from ethanol-based Organosolv treatment
Industrial Crops and Products, 2014Co-Authors: Wouter J. J. Huijgen, Galina Telysheva, Alexandr Arshanitsa, R.j.a. Gosselink, P J De WildAbstract:Abstract Non-purified lignins resulting from ethanol-based Organosolv fractionation of wheat straw were characterized for the presence of impurities (carbohydrates and ash), functional groups (hydroxyl, carboxyl and methoxyl), phenyl-propanoid structural moieties, molar mass distribution and thermal behavior. In accordance with its herbaceous nature, the syringyl/guaiacyl-ratio of the wheat straw lignins was substantially lower than of Alcell lignin. In addition, the content of p -hydroxyphenyl and carboxyl groups is substantially higher for the wheat straw lignins. The non-purified Organosolv lignins had a high purity with 0.4–5.2% carbohydrate impurities, both originating from lignin to carbohydrate complexes and residual Organosolv liquor. The use of H 2 SO 4 in the Organosolv process improved the lignin yield, but at low acid doses increased the carbohydrate impurities. For applications where a low amount of carbohydrates is important, lignin from a high-temperature autocatalytic Organosolv process was found to be preferred. The highest content of total hydroxyl groups was determined when lignins were produced using 30 mM H 2 SO 4 as catalyst or 50% w/w aqueous ethanol as solvent for the Organosolv process. Aliphatic hydroxyl groups, the most predominant type of hydroxyl groups present originating for a substantial part from residual carbohydrates, were found to decrease with reaction time and ethanol proportion of the Organosolv solvent. The correlations between Organosolv process conditions and lignin characteristics determined can facilitate the use of Organosolv lignins in value-added applications such as in polymers and resins and as a feedstock for bio-based aromatics.
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Fractionation of wheat straw by prehydrolysis, Organosolv delignification and enzymatic hydrolysis for production of sugars and lignin.
Bioresource Technology, 2012Co-Authors: Wouter J. J. Huijgen, A. T. Smit, P J De WildAbstract:Abstract Wheat straw was fractionated using a three-step biorefining approach: (1) aqueous pretreatment for hemicellulose prehydrolysis into sugars, (2) Organosolv delignification, and (3) enzymatic cellulose hydrolysis into glucose. Prehydrolysis was applied to avoid degradation of hemicellulose sugars during Organosolv delignification. Maximum xylose yield obtained was 67% or 0.17 kg/kg straw (prehydrolysis: 175 °C, 30 min, 20 mM H2SO4) compared to 4% in case of Organosolv without prehydrolysis (Organosolv: 200 °C, 60 min, 60% w/w aqueous ethanol). Prehydrolysis was found to reduce the lignin yield by Organosolv delignification due to the formation of ‘pseudo-lignin’ and lignin recondensation during prehydrolysis. This reduction could partly be compensated by increasing the temperature of the Organosolv delignification step. Prehydrolysis substantially improved the enzymatic cellulose digestibility from 49% after Organosolv without prehydrolysis to 80% (20 FPU/g substrate). Increasing the Organosolv delignification temperature to 220 °C resulted in a maximum enzymatic glucose yield of 93% or 0.36 kg/kg straw.
Nicolas Brosse - One of the best experts on this subject based on the ideXlab platform.
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Production of oil palm (Elaeis guineensis) fronds lignin-derived non-toxic aldehyde for eco-friendly wood adhesive
International Journal of Biological Macromolecules, 2018Co-Authors: M. Hazwan Hussin, Noraini Abdul Samad, Nur Hanis Abd. Latif, Nurul Adilla Rozuli, Siti Baidurah Yusoff, François Gambier, Nicolas BrosseAbstract:Lignocellulosic materials can significantly contribute to the development of eco-friendly wood adhesives. In this work, glyoxal-phenolic resins for plywood were prepared using Organosolv lignin, which was isolated from black liquor recovered from Organosolv pulping of oil palm fronds (OPF) and considered to be an alternative to phenol. Glyoxal, which is a dialdehyde obtained from several natural resources, was used as substitute for formaldehyde. The structure of Organosolv lignin and the resins were characterized by FTIR and NMR, and for thermal stability by TGA and DSC. The resins were further studied for their viscosity, pH, solids content and gel times. The resins performance as wood adhesive was further established from mechanical test in terms of tensile strength and modulus of elasticity (MOE) to obtain the optimum ratios of Organosolv lignin, which replaces phenol in Organosolv lignin phenol glyoxal (OLPG) resins. The adhesive composition having 50% (w/w) of phenol substituted by Organosolv lignin, termed as 50% OLPG showed highest adhesive strength compared to phenol formaldehyde (PF) commercial adhesive.
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Antioxidant and anticorrosive properties of oil palm frond lignins extracted with different techniques
Annals of Forest Science, 2015Co-Authors: M. Hazwan Hussin, Afidah Abdul Rahim, Mohamad Nasir Mohamad Ibrahim, Dominique Perrin, Affaizza Mohd Shah, Nicolas BrosseAbstract:Context Oil palm ( Elaeis guineensis Jacq.) fronds are produced as waste during the harvest of oil palm fruits. It mainly consists of cellulose, lignin, and hemicelluloses. Lignins like other polyphenols are potent free radical scavengers and are considered to be a valuable source of antioxidant phenolic compounds. Aims The aim was to quantify the antioxidant properties of lignins extracted from oil palm biomass using Kraft, soda, and Organosolv pulping. The potential of the extracted lignins as inhibitors of mild steel corrosion was also assessed. Methods Ground and dried 1–3-mm-mesh-size oil palm fronds were submitted to Kraft, soda, and Organosolv pulping in rotary digesters. The extracted lignin was characterized and oxygen uptake was measured. Anticorrosion properties of extracted lignins were monitored via electrochemical measurements and surface analysis. Results Soda-extracted lignins displayed the highest antioxidant activities as compared to Kraft and ethanol Organosolv lignins. The highest inhibition of corrosion of mild steel was reached in the presence of soda-extracted lignins. Conclusion Oil palm fronds are potential sources of lignins usable as green antioxidant for corrosion inhibition of mild steel.
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Investigation on the structure and antioxidant properties of modified lignin obtained by different combinative processes of oil palm fronds (OPF) biomass
Industrial Crops and Products, 2014Co-Authors: M. Hazwan Hussin, Afidah Abdul Rahim, Mohamad Nasir Mohamad Ibrahim, Mehdi Yemloul, Dominique Perrin, Nicolas BrosseAbstract:The present work reports on the structural characteristic and antioxidant activity of the ethanol Organosolv lignin obtained from oil palm fronds (OPF) via different pretreatment combinative processes. Physicochemical analyses of pretreated lignins have shown that autohydrolysis method prior to Organosolv pulping gave smaller fragments of lignin with higher phenolic hydroxyl content compared to dilute sulphuric acid method. Indeed, repolymerization tends to occur during dilute sulphuric acid pretreatment, affecting its lignin structure and antioxidant activity. Chemical modification of lignin by utilizing organic scavenger (2-naphthol) seems to improve the properties of lignin by reducing the possibility of condensation reaction. Oxygen uptake measurement has shown that the antioxidant activity of the different pretreated Organosolv lignins (autohydrolyzed lignin, AH EOL: 82%> autohydrolyzed +2-naphthol lignin, AHN EOL: 78%> dilute sulphuric acid treated lignin, DAP EOL: 75%) were closely related to its average molecular weight and phenolic hydroxyl content.
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Impact of catalytic oil palm fronds (OPF) pulping on Organosolv lignin properties.
Polymer Degradation and Stability, 2014Co-Authors: M. Hazwan Hussin, Afidah Abdul Rahim, Mohamad Nasir Mohamad Ibrahim, Mehdi Yemloul, Dominique Perrin, Nicolas BrosseAbstract:Abstract This article sheds light on the structural characteristic and antioxidant activity of the ethanol Organosolv lignin extracted from oil palm fronds (OPF) via incorporation of 1,8-dihydroxyanthraquinone during the delignification process. The resulting modified Organosolv lignin (DEOL) was studied by 31 P NMR, HSQC, HMBC and GPC. It was proposed that addition of a catalytic amount of 1,8-dihydroxyanthraquinone during pulping process; (1) enhanced the dissolution of lignin and the delignification rate, (2) improved the solubility of the resulting modified lignin (DEOL) by reducing its hydrophobicity properties and (3) improved its antioxidant activity compared to untreated Organosolv lignin (EOL) (DEOL: 78% and EOL: 53% of Oxygen Uptake Inhibition (OUI) respectively). It was shown that antioxidant activity was closely related to its average molecular weight and phenolic hydroxyl content.
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physicochemical characterization of alkaline and ethanol Organosolv lignins from oil palm elaeis guineensis fronds as phenol substitutes for green material applications
Industrial Crops and Products, 2013Co-Authors: Afidah Abdul Rahim, Mohamad Nasir Mohamad Ibrahim, Hazwan M Hussin, Nicolas BrosseAbstract:Abstract In the present work, lignin isolation and physicochemical features from oil palm fronds (OPF) black liquor using Kraft, soda and Organosolv pulping have been studied. The characterization of lignin samples by means of FTIR, 1H and 13C NMR has shown that different types of hydroxyl functional groups were obtained from different delignification processes. It was revealed that the lignin samples contained substantial amounts of non-condensed guaiacyl and syringyl unit with fewer p-hydroxyphenyl units. The GSH molar ratio of Kraft, soda and Organosolv lignin was assigned to 26:51:21, 21:49:30 and 23:67:10, respectively, upon quantification. The significant differences in the physicochemical features of the lignin isolated with alkali and Organosolv treatments may be of great interest as a promising alternative for its revalorization.
Ingyu Choi - One of the best experts on this subject based on the ideXlab platform.
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Simultaneous production of glucose, furfural, and ethanol Organosolv lignin for total utilization of high recalcitrant biomass by Organosolv pretreatment
Renewable Energy, 2019Co-Authors: June-ho Choi, Soo-kyeong Jang, Jong-hwa Kim, Se-yeong Park, Jong-chan Kim, Hanseob Jeong, Ho-yong Kim, Ingyu ChoiAbstract:Abstract The main purpose of this study was simultaneous production of glucose, ethanol Organosolv lignin (EOL), and furfural for total utilization of lignocellulosic biomass to improve economics of biorefinery. The glucose production (37.1 g, under conditions of 160 °C with 1% sulfuric acid) was significantly increased after Organosolv pretreatment, dissolving 11.4 g of the initial hemicellulose-derived sugars and 22.6 g of the initial lignin. Progressively, Organosolv lignin precipitation and furfural production processes were conducted using the liquid hydrolysates obtained after Organosolv pretreatment. 12 g of EOL (at 160 °C, 1% sulfuric acid) was yielded with the remaining residues of soluble lignin-derived compounds in the liquid hydrolysates. Also, 7.9 g of furfural (at 160 °C, 1% sulfuric acid) was observed after additional acid-catalyzed treatment from the liquid hydrolysates. Consequently, a high yield of glucose, EOL and furfural can be obtained simultaneously using ethanol Organosolv pretreatment.
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structural changes in lignin during Organosolv pretreatment of liriodendron tulipifera and the effect on enzymatic hydrolysis
Biomass & Bioenergy, 2012Co-Authors: Bon-wook Koo, KI SEOB GWAK, Joonweon Choi, Soo-min Lee, Hwanmyeong Yeo, Byeongcheol Min, Ingyu ChoiAbstract:Abstract Although Organosolv pretreatment removed substantial amounts of lignin and xylan, the yield of glucan which is a major sugar source for fermentation to ethanol is more than 90% in most conditions of the Organosolv pretreatment. Relative lignin contents of all pretreated biomass were more than 200 g kg −1 , however enzymatic conversions were increased dramatically comparing to untreated biomass. Therefore the correlation between lignin and enzymatic hydrolysis could not be explained just by lignin content, and other changes resulting from lignin removal affected enzymatic hydrolysis. Results on enzymatic conversion and sugar recovery suggested that the critical temperature improving enzymatic hydrolysis significantly was between 120 °C and 130 °C. Microscopic analysis using Field emission scanning electron microscopy (FE-SEM) showed that structural lignin changes happened through Organosolv pretreatment. Lignins were isolated from lignin carbohydrate complex (LCC) at the initial stage and then migrated to the surface of biomass. The isolated and migrated lignins were finally redistributed onto surface. These structural changes formed droplets on surface and increased pore volume in pretreated biomass. The increase in pore volume also increased available surface area and enzyme adsorption at initial stage, and thus enzymatic conversion increased significantly through Organosolv pretreatment. It was verified that the droplets were mainly composed of lignin and the lignin droplets inhibited enzymatic hydrolysis through adsorption with cellulase.
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Organosolv pretreatment of Liriodendron tulipifera and simultaneous saccharification and fermentation for bioethanol production
Biomass and Bioenergy, 2011Co-Authors: Bon-wook Koo, Ho-yong Kim, Nahyun Park, Soo-min Lee, Hwanmyeong Yeo, Ingyu ChoiAbstract:An acid-free Organosolv process was proposed to overcome the problems caused by acid catalyst in Organosolv process, thereby producing ethanol from Liriodendron tulipifera effectively. Although relative lignin contents were above 20%, enzymatic conversion increased significantly to 65% at all conditions, and thus correlation between lignin and enzymatic conversion could not be explained using relative lignin content. Enzymatic conversion increased significantly above 65% regardless of temperature, which suggests the Organosolv pretreatment with sodium hydroxide can be performed at lower temperature. FE-SEM showed that the process made the structure loose and broke down biomass through lignin dissolution. Wrinkle formation by alkaline swelling was also observed and it might increase surface area. Although pore-volume increased slightly, it was not the sole key factor for the Organosolv pretreatment with sodium hydroxide. Increase in surface area and enzyme adsorption enhanced the enzymatic hydrolysis. Ethanol of 96% could be produced theoretically and it suggested that the acid-free Organosolv process was an effective pretreatment method for bioethanol production from L. tulipifera.
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investigation of the effective catalyst for Organosolv pretreatment of liriodendron tulipifera
Journal of the Korean wood science and technology, 2010Co-Authors: KI SEOB GWAK, Joonweon Choi, Ingyu ChoiAbstract:ABSTRACT Organosolv pretreatments which utilized sulfuric acid, sodium hydroxide and ammonia as catalysts were conducted to screen the effective catalyst for Organosolv pretreatment of Liriodendron tulipifera. The enzy-matic hydrolysis was achieved effectively with sulfuric acid (74.2%) and sodium hydroxide (63.7%). They were thus considered as effective catalysts for Organosolv pretreatment of L. tulipifera. The Organosolv pre-treatments with sulfuric acid and sodium hydroxide showed a different behavior on the reaction mechanism. The pretreatment with sulfuric acid increased the biomass roughness and pore numbers. On the other hand, the pretreatment with sodium hydroxide enhanced the surface area due to the size reduction and minor defiberization which were caused by hemicellulose degradation at an initial stage and more de-fiberization by lignin degradation at a later stage. The Organosolv pretreatment with sodium hydroxide was performed at several different conditions to evaluate effectiveness of sodium hydroxide as a catalyst for Organosolv pretreatment. According to the results of enzymatic digestibility, the changes of chemical com-position and the morphological analysis of pretreated biomass, it was suggested that the pretreatment time impacted primarily on enzymatic hydrolysis. Increase in surface area during the pretreatment was a major cause for improvement in enzymatic digestibility when sodium hydroxide was used as a catalyst. Keywords : Liriodendron tulipifera, Organosolv pretreatment, sulfuric acid catalyst, sodium hydroxide cat-alyst, enzymatic hydrolysis
Arthur J Ragauskas - One of the best experts on this subject based on the ideXlab platform.
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Insights of ethanol Organosolv pretreatment on lignin properties of Broussonetia papyrifera.
ACS Sustainable Chemistry & Engineering, 2018Co-Authors: Lan Yao, Arthur J Ragauskas, Chang Geun Yoo, Xianzhi Meng, Congxin Chen, Chengyu Dong, Haitao YangAbstract:Delignification of Broussonetia papyrifera during ethanol Organosolv pretreatment was studied. Milled wood lignin (MWL), the ethanol Organosolv lignin recovered at 5 min (PL5), 10 min (PL10), and 60 min (PL60) during the pretreatment, and the residual lignin (RL60) after the pretreatment were characterized and compared. GPC results demonstrated that the weight-average molecular weights (Mw) of the ethanol Organosolv lignin fractions increased as the pretreatment time extended from 5 to 60 min. 31P NMR analysis revealed that the content of aliphatic OH decreased in the following order: RL60 < PL60 < PL5 < PL10 < MWL. HSQC NMR results suggested that the contents of syringyl, guaiacyl, p-hydroxybenzoate unit, phenylcoumaran, and resinol in the solubilized lignin fractions were significantly changed during the pretreatment. In addition, a significant portion of β-O-4 interunit linkages of lignin was cleaved during the pretreatment, leading to the formation of stilbene structures in lignin samples such as PL60.
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Effects of Organosolv and ammonia pretreatments on lignin properties and its inhibition for enzymatic hydrolysis
Green Chemistry, 2017Co-Authors: Chang Geun Yoo, Xianzhi Meng, Arthur J RagauskasAbstract:Lignin offers structural support and protection for plant cell walls; however, it also contributes to biomass recalcitrance and the costs of biofuel production via the biological pathway. Organosolv and ammonia pretreatments have been developed to reduce biomass recalcitrance and improve sugar release performance during enzymatic hydrolysis. It is believed that lignin properties are related to its inhibition on enzymatic hydrolysis; therefore, understanding the characteristics of lignin is a key for effective biomass conversion to biofuels. In this study, an Organosolv pretreatment using 60% ethanol with 1.25% H2SO4 significantly deconstructed poplar lignin and reduced its molecular weights due to the cleavage of lignin inter-unit linkages. The Organosolv pretreatment increased the contents of phenolic OH units and the lignin residue showed a high cellulase maximum adsorption capacity. Ammonia pretreatment with 5% ammonium hydroxide was not as effective as Organosolv pretreatment on lignin deconstruction. Organosolv lignin residue had lower lignin S/G ratio than the untreated one. Compared to the Organosolv lignin residue and untreated lignin, ammonia lignin residue had a higher cellulase adsorption affinity. In addition, the effects of lignin on cellulose hydrolysis was investigated and the results suggested that the presence of lignin with cellulose substrates reduced cellulose hydrolysis, and its inhibitory effect was primarily determined by the lignin properties after each pretreatment. The Organosolv pretreatment resulted in a slightly lower cellulase binding strength (249.7 mL g−1) on poplar lignin than that on untreated samples (261.1 mL g−1), while ammonia lignin residue showed a higher cellulase binding strength (402.8 mL g−1) and had more significant inhibition effect on cellulose hydrolysis. These results demonstrated that the binding strength significantly affected the lignin-derived inhibition on enzymatic hydrolysis of cellulose in the cellulose-lignin mixtures.
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physicochemical characterization of ethanol Organosolv lignin eol from eucalyptus globulus effect of extraction conditions on the molecular structure
Polymer Degradation and Stability, 2014Co-Authors: Mauricio Yanezs, Poulomi Sannigrahi, Betty Matsuhiro, Carolina Nunez, Shaobo Pan, Christopher A Hubbell, Arthur J RagauskasAbstract:Abstract The aim of the present study was to investigate the effect of extraction conditions, mainly severity factor (H-factor = 3980–14,500) on the molecular structure of ethanol Organosolv lignins extracted from Eucalyptus globulus . Isolated lignins were structurally characterized by 1 H NMR, 31 P NMR, UV–Vis, FT-IR spectroscopy and gel permeation chromatography. The results showed that an increase in the severity of the pretreatment decreased the molecular weight of the lignins within a 36–56% range with respect to the untreated lignin (MWL). Moreover, the increase in severity of the Organosolv treatment was accompanied by strong decrease in the content of aliphatic hydroxyl groups and by an increase of syringyl phenolic units and condensed phenolic structures. The condensed phenolic structures quantified in the Organosolv lignin correspond to resinol, phenylcoumaran, dibenzodioxocin, spirodienone and β-1′ linkages.
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Design and simulation of an Organosolv process for bioethanol production
Biomass Conversion and Biorefinery, 2013Co-Authors: Jesse Kautto, Matthew J. Realff, Arthur J RagauskasAbstract:Organosolv pulping can be used as a pretreatment step in bioethanol production. In addition to ethanol, Organosolv pulping allows for the production of a pure lignin product and other co-products. Based on publicly available information, conceptual process design and simulation model were developed for an Organosolv process. The simulation model was used to calculate the mass and energy balances and approximate fossil-based carbon dioxide (CO2) emissions for the process. With a hardwood feed of 2,350 dry metric tons (MT) per day, 459 MT/day (53.9 million gallons per year) of ethanol was produced. This corresponded to a carbohydrate to ethanol conversion of 64 %. The production rates of lignin, furfural, and acetic acid were 310, 6.6, and 30.3 MT/day, respectively. The energy balance indicated that the process was not energy self-sufficient. In addition to bark and organic residues combusted to produce energy, external fuel (natural gas) was needed to cover the steam demand. This was largely due to the energy consumed in recovering the solvent. Compared to a dilute acid bioethanol process, the Organosolv process was estimated to consume 34 % more energy. Allocating all emissions from natural gas combustion to the produced ethanol led to fossil CO2 emissions of 13.5 g per megajoule (MJ) of ethanol. The total fossil CO2 emissions of the process, including also feedstock transportation and other less significant emission sources, would almost certainly not exceed the US Renewable Fuel Standard threshold limit (36.5 g CO2/MJ ethanol).
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enzymatic hydrolysis of Organosolv kanlow switchgrass and its impact on cellulose crystallinity and degree of polymerization
Energy and Environmental Science, 2011Co-Authors: Carolina Cateto, Gang Hu, Arthur J RagauskasAbstract:In this work the potential of Organosolv treated Kanlow switchgrass for ethanol production was determined and the changes imparted to cellulose crystallinity and degree of polymerization (DP) along the course of enzymatic hydrolysis were assessed. The Organosolv pretreatment yielded a substrate that was readily hydrolyzed by cellulases allowing 92.0% recovery of the glucan present in untreated switchgrass after 72 h of enzymatic hydrolysis. Cellulose crystallinity remained approximately constant after Organosolv pretreatment and additionally during the course of enzymatic hydrolysis (8 h of enzymatic hydrolysis). The degree of polymerization decreased upon Organosolv pretreatment. During enzymatic hydrolysis the DP decreased for the first two hours and thereafter remained approximately constant (4–8 hours). The polydispersity index showed a small increase along the course of enzymatic hydrolysis (0–8 hours). The obtained results indicated the occurrence of a “peeling off” type mechanism.