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Arvind Varma - One of the best experts on this subject based on the ideXlab platform.
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A Comparison of Ammonia Borane Dehydrogenation Methods for Proton-Exchange-Membrane Fuel Cell Vehicles: Hydrogen Yield and Ammonia Formation and Its Removal
Industrial & Engineering Chemistry Research, 2011Co-Authors: Ahmad Al-kukhun, Hyun Tae Hwang, Arvind VarmaAbstract:Current promising methods to release hydrogen from ammonia borane (NH3BH3, AB; 19.6 wt % H2) including neat thermolysis, thermolysis in ionic liquid bmimCl with or without proton sponge, thermolysis with nano-BN and Hydrothermolysis, were investigated for hydrogen yield and ammonia formation. It was found that even trace moisture influences AB dehydrogenation significantly. The Hydrothermolysis at 85 °C (13.5 wt % H2, 1 mol % NH3) and thermolysis in bmimCl with 3 wt % moisture at 110 °C (13 wt % H2, 0.2 mol % NH3) methods were found to be the most promising. Since the target for a proton exchange membrane (PEM) fuel cell is an ammonia concentration less than 0.1 ppm, different purification methods were evaluated. Using experiments and simulations, the proposed ammonia removal method, involving absorption in water followed by adsorption on carbon, was optimized and tested. This study demonstrates that, with high hydrogen yield and an effective method to remove ammonia and borazine, AB dehydrogenation is an...
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Hydrogen generation from noncatalytic Hydrothermolysis of ammonia borane for vehicle applications
AIChE Journal, 2011Co-Authors: Moiz Diwan, Ahmad Al-kukhun, Hyun Tae Hwang, Arvind VarmaAbstract:Ammonia borane (AB) is a promising hydrogen storage material as it contains 19.6 wt % hydrogen. In this article, our recently developed Hydrothermolysis approach to release hydrogen is studied over a wide range of AB concentrations (688 wt at pressure 14.7 and 200 psia, and temperature 85135C. It is shown that with increasing AB concentration up to 77 wt the H2 yield increases, and that the role of thermolysis, when compared with hydrolysis, increases. The maximum hydrogen storage capacity, obtained at 77 wt % AB and Treactor 85C along with rapid kinetics, was 11.6 and 14.3 wt % at pressure 14.7 and 200 psia, respectively. To our knowledge, on a material basis, the AB Hydrothermolysis process is the first one to provide such high hydrogen yield values at near PEM fuel cell operating temperatures without use of catalyst, and thus is promising for use in fuel cellbased vehicle applications. 2010 American Institute of Chemical Engineers AIChE J, 2011
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Hydrogen for Vehicle Applications from Hydrothermolysis of Ammonia Borane: Hydrogen Yield, Thermal Characteristics, and Ammonia Formation
Industrial & Engineering Chemistry Research, 2010Co-Authors: Hyun Tae Hwang, Ahmad Al-kukhun, Arvind VarmaAbstract:Among chemical hydrides, ammonia borane (AB) is of interest as a hydrogen storage material due to its high hydrogen capacity (19.6 wt %). In this paper, our recently developed Hydrothermolysis process was investigated over a wide range of AB weight percentages (wt %) in water, pressures, and heating rates. It was found that hydrogen yield and thermal characteristics were influenced by these operating conditions. Ammonia generation was also observed during AB Hydrothermolysis, where 14―53% of AB was converted to NH 3 depending on the reaction conditions. It is remarkable that some AB (2-4%) was converted to NH 3 , which must be removed for use in proton exchange membrane (PEM) fuel cells, even by neat thermolysis. It was also found that during the Hydrothermolysis reaction at T rcactor of 85 °C, the T sample can exceed 500 °C, where AB can be completely decomposed to boron nitride (BN). The 11 B NMR characterization of Hydrothermolysis products showed compounds with B―O and B―N bonds. This paper suggests directions for future research to identify optimal conditions, where the Hydrothermolysis process provides the best balance between H 2 yield and undesirable products, for PEM fuel cell vehicle applications.
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transport characteristics of dehydrogenated ammonia borane and sodium borohydride spent fuels
International Journal of Hydrogen Energy, 2010Co-Authors: Sumit Basu, Moiz Diwan, Mohamad G Abiad, Yuan Zheng, Osvaldo H Campanella, Arvind VarmaAbstract:Abstract Ammonia borane (AB) and sodium borohydride (SBH) are candidate materials for on-board hydrogen storage that can be dehydrogenated upon demand. The rheological properties of the dehydrogenated by-products are important to quantify their removal and transportability from the hydrogen storage system. This paper presents visco-elastic property (elastic stiffness and viscous damping) measurements of the spent fuels obtained from AB hydrolysis, Hydrothermolysis and thermolysis; and SBH hydrolysis. Smaller stiffness and larger mobility (or smaller viscous damping) indicate better transportability of the spent fuel. In addition, flow property (dynamic angle of repose and avalanching time) measurements for the hydrolysis spent fuels of AB and SBH are also presented. Comparing with the SBH hydrolysis spent fuel, the AB hydrolysis spent fuel had a lower stiffness and larger mobility, as well as lower angles of dynamic repose and avalanche power peaks, indicating that it is more transportable. Among all the investigated AB spent fuels in the present study, those obtained from its neat thermolysis (at 120 °C) and Hydrothermolysis (40–70 wt%) were found to be the most transportable, followed by-products of its hydrolysis and ionic solvent-aided thermolysis, respectively.
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Noncatalytic Hydrothermolysis of ammonia borane
International Journal of Hydrogen Energy, 2008Co-Authors: Moiz Diwan, Victor Diakov, Evgeny Shafirovich, Arvind VarmaAbstract:Abstract Hydrolysis of ammonia borane (AB) is attractive as a chemical method for hydrogen storage. The use of catalysts is, however, usually required. In the present paper, two new methods for releasing hydrogen from AB and water are investigated which do not involve any catalyst. One method is based on combustion of AB mixtures with nanoscale aluminum powder and gelled water. It is shown experimentally that these mixtures, upon ignition, exhibit self-sustained combustion with hydrogen release from both AB and water. The other method involves external heating of aqueous AB solutions to temperatures 120 °C or higher, under argon pressure to avoid water boiling. To clarify the reaction mechanism, isotopic experiments using D 2 O instead of H 2 O were conducted. It is shown that heating AB/D 2 O solution to temperatures 117–170 °C releases 3 equiv. of hydrogen per mole AB, where 2–2.1 equiv. originate from AB and 0.9–1 equiv. from water. The prospects of both methods for hydrogen storage are discussed.
Ibrahim M. Banat - One of the best experts on this subject based on the ideXlab platform.
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Ethanol Production from Sugarcane Bagasse Using SSF Process and Thermotolerant Yeast
Transactions of the ASABE, 2015Co-Authors: Gislene Mota Da Silva, Ibrahim M. Banat, Raquel L. C. Giordano, Antonio José Gonçalves Cruz, Karthikeyan D. Ramachandriya, Mark R. WilkinsAbstract:Abstract. Sugarcane bagasse (SCB) pretreated by Hydrothermolysis at 195°C for 10 min was used as a substrate for ethanol production in a simultaneous saccharification and fermentation (SSF) process with the thermotolerant yeast Kluyveromyces marxianus IMB3 at 45°C. SSF was carried out for 7 days using 15 and 30 filter paper units (FPU) cellulase g -1 treated SCB (Accellerase 1500) to determine the effect of enzyme loading on ethanol production. Different pretreated dry solids loadings of 10% and 15% (w/w) were investigated in this work during enzymatic hydrolysis. Results showed 89.7% hemicellulose removal during pretreatment and glucan recovery of 97.8%. The highest ethanol concentration of 29.2 g L -1 was obtained with 30 FPU cellulase g -1 treated SCB within 72 h, which was equivalent to 58.9% of the maximum theoretical ethanol yield.
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Simultaneous saccharification and fermentation of Kanlow switchgrass by thermotolerant Kluyveromyces marxianus IMB3: the effect of enzyme loading, temperature and higher solid loadings.
Bioresource technology, 2011Co-Authors: Naveen K. Pessani, Hasan K. Atiyeh, Mark R. Wilkins, Danielle D. Bellmer, Ibrahim M. BanatAbstract:Abstract Switchgrass ( Panicum virgatum ) was subjected to Hydrothermolysis pretreatment and then used to study the effect of enzyme loading and temperature in a simultaneous saccharification and fermentation (SSF) with the thermotolerant yeast strain Kluyveromyces marxianus IMB3 at 8% solid loading. Various loadings of Accellerase 1500 between 0.1 and 1.1 mL g −1 glucan were tested in SSF at 45 °C (activity of enzyme was 82.2 FPU mL −1 ). The optimum enzyme loading was 0.7 mL g −1 glucan based on the six different enzyme loadings tested. SSFs were performed at 37, 41 and 45 °C with an enzyme loading of 0.7 mL g −1 glucan. The highest ethanol concentration of 22.5 g L −1 was obtained after 168 h with SSF at 45 °C, which was equivalent to 86% yield. Four different batch and fed-batch strategies were evaluated using a total solid loading of 12% (dry basis). About 32 g L −1 ethanol was produced with the four strategies, which was equivalent to 82% yield.
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Effect of Hydrothermolysis process conditions on pretreated switchgrass composition and ethanol yield by SSF with Kluyveromyces marxianus IMB4.
Process Biochemistry, 2009Co-Authors: Lilis Suryawati, Mark R. Wilkins, Danielle D. Bellmer, Raymond L. Huhnke, Niels O. Maness, Ibrahim M. BanatAbstract:Hot compressed liquid water was used to treat switchgrass in a method called Hydrothermolysis to disrupt lignin, dissolve hemicellulose, and increase accessibility of cellulose to cellulase. Three temperatures (190, 200, and 210 °C) and hold times (10, 15, and 20 min) were tested. Switchgrass treated at 190 °C for 10 min had the greatest xylan recovery in the prehydrolyzate. Less than 0.65 g/L glucose were released into the prehydrolyzate for all pretreatment conditions, indicating most glucose was retained as cellulose in the solid substrate. 5-Hydroxymethylfurfural (HMF) and furfural formation in the prehydrolyzate were found to be less than 1 g/L for all treatments. The highest concentration of ethanol, 16.8 g/L (72% of theoretical), was produced from switchgrass pretreated at 210 °C and 15 min using simultaneous saccharification and fermentation (SSF) at 45 °C with the thermotolerant yeast Kluyveromyces marxianus IMB4 and 15 FPU cellulase/g glucan.
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Simultaneous Saccharification and Fermentation of Pretreated Switchgrass with Kluyveromyces marxianus IMB strains
2008 Providence Rhode Island June 29 - July 2 2008, 2008Co-Authors: Brian A. Faga, Mark R. Wilkins, Danielle D. Bellmer, Raymond L. Huhnke, Ibrahim M. BanatAbstract:Switchgrass was pretreated by Hydrothermolysis at 200 °C for 10 min. The resulting solids had a glucan content of 54%. Pretreated switchgrass containing 4 g of glucan was used in a simultaneous saccharification and fermentation (SSF) process with five thermotolerant strains of K. marxianus yeast and 60 FPU of a commercial cellulase enzyme mixture. The SSFs were performed for 7 d at 45 °C and buffered at pH 5.5. IMB 3 provided the best ethanol production results. After 72 and 96 h, IMB 3 produced 71% and 82% of theoretical maximum ethanol from glucose, respectively. None of the other strains achieved greater than 80% theoretical conversion.
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Effect of Hydrothermolysis on ethanol yield from Alamo switchgrass using a thermotolerant yeast
2007 Minneapolis Minnesota June 17-20 2007, 2007Co-Authors: Lilis Suryawati, Mark R. Wilkins, Danielle D. Bellmer, Raymond L. Huhnke, Niels O. Maness, Ibrahim M. BanatAbstract:Switchgrass is a perennial grass that has potential as a feedstock for ethanol production. Using switchgrass for ethanol production would reduce dependence on food crops, such as corn, that are currently used for fuel ethanol. Hot compressed liquid water was used to treat Alamo switchgrass in a method called Hydrothermolysis to disrupt lignin, dissolve hemicellulose, and increase accessibility of cellulose to hydrolysis enzymes. Hydrothermolysis was selected instead of other common methods to minimize formation of inhibitors, chemical use, and corrosion of process equipment. Three temperatures (190, 200, and 210 °C) and hold times (10, 15, and 20 min) were used to pretreat Alamo switchgrass at 10% solids to prepare it for SSF (Simultaneous saccharification and fermentation). Prehydrolyzate from switchgrass treated at 190 °C for 10 min had the greatest xylan recovery in the hydrolyzate. From all treatment conditions, less than 0.65 g/L glucose were released into the prehydrolyzate, indicating most glucose was retained as cellulose in the solid substrate. HMF (5-hydroxymethylfurfural) and furfural formation in the prehydrolyzate were found to be less than 1 g/L for all treatments. The highest theoretical yield of ethanol (82%, 18.6 g/L) was produced from switchgrass pretreated at 200°C and 10 min using SSF at 45oC with thermotolerant yeast Kluyveromyces marxianus IMB 4 and 15 FPU cellulase/g glucan loading. The glucan loading for SSF was 40 g/L.
Mark R. Wilkins - One of the best experts on this subject based on the ideXlab platform.
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Ethanol Production from Sugarcane Bagasse Using SSF Process and Thermotolerant Yeast
Transactions of the ASABE, 2015Co-Authors: Gislene Mota Da Silva, Ibrahim M. Banat, Raquel L. C. Giordano, Antonio José Gonçalves Cruz, Karthikeyan D. Ramachandriya, Mark R. WilkinsAbstract:Abstract. Sugarcane bagasse (SCB) pretreated by Hydrothermolysis at 195°C for 10 min was used as a substrate for ethanol production in a simultaneous saccharification and fermentation (SSF) process with the thermotolerant yeast Kluyveromyces marxianus IMB3 at 45°C. SSF was carried out for 7 days using 15 and 30 filter paper units (FPU) cellulase g -1 treated SCB (Accellerase 1500) to determine the effect of enzyme loading on ethanol production. Different pretreated dry solids loadings of 10% and 15% (w/w) were investigated in this work during enzymatic hydrolysis. Results showed 89.7% hemicellulose removal during pretreatment and glucan recovery of 97.8%. The highest ethanol concentration of 29.2 g L -1 was obtained with 30 FPU cellulase g -1 treated SCB within 72 h, which was equivalent to 58.9% of the maximum theoretical ethanol yield.
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Butanol production from Hydrothermolysis-pretreated switchgrass: Quantification of inhibitors and detoxification of hydrolyzate.
Bioresource technology, 2015Co-Authors: Kan Liu, Hasan K. Atiyeh, Oscar Pardo-planas, Thaddeus Chukwuemeka Ezeji, Victor Ujor, Jonathan C. Overton, Kalli Berning, Mark R. Wilkins, Ralph S. TannerAbstract:The present study evaluated butanol production from switchgrass based on Hydrothermolysis pretreatment. The inhibitors present in the hydrolyzates were measured. Results showed poor butanol production (1g/L) with non-detoxified hydrolyzate. However, adjusting the pH of the non-detoxified hydrolyzate to 6 and adding 4 g/L CaCO3 increased butanol formation to about 6g/L. There was about 1g/L soluble lignin content (SLC), and various levels of furanic and phenolic compounds found in the non-detoxified hydrolyzate. Detoxification of hydrolyzates with activated carbon increased the butanol titer to 11 g/L with a total acetone, butanol and ethanol (ABE) concentration of 17 g/L. These results show the potential of butanol production from Hydrothermolysis pretreated switchgrass.
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Simultaneous saccharification and fermentation of Kanlow switchgrass by thermotolerant Kluyveromyces marxianus IMB3: the effect of enzyme loading, temperature and higher solid loadings.
Bioresource technology, 2011Co-Authors: Naveen K. Pessani, Hasan K. Atiyeh, Mark R. Wilkins, Danielle D. Bellmer, Ibrahim M. BanatAbstract:Abstract Switchgrass ( Panicum virgatum ) was subjected to Hydrothermolysis pretreatment and then used to study the effect of enzyme loading and temperature in a simultaneous saccharification and fermentation (SSF) with the thermotolerant yeast strain Kluyveromyces marxianus IMB3 at 8% solid loading. Various loadings of Accellerase 1500 between 0.1 and 1.1 mL g −1 glucan were tested in SSF at 45 °C (activity of enzyme was 82.2 FPU mL −1 ). The optimum enzyme loading was 0.7 mL g −1 glucan based on the six different enzyme loadings tested. SSFs were performed at 37, 41 and 45 °C with an enzyme loading of 0.7 mL g −1 glucan. The highest ethanol concentration of 22.5 g L −1 was obtained after 168 h with SSF at 45 °C, which was equivalent to 86% yield. Four different batch and fed-batch strategies were evaluated using a total solid loading of 12% (dry basis). About 32 g L −1 ethanol was produced with the four strategies, which was equivalent to 82% yield.
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Effect of Hydrothermolysis process conditions on pretreated switchgrass composition and ethanol yield by SSF with Kluyveromyces marxianus IMB4.
Process Biochemistry, 2009Co-Authors: Lilis Suryawati, Mark R. Wilkins, Danielle D. Bellmer, Raymond L. Huhnke, Niels O. Maness, Ibrahim M. BanatAbstract:Hot compressed liquid water was used to treat switchgrass in a method called Hydrothermolysis to disrupt lignin, dissolve hemicellulose, and increase accessibility of cellulose to cellulase. Three temperatures (190, 200, and 210 °C) and hold times (10, 15, and 20 min) were tested. Switchgrass treated at 190 °C for 10 min had the greatest xylan recovery in the prehydrolyzate. Less than 0.65 g/L glucose were released into the prehydrolyzate for all pretreatment conditions, indicating most glucose was retained as cellulose in the solid substrate. 5-Hydroxymethylfurfural (HMF) and furfural formation in the prehydrolyzate were found to be less than 1 g/L for all treatments. The highest concentration of ethanol, 16.8 g/L (72% of theoretical), was produced from switchgrass pretreated at 210 °C and 15 min using simultaneous saccharification and fermentation (SSF) at 45 °C with the thermotolerant yeast Kluyveromyces marxianus IMB4 and 15 FPU cellulase/g glucan.
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Simultaneous Saccharification and Fermentation of Pretreated Switchgrass with Kluyveromyces marxianus IMB strains
2008 Providence Rhode Island June 29 - July 2 2008, 2008Co-Authors: Brian A. Faga, Mark R. Wilkins, Danielle D. Bellmer, Raymond L. Huhnke, Ibrahim M. BanatAbstract:Switchgrass was pretreated by Hydrothermolysis at 200 °C for 10 min. The resulting solids had a glucan content of 54%. Pretreated switchgrass containing 4 g of glucan was used in a simultaneous saccharification and fermentation (SSF) process with five thermotolerant strains of K. marxianus yeast and 60 FPU of a commercial cellulase enzyme mixture. The SSFs were performed for 7 d at 45 °C and buffered at pH 5.5. IMB 3 provided the best ethanol production results. After 72 and 96 h, IMB 3 produced 71% and 82% of theoretical maximum ethanol from glucose, respectively. None of the other strains achieved greater than 80% theoretical conversion.
Herbert Sixta - One of the best experts on this subject based on the ideXlab platform.
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Hydrothermolysis of pine wood
Biomass and Bioenergy, 2018Co-Authors: Marina Ståhl, Kaarlo Nieminen, Herbert SixtaAbstract:Abstract The objective of this research was to obtain a better fundamental understanding of the extraction of lignin and carbohydrates from pine wood during Hydrothermolysis at elevated temperatures. The treatment was performed in a batch reactor at three different temperatures (200, 220 and 240 °C) and a liquid-to-wood ratio of 40:1. It was found that up to 35% of native pine lignin solubilized at 240 °C within a few minutes of reaction time. Delignification kinetics of wood during Hydrothermolysis was successfully modeled by the assumption of simultaneous dissolution (depolymerization) and condensations reactions of lignin. Two distinct lignin fractions, so-called soluble and insoluble lignin were found in the hydrolysates and can be considered as potential material for the production of high-value products. Complete removal of pine wood hemicellulose was achieved at a concomitant cellulose yield loss of about 12.5%. Up to 85% of pine wood mannan could be recovered from the hydrolysate as manno-oligosaccharides, in contrast to only 46% of xylo-oligosaccharides. Kinetic models fitting experimental data are proposed to explain degradation and conversion reactions of two main hemicellulosic components of pine wood, xylan and mannan. Overall, this study provides initial fundamental knowledge required for potentially efficient utilization of softwoods using wood biorefinery concept.
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xylo oligosaccharide xos formation through Hydrothermolysis of xylan derived from viscose process
Macromolecular Symposia, 2005Co-Authors: Alexandra Griebl, Thomas Lange, Hedda K. Weber, Walter Milacher, Herbert SixtaAbstract:Xylo-oligosaccharides (XOS) have gained growing interest during the past decade owing to their beneficial influence on health. At the same time, a trend to a more effective utilization of biomass and biomass degradation products can be observed. As a consequence, also the steeping-lye of the viscose process is discussed as a potential source of new products based on xylans, xylooligosaccharides, xylose, and different xylose degradation products, thus being a driving force for the development of appropriate production processes. Therefore, xylan isolated from the steeping-lye was subjected to hydrothermal degradation for production of xylo-oligosaccharides (XOS). The experiments were carried out at 120, 150, and 180 °C, respectively. This hydrothermal treatment led to a soluble fraction, consisting of neutral and acidic XOS, and an insoluble residue predominantly made up of highly crystalline cellulose. A mass balance was established to calculate the activation energy for hydrothermal xylan degradation from weight loss kinetics. The degree of polymerization (DP) of the neutral product fraction could be influenced in a wide range by the reaction conditions applied. Acidic XOS were further characterized using mass spectrometry (MS). A 4-O-methylglucuronic acid residue α-(1,3)-linked to the xylose backbone was detected as a new structural element in alkaline degradation products derived from beech wood xylan.
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Xylo‐Oligosaccharide (XOS) Formation through Hydrothermolysis of Xylan Derived from Viscose Process
Macromolecular Symposia, 2005Co-Authors: Alexandra Griebl, Thomas Lange, Hedda K. Weber, Walter Milacher, Herbert SixtaAbstract:Xylo-oligosaccharides (XOS) have gained growing interest during the past decade owing to their beneficial influence on health. At the same time, a trend to a more effective utilization of biomass and biomass degradation products can be observed. As a consequence, also the steeping-lye of the viscose process is discussed as a potential source of new products based on xylans, xylooligosaccharides, xylose, and different xylose degradation products, thus being a driving force for the development of appropriate production processes. Therefore, xylan isolated from the steeping-lye was subjected to hydrothermal degradation for production of xylo-oligosaccharides (XOS). The experiments were carried out at 120, 150, and 180 °C, respectively. This hydrothermal treatment led to a soluble fraction, consisting of neutral and acidic XOS, and an insoluble residue predominantly made up of highly crystalline cellulose. A mass balance was established to calculate the activation energy for hydrothermal xylan degradation from weight loss kinetics. The degree of polymerization (DP) of the neutral product fraction could be influenced in a wide range by the reaction conditions applied. Acidic XOS were further characterized using mass spectrometry (MS). A 4-O-methylglucuronic acid residue α-(1,3)-linked to the xylose backbone was detected as a new structural element in alkaline degradation products derived from beech wood xylan.
Juanita Freer - One of the best experts on this subject based on the ideXlab platform.
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Optimal Pretreatment of Eucalyptus globulus by Hydrothermolysis and Alkaline Extraction for Microbial Production of Ethanol and Xylitol
Industrial & Engineering Chemistry Research, 2013Co-Authors: Jean Franco Castro, Carolina Parra, Jaime Baeza, Mauricio Yáñez-s, Jonathan Rojas, Regis Teixeira Mendonça, Juanita FreerAbstract:Fractionation of Eucalyptus globulus wood chips is mandatory for developing a biorefinery process. In order to achieve this, products released from Hydrothermolysis pretreatment were studied within the severity (log R0) range 3.3–4.5. The highest solubilized xylose yield was 56% (DWB) at log R0 3.9. Values higher than log R0 4.1 have led to high xylose dehydration rates. Detoxification steps applied to the liquor removed acetic acid (55%), furfural (94%), and hydroxymethylfurfural (HMF) (31%). Fermentation of liquor with Candida guilliermondii resulted in a xylitol yield of 0.37 g of xylitol produced per gram of xylose consumed (equivalent to 71% of the control with pure xylose). Pulp-1 (from Hydrothermolysis pretreatment) was further pretreated with NaOH for lignin removal (obtaining Pulp-2). Cellulose composition in Pulp-1 and Pulp-2 remains almost unaltered; lignin content in Pulp-2 was 50% lower than in Pulp-1. Simultaneous saccharification and fermentation (SSF) experiments for both pulps reached sim...
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β-Glucosidase immobilisation on synthetic superparamagnetic magnetite nanoparticles and their application in saccharification of wheat straw andEucalyptus globuluspulps
Journal of Experimental Nanoscience, 2012Co-Authors: R. Valenzuela, Jean Franco Castro, Carolina Parra, Jaime Baeza, Nelson Durán, Juanita FreerAbstract:β-Glucosidase from Trichoderma reesei was immobilised on synthetic superparamagnetic magnetite (Fe3O4) nanoparticles with a mean diameter of 10 nm and were used to supplement cellulase in the enzymatic hydrolysis of three substrates: wheat straw pretreated by steam explosion, Eucalyptus globulus pretreated by Hydrothermolysis and E. globulus pretreated by Hydrothermolysis followed by alkaline extraction. The hydrolysis yields for each pretreated material, using immobilised β-glucosidase (I-βG) and free cellulase, were 76.1%, 83.6% and 75.6%, respectively, and resulted in an improved hydrolysis yields compared with only cellulase. These yields were at most 10% lower than yields reached with free enzymes. The (I-βG) was magnetically recovered and successfully reused twice. The differences in the hydrolysis yields were not significant (p > 0.05) in the case of steam-exploded wheat straw and E. globulus pretreated by Hydrothermolysis followed by alkaline extraction. The immobilisation of enzymes provides an o...
