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Harshad Velankar - One of the best experts on this subject based on the ideXlab platform.
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Assisted Single-Step Acid Pretreatment Process for Enhanced Delignification of Rice Straw for Bioethanol Production
ACS Sustainable Chemistry & Engineering, 2018Co-Authors: Thulluri Chiranjeevi, Anu Jose Mattam, Kusum K. Vishwakarma, Addepally Uma, V.c. Rao Peddy, Sriganesh Gandham, Harshad VelankarAbstract:Dilute Acid Pretreatment of lignocellulosic biomass at higher temperatures (>160 °C) solubilizes/removes hemicelluloses (xylan, arabinan, mannan, galactan) and Acid-soluble lignin (ASL), but, it does not remove Acid-insoluble lignin (AIL). During Acid Pretreatment, the condensation and redeposition of coalesced lignin over cellulose fibers reduces the access of cellulose to cellulases. For higher delignification, various multistage Pretreatments are available, however, all these are energy/chemical intensive methods. Therefore, an effective Pretreatment which provides increased cellulose accessibility by enhanced removal of hemicelluloses and lignin in a single-step would be preferred. Our investigation reports a novel assisted single-step Acid Pretreatment (ASAP) process for enhanced delignification of biomass under Acidic conditions. Pretreatment of rice straw (particle size of 20 mm) with H2SO4 (0.75% v/v) + boric Acid (1% w/v) + glycerol (0.5% v/v) (solid/liquid (S/L), 1:5) at 150 °C for 20 min remove...
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Assisted Single-Step Acid Pretreatment Process for Enhanced Delignification of Rice Straw for Bioethanol Production
2018Co-Authors: Thulluri Chiranjeevi, Anu Jose Mattam, Kusum K. Vishwakarma, Addepally Uma, V.c. Rao Peddy, Sriganesh Gandham, Harshad VelankarAbstract:Dilute Acid Pretreatment of lignocellulosic biomass at higher temperatures (>160 °C) solubilizes/removes hemicelluloses (xylan, arabinan, mannan, galactan) and Acid-soluble lignin (ASL), but, it does not remove Acid-insoluble lignin (AIL). During Acid Pretreatment, the condensation and redeposition of coalesced lignin over cellulose fibers reduces the access of cellulose to cellulases. For higher delignification, various multistage Pretreatments are available, however, all these are energy/chemical intensive methods. Therefore, an effective Pretreatment which provides increased cellulose accessibility by enhanced removal of hemicelluloses and lignin in a single-step would be preferred. Our investigation reports a novel assisted single-step Acid Pretreatment (ASAP) process for enhanced delignification of biomass under Acidic conditions. Pretreatment of rice straw (particle size of 20 mm) with H2SO4 (0.75% v/v) + boric Acid (1% w/v) + glycerol (0.5% v/v) (solid/liquid (S/L), 1:5) at 150 °C for 20 min removed hemicelluloses completely, 44% of the lignin, and ∼48.5% of the silica leaving a solid consisting of 69 ± 1.5% glucan, 0.7 ± 0.06% ASL, 20 ± 2.0% AIL, and 12 ± 1.5% silica. The C/L (cellulose/lignin) ratio of solids resulted from ASAP was found to be > 3.00, while it was < 2.00 for Acid only and untreated solids. Enzymatic hydrolysis of ASAP treated biomass with enzyme loadings of 20 FPU g–1 at 15% (w/v) solids concentration gave about 72% glucan conversion to glucose. This amount of glucose was around 2.6 times higher than obtained with enzymatic hydrolysis of Acid-only-pretreated solids and 4.2 times higher than untreated rice straw (control). Therefore, the assisted-Acid Pretreatment dramatically enhanced delignification of rice straw and thereby glucan-to-glucose conversion
Eulogio Castro - One of the best experts on this subject based on the ideXlab platform.
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Application of a combined fungal and diluted Acid Pretreatment on olive tree biomass
Industrial Crops and Products, 2018Co-Authors: José Carlos Martínez-patiño, Thelmo A. Lu-chau, Beatriz Gullón, Encarnación Ruiz, Inmaculada Romero, Eulogio Castro, Juan M. LemaAbstract:Abstract A biological Pretreatment of olive tree biomass (OTB) was carried out. First, seven white-rot fungi (WRF) were screened on solid-state fermentations by analyzing the substrate composition, ligninolytic enzymes production and enzymatic hydrolysis yields at three different Pretreatment times (15, 30 and 45 days). Glucose released by enzymatic hydrolysis of OTB pretreated with Irpex lacteus for 45 days doubled that obtained with the control (non-inoculated). In addition, to enhance this yield, the combination of fungal Pretreatment with a chemical Pretreatment was studied. It was also found that the order of the Pretreatment combination has a relevant effect on the glucose yield. Thereby, the best option determined, fungal Pretreatment with I. lacteus after 28 days of culture followed by diluted Acid Pretreatment (2% w/v H2SO4, 130 °C and 90 min), enhanced 34% the enzymatic hydrolysis yield compared with the Acid Pretreatment alone. Applying the best Pretreatment combination, the overall sugar yield of the whole process (sequential Pretreatment plus enzymatic hydrolysis) was 51% of the theoretical yield.
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Optimization of dilute Acid Pretreatment of Agave lechuguilla and ethanol production by co-fermentation with Escherichia coli MM160
Industrial Crops and Products, 2018Co-Authors: Deniss I. Díaz-blanco, Encarnación Ruiz, Inmaculada Romero, Jesús R. De La Cruz, Juan C. López-linares, Thelma K. Morales-martínez, Leopoldo J. Rios-gonzález, Eulogio CastroAbstract:Abstract Agave lechuguilla is a common plant of Northern Mexico that can be used as feedstock in the context of a biorefinery without competition for food use. In this work, the production of fermentable sugars from this biomass has been studied for the first time using dilute sulfuric Acid Pretreatment. An experimental design and response surface methodology were applied with temperature (160–200 °C) and Acid concentration (0.5–1.5% w/v) chosen as factors. The Pretreatment conditions were expressed in a combined severity factor, which ranged from −0.75 to 2.38. According to an optimization criterion that maximizes hemicellulosic sugar recovery in the prehydrolysate and glucose recovery by enzymatic hydrolysis, optimal conditions for Acid Pretreatment of agave were found to be 180 °C and 1.24% (w/v) H2SO4 at 10% biomass loading. These optimal conditions yielded 87% hemicellulosic sugar recovery and 68 g glucose/100 g glucose in raw agave. The whole slurry resulting from Acid Pretreatment of agave at optimal conditions was enzymatically saccharified yielding a sugar solution that was co-fermented by the ethanologenic Escherichia coli MM160. This process configuration allowed the fermentation of all sugars in raw A. lechuguilla in a single step reaching an ethanol yield of 73.3%.
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conversion of olive tree biomass into fermentable sugars by dilute Acid Pretreatment and enzymatic saccharification
Bioresource Technology, 2008Co-Authors: Cristobal Cara, Encarnación Ruiz, J M Oliva, Felicia Saez, Eulogio CastroAbstract:Abstract The production of fermentable sugars from olive tree biomass was studied by dilute Acid Pretreatment and further saccharification of the pretreated solid residues. Pretreatment was performed at 0.2%, 0.6%, 1.0% and 1.4% (w/w) sulphuric Acid concentrations while temperature was in the range 170–210 °C. Attention is paid to sugar recovery both in the liquid fraction issued from Pretreatment (prehydrolysate) and that in the water-insoluble solid (WIS). As a maximum, 83% of hemicellulosic sugars in the raw material were recovered in the prehydrolysate obtained at 170 °C, 1% sulphuric Acid concentration, but the enzyme accessibility of the corresponding pretreated solid was not very high. In turn, the maximum enzymatic hydrolysis yield (76.5%) was attained from a pretreated solid (at 210 °C, 1.4% Acid concentration) in which cellulose solubilization was detected; moreover, sugar recovery in the prehydrolysate was the poorest one among all the experiments performed. To take account of fermentable sugars generated by Pretreatment and the glucose released by enzymatic hydrolysis, an overall sugar yield was calculated. The maximum value (36.3 g sugar/100 g raw material) was obtained when pretreating olive tree biomass at 180 °C and 1% sulphuric Acid concentration, representing 75% of all sugars in the raw material. Dilute Acid Pretreatment improves results compared to water Pretreatment.
Michael E Himmel - One of the best experts on this subject based on the ideXlab platform.
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Chemical and Structural Effects on the Rate of Xylan Hydrolysis during Dilute Acid Pretreatment of Poplar Wood
2019Co-Authors: Ashutosh Mittal, Bryon S Donohoe, Michael E Himmel, Heidi M. Pilath, Yves Parent, Siddharth G. Chatterjee, John M. Yarbrough, Stuart K. Black, Mark R. Nimlos, David K JohnsonAbstract:Economic biofuel production requires high sugar yields during biomass Pretreatment, however, the chemical and structural features of biomass can be obstructive toward efficient xylose hydrolysis. Here, we tested the hindrance imposed by the multiscale structure of biomass on the hydrolysis of xylan during dilute Acid Pretreatment by studying the effects of both the chemical nature of xylan and physical structure of biomass. Dilute Acid Pretreatment of poplar wood at particle sizes ranging from 10 μm to 10 mm was conducted, however, no significant differences in the rates of xylan hydrolysis were observed over more than 2 orders of magnitude in particle size. A significant reduction in the rate of xylan hydrolysis was observed when compared to the intrinsic rate of hydrolysis for isolated xylan. Thus, it appears likely that the chemical structure of xylan and/or the interaction of xylan with other polymers in the cell wall matrix have greater effects on xylan hydrolysis rates than mass transfer limitations
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elucidating the role of ferrous ion cocatalyst in enhancing dilute Acid Pretreatment of lignocellulosic biomass
Biotechnology for Biofuels, 2011Co-Authors: Hui Wei, Bryon S Donohoe, Todd B Vinzant, Peter N Ciesielski, Weiwei Wang, L M Gedvilas, Yining Zeng, David K Johnson, Shi You Ding, Michael E HimmelAbstract:Background Recently developed iron cocatalyst enhancement of dilute Acid Pretreatment of biomass is a promising approach for enhancing sugar release from recalcitrant lignocellulosic biomass. However, very little is known about the underlying mechanisms of this enhancement. In the current study, our aim was to identify several essential factors that contribute to ferrous ion-enhanced efficiency during dilute Acid Pretreatment of biomass and to initiate the investigation of the mechanisms that result in this enhancement.
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Redistribution of xylan in maize cell walls during dilute Acid Pretreatment.
Biotechnology and bioengineering, 2009Co-Authors: Roman Brunecky, Bryon S Donohoe, Todd B Vinzant, David K Johnson, Stephanie E. Porter, Michael E HimmelAbstract:Developing processes for the conversion of biomass for use in transportation fuels production is becoming a critically important economic and engineering challenge. Dilute Acid Pretreatment is a promising technology for increasing the enzymatic digestibility of lignocellulosic biomass. However, a deeper understanding of the pretreatability of biomass is needed so that the rate of formation and yields of sugars can be increased. Xylan is an important hemicellulosic component of the plant cell wall and acts as a barrier to cellulose, essentially blocking cellulase action. To better understand xylan hydrolysis in corn stover, we have studied changes in the distribution of xylan caused by dilute Acid Pretreatment using correlative microscopy. A dramatic loss of xylan antibody signal from the center of the cell wall and an increase or retention of xylan at the plasma membrane interface and middle lamella of the cell were observed by confocal laser scanning microscopy (CLSM). We also observed a reduction in xylan fluorescence signal by CLSM that is generally consistent with the decrease in xylan content measured experimentally in the bulk sample, however, the compartmentalization of this xylan retention was not anticipated.
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Dilute sulfuric Acid Pretreatment of hardwood bark
Bioresource Technology, 1991Co-Authors: R. Torget, Michael E Himmel, Karel GrohmannAbstract:Abstract Bark constitutes a significant portion of total tree biomass. Its removal from tree stems and whole tree chips requires special equipment and increases energy consumption in chemomechanical Pretreatments needed for efficient enzymatic hydrolysis of cellulose to sugars. Since the utilization of bark for biological conversion could also increase the supply of sugar from tree biomass over that available from wood alone, we have undertaken a preliminary investigation of dilute Acid Pretreatment for four barks from hardwood trees. The results indicate that bark from three poplar trees (aspen and two poplar hybrids) is susceptible to dilute Acid Pretreatment. However, the bark from sweetgum ( Liquidambar styraciflua ) was unresponsive and high levels of enzymatic digestibility of cellulose were not observed either before or after Pretreatment of this bark.
Shuichi Sugita - One of the best experts on this subject based on the ideXlab platform.
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study on the pozzolanic properties of rice husk ash by hydrochloric Acid Pretreatment
Cement and Concrete Research, 2004Co-Authors: Qingge Feng, Hirohito Yamamichi, Masami Shoya, Shuichi SugitaAbstract:The pozzolanic properties of rice husk ash by hydrochloric Acid Pretreatment are reported in the paper. Three methods have been used to estimate the pozzolanic activity of rice husk ash. The heat evolution and the hydration heat of cement, the Ca(OH)2 content in the mortar and the pore size distribution of mortar are determined. It is shown that compare with the rice husk ash heated untreated rice husk, the sensitivity of pozzolanic activity of the rice husk ash heated hydrochloric Acid Pretreatment rice husk to burning conditions is reduced. The pozzolanic activity of rice husk ash by Pretreatment is not only stabilized but also enhanced obviously. The kinetics of reaction of rice husk ash with lime is consistent with diffusion control and can be represented by the Jander diffusion equation. A significant increase in the strength of the rice husk ash (pretreated) specimen is observed. The results of heat evolution indicate that the rice husk ash by Pretreatment shows the behavior in the increase of hydration of cement. The cement mortar added with the rice husk ash by Pretreatment has lower Ca(OH)2 content after 7 days and the pore size distribution of the mortar with the rice husk ash with Pretreatment shows a tendency to shift towards the smaller pore size.
Thulluri Chiranjeevi - One of the best experts on this subject based on the ideXlab platform.
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Assisted Single-Step Acid Pretreatment Process for Enhanced Delignification of Rice Straw for Bioethanol Production
ACS Sustainable Chemistry & Engineering, 2018Co-Authors: Thulluri Chiranjeevi, Anu Jose Mattam, Kusum K. Vishwakarma, Addepally Uma, V.c. Rao Peddy, Sriganesh Gandham, Harshad VelankarAbstract:Dilute Acid Pretreatment of lignocellulosic biomass at higher temperatures (>160 °C) solubilizes/removes hemicelluloses (xylan, arabinan, mannan, galactan) and Acid-soluble lignin (ASL), but, it does not remove Acid-insoluble lignin (AIL). During Acid Pretreatment, the condensation and redeposition of coalesced lignin over cellulose fibers reduces the access of cellulose to cellulases. For higher delignification, various multistage Pretreatments are available, however, all these are energy/chemical intensive methods. Therefore, an effective Pretreatment which provides increased cellulose accessibility by enhanced removal of hemicelluloses and lignin in a single-step would be preferred. Our investigation reports a novel assisted single-step Acid Pretreatment (ASAP) process for enhanced delignification of biomass under Acidic conditions. Pretreatment of rice straw (particle size of 20 mm) with H2SO4 (0.75% v/v) + boric Acid (1% w/v) + glycerol (0.5% v/v) (solid/liquid (S/L), 1:5) at 150 °C for 20 min remove...
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Assisted Single-Step Acid Pretreatment Process for Enhanced Delignification of Rice Straw for Bioethanol Production
2018Co-Authors: Thulluri Chiranjeevi, Anu Jose Mattam, Kusum K. Vishwakarma, Addepally Uma, V.c. Rao Peddy, Sriganesh Gandham, Harshad VelankarAbstract:Dilute Acid Pretreatment of lignocellulosic biomass at higher temperatures (>160 °C) solubilizes/removes hemicelluloses (xylan, arabinan, mannan, galactan) and Acid-soluble lignin (ASL), but, it does not remove Acid-insoluble lignin (AIL). During Acid Pretreatment, the condensation and redeposition of coalesced lignin over cellulose fibers reduces the access of cellulose to cellulases. For higher delignification, various multistage Pretreatments are available, however, all these are energy/chemical intensive methods. Therefore, an effective Pretreatment which provides increased cellulose accessibility by enhanced removal of hemicelluloses and lignin in a single-step would be preferred. Our investigation reports a novel assisted single-step Acid Pretreatment (ASAP) process for enhanced delignification of biomass under Acidic conditions. Pretreatment of rice straw (particle size of 20 mm) with H2SO4 (0.75% v/v) + boric Acid (1% w/v) + glycerol (0.5% v/v) (solid/liquid (S/L), 1:5) at 150 °C for 20 min removed hemicelluloses completely, 44% of the lignin, and ∼48.5% of the silica leaving a solid consisting of 69 ± 1.5% glucan, 0.7 ± 0.06% ASL, 20 ± 2.0% AIL, and 12 ± 1.5% silica. The C/L (cellulose/lignin) ratio of solids resulted from ASAP was found to be > 3.00, while it was < 2.00 for Acid only and untreated solids. Enzymatic hydrolysis of ASAP treated biomass with enzyme loadings of 20 FPU g–1 at 15% (w/v) solids concentration gave about 72% glucan conversion to glucose. This amount of glucose was around 2.6 times higher than obtained with enzymatic hydrolysis of Acid-only-pretreated solids and 4.2 times higher than untreated rice straw (control). Therefore, the assisted-Acid Pretreatment dramatically enhanced delignification of rice straw and thereby glucan-to-glucose conversion
