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Parag R Gogate - One of the best experts on this subject based on the ideXlab platform.
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intensification of Delignification and subsequent hydrolysis for the fermentable sugar production from lignocellulosic biomass using ultrasonic irradiation
Ultrasonics Sonochemistry, 2018Co-Authors: Preeti B Subhedar, Pearl Ray, Parag R GogateAbstract:The present work deals with intensification of Delignification and subsequent enzymatic hydrolysis of sustainable biomass such as groundnut shells, coconut coir and pistachio shells using ultrasound assisted approach so as to develop an economical approach for obtaining bioethanol. Process intensification, in the current context, is referred to as any improvements giving enhanced rates possibly with lower energy and chemical as well as enzyme requirement for Delignification and hydrolysis respectively. Conventional processing for both Delignification and enzymatic hydrolysis has also been investigated for establishing the degree of intensification. The obtained results for Delignification of biomass established that for conventional alkaline treatment, the extent of Delignification for the case of groundnut shells, coconut coir and pistachio shells were 41.8, 45.9 and 38% which increased to 71.1, 89.5 and 78.9% respectively giving almost 80-100% increase for the ultrasound assisted approach. Under optimized conditions, the conventional approach resulted in reducing sugar yields as 10.2, 12.1 and 8.1g/L for groundnut shells, coconut coir and pistachio shells respectively whereas for the case of ultrasound-assisted enzymatic hydrolysis, the obtained yields were 21.3, 23.9 and 18.4g/L in same order of biomass. The material samples were characterized by several characterization techniques for establishing the morphological changes obtained due to the use of ultrasound which were found to be favorable for enhanced Delignification and hydrolysis for the ultrasound assisted approach. Overall, the results of this work establish the process intensification benefits due to the application of ultrasound for different sustainable biomass with mechanistic understanding based on the morphological analyses.
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alkaline and ultrasound assisted alkaline pretreatment for intensification of Delignification process from sustainable raw material
Ultrasonics Sonochemistry, 2014Co-Authors: Preeti B Subhedar, Parag R GogateAbstract:Abstract Alkaline and ultrasound-assisted alkaline pretreatment under mild operating conditions have been investigated for intensification of Delignification. The effect of NaOH concentration, biomass loading, temperature, ultrasonic power and duty cycle on the Delignification has been studied. Most favorable conditions for only alkaline pretreatment were alkali concentration of 1.75 N, solid loading of 0.8% (w/v), temperature of 353 K and pretreatment time of 6 h and under these conditions, 40.2% Delignification was obtained. In case of ultrasound-assisted alkaline approach, most favorable conditions obtained were alkali concentration of 1 N, paper loading of 0.5% (w/v), sonication power of 100 W, duty cycle of 80% and pretreatment time of 70 min and the Delignification obtained in ultrasound-assisted alkaline approach under these conditions was 80%. The material samples were characterized by FTIR, SEM, XRD and TGA technique. The lignin was recovered from solution by precipitation method and was characterized by FTIR, GPC and TGA technique.
Dehua Liu - One of the best experts on this subject based on the ideXlab platform.
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Structural Features of Formiline Pretreated Sugar Cane Bagasse and Their Impact on the Enzymatic Hydrolysis of Cellulose
2016Co-Authors: Xuebing Zhao, Dehua LiuAbstract:Enzymatic digestibility of sugar cane bagasse could be greatly enhanced by Formiline pretreatment, which comprises a formic acid (FA) Delignification followed by an alkaline deformylation. The FA can be easily recovered and recycled for Delignification, indicating that this pretreatment is a green process for biomass fractionation. It was found that removing hemicelluloses and lignin during pretreatment contributed to the increase of cellulose accessibility; however, Delignification seemed to be more important for exposing cellulose fibers. The compact cell wall structure of raw bagasse was destroyed by removing considerable parts of lignin and hemicelluloses with liberation of cellulose fibers, and the specific surface area of the pretreated substrates increased by more than 2-fold. However, formylation of cellulose took place during FA Delignification, which showed significant negative impact on the initial enzymatic hydrolysis rate and enzymatic polysaccharide conversion at 120 h. Removing formyl groups by alkaline post-treatment could well recover the cellulose digestibility but without significant alteration of the substrate structure
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kinetic modeling and mechanisms of acid catalyzed Delignification of sugarcane bagasse by aqueous acetic acid
Bioenergy Research, 2013Co-Authors: Xuebing Zhao, Dehua LiuAbstract:Organosolv pretreatment of lignocellulose pertains to a biomass fractionation process to obtain cellulosic pulp, high-purity lignin, and hemicellulosic syrup. In the present work, sugarcane bagasse was delignified by aqueous acetic acid (AcH) under atmospheric pressure with addition of sulfuric acid (SA) as a catalyst. Based on the multilayered structure of plant cell wall and the inhibitive effect of dissolved lignin on Delignification rate, a novel pseudo-homogeneous kinetic model was proposed by introducing the concept of “potential degree of Delignification (dD)” into the model. It was found that Delignification rate was a first-order reaction with respect to SA concentration, while AcH concentration showed a high reaction order to Delignification rate. The activation energy for Delignification was determined to be 64.41 kJ/mol. The relationships of kinetic constants and dD with reaction temperature, AcH, and SA concentrations were determined according to experimental data. Mechanism analysis indicated that cleavage of α-aryl ethers bonds were mainly responsible for the formation of lignin fragments. AcH concentration affected the solubility parameter (δ value) of AcH solution and the ability to form hydrogen bonds with lignin fragments. Therefore, the driving force for solubilizing lignin fragments increased with AcH concentration, and thus AcH concentration had a very significant influence on Delignification rate.
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fractionating pretreatment of sugarcane bagasse by aqueous formic acid with direct recycle of spent liquor to increase cellulose digestibility the formiline process
Bioresource Technology, 2012Co-Authors: Xuebing Zhao, Dehua LiuAbstract:Abstract A lignocellulose pretreatment process was developed with formic acid Delignification (FAD) followed by alkaline deformylation (AD), which was termed as Formiline process. In FAD, more than 80% of lignin and hemicellulose were removed, but cellulose formylation also happened. Formic acid concentration (FAC) was the most important factor affecting Delignification and cellulose formylation. Increasing FAC could enhance degree of Delignification but also increased cellulose formylation. The presence of formyl group could inhibit the enzymatic hydrolysis of cellulose; however, removing formyl group with a small loading of alkali well recovered cellulose digestibility. The spent liquor could be directly recycled for Delignification thus significantly decreasing energy consumption in solvent recovery. The Formiline-pretreated substrates showed an excellent enzymatic digestibility and could be very well converted to ethanol by simultaneous saccharafication and fermentation (SSF). The final ethanol concentrations were 55.4 and 80.1 g/L respectively at initial solid consistencies of 15% and 20%.
Preeti B Subhedar - One of the best experts on this subject based on the ideXlab platform.
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intensification of Delignification and subsequent hydrolysis for the fermentable sugar production from lignocellulosic biomass using ultrasonic irradiation
Ultrasonics Sonochemistry, 2018Co-Authors: Preeti B Subhedar, Pearl Ray, Parag R GogateAbstract:The present work deals with intensification of Delignification and subsequent enzymatic hydrolysis of sustainable biomass such as groundnut shells, coconut coir and pistachio shells using ultrasound assisted approach so as to develop an economical approach for obtaining bioethanol. Process intensification, in the current context, is referred to as any improvements giving enhanced rates possibly with lower energy and chemical as well as enzyme requirement for Delignification and hydrolysis respectively. Conventional processing for both Delignification and enzymatic hydrolysis has also been investigated for establishing the degree of intensification. The obtained results for Delignification of biomass established that for conventional alkaline treatment, the extent of Delignification for the case of groundnut shells, coconut coir and pistachio shells were 41.8, 45.9 and 38% which increased to 71.1, 89.5 and 78.9% respectively giving almost 80-100% increase for the ultrasound assisted approach. Under optimized conditions, the conventional approach resulted in reducing sugar yields as 10.2, 12.1 and 8.1g/L for groundnut shells, coconut coir and pistachio shells respectively whereas for the case of ultrasound-assisted enzymatic hydrolysis, the obtained yields were 21.3, 23.9 and 18.4g/L in same order of biomass. The material samples were characterized by several characterization techniques for establishing the morphological changes obtained due to the use of ultrasound which were found to be favorable for enhanced Delignification and hydrolysis for the ultrasound assisted approach. Overall, the results of this work establish the process intensification benefits due to the application of ultrasound for different sustainable biomass with mechanistic understanding based on the morphological analyses.
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alkaline and ultrasound assisted alkaline pretreatment for intensification of Delignification process from sustainable raw material
Ultrasonics Sonochemistry, 2014Co-Authors: Preeti B Subhedar, Parag R GogateAbstract:Abstract Alkaline and ultrasound-assisted alkaline pretreatment under mild operating conditions have been investigated for intensification of Delignification. The effect of NaOH concentration, biomass loading, temperature, ultrasonic power and duty cycle on the Delignification has been studied. Most favorable conditions for only alkaline pretreatment were alkali concentration of 1.75 N, solid loading of 0.8% (w/v), temperature of 353 K and pretreatment time of 6 h and under these conditions, 40.2% Delignification was obtained. In case of ultrasound-assisted alkaline approach, most favorable conditions obtained were alkali concentration of 1 N, paper loading of 0.5% (w/v), sonication power of 100 W, duty cycle of 80% and pretreatment time of 70 min and the Delignification obtained in ultrasound-assisted alkaline approach under these conditions was 80%. The material samples were characterized by FTIR, SEM, XRD and TGA technique. The lignin was recovered from solution by precipitation method and was characterized by FTIR, GPC and TGA technique.
Arthur J Ragauskas - One of the best experts on this subject based on the ideXlab platform.
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maximizing enzymatic hydrolysis efficiency of bamboo with a mild ethanol assistant alkaline peroxide pretreatment
Bioresource Technology, 2020Co-Authors: Arthur J Ragauskas, Chen Huang, Guigan Fang, Yang Zhou, Xianzhi Meng, Yongjun Deng, Kuizhong ShenAbstract:Abstract To overcome the Delignification saturation point in traditional alkaline hydrogen peroxide pretreatment (AHP), a powerful modified AHP Delignification methodology was established by introducing ethanol into the system. The pretreatment caused significant lignin removal of bamboo at elevated pretreatment temperature with the highest lignin removal reaching 80.0% at 100 °C, higher than that (74.9% lignin removal) in pretreatment without the ethanol assistance. In addition, a certain amount of carbohydrates was also solubilized during the process whose recovery was 83.3% (glucan) and 67.6% (hemicellulose), respectively. The pretreated solid exhibited excellent enzymatic digestibility, with hydrolysis yields of ~100% and 95.7% for glucan and xylan, respectively. Our studies further indicate that this Delignification methodology is versatile for hardwood and herbaceous plants, but does not perform well on softwood.
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effect of acid chlorite Delignification on cellulose degree of polymerization
Bioresource Technology, 2010Co-Authors: Christopher A Hubbell, Arthur J RagauskasAbstract:Two types of pure cellulose, Avicel PH-101 and Whatman filter paper, were treated with an acid-chlorite Delignification procedure in the presence of varying amounts of incorporated lignin, and the molecular weight distributions and degrees of polymerization (DP) of derivatized cellulose were determined by gel permeation chromatography (GPC). Avicel samples with 0% added lignin showed a DP reduction of nearly 5% during acid-chlorite Delignification, compared to a 1% drop in DP with 30% added lignin. Lignin-free filter paper samples showed a DP reduction of nearly 35% after hollocellulose Delignification. This drop in DP was reduced to less than 12% for samples which contained 30% lignin. Thus, the presence of lignin in biomass samples minimized the DP reduction of cellulose due to acid catalyzed cleavage during acid-chlorite Delignification.
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investigation of laccase n hydroxybenzotriazole Delignification of kraft pulp
Journal of Wood Chemistry and Technology, 1998Co-Authors: James E. Sealey, Arthur J RagauskasAbstract:Abstract N-hydroxybenzotriazole, a mediator for laccase Delignification of kraft pulps, was shown to be unstable under the biobleaching conditions. The treatment of N-hydroxybenzotriazole either with laccase alone or in the presence of kraft pulp yielded benzotriazole. The reductive conversion of N-hydroxybenzotriazole to benzotriazole was found to occur rapidly in the presence of pulp. Furthermore, benzotriazole was found to be inactive as a mediator for laccase catalyzed Delignification of kraft pulps. Hence, the overall conversion of N-hydroxybenzotriazole to benzotriazole is detrimental towards the bio-Delignification process.
Weixin Zhong - One of the best experts on this subject based on the ideXlab platform.
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fungal treatment of cornstalks enhances the Delignification and xylan loss during mild alkaline pretreatment and enzymatic digestibility of glucan
Bioresource Technology, 2010Co-Authors: Hongbo Yu, Wanqing Du, Ji Zhang, Xiaoyu Zhang, Weixin ZhongAbstract:Abstract Fungal treatment with Irpex lacteus was used to enhance the Delignification and xylan loss during mild alkaline pretreatment and subsequent enzymatic conversion in this research. The 15-day bio-treatment can modify the lignin structure and increase losses of lignin (from 75.67% to 80.00%) and xylan (from 40.68% to 51.37%) during alkaline pretreatment, making the enzymatic conversion more efficient. The high digestibility of glucan can be obtained after the bio-treatment and alkaline pretreatment at near room-temperature (30 °C), and the maximum digestibility increased 14% in comparison with that after the sole alkaline pretreatment. The bio-treatment enhanced Delignification and glucan digestibility more significantly when the alkaline pretreatment was performed at lower severity. Additionally, Nuclei Growth model with a time-dependent rate constant can describe well the Delignification and xylan loss. Results indicated that the bio-treatment increased the rate constant of initial reaction, but accelerated the decline of rate constant during alkaline pretreatment.
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fungal treatment of cornstalks enhances the Delignification and xylan loss during mild alkaline pretreatment and enzymatic digestibility of glucan
Bioresource Technology, 2010Co-Authors: Ji Zhang, Xiaoyu Zhang, Weixin ZhongAbstract:Fungal treatment with Irpex lacteus was used to enhance the Delignification and xylan loss during mild alkaline pretreatment and subsequent enzymatic conversion in this research. The 15-day bio-treatment can modify the lignin structure and increase losses of lignin (from 75.67% to 80.00%) and xylan (from 40.68% to 51.37%) during alkaline pretreatment, making the enzymatic conversion more efficient. The high digestibility of glucan can be obtained after the bio-treatment and alkaline pretreatment at near room-temperature (30 degrees C), and the maximum digestibility increased 14% in comparison with that after the sole alkaline pretreatment. The bio-treatment enhanced Delignification and glucan digestibility more significantly when the alkaline pretreatment was performed at lower severity. Additionally, Nuclei Growth model with a time-dependent rate constant can describe well the Delignification and xylan loss. Results indicated that the bio-treatment increased the rate constant of initial reaction, but accelerated the decline of rate constant during alkaline pretreatment.