scholarly journals Effect of Lignocellulose-Derived Inhibitors on Growth of and Ethanol Production by Growth-Arrested Corynebacterium glutamicum R

2007 ◽  
Vol 73 (7) ◽  
pp. 2349-2353 ◽  
Author(s):  
Shinsuke Sakai ◽  
Yoshiki Tsuchida ◽  
Shohei Okino ◽  
Osamu Ichihashi ◽  
Hideo Kawaguchi ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Organic Acids ◽  
Ethanol Production ◽  
Corynebacterium Glutamicum ◽  
Cellulosic Ethanol ◽  
Ethanol Productivity ◽  
Fermentation Inhibitors

ABSTRACT In cellulosic ethanol production, pretreatment of a biomass to facilitate enzymatic hydrolysis inevitably yields fermentation inhibitors such as organic acids, furans, and phenols. With representative inhibitors included in the medium at various concentrations, individually or in various combinations, ethanol production by Corynebacterium glutamicum R under growth-arrested conditions was investigated. In the presence of various inhibitors, the 62 to 100% ethanol productivity retained by the C. glutamicum R-dependent method far exceeded that retained by previously reported methods.

scholarly journals Techno-Economic Implications of Fed-Batch Enzymatic Hydrolysis

Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 847 ◽  
Author(s):  
Ellen Argo ◽  
Deepak R. Keshwani
Keyword(s):  
Enzymatic Hydrolysis ◽  
Ethanol Production ◽  
Process Simulation ◽  
Cellulosic Ethanol ◽  
Production Cost ◽  
Simulation Software ◽  
Labor Costs ◽  
Fed Batch ◽  
Capital Costs ◽  
Plant Capacity

Fed-batch enzymatic hydrolysis has the potential to improve the overall process of converting cellulosic biomass into ethanol. This paper utilizes a process simulation approach to identify and quantify techno-economic differences between batch and fed-batch enzymatic hydrolysis in cellulosic ethanol production. The entire process of converting corn stover into ethanol was simulated using SuperPro Designer simulation software. The analysis was conducted for a plant capacity of 2000 metric tons of dry biomass per day. A literature review was used to identify baseline parameters for the process. The sensitivity of the ethanol production cost to changes in sugar conversion efficiency, plant capacity, biomass cost, power cost, labor cost, and enzyme cost was evaluated using the process simulation. For the base scenario, the ethanol unit production cost was approximately $0.10/gallon lower for fed-batch hydrolysis. The greatest differences were seen in facilities costs, labor costs, and capital costs. Using a fed-batch operation decreased facilities costs by 41%, labor costs by 21%, and capital costs by 15%. The sensitivity analysis found that cost of biomass had the greatest effect on ethanol production cost, and in general, the results support the proposition that fed-batch enzymatic hydrolysis does improve the techno-economics of cellulosic ethanol production.

Strategies for the Cellulosic Ethanol Production by Using High-Concentration Poly(ethylene glycol) in the Pretreatment, Enzymatic Hydrolysis, and Fermentation Steps

2021 ◽  
Author(s):  
Cleitiane da Costa Nogueira ◽  
Carlos Eduardo de Araújo Padilha ◽  
Alexande de Araújo Gilherme ◽  
Domingos Fabiano Santana de Souza ◽  
Jackson Araújo de Oliveira ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Ethylene Glycol ◽  
Ethanol Production ◽  
Cellulosic Ethanol ◽  
Poly Ethylene Glycol ◽  
High Concentration ◽  
Poly Ethylene

Comparison of Low-Temperature Alkali/Urea Pretreatments for Ethanol Production from Wheat Straw

2021 ◽  
Vol 15 (3) ◽  
pp. 399-407
Author(s):  
Zahoor ◽  
Wen Wang ◽  
Xuesong Tan ◽  
Qiang Yu ◽  
Yongming Sun ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Enzymatic Hydrolysis ◽  
Low Temperature ◽  
Ethanol Production ◽  
Wheat Straw ◽  
Response Surface ◽  
Cellulosic Ethanol ◽  
Enzymatic Saccharification ◽  
Hydrolysis Of ◽  
Bioethanol Yield

NaOH/urea (NU) pretreatment at lower than 0 °C has been frequently applied for improving bio-conversion of lignocellulose, but the wastewater generated from the pretreatment process is hard to dispose. KOH/urea (KU) pretreatment for enhancing bioconversion of lignocellulose has recently attracted researchers’ attention due to the recycling of wastewater for facilitating crops’ growth. This study compared the effects of NU and KU pretreatments at cold conditions on the enzymatic hydrolysis and bioethanol yield from wheat straw (WS). By using response surface methodology an optimal pretreatment with an equal ratio of alkali/urea (4% w/v) at −20 °C for 3 h was established. The enzymatic hydrolysis of KU-treated WS was 81.17%, which was similar to that of NU-treated WS (83.72%) under the same condition. It means that KU pretreatment has equal ability to NU pretreatment to improve enzymatic saccharification of lignocellulose. KU pretreatment has the promising potential to replace NU pretreatment for facilitating bioconversion of lignocellulose in cold conditions due to the clean way to recycle its wastewater as fertilizer for crop growth. Hence, KU pretreatment combined with enzymatic hydrolysis and fermentation could be a promising green way to cellulosic ethanol production with zero waste emission.

Use of ionic liquids for improvement of cellulosic ethanol production

BioResources ◽  
2010 ◽  
Vol 6 (1) ◽  
pp. 1-2
Author(s):  
Qijun Wang ◽  
Yuanxin Wu ◽  
Shengdong Zhu
Keyword(s):  
Ionic Liquids ◽  
Enzymatic Hydrolysis ◽  
Ethanol Production ◽  
Lignocellulosic Biomass ◽  
Cellulosic Ethanol ◽  
Heterogeneous Reaction ◽  
Reaction System ◽  
The Other ◽  
Fermentable Sugars ◽  
Hydrolysis Process

Cellulosic ethanol production has drawn much attention in recent years. However, there remain significant technical challenges before such production can be considered as economically feasible at an industrial scale. Among them, the efficient conversion of carbohydrates in lignocellulosic biomass into fermentable sugars is one of the most challenging technical difficulties in cellulosic ethanol production. Use of ionic liquids has opened new avenues to solve this problem by two different pathways. One is pretreatment of lignocellulosic biomass using ionic liquids to increase its enzymatic hydrolysis efficiency. The other is to transform the hydrolysis process of lignocellulosic biomass from a heterogeneous reaction system to a homogeneous one by dissolving it into ionic liquids, thus improving its hydrolysis efficiency.

scholarly journals Microwave-assisted hydrotropic pretreatment as a new and highly efficient way to cellulosic ethanol production from maize distillery stillage

2021 ◽  
Author(s):  
Mikulski Dawid ◽  
Kłosowski Grzegorz
Keyword(s):  
Ethanol Production ◽  
Cellulosic Ethanol ◽  
Enzymatic Degradation ◽  
Ethanol Concentration ◽  
Process Conditions ◽  
Fermentation Inhibitors ◽  
Microwave Assisted ◽  
Theoretical Yield ◽  
High Level ◽  
Very High

Abstract Aim of the study was to assess the suitability of the combined use of microwave radiation and sodium cumene sulfonate under optimized process conditions for the preparation of maize stillage biomass as a raw material for the production of cellulosic ethanol. The key parameter guaranteeing a high level of lignin removal from biomass (ca. 44%) was concentration of hydrotrope. Even at high biomass concentration (16% w/v) and a cellulase enzyme dose of about 4 filter-paper units/g, maize stillage biomass subjected to microwave-assisted hydrotropic pretreatment was highly susceptible to enzymatic degradation, which resulted in 80% hydrolysis yield. It is possible to obtain a fermentation medium with a very high glucose concentration (up to 80 g/L), without fermentation inhibitors and, as a consequence, to reach a very high level of sugar conversion to ethanol (concentration above 40 g/L), even as much as 95% of theoretical yield. Microwave hydrotropic treatment with sodium cumene sulfonate is a very effective way to prepare waste maize stillage biomass for the production of cellulosic ethanol. The degradation of the lignocellulose structure by the simultaneous use of microwaves and hydrotropes ensured a high degree of conversion of structural polysaccharides to bioethanol. The method provides a high level of enzymatic degradation of cellulose, leading to a medium with high content of released sugars suitable for bioconversion, which is in line with assumptions of the second-generation ethanol production technology. Key points • Microwave-assisted hydrotropic pretreatment is a new way to cellulosic ethanol production. • Microwave-assisted hydrotropic delignification removes 44% of lignin from biomass. • No fermentation inhibitors are obtained after microwave-assisted hydrotropic pretreatment. • High ethanol concentration (above 40 g/L) and fermentation yield (95% of theoretical yield) from biomass after microwave-assisted hydrotropic pretreatment.

scholarly journals Microwave-assisted hydrotropic pretreatment as a new and highly efficient way to cellulosic ethanol production from maize distillery stillage

2020 ◽  
Author(s):  
Mikulski Dawid ◽  
Grzegorz Kłosowski
Keyword(s):  
Ethanol Production ◽  
Production Technology ◽  
Cellulosic Ethanol ◽  
Enzymatic Degradation ◽  
Raw Material ◽  
Fermentation Inhibitors ◽  
Microwave Assisted ◽  
High Level ◽  
Very High ◽  
Second Generation Ethanol

Abstract Background: The development of the second generation ethanol production technology requires new, highly effective methods of pretreatment of lignocellulosic biomass, which reduces lignin content, eliminates fermentation inhibitors, and makes the biomass susceptible to hydrolysis using cellulolytic enzymes. New pretreatment methods should be adapted to the processing of lignocellulosic waste biomass from various industries. One of the problems is the management of grain stillage, which is waste from the production of first generation ethanol.Results: The aim of the study was to assess the suitability of the combined use of microwave radiation and sodium cumene sulfonate under optimized process conditions for the preparation of maize stillage biomass as a raw material for the production of cellulosic ethanol. The key parameter guaranteeing a high level of lignin removal from biomass (ca. 44%) was the concentration of hydrotrope. The highest organic matter extraction from biomass (67.00±1.68%) was observed for 20% v/v sodium cumene sulfonate, ca. 117 PSI (microwave heating) and 30 min exposure time. Even at high biomass concentration (16% w/v) and a cellulose enzyme dose of about 4 FPU/g, maize stillage biomass subjected to microwave-assisted hydrotropic pretreatment was highly susceptible to enzymatic degradation, which resulted in 80% hydrolysis yield. The stillage biomass processed in this way is a very good raw material for the production of cellulosic ethanol. It is possible to obtain a fermentation medium with a very high glucose concentration (up to 80 g/L), without fermentation inhibitors (such as 5-HMF, furfural, lignin degradation products) and, as a consequence, to reach a very high level of sugar conversion to ethanol, even as much as 95% of theoretical yield.Conclusions: Microwave hydrotropic treatment with sodium cumene sulfonate is a very effective way to prepare waste maize stillage biomass for the production of cellulosic ethanol. The method provides a high level of enzymatic degradation of cellulose, leading to a medium with high content of released sugars suitable for bioconversion, which is in line with the assumptions of the second generation ethanol production technology.

scholarly journals Efficient hydrolysis and ethanol production from rice straw by pretreatment with organic acids and effluent of biogas plant

RSC Advances ◽  
2017 ◽  
Vol 7 (80) ◽  
pp. 50537-50545 ◽  
Author(s):  
Forough Momayez ◽  
Keikhosro Karimi ◽  
Shiva Karimi ◽  
Ilona Sárvári Horváth
Keyword(s):  
Enzymatic Hydrolysis ◽  
Organic Acids ◽  
Ethanol Production ◽  
Propionic Acid ◽  
Rice Straw ◽  
Biogas Plant

Effects of biogas effluent and its organic ingredients, i.e., acetic, butyric, lactic, and propionic acid, for the pretreatment of rice straw on enzymatic hydrolysis and ethanol production was studied.

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