scholarly journals Pretreatment Ethanol From Cellulosic

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Endah Retno Dyartanti ◽  
Margono Margono ◽  
Ike Puji Lestari ◽  
Muhamad Iqbal Putra ◽  
Ulfa Intan Pratiwi
Keyword(s):  
Hot Water ◽  
Dilute Acid Pretreatment ◽  
Process Conditions ◽  
Dilute Acid ◽  
Acid Pretreatment ◽  
Thermal Stabilities ◽  
Cellulose Accessibility ◽  
Ammonia Fiber Explosion ◽  
Hemicellulose Degradation ◽  
Pre Treatment

<p><strong>Abstract.</strong> Pre-treatment is an important tool for practical cellulose conversion processes and can be carried out in different ways such as mechanical pre-treatment, steam explosion, ammonia fiber explosion, supercritical CO2 treatment, alkali or acid pretreatment, ozone pre-treatment, physicochemical pretreatment, dilute-acid pretreatment and biological pre-treatment. Biomass pretreatment with hot water (HW) is the most investigated physicochemical method use the differences in the thermal stabilities of the major components of lignocellulosic materials. Acid pretreatment of lignocellulosic biomass aims at increasing the sugar substrate digestibility, defined as the concentration of reducing sugars after the hydrolysis, by microorganisms. Acid hydrolysis is an attractive pretreatment method as the hemicellulose degradation runs with the efficiency of approximately 20-90%, depending on the process conditions. Dilute acid (DA) processes with continued research and development, no significant breakthroughs have been made to raise the glucose yields much higher than 65-70%. Acid pretreatment is much more effective than water and alkaline pretreatment in terms of cellulose accessibility increase compared with DA and HW pretreatment.</p><p> </p><p><strong>Keywords:</strong> ethanol, cellulosic, pre-treatment</p>

Dilute Acid Pretreatment of Wheat Straw: A Predictive Model for Energy Consumption Using Response Surface Methodology

2013 ◽  
Author(s):  
Xiaoxu Song ◽  
Meng Zhang ◽  
Z. J. Pei ◽  
A. J. Nottingham ◽  
P. F. Zhang
Keyword(s):  
Response Surface Methodology ◽  
Energy Consumption ◽  
Response Surface ◽  
Minimum Energy ◽  
Solid Content ◽  
Dilute Acid Pretreatment ◽  
Process Conditions ◽  
Dilute Acid ◽  
Acid Pretreatment ◽  
Minimum Energy Consumption

Response surface methodology was used to study the effects of parameters namely, time, temperature, and solid content and to optimize the process conditions for the minimum energy consumption in dilute acid pretreatment. Box-Behnken design using response surface methodology was employed. Effects of time and temperature are significant at the significant level of α = 0.05. Longer time and higher temperature result in higher power energy consumption. The best optimal values of the process conditions are time 14–21 min and temperature 129–139 °C.

Hot water and dilute acid pretreatment of high and low specific gravity Populus deltoides clones

2010 ◽  
Vol 38 (2) ◽  
pp. 355-361 ◽  
Author(s):  
Elizabeth M. Martin ◽  
Kris A. Bunnell ◽  
Ching-Shuan Lau ◽  
Matthew H. Pelkki ◽  
David W. Patterson ◽  
...  
Keyword(s):  
Specific Gravity ◽  
Populus Deltoides ◽  
Hot Water ◽  
Dilute Acid Pretreatment ◽  
Dilute Acid ◽  
Acid Pretreatment

scholarly journals Effect of Dilute Acid - Alkaline Pretreatment on Rice Husk Composition and Hydrodynamic Modeling with CFD

2019 ◽  
Vol 4 (1) ◽  
pp. 18
Author(s):  
Novia Novia ◽  
Vishnu K Pareek ◽  
Hermansyah Hermansyah ◽  
Asyeni Miftahul Jannah
Keyword(s):  
Rice Husk ◽  
Lignin Content ◽  
Hydrodynamic Modeling ◽  
Alkaline Pretreatment ◽  
Hot Water ◽  
Dilute Acid Pretreatment ◽  
Cfd Modeling ◽  
Cellulose Content ◽  
Dilute Acid ◽  
Acid Pretreatment

The high cellulosic content of rice husk can be utilized as a feedstock for pulp and biofuel. Pretreatment is necessary to break the bonds in the complex lignocellulose matrices addressing the cellulose access. This work aims to utilize the rice husk using dilute acid and alkaline pretreatment experimentally and CFD modeling. The study consists of three series of research. The first stage was the dilute acid pretreatment with sulfuric acid concentration of 1% to 5% (v/v) at 85°C for 60 minutes, and alkaline pretreatment with NaOH concentration of 1% to 5% (w/v) at 85oC for 30 minutes separately. The second stage used the combination of both pretreatment. Moreover the last stage of research was hydrodynamic modeling of pretreatment process by CFD (ANSYS FLUENT 16). The experimental results showed that the lowest lignin content after acid pretreatment was about 10.74%. Alkaline pretreatment produced the lowest lignin content of 4.35%. The highest cellulose content was 66.75 % for acid-alkaline pretreatment. The lowest content of lignin was about 6.09% for acid-alkaline pretreatment. The lowest performance of alkaline pretreatment on HWS (hot water solubility) of about 7.34% can be enhanced to 9.71% by using a combination alkaline-acid. The combined pretreatments result hemicellulose of about 9.59% (alkaline-acid) and 9.27% (acid-alkaline). Modeling results showed that the mixing area had the minimum pressure of about -6250 Pa which is vortex leading minimum efficiency of mixing. The rice husk flowed upward to the upper level and mixed with reagent in the perfect mixing.  

Effect of freeze storage on hemicellulose degradation and enzymatic hydrolysis by dilute-acid pretreatment of Mongolian oak

Fuel ◽  
2016 ◽  
Vol 165 ◽  
pp. 145-151 ◽  
Author(s):  
Han-Seob Jeong ◽  
Soo-Kyeong Jang ◽  
Ho-Yong Kim ◽  
Hwanmyeong Yeo ◽  
Joon Weon Choi ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Dilute Acid Pretreatment ◽  
Freeze Storage ◽  
Dilute Acid ◽  
Acid Pretreatment ◽  
Hemicellulose Degradation ◽  
Mongolian Oak

scholarly journals Understanding the effects of different residual lignin fractions in acid-pretreated bamboo residues on its enzymatic digestibility

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Wenqian Lin ◽  
Jinlai Yang ◽  
Yayue Zheng ◽  
Caoxing Huang ◽  
Qiang Yong
Keyword(s):  
Enzymatic Hydrolysis ◽  
Negative Impact ◽  
Dilute Acid Pretreatment ◽  
Residual Lignin ◽  
Dilute Acid ◽  
Enzymatic Digestibility ◽  
Acid Pretreatment ◽  
Organic Reagents ◽  
Milled Wood Lignin ◽  
Affinity Constants

Abstract Background During the dilute acid pretreatment process, the resulting pseudo-lignin and lignin droplets deposited on the surface of lignocellulose and inhibit the enzymatic digestibility of cellulose in lignocellulose. However, how these lignins interact with cellulase enzymes and then affect enzymatic hydrolysis is still unknown. In this work, different fractions of surface lignin (SL) obtained from dilute acid-pretreated bamboo residues (DAP-BR) were extracted by various organic reagents and the residual lignin in extracted DAP-BR was obtained by the milled wood lignin (MWL) method. All of the lignin fractions obtained from DAP-BR were used to investigate the mechanism for interaction between lignin and cellulase using surface plasmon resonance (SPR) technology to understand how they affect enzymatic hydrolysis Results The results showed that removing surface lignin significantly decreased the yield for enzymatic hydrolysis DAP-BR from 36.5% to 18.6%. The addition of MWL samples to Avicel inhibited its enzymatic hydrolysis, while different SL samples showed slight increases in enzymatic digestibility. Due to the higher molecular weight and hydrophobicity of MWL samples versus SL samples, a stronger affinity for MWL (KD = 6.8–24.7 nM) was found versus that of SL (KD = 39.4–52.6 nM) by SPR analysis. The affinity constants of all tested lignins exhibited good correlations (r > 0.6) with the effects on enzymatic digestibility of extracted DAP-BR and Avicel. Conclusions This work revealed that the surface lignin on DAP-BR is necessary for maintaining enzyme digestibility levels, and its removal has a negative impact on substrate digestibility.

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