scholarly journals Impact of particle size reduction on high gravity enzymatic hydrolysis of steam-exploded wheat straw

2021 ◽  
Vol 3 (12) ◽  
Author(s):  
Luis Hoppert ◽  
Daniel Einfalt

AbstractEconomically feasible bioethanol production from lignocellulosic biomass requires solid loadings ≥ 15% dry matter (DM, w/w). However, increased solid loadings can lead to process difficulties, which are characterized by high apparent slurry viscosity, insufficient substrate mixing and limited water availability, resulting in reduced final glucose yields. To overcome these limitations, this study focused on enzymatic hydrolysis of 10–35% DM solid loadings with steam-exploded wheat straw in two different particle sizes. At solid loadings of 20 and 25% DM small particle size of ≤ 2.5 mm yielded 16.9 ± 1.1% and 10.2 ± 1.4% increased final glucose concentrations compared to large particle size of 30 ± 20 mm. Small particle size also positively influenced slurry viscosity and, therefore, miscibility. As a key finding of this investigation, high gravity enzymatic hydrolysis with solid loadings of 30–35% DM was indeed successfully employed when wheat straw was applied in small particle size. Here, the highest final glucose yield was achieved with 127.9 ± 4.9 g L−1 at 35% DM solid loading. An increase in the solid loading from 10 to 35% DM in small particle size experiments resulted in a 460% increase in the final glucose concentration.

2021 ◽  
Author(s):  
Hui Zhang ◽  
Junhui Wu

Abstract To maximize fermentable sugars production, response surface methodology (RSM) was adopted to optimize pretreatment and enzymatic hydrolysis of wheat straw powder (WSP) using the crude cellulases preparation containing xylanases from Aspergillus niger HQ-1. Factors of pretreatment including sodium hydroxide concentration, pretreatment time and temperature were found to have significant effects on sugars production. Results indicated that WSP with particle size 0.3 mm should be pretreated using 1.8% (w/v) sodium hydroxide solution with 25.0% (w/v) of solid loading at 94.0°C for 46.0 min and the optimized pretreatment conditions could result in 90.9% of cellulose recovery, 54.6% of hemicellulose recovery and 72.7% of lignin removal, respectively. Furthermore, variables of enzymatic hydrolysis including enzyme loading, biomass loading and reaction time were proved to have significant effects on sugars yields. After hydrolysis at 50°C for 44.8 h with 7.1% (w/v) of biomass loading, 8.1 FPU/g of enzyme loading and 0.2% (w/v) of Tween-80, maximum yields of reducing sugar (632.92 mg/g) and xylose (149.83 mg/g) could be obtained, respectively. In addition, holocellulose and hemicellulose conversion were 81.6% and 80.0%, respectively. To the best of our knowledge, this is the first report about systematic optimization of sodium hydroxide pretreatment and enzymatic hydrolysis of WSP using RSM.


Author(s):  
Dr. Jambla Neha ◽  
Saroch Vikas ◽  
Johar Smita

Rasashastra deals with the Rasa Aushadhis, the drugs of metallic and mineral origin. Mercury is used in most of the Rasaaushadhis. The toxicity of Mineral and metallic preparations are reduced to such an extent by various procedures of Shodhana, Marana etc. that Mercury converts its inherent property of toxicity into medicinal property. Rasa Aushadhis works quickly on the body because due to their small particle size, their absorption starts from the oral mucosa itself. The action of drugs depends largely upon the Anupana i.e. the vehicle for the drug. Rasacharayas have mentioned various Rasa preparations like Bhasmas, Parpati, Pottali, Manduras, Karpooras etc. along with their doses, dose schedule and Anupana / Sahapana etc. The principles of Rasaaushadhis when correlated in modern era are found to be scientifically accurate. We may say that Rasacharyas had already mastered the science of nanotechnology, purification, action of metabolic catalysts, biotransformation and preservation of medicines. The Ayurvedic drugs can be harmful for our body when not administered in proper dosage as per mentioned in classic literatures.


RSC Advances ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1952-1959
Author(s):  
Yi Zhao ◽  
Fangfang Peng ◽  
Yangchuan Ke

Emulsion with small particle size and good stability stabilized by emulsifiers was successfully prepared for EOR application.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Lin Dai ◽  
Tian Huang ◽  
Kankan Jiang ◽  
Xin Zhou ◽  
Yong Xu

Abstract Background Pretreatment is the key step for utilizing lignocellulosic biomass, which can extract cellulose from lignin and disrupt its recalcitrant crystalline structure to allow much more effective enzymatic hydrolysis; and organic acids pretreatment with dual benefic for generating xylooligosaccharides and boosting enzymatic hydrolysis has been widely used in adding values to lignocellulose materials. In this work, furoic acid, a novel recyclable organic acid as catalyst, was employed to pretreat sugarcane bagasse to recover the xylooligosaccharides fraction from hemicellulose and boost the subsequent cellulose saccharification. Results The FA-assisted hydrolysis of sugarcane bagasse using 3% furoic acid at 170 °C for 15 min resulted in the highest xylooligosaccharides yield of 45.6%; subsequently, 83.1 g/L of glucose was harvested by a fed-batch operation with a solid loading of 15%. Overall, a total of 120 g of xylooligosaccharides and 335 g glucose could be collected from 1000 g sugarcane bagasse starting from the furoic acid pretreatment. Furthermore, furoic acid can be easily recovered by cooling crystallization. Conclusion This work put forward a novel furoic acid pretreatment method to convert sugarcane bagasse into xylooligosaccharides and glucose, which provides a strategy that the sugar and nutraceutical industries can be used to reduce the production cost. The developed process showed that the yields of xylooligosaccharides and byproducts were controllable by shortening the reaction time; meanwhile, the recyclability of furoic acid also can potentially reduce the pretreatment cost and potentially replace the traditional mineral acids pretreatment.


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