scholarly journals Insights on Monosaccharides and Bioethanol Production from Sweet Sorghum Stalks Using Dilute Acid Pretreatment

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1486
Author(s):  
Cristian-Teodor Buruiană ◽  
Luminița Georgescu ◽  
Simona-Florina Isticioaia ◽  
Oana Emilia Constantin ◽  
Camelia Vizireanu ◽  
...  

Sweet sorghum is a unique bioenergy crop that produces stalks with fermentable free sugars. The purpose of this study was to evaluate how the production of hemicellulosic saccharides and bioethanol from sweet sorghum stalks (SSS) can be influenced by a dilute sulfuric acid (H2SO4) pretreatment under different isothermal conditions. The bioethanol production from untreated SSS and pretreated solid phases was achieved through the Simultaneous Saccharification and Fermentation (SSF) process. A good SSS fractionation and an extensive hemicellulose hydrolysis into soluble saccharides were obtained, the most abundant hemicellulose-derived compounds present in the pretreated liquid phase being monosaccharides, with up to 17.22 g/L of glucose and 16.64 g/L of xylose in the pretreatments performed with 3% and 1% H2SO4 for 30 min at 134 °C, respectively. The SSF process of untreated SSS allowed a maximum bioethanol concentration of 9.78 g/L, corresponding to a maximum glucan conversion into ethanol of 49.8%. Bioethanol production from untreated SSS led to a higher bioethanol concentration and conversion than in the case of using acid pretreated solid phases obtained under the most severe conditions (with 3% H2SO4 for 30, 60 and 120 min at 134 °C), suggesting that, in the case of this biomass naturally rich in soluble sugars, the acidic pretreatment could negatively influence the fermentative process.

2019 ◽  
Vol 9 (13) ◽  
pp. 2685 ◽  
Author(s):  
Emily M. Geiger ◽  
Dibyendu Sarkar ◽  
Rupali Datta

Metal-contaminated soil could be sustainably used for biofuel feedstock production if the harvested biomass is amenable to bioethanol production. A 60-day greenhouse experiment was performed to evaluate (1) the potential of vetiver grass to phytostabilize soil contaminated with copper (Cu), and (2) the impact of Cu exposure on its lignocellulosic composition and downstream bioethanol production. Dilute acid pretreatment, enzymatic hydrolysis, and fermentation parameters were optimized sequentially for vetiver grass using response surface methodology (RSM). Results indicate that the lignocellulosic composition of vetiver grown on Cu-rich soil was favorably altered with a significant decrease in lignin and increase in hemicellulose and cellulose content. Hydrolysates produced from Cu exposed biomass achieved a significantly greater ethanol yield and volumetric productivity compared to those of the control biomass. Upon pretreatment, the hemicellulosic hydrolysate showed an increase in total sugars per liter by 204.7% of the predicted yield. After fermentation, 110% of the predicted ethanol yield was obtained for the vetiver grown on Cu-contaminated soil. By contrast, for vetiver grown on uncontaminated soil a 62.3% of theoretical ethanol yield was achieved, indicating that vetiver has the potential to serve the dual purpose of phytoremediation and biofuel feedstock generation on contaminated sites.


2016 ◽  
Vol 21 (6) ◽  
pp. 733-742 ◽  
Author(s):  
Hah Young Yoo ◽  
Xiaoguang Yang ◽  
Dong Sup Kim ◽  
Soo Kweon Lee ◽  
Pongtharin Lotrakul ◽  
...  

2019 ◽  
Vol 8 (4) ◽  
pp. 290-301
Author(s):  
Fatima Zahra Zouhair ◽  
Younes En-Nahli ◽  
Mohammed Rachid Kabbour ◽  
Fatima Ebich ◽  
Aouatif Benali ◽  
...  

The present work describes comparative dilute acid pretreatment of the argan pulp (residue produced during the argan oil extraction) used as an economical source for bioethanol production. Response surface methodology was used to optimize the pretreatment process and to explore the effect of operational parameters (acid concentration, temperature, time and biomass loading), depending on the acid type (HCl, H2SO4) and pretreatment approach, on total and reducing sugars recovery, in addition to phenolic compounds rate as inhibitors produced during pretreatment process. Experimental results predict an optimal yield of total and reducing sugars of 171.46 mg/ml and 54.83 mg/ml, respectively, were achieved at an optimized time of 30 min with 7% of sulfuric acid at 160°C using 40 % for biomass loading.


2018 ◽  
Vol 124 ◽  
pp. 166-176 ◽  
Author(s):  
Eduardo K. Kleingesinds ◽  
Álvaro H.M. José ◽  
Larissa P. Brumano ◽  
Talita Silva-Fernandes ◽  
Durval Rodrigues ◽  
...  

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