scholarly journals Valorisation of bambara and cowpea haulms for bioethanol production

2020 ◽  
Author(s):  
◽  
Somiame Itseme Okuofu
Keyword(s):  
Ethanol Yield ◽  
Promising Result ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Enzymatic Saccharification ◽  
Deep Eutectic Solvents ◽  
Sugar Yield ◽  
Dilute Acid Pretreatment ◽  
Bioethanol Production ◽  
Dilute Acid

Bambara and cowpea are important pulses grown in semi-arid South Africa due to their balanced nutrient profile and drought resilient capacity. The haulm is the lignocellulosic residue obtained after grain harvest and are rich in carbohydrates. However, these haulms are underutilised and under researched. The aim of the study, therefore, was to investigate the potential to valorise bambara haulms (BGH) and cowpea haulms (CH) to bioethanol which is the most promising biofuel with commercial prospects currently. The structural and chemical composition of BGH and CH was elucidated using techniques such as compositional analysis, XRD, FTIR, ICP-AES, and SEM. Results indicated a volatile matter and fixed carbon mass fraction of 77.70% and 13.15% (w/w) in BGH and 76.16% and 16.26% (w/w) in CH respectively. The polysaccharides make up the largest fraction (51%), followed by extractives (> 20%), while the lignin in BGH (12%) and CH (10%) was low. X-ray diffraction pattern showed a higher percentage of amorphous regions in BGH (78%) than CH (56%). CH was then subjected to dilute acid pretreatment (DAP) to enhance biosugar production for bioethanol fermentation. The effects of operational factors for DAP including temperature, time, and acid concentration on sugar yield and inhibitor formation was investigated and optimised using response surface methodology (RSM). The solid recovered after DAP was subjected to prehydrolysis with simultaneous saccharification and fermentation (PSSF). In addition, the pretreatment hydrolysate was detoxified and fermented to ethanol using cocultures of Saccharomyces cerevisiae BY4743 and Scheffersomyces stipitis wild type (PsY633). A total ethanol titre of 15.67 g/L was obtained corresponding to 75% conversion efficiency. On the other hand, BGH was subjected to deep eutectic solvent (DES) pretreatment. Five deep eutectic solvents were prepared and screened for their effectiveness in improving enzymatic sugar yield. This was achieved by pretreating BGH with each DES followed by a 48 h enzymatic saccharification. Choline chloride – lactic acid (ChCl-LA) treatment provided the most promising result and was further optimised by investigating the effect of different temperatures and time on cellulose loss and enzymatic sugar yield. ChCl-LA pretreatment at 100°C for 1 h was observed to be the best condition for maximum sugar recovery. The hydrolysate thus obtained was concentrated and fermented for 72 h with S. cerevisiae BY4743. A maximum ethanol yield of 11.57 g/L was obtained. From the results, it is evident that bambara and cowpea haulm are promising substrates for bioethanol production. Dilute acid hydrolysis was shown to be effective in the pretreatment of CH with over 85% of the theoretical sugar recoverable for conversion to bioethanol. In addition, deep eutectic solvents are effective media for breaking the recalcitrance in BGH to achieve high sugar yield for conversion to bioethanol. However, further studies are required to reduce cellulose loss during pretreatment to improve bioethanol yield.

Intensification of bioethanol production by using Tween 80 to enhance dilute acid pretreatment and enzymatic saccharification of corncob

2018 ◽  
Vol 124 ◽  
pp. 166-176 ◽  
Author(s):  
Eduardo K. Kleingesinds ◽  
Álvaro H.M. José ◽  
Larissa P. Brumano ◽  
Talita Silva-Fernandes ◽  
Durval Rodrigues ◽  
...  
Keyword(s):  
Enzymatic Saccharification ◽  
Tween 80 ◽  
Dilute Acid Pretreatment ◽  
Bioethanol Production ◽  
Dilute Acid ◽  
Acid Pretreatment

Dilute acid pretreatment and enzymatic saccharification of sugarcane tops for bioethanol production

2011 ◽  
Vol 102 (23) ◽  
pp. 10915-10921 ◽  
Author(s):  
Raveendran Sindhu ◽  
Mathiyazhakan Kuttiraja ◽  
Parameswaran Binod ◽  
Kanakambaran Usha Janu ◽  
Rajeev K. Sukumaran ◽  
...  
Keyword(s):  
Enzymatic Saccharification ◽  
Dilute Acid Pretreatment ◽  
Bioethanol Production ◽  
Dilute Acid ◽  
Acid Pretreatment

scholarly journals Effect of Dilute Acid and Alkaline Pretreatment of Typha australis (Typha Grass) for Bioethanol Production

2018 ◽  
pp. 1-6
Author(s):  
Bala, Auwalu ◽  
Farouq, Ahmad Ali ◽  
Ibrahim, Aliyu Dabai ◽  
Muhammad, Chika
Keyword(s):  
Enzymatic Saccharification ◽  
Reducing Sugar ◽  
Hot Water ◽  
Dilute Acid Pretreatment ◽  
Sugar Concentration ◽  
Bioethanol Production ◽  
Dilute Acid ◽  
Liquid Hot Water ◽  
Typha Australis ◽  
Reducing Sugar Concentration

Typha australis (Typha grass) obtained from Kware Lake was used in this research to produce bioethanol. Different pretreatment methods including dilute acid (0.2M H2SO4), dilute alkaline (0.2M NaOH) and liquid hot water pretreatments were used to pretreat the Typha grass sample before enzymatic saccharification for 7 days using Aspergillus niger isolated from soil sediment and the hydrolysate was seeded with Saccharomyces cerevisiae isolated from palm wine to produce bioethanol. HPLC was used to analyze bioethanol product. The result showed that pretreatment with 0.2M H2SO4 removed more hemicelluloses (7.0%) when compared with other pretreatment methods used, but pretreatment with 0.2M NaOH and liquid hot water removed more lignin (14.29%) than dilute acid pretreatment. The highest percentage reducing sugar concentration of 0.58% was obtained from lower part of the sample pretreated with liquid hot water while Typha grass pretreated with 0.2M H2SO4 and 0.2M NaOH produced the highest percentage reducing sugar concentration of 0.32% each from the upper part of the sample. Also, the highest Bioethanol concentration of 2.07% was obtained at day 6 of fermentation from the Typha grass pretreated with liquid hot water while Typha grass pretreated with 0.2M H2SO4 and 0.2M NaOH produced highest Bioethanol concentration of 0.43% and 0.54% respectively. The results indicate that Typha grass can be harnessed for bioethanol production thereby reducing their negative impact on Lakes.

scholarly journals Comparison of Corn Stover Pretreatments with Lewis Acid Catalyzed Choline Chloride, Glycerol and Choline Chloride-Glycerol Deep Eutectic Solvent

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1170
Author(s):  
Yuan Zhu ◽  
Benkun Qi ◽  
Xinquan Liang ◽  
Jianquan Luo ◽  
Yinhua Wan
Keyword(s):  
Corn Stover ◽  
Lewis Acid ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Enzymatic Saccharification ◽  
Glycerol Solution ◽  
Cellulose Conversion ◽  
Biomass Processing ◽  
Acid Catalyzed ◽  
Highly Correlated

Herein, corn stover (CS) was pretreated by less corrosive lewis acid FeCl3 acidified solutions of neat and aqueous deep eutectic solvent (DES), aqueous ChCl and glycerol at 120 °C for 4 h with single FeCl3 pretreatment as control. It was unexpected that acidified solutions of both ChCl and glycerol were found to be more efficient at removing lignin and xylan, leading to higher enzymatic digestibility of pretreated CS than acidified DES. Comparatively, acidified ChCl solution exhibited better pretreatment performance than acidified glycerol solution. In addition, 20 wt% water in DES dramatically reduced the capability of DES for delignification and xylan removal and subsequent enzymatic cellulose saccharification of pretreated CS. Correlation analysis showed that enzymatic saccharification of pretreated CS was highly correlated to delignification and cellulose crystallinity, but lowly correlated to xylan removal. Recyclability experiments of different acidified pretreatment solutions showed progressive decrease in the pretreatment performance with increasing recycling runs. After four cycles, the smallest decrease in enzymatic cellulose conversion (22.07%) was observed from acidified neat DES pretreatment, while the largest decrease (43.80%) was from acidified ChCl pretreatment. Those findings would provide useful information for biomass processing with ChCl, glycerol and ChCl-glycerol DES.

Toxico-metabolomics study of a deep eutectic solvent comprising choline chloride and urea suggests in vivo toxicity involving oxidative stress and ammonia stress

2021 ◽  
Vol 23 (3) ◽  
pp. 1300-1311 ◽  
Author(s):  
Dasom Jung ◽  
Jae Back Jung ◽  
Seulgi Kang ◽  
Ke Li ◽  
Inseon Hwang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
In Vivo Toxicity ◽  
Metabolomics Study ◽  
Ammonia Stress

The in vitro and in vivo studies suggest that choline chloride-based deep eutectic solvents may not be considered as pure, safe mixtures even if they consist of safe compounds.

scholarly journals Deep Eutectic Solvents Based Choline Chloride for Enzymatic Biodiesel Production from Degumming Palm Oil

2020 ◽  
Vol 32 (4) ◽  
pp. 733-738 ◽  
Author(s):  
R. Manurung ◽  
Taslim ◽  
A.G.A. Siregar
Keyword(s):  
Palm Oil ◽  
Raw Materials ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
Biodiesel Production ◽  
Chloride Salt ◽  
Enzymatic Reactions ◽  
Potential Applications ◽  
Palm Oil Biodiesel

Deep eutectic solvents (DESs) have numerous potential applications as cosolvents. In this study, use of DES as organic solvents for enzymatic biodiesel production from degumming palm oil (DPO) was investigated. Deep eutectic solvent was synthesized using choline chloride salt (ChCl) compounds with glycerol and 1,2-propanediol. Deep eutectic solvent was characterized by viscosity, density, pH and freezing values, which were tested for effectiveness by enzymatic reactions for the production of palm biodiesel with raw materials DPO. Deep eutectic solvent of ChCl and glycerol produced the highest biodiesel yield (98.98%); weight of DES was only 0.5 % of that of the oil. In addition, the use of DES maintained the activity and stability of novozym enzymes, which was assessed as the yield until the 6th usage, which was 95.07 % biodiesel yield compared with the yield without using DES. Hence, using DES, glycerol in enzymatic biodiesel production had high potentiality as an organic solvent for palm oil biodiesel production

Deep eutectic solvent delignification: Impact of initial lignin

BioResources ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. 7301-7310
Author(s):  
Veronika Majová ◽  
Silvia Horanová ◽  
Andrea Škulcová ◽  
Jozef Šima ◽  
Michal Jablonský
Keyword(s):  
Lactic Acid ◽  
Oxalic Acid ◽  
Lignin Content ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
Kappa Number ◽  
Kraft Pulps ◽  
Oxygen Delignification ◽  
Detailed Understanding

This study aimed to resolve the issue of the lack of detailed understanding of the effect of initial lignin content in hardwood kraft pulps on pulp delignification by deep eutectic solvents. The authors used Kappa number of the concerned pulp, intrinsic viscosity, and selectivity and efficiency of delignification as the parameters of the effect. The pulp (50 g oven dry pulp) was treated with four different DESs systems based on choline chloride with lactic acid (1:9), oxalic acid (1:1), malic acid (1:1), and system alanine:lactic acid (1:9); the results were compared to those reached by oxygen delignification. The results showed that the pulp with a higher initial lignin content had a greater fraction of easily removed lignin fragments.

scholarly journals Evaluation of Copper-Contaminated Marginal Land for the Cultivation of Vetiver Grass (Chrysopogon zizanioides) as a Lignocellulosic Feedstock and its Impact on Downstream Bioethanol Production

2019 ◽  
Vol 9 (13) ◽  
pp. 2685 ◽  
Author(s):  
Emily M. Geiger ◽  
Dibyendu Sarkar ◽  
Rupali Datta
Keyword(s):  
Contaminated Soil ◽  
Ethanol Yield ◽  
Dilute Acid Pretreatment ◽  
Cellulose Content ◽  
Bioethanol Production ◽  
Vetiver Grass ◽  
Acid Pretreatment ◽  
Biofuel Feedstock ◽  
Lignocellulosic Feedstock ◽  
The Impact

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.

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