Integrated bioethanol production to boost low-concentrated cellulosic ethanol without sacrificing ethanol yield

2018 ◽  
Vol 250 ◽  
pp. 299-305 ◽  
Author(s):  
Youjie Xu ◽  
Meng Zhang ◽  
Kraig Roozeboom ◽  
Donghai Wang
2021 ◽  
Vol 29 ◽  
pp. 13-19
Author(s):  
R. Y. Blume ◽  
O.V. Melnychuk ◽  
S.P. Ozheredov ◽  
D.B. Rakhmetov ◽  
Y.B. Blume

Aim. Main aim of this research was the evaluation of theoretical bioethanol yield (per ha) from hexaploid giant miscanthus (Miscanthus х giganteus) and further comparison with conventional triploid form as well as with other bioethanol crops. Methods. Several mathematic functions were determined that describe yearly yield dynamics and equations, which were used in calculations of theoretical bioethanol yield. Results. The theoretical bioethanol yield was evaluated for different hexaploid miscanthus lines. The most productive in terms of ethanol yield were lines 108 and 202, from which potential bioethanol yield was found to be higher than in control line (6451 L/ha) by 10.7 % and 14.2% respectively and can reach 7144 L/ha and 7684 L/ha. Conclusions. It was determined that the most productive lines of polyploid miscanthus (lines 108 and 202) are able to compete with other plant cellulosic feedstocks for second-generation bioethanol production in Ukraine. However, these lines show bioethanol productivity than sweet sorghum, in the case when sweet sorghum is processed for obtainment of both first- and second-generation bioethanol. Keywords: bioenergy crops, biofuels, giant miscanthus, Miscanthus, polyploidy, second-generation bioethanol.


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.


2017 ◽  
Vol 39 (5) ◽  
pp. 533
Author(s):  
Cleidiane Samara Murari ◽  
Débora Cristina Moraes Niz da Silva ◽  
Bruna Lima da Silva ◽  
Vanildo Luiz Del Bianchi

The present study aimed the utilization of the cheese whey as substrate for ethanol production by Kluyveromyces marxianus.  Was studied the effect of the initial concentration of cheese whey (M1 57,6 g L-1; M2 45,6 g L-1; M3 32,5 g L-1 e M4 18,8 g L-1) on the alcoholic fermentation. After sterilization, the medium were incubated at 30ºC for 48 hours, performing analysis of lactose, proteins, ethanol, cell growth and chemical oxygen demand. According to the results, the medium M1 (the highest concentration) showed a higher production and productivity of ethanol 16.9 g L-1 and 1.26 g L.h-1, respectively, and also obtained the highest production and productivity of cell of 5.8 g L-1 and 0.40 g L.h-1, respectively. However, in terms of ethanol yield, the most satisfactory result was obtained with the M3 medium with 82.30% in 12 hours of fermentation. The organic substances content has been reduced in relation to COD in the medium M4 in 82.28%, representing a promising alternative for valorization of cheese whey as an effective alternative to obtain a renewable source of biofuel.


2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Ian P. Wood ◽  
Nikolaus Wellner ◽  
Adam Elliston ◽  
David R. Wilson ◽  
Ian Bancroft ◽  
...  

2015 ◽  
Vol 112 (7) ◽  
pp. 2222-2226 ◽  
Author(s):  
Timothy A. Kremer ◽  
Breah LaSarre ◽  
Amanda L. Posto ◽  
James B. McKinlay

A nascent cellulosic ethanol industry is struggling to become cost-competitive against corn ethanol and gasoline. Millions of dollars are spent on nitrogen supplements to make up for the low nitrogen content of the cellulosic feedstock. Here we show for the first time to our knowledge that the ethanol-producing bacterium,Zymomonas mobilis, can use N2gas in lieu of traditional nitrogen supplements. Despite being an electron-intensive process, N2fixation byZ. mobilisdid not divert electrons away from ethanol production, as the ethanol yield was greater than 97% of the theoretical maximum. In a defined medium,Z. mobilisproduced ethanol 50% faster per cell and generated half the unwanted biomass when supplied N2instead of ammonium. In a cellulosic feedstock-derived medium,Z. mobilisachieved a similar cell density and a slightly higher ethanol yield when supplied N2instead of the industrial nitrogen supplement, corn steep liquor. We estimate that N2-utilizingZ. mobiliscould save a cellulosic ethanol production facility more than $1 million/y.


2011 ◽  
Vol 8 (4) ◽  
pp. 1951-1957 ◽  
Author(s):  
G. Sathya Geetha ◽  
A. Navaneetha Gopalakrishnan

The state of art for the bioethanol production from paper fibre residue using diluted alkali hydrolysis and fermentation processes was evaluated. Hydrolysis of paper fibre residue with diluted sodium hydroxide at various time period, temperature and concentration were investigated. The paper fibre residue was pre-steamed, impregnated with diluted NaOH (0 to 25%) and subsequently hydrolyzed in a reactor at temperatures that ranged between 30 to 50oC, for reaction time between 30 minutes to 150 minutes. The highest yield of monosaccharide (indicating the efficient hydrolysis of cellulose and hemi cellulose) was found at a temperature of 35oC for a reaction time of 90 minutes. Fermentability of hemicelluloses hydrolysate was tested using monosaccharide fermenting microorganismPenicillium chrysogenumandSaccharomyces cereviacea. The fermentability of the hydrolysate decreased strongly for hydrolysate produced at temperature higher than 50oC. The ethanol concentration of monosaccharide hydrolysate was found to be 34.06 g/L and the ethanol yield was 0.097 g/g.


2020 ◽  
Author(s):  
◽  
Somiame Itseme Okuofu

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.


2020 ◽  
Author(s):  
S.P. Rakshitha ◽  
K. V. Keerthana ◽  
P. Anjuna ◽  
S.G. Sangam ◽  
K. Sandesh ◽  
...  

Abstract Current technologies for the production of biofuels from various renewable feedstocks have considerably captured vast scientific attention due to the fact that they can be used as an alternative fuels. Bioethanol being one of the most interesting biofuels and due to its positive impact on the environment has been categorised significantly in terms of scientific and technological investments. The aim of this study was to investigate, tubers of Amorphophallus paeoniifolius biomass as a feedstock for bioethanol production. The composition analysis of A.paeoniifolius tubers revealed high carbohydrate content (78.30 ± 0.33%). The feedstock was subjected to physicochemical pretreatment by treating with dilute acid followed by pressure cooking. The pretreatment factors were optimized by CCD using RSM approach. The optimum condition was found to be 1.32%v/v of HCl, 5.83%w/v of Elephant Foot Yam Biomass and 66.84 min of pressure cooking time yielding 45.87 g/L of total sugar. The second order polynomial equation was generated for the saccharification of the biomass and validated with R2 0.89. The fermentation of pretreated biomass in the presence of Saccharomyces cerevisiae MTCC170 yielded 22.12 ± 0.62 g/L of bioethanol at 120 h utilising 92% of initial total sugar. The resultant ethanol yield and productivity was estimated to be 0.51 g/g and 0.30 g/L.h respectively. The Gompertz model equation was applied to experimental data using nonlinear regression with the least square method and the kinetic fermentation parameters such as maximum ethanol concentration (Pm), production rate (rpm) and lag phase (h) were estimated to be Pm =21.90 g/L, rpm =0.57 g/L.h and tL =8.22 h.


2021 ◽  
Vol 55 (5-6) ◽  
pp. 629-635
Author(s):  
AMINA ALLOUACHE ◽  
AZIZA MAJDA ◽  
AHMED ZAID TOUDERT ◽  
ABDELTIF AMRANE ◽  
MERCEDES BALLESTEROS

Nowadays, the use of biofuels has become an unavoidable solution to the depletion of fossil fuels and global warming. The controversy over the use of food crops for the production of the first-generation biofuels and deforestation caused by the second-generation ones has forced the transition to the third generation of biofuels, which avoids the use of arable land and edible products, and does not threaten biodiversity. This generation is based on the marine and freshwater biomass, which has the advantages of being abundant or even invasive, easy to cultivate and having a good energetic potential. Bioethanol production from Ulva lactuca, a local marine macroalgae collected from the west coast of Algiers, was examined in this study. Ulva lactuca showed a good energetic potential due to its carbohydrate-rich content: 9.57% of cellulose, 6.9% of hemicellulose and low lignin content of 5.11%. Ethanol was produced following the separate hydrolysis and fermentation process (SHF), preceded by a thermal acid pretreatment at 120 °C during 15 min. Enzymatic hydrolysis was performed using a commercial cellulase (Celluclast 1.5 L), which saccharified the cellulose contained in the green seaweed, releasing about 85.01% of the total glucose, corresponding to 7.21 g/L after 96 h of enzymatic hydrolysis at pH 5 and 45 °C. About 3.52 g/L of ethanol was produced after 48 h of fermentation using Saccharomyces cerevisiae at 30 °C and pH 5, leading to a high ethanol yield of 0.41 g of ethanol/g of glucose.


Author(s):  
Zane Aunina ◽  
Gatis Bazbauers ◽  
Karlis Valters

Feasibility of Bioethanol Production From Lignocellulosic Biomass The objective of the paper is to discuss the potential of cellulosic ethanol production processes and compare them, to find the most appropriate production method for Latvia's situation, to perform theoretical calculations and to determine the potential ethanol price. In addition, price forecasts for future cellulosic and grain ethanol are compared. A feasibility estimate to determine the price of cellulosic ethanol in Latvia, if production were started in 2010, was made. The grain and cellulosic ethanol price comparison (future forecast) was made through to the year 2018.


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