Feasibility Of Ethanol Production Research Articles

Ethanol production from waste pizza by enzymatic hydrolysis and fermentation

In this work, the feasibility of ethanol production from waste pizza (WP) by enzymatic hydrolysis and fermentation was investigated. The effects of enzyme volumes (0.02-0.08 mL/L) and WP mass ratios (50−160 g/L) on the performance of enzymatic hydrolysis and ethanol fermentation were also examined. It was observed that the lowest enzyme volume (0.02 mL/L) could completely hydrolyze WP with mass ratio of 50 g/L. The reducing sugar (RS) increased obviously with increasing of WP mass ratio from 50 g/L to 160 g/L when the enzyme volume of 0.02 mL/L was applied. The WP hydrolysate was utilized as substrate for bio-ethanol production with the highest cumulative ethanol production of 27.58 g/L and ethanol yield of 0.292 g/g WP, respectively. To our knowledge, this is the first study to report ethanol production from WP by enzymatic hydrolysis and fermentation.

Enhanced ethanol production from lignocellulosic hydrolysates by inhibiting the hydrogen synthesis in Thermoanaerobacterium aotearoense SCUT27(Δldh)

AbstractBACKGROUNDThermophilic anaerobic bacteria have gained increased interest as a desirable biological catalyst for bioethanol production from lignocellulosic biomass. However, by‐products such as lactic acid, acetic acid and hydrogen (H2) not only lead to low ethanol yield but also increase the difficulty of ethanol purification. Considering that ethanol production is dependent on the supply of NADH, blocking or inhibiting lactic acid (by knocking out ldh) and H2 formation should be a reliable strategy to further increase the ethanol production.RESULTSComparative genome analysis indicated that three hydrogenase gene clusters (hyd, ech and hfs) were identified in Thermoanaerobacterium aotearoense SCUT27, and they were proved to be related to H2 production by gene knockout. Deletion of hyd or ech in SCUT27(Δldh) showed a decrease in substrate consumption and ethanol production, while hfsB gene knockout resulted in significant improvement in overall fermentation performance. Compared with SCUT27(Δldh), the ethanol concentration, yield and productivity of SCUT27(Δldh/ΔhfsB) were increased from 25.15 ± 0.45 g L−1, 0.33 ± 0.01 g g−1 and 0.30 ± 0.01 g L−1 h−1 to 39.64 ± 0.16 g L−1, 0.36 ± 0.00 g g−1 and 0.41 ± 0.01 g L−1 h−1 respectively using glucose in fed‐batch fermentation. The enhanced ethanol production was due to the increased NADH supply and alcohol dehydrogenase activity. Finally, the feasibility of ethanol production by SCUT27(Δldh/ΔhfsB) from hydrolysates of soybean hull, wheat straw, corn cob and corn straw was demonstrated.CONCLUSIONKnocking out the ldh and hfsB in SCUT27 is an efficient strategy for diverting carbon flux and NADH towards ethanol production, and the resulting strain SCUT27(Δldh/ΔhfsB) has great potential in the production of ethanol from lignocellulosic hydrolysates. © 2019 Society of Chemical Industry

Opuntia ficus-indica cladodes as feedstock for ethanol production by Kluyveromyces marxianus and Saccharomyces cerevisiae.

The feasibility of ethanol production using an enzymatic hydrolysate of pretreated cladodes of Opuntia ficus-indica (prickly pear cactus) as carbohydrate feedstock was investigated, including a comprehensive chemical analysis of the cladode biomass and the effects of limited aeration on the fermentation profiles and sugar utilization. The low xylose and negligible mannose content of the cladode biomass used in this study suggested that the hemicellulose structure of the O. ficus-indica cladode was atypical of hardwood or softwood hemicelluloses. Separate hydrolysis and fermentation and simultaneous saccharification and fermentation procedures using Kluyveromyces marxianus and Saccharomyces cerevisiae at 40 and 35 °C, respectively, gave similar ethanol yields under non-aerated conditions. In oxygen-limited cultures K. marxianus exhibited almost double the ethanol productivity compared to non-aerated cultures, although after sugar depletion utilization of the produced ethanol was evident. Ethanol concentrations of up to 19.5 and 20.6 g l−1 were obtained with K. marxianus and S. cerevisiae, respectively, representing 66 and 70 % of the theoretical yield on total sugars in the hydrolysate. Because of the low xylan content of the cladode biomass, a yeast capable of xylose fermentation might not be a prerequisite for ethanol production. K. marxianus, therefore, has potential as an alternative to S. cerevisiae for bioethanol production. However, the relatively low concentration of fermentable sugars in the O. ficus-indica cladode hydrolysate presents a technical constraint for commercial exploitation.

Enhanced Enzymatic Hydrolysis of Waste Paper for Ethanol Production Using Separate Saccharification and Fermentation

Ethanol produced from lignocellulosic biomass is a renewable alternative to diminishing petroleum-based liquid fuels. In this study, the feasibility of ethanol production from waste paper using the separate hydrolysis and fermentation (SHF) was investigated. Two types of waste paper materials, newspaper and office paper, were evaluated for their potential to be used as a renewable feedstock for the production of fermentable sugars via enzymatic hydrolysis of their cellulose fractions. Hydrolysis step was conducted with a mixture of cellulolytic enzymes produced locally by Trichoderma reesei Rut-C30 (cellulase-overproducing mutant) and Aspergillus niger F38 cultures. Surfactant pretreatment effect on waste paper enzymatic digestibility was studied and Triton X-100 at 0.5 % (w w(-1)) has improved the digestibility of newspaper about 45 %. The effects of three factors (dry matter quantity, phosphoric acid pretreatment and hydrolysis time) on the extent of saccharification were also assessed and quantified by using a methodical approach based on response surface methodology. Under optimal hydrolysis conditions, maximum degrees of saccharification of newspaper and office paper were 67 and 92 %, respectively. Sugars released from waste paper were subsequently converted into ethanol (0.38 g ethanol g(-1) sugar) with Saccharomyces cerevisiae CTM-30101.

Alternative Fuel from Agricultural Waste

Waste can be minimized by reuse or recover by the process due disposal of the waste is big issue for environment. So many organization are working for to utilized the waste for energy recovery. Field crops offer potential source of fuel, offering promise as large-scale energy and based on its genetic diversity, climatic adaptation, and biomass and sugar production. Lignocellulosic biomass is the most abundant organic raw material in the world. Production of ethanol from renewable lignocellulosic resources may improve energy availability, decrease air pollution and diminish atmospheric CO2 accumulation. Presently this work was to evaluate the feasibility of ethanol production and optimization from Rice husk by using commercial bakery yeast, i.e., S. cereviciae. The experiment was conducted, at fermentation temperature 30 °C and pH 5, and treated using different acid concentrations and residence times. Rice husk was hydrolyzed by refluxing, a solid to liquid ratio of 1:10, using dilute sulfuric acid (1 to 5 %) and distilled water at hydrolysis time of 1 to 11 hours keeping boiling temperature. 90 % maximum total sugar concentration was obtained at 5 h acid free hydrolysis. Based on these hydrolysis results, fermentation process was performed.Â

Economic feasibility of ethanol production from biomass and waste resources via catalytic reaction

An economic evaluation of ethanol (EtOH) production from a thermo-chemical process derived from biomass/waste feedstocks was conducted. The influence of feed amounts, catalytic conversions, and EtOH selling prices was examined as these are the major variables for the economic evaluation of biomass/wastes conversion to EtOH. Among the three feedstock systems of biomass, high-moisture municipal solid waste (MSW), and plastic waste, the plastic waste has far better economic feasibility, with a payback period of 2-5 years at maximum CO conversion (40%) from syngas to ethanol, due to its higher heating value in comparison with biomass and high-moisture MSW. The heating value of the feedstock is a key factor in determining the overall economic efficiency in a thermo-chemical EtOH production system. Furthermore, enhancement of the CO conversion (related to catalytic activity) from syngas to EtOH using a low cost catalyst is necessary to retain economic efficiency because the CO conversion and cost consideration of catalyst are crucial factors to reduce the payback period.

Optimization of ethanol production from thick juice: A response surface methodology approach

The course of fermentation of thick juice as intermediate product of sugar beet processing by yeast Saccharomyces cerevisiae was studied in the paper. The feasibility of ethanol production from thick juice was experimentally confirmed in batch fermentation in a bioreactor of 1.5L working volume. Important parameters for modelling of the process using response surface methodology were defined by analyzing the results of the course of fermentation. For description of the response function of the number of yeast cell number, ethanol volume fraction and total sugar mass fraction during fermentation, the effects of initial sugar content in the range 5–25% w/v and duration of fermentation in the range 0–48h, were examined. Obtained models have contributed to a better understanding of the impact of different initial sugar mass fractions, fermentation time and interactions of these factors on the selected responses. Optimization of multiple responses was also simultaneously performed i.e. maximization of both yeast cell number and ethanol volume fraction while residual total sugar mass fraction was minimized. Results of optimization suggest that the optimal conditions are fermentation time of 46h and initial sugar mass fraction of 20.67%. Further research was performed to validate the obtained results and confirm their applicability in the enlarged scale. The results obtained during the fermentation in bioreactor of 10L working volume under optimal conditions defined for fermentation in the bioreactor of 1.5L working volume were in good correlation.

Feasibility of producing ethanol from food waste

Food waste generated in Korea is rich in carbohydrate as high as 65% of total solids. Using the food waste, the feasibility of ethanol production was investigated in a lab-scale fermentor. Pretreatment with hydrolyzing enzymes including carbohydrase, glucoamylase, cellulase and protease were tested for hydrolysis of food waste. The carbohydrase was able to hydrolyze and produce glucose with a glucose yield of 0.63 g glucose/g total solid. Enzymatic hydrolysis and ethanol fermentation by using carbohydrase and Saccharomyces cerevisiae were conducted in the batch mode. For separated hydrolysis and fermentation (SHF), ethanol concentration reached at the level corresponding to an ethanol yield of 0.43 g ethanol/g total solids. For simultaneous saccharification and fermentation (SSF), the ethanol yield was 0.31 g ethanol/g total solids. During the continuous operation of SHF, the volumetric ethanol production rate was 1.18 g/l h with an ethanol yield of 0.3 g ethanol/g total solids. For SSF process, the volumetric ethanol production rate was 0.8 g/l h with an ethanol yield of 0.2 g ethanol/g total solids.

Ethanol production from acid hydrolysates based on the construction and demolition wood waste using Pichia stipitis

The feasibility of ethanol production from the construction and demolition (C&D) wood waste acid hydrolysates was investigated. The chemical compositions of the classified C&D wood waste were analyzed. Concentrated sulfuric acid hydrolysis was used to obtain the saccharide hydrolysates and the inhibitors in the hydrolysates were also analyzed. The C&D wood waste composed of lumber, plywood, particleboard, and medium density fiberboard (MDF) had polysaccharide (cellulose, xylan, and glucomannan) fractions of 60.7–67.9%. The sugar composition (glucose, xylose, and mannose) of the C&D wood wastes varied according to the type of wood. The additives used in the wood processing did not appear to be released into the saccharide solution under acid hydrolysis. Although some fermentation inhibitors were detected in the hydrolysates, they did not affect the ethanol production by Pichia stipitis. The hexose sugar-based ethanol yield and ethanol yield efficiency were 0.42–0.46 g ethanol/g substrate and 84.7–90.7%, respectively. Therefore, the C&D wood wastes dumped in landfill sites could be used as a raw material feedstock for the production of bioethanol.

Feasibility of ethanol production with enhanced sugar concentration in bagasse hydrolysate at high temperature using Kluyveromyces sp. IIPE453

Background: Ethanol from lignocellulosic biomass and nonfood sources has caught worldwide attention because of its potential use as an alternative automotive fuel. Results: In batch fermentation using Kluyveromyces sp. IIPE453 at 50°C on bagasse hydrolysate containing total fermenting sugar concentration 35 ±1.9 g l-1, the strain could produce ethanol concentration 14.5 ± 0.2 g l-1 with ethanol productivity 0.71 ± 0.001 g l-1 h-1 as compared with sugarcane juice 2 ± 0.04 g l-1 h-1, molasses 2.6 ± 0.05 g l-1 h-1 and mahua flower extract 3.4 ± 0.06 g l-1 h-1. In addition, the fermentation was carried out with enhanced sugar concentration in bagasse hydrolysate by mixing sugarcane juice, molasses and extract of mahua flowers. The ethanol productivities upon mixture of bagasse hydrolysate with sugarcane juice, molasses and extract of mahua flowers were 1.7 ± 0.06 g l-1 h-1, 1.75 ± 0.03 g l-1 h-1 and 2.57 ± 0.1 g l-1 h-1, respectively. Conclusion: The ethanol productivity could be increased by enhancing sugar concentration in bagasse hydrolysate. The product inhibition could be minimized by in situ ethanol recovery at high temperature.

Feasibility of ethanol production from coffee husks

Feasibility of ethanol production from coffee husks

Feasibility of ethanol production from cultivated sugarcane varieties of punjab

Alcohol production potential of six sugarcane varieties of different maturity groups (CoJ 83, CoJ 85, CoJ 82, CoJ 84, CoJ 88 and Col 148) were evaluated in both the plant and ratoon crops at PAU, SRS, Jalandhar, India. CoJ 88 was found to be the best variety having best combination of juice quality (CCS % = 13.42 & 13.85 and alcohol production L/t cane=67.28 & 69.10 ( values of alcohol production from juice are 27 % less than the actual potential of varieties which accounted for processing losses in factory) and yield (85.85 & 66.35 t/ha) which resulted in high potential of sugar and alcohol production per unit area (CCS = 11.52 & 9.19 t/ha and alcohol production = 57.76 & 45.85 hecto L/ha) in plant and ratoon crops respectively. It had good potential for alcohol production throughout the crushing season. On the basis of these studies, it was also concluded that contribution of sucrose content was much higher as compared to reducing sugars towards alcohol production so the strategy for selection of genotypes at various development stages of varieties for high alcohol production would remain same as for high sucrose (white sugar) production.

Operability and feasibility of ethanol production by immobilizedZymomonas mobilis in a fluidized-bed bioreactor

Studies have been carried out using immobilized Z.mobilis in fluidized-bed bioreactors and have emphasized operation during high productivity and conversion. The bacteria are immobilized within small uniform beads (~1 to 1.5-mm diam) of K-carrageenan at cell loadings of 15-50 g (dry wt)/L. Conversion and productivity were measured under a variety of conditions, including feedstocks, flow rates, temperature, pH, and column sizes (up to 2.5 m tall). Volumetric productivities of 50-120 g EtOH/h-L reactor volume have been achieved. Productivities of 60 g/h-L are demonstrated from a 15% feed with residual glucose concentrations of less than 0.1% and 7.4% EtOH in the tallest fermentor. Among feeds of 10, 15, and 20% dextrose, the 15% gave the highest productivity and avoided substrate inhibition. A temperature of 30°C and pH 5 were the optimum conditions. The ethanol yield was shown to be nearly constant at 0.49 g EtOH/g glucose, or 97% of the theoretical under a variety of conditions and transients. The biocatalyst beads have been shown to remain active for two months. Nonsterile feed has been used for weeks without detrimental contamination. The advantages of this advanced bioreactor system over conventional batch technology are discussed.