• Advances in Energy Research
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• v.4 no.1
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• pp.69-86
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• 2016

The quest to reduce the level of overdependence on fossil fuel product and to provide all required information on proven existing alternatives for renewable energy has resulted into rapid growth of research globally to identify efficient alternative renewable energy sources and the process technologies that are sustainable and environmentally friendly. The present study is aimed at production and characterization of bioethanol produced from sugarcane juice using a $2^4$ factorial design investigating the effect of four parameters (reaction temperature, time, concentration of bacteria used and amount of substrate). The optimum bioethanol yield of 19.3% was achieved at a reaction temperature of $30^{\circ}C$, time of 72 hours, yeast concentration of 2 g and 300 g concentration of substrate (sugarcane juice). The result of statistical analysis of variance shows that the concentration of yeast had the highest effect of 7.325 and % contribution of 82.72% while the substrate concentration had the lowest effect and % contribution of -0.25 and 0.096% respectively. The bioethanol produced was then characterized for some fuel properties such as flash point, specific gravity, cloud point, pour point, sulphur content, acidity, density and kinematic viscosity. The results of bioethanol characterization conform to American society for testing and materials (ASTM) standard. Hence, sugarcane juice is a good and sustainable feedstock for bioethanol production in Nigeria owing relative abundance, cheap source of supply and available land for large scale production.

• Economic and Environmental Geology
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• v.45 no.5
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• pp.589-597
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• 2012

Recently, an understanding of new sources of liquid hydrocarbons such as bioethanol is economically very important. Bioethanol is actually ethyl alcohol or also referred to as ethanol, identical to drinking alcohol by its composition. There are mainly two ways of producing ethanol, namely by synthesis of hydrocarbons and from biomass. Only the second approach deserves the terminology 'bioethanol'. The present dissertation is also designed with purpose of developing the energy-saving process for the separation of bioethanol. The world population is expected to grow past 8 billion by 2030 which are almost 60% in Asia Pacific. History has shown that energy use rises much faster than population expands. World wide demand for energy will increase significantly during the next 15 years driven by population growth and the transition of emerging markets into the global economy. In developing nations, a smaller increment in GDP per capita yields a higher increment in energy consumption compared to developed countries. In this study, we analised total 2,454 dissertations for the bioethanol during the 2001~2012 periods by the programs of 'web of science' and 'recently developped program by Korea Institute of Science Technology Information'.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1460-1471
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• 2013

Microalgal biofuel production from wastewater has economic and environmental advantages. This article investigates the lipid production from high chemical oxygen demand (COD) bioethanol wastewater without dilution or additional nutrients, using a newly isolated heterotrophic microalga, Chlorella vulgaris LAM-Q. To enhance lipid accumulation, the combined effects of important operational parameters were studied via response surface methodology. The optimal conditions were found to be temperature of $22.8^{\circ}C$, initial pH of 6.7, and inoculum density of $1.2{\times}10^8cells/ml$. Under these conditions, the lipid productivity reached 195.96 mg/l/d, which was markedly higher than previously reported values in similar systems. According to the fatty acid composition, the obtained lipids were suitable feedstock for biodiesel production. Meanwhile, 61.40% of COD, 51.24% of total nitrogen, and 58.76% of total phosphorus were removed from the bioethanol wastewater during microalgal growth. In addition, 19.17% of the energy contained in the wastewater was transferred to the microalgal biomass in the fermentation process. These findings suggest that C. vulgaris LAM-Q can efficiently produce lipids from high-concentration bioethanol wastewater, and simultaneously performs wastewater treatment.

• KSBB Journal
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• v.26 no.5
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• pp.417-421
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• 2011

Because beverage waste contains a lot of sugar, it can be used as a valuable resource for energy. But beverage waste is discharged through the water treatment. To prevent the waste of the energy resource, we produced bioethanol by using beverage waste in this study. In order to produce bioethanol, we added distillers stillage and NaOH for fermentation condition (nutrients and pH adjustment). As a results, ethanol concentration was 5.92 vol%. In contrast, ethanol concentration of blank (not added nutrients) was low and fermentation rate was very slow. Because components of the distillers stillage help the yeast growth, fermentation yield and rate was improved. Finally, we operated distillation and dehydration process by using fermented mash and produced fuel bioethanol (more than 99.5 wt%). We think that this results may provide useful information with application of commercial ethanol production using beverage waste.

• Journal of Microbiology and Biotechnology
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• v.29 no.6
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• pp.905-912
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• 2019

Bioethanol has attracted much attention in recent decades as a sustainable and environmentally friendly alternative energy source. In this study, we compared the production of bioethanol by Candida molischiana and Saccharomyces cerevisiae at different initial concentrations of cellobiose and glucose. The results showed that C. molischiana can utilize both glucose and cellobiose, whereas S. cerevisiae can only utilize glucose. The ethanol yields were 43-51% from different initial concentrations of carbon source. In addition, different concentrations of microcrystalline cellulose (Avicel) were directly converted to ethanol by a combination of Trichoderma reesei and two yeasts. Cellulose was first hydrolyzed by a fully enzymatic saccharification process using T. reesei cellulases, and the reducing sugars and glucose produced during the process were further used as carbon source for bioethanol production by C. molischiana or S. cerevisiae. Sequential culture of T. reesei and two yeasts revealed that C. molischiana was more efficient for bioconversion of sugars to ethanol than S. cerevisiae. When 20 g/l Avicel was used as a carbon source, the maximum reducing sugar, glucose, and ethanol yields were 42%, 26%, and 20%, respectively. The maximum concentrations of reducing sugar, glucose, and ethanol were 10.9, 8.57, and 5.95 g/l, respectively, at 120 h by the combination of T. reesei and C. molischiana from 50 g/l Avicel.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.6
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• pp.648-653
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• 2018

Bran of barley causes high viscosity in bioethanol production due to the large amount of ${\beta}$-glucans and fiber. High viscosity is the main cause of decreased productivity and decreased facility efficiency in ethanol production. In order to prevent high viscosity, this study investigated the possibility of bioethanol from barley by debranning. As a result, it was able to reduced the viscosity (22.8 cP to 17.5 cP). And the fermentation speed and yield were improved as the activity of the enzyme and activity of yeast was also increased was improved due to the removal of non-fermentable components. In conclusion, debranning was advantageous in two ways. Firstly, bran removal increased the starch content of the feedstock and decreased viscosity of mash, improving ethanol fermentation. Secondly, by-products produced by debranning can use valuable products. It was remarkable results to the feasibility of bioethanol production from debranned barley.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.6
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• pp.697-703
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• 2017

This study investigated the high-efficient process for bioethanol from barley by various condition. First, higher concentrations of ethanol could be produced without loss of yield by using reducing water consumption. This is because it could prevent to increase viscosity despite reducing water consumption. Second, the ethanol yield could be improved by using reducing particle size of biomass (increase of enzyme reactive surface). Third, The addition of protease could have a considerable effect on yield of fermentation, which provides nutrients to the yeast. This results showed that bioethanol production would provide efficient ethanol production and lower production costs.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.548-548
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• 2006

• Journal of Microbiology and Biotechnology
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• v.27 no.6
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• pp.1112-1119
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• 2017

The aim of this study was to develop a potential process for bioethanol production from Hydrodictyon reticulatum (HR), a filamentous freshwater alga, using Saccharomyces cerevisiae (KCTC7017). From the sugar solutions prepared by the four different hydrolysis methods, bioethanol production ranged from 11.0 g/100 g dried material (acid hydrolysis) to 22.3 g/100 g dried material (enzymatic hydrolysis, EH). Bioethanol was fermented from a highly concentrated sugar solution obtained by a decompression-mediated (vacuum) enrichment method (VE). As the results, ethanol was more efficiently produced from HR when sugar solutions were concentrated by VE following EH (EH/VE). Using multiple feeding of the sugar solution prepared by EH/VE from HR, ethanol reached up to a concentration of 54.3 g/l, corresponding to 24.9 g/100 g dried material, which attained the economic level of product concentration (approximately 5%). The results indicate that by using HR, it is feasible to establish a bioethanol production process, which is effective for using microalgae as the raw material for ethanol production.

• KSBB Journal
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• v.31 no.1
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• pp.73-78
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• 2016

The aim of this study attempted to verify the possibility of bioethanol production using wasted medium density fiberboard (wMDF). In order to produce bioethanol from wood cellulosic materials must be carried out the process of pretreatment, saccharification, fermentation and distillation. First, the wMDF was pretreated using sodium chlorite and pretreated wMDF was prepared to 8% slurry and then slurry was saccharified with the commercial enzyme (Cellic CTec3). The fermentable sugar and pH of saccharified substrate were about 5.5% glucose and 4.4, respectively. Herein we compared the results of ethanol yield according to the nutrients added or without addition to increase ethanol yield. Ethanol fermentation was finished in about 24 hours, but it was delayed in experimental group without nutrients. Ethanol content and fermentation ratio of the final fermented mash prepared by utilizing jar fermenter was 25.40 g/L and 86.64%, respectively. At this time, the maximum ethanol productivity was confirmed as 1.78 g/Lh (ethanol content 21.38 g/L, 12 h), and the overall ethanol productivity was 1.05 g/Lh (ethanol content 25.27 g/L, 24 h). Using fermented liquid we could produced bioethanol 95.37% by continuous distillator packed with copper element in laboratory scale. These results show that wMDF has a potential valuable for bioethanol production.