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Hydrogen and ethanol production from glycerol-containing wastes discharged after biodiesel manufacturing process

Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Japan.
Journal of Bioscience and Bioengineering (Impact Factor: 1.79). 10/2005; 100(3):260-5. DOI: 10.1263/jbb.100.260
Source: PubMed

ABSTRACT H2 and ethanol production from glycerol-containing wastes discharged after a manufacturing process for biodiesel fuel (biodiesel wastes) using Enterobacter aerogenes HU-101 was evaluated. The biodiesel wastes should be diluted with a synthetic medium to increase the rate of glycerol utilization and the addition of yeast extract and tryptone to the synthetic medium accelerated the production of H2 and ethanol. The yields of H2 and ethanol decreased with an increase in the concentrations of biodiesel wastes and commercially available glycerol (pure glycerol). Furthermore, the rates of H2 and ethanol production from biodiesel wastes were much lower than those at the same concentration of pure glycerol, partially due to a high salt content in the wastes. In continuous culture with a packed-bed reactor using self-immobilized cells, the maximum rate of H2 production from pure glycerol was 80 mmol/l/h yielding ethanol at 0.8 mol/mol-glycerol, while that from biodiesel wastes was only 30 mmol/l/h. However, using porous ceramics as a support material to fix cells in the reactor, the maximum H2 production rate from biodiesel wastes reached 63 mmol/l/h obtaining an ethanol yield of 0.85 mol/mol-glycerol.

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Available from: Yutaka Nakashimada, Jul 21, 2015
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    • "Crude glycerol from biodiesel manufacturing plant may contain up to 25%(w/w) methanol[22] and from different studies it has been concluded that biodiesel waste containing methanol is inhibitory to microbial growth and may be toxic to the environment, if released without proper treatment[23] [24]. Excess methanol present in crude glycerol may contaminate the ground water. "
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    ABSTRACT: Tremendous increase in urbanization leads to the rapid depletion of fossil fuels which results in the search of alternate renewable energy. Amongst various range of alternate sources of renewable energy biodiesel is found to be potential fuel which can satisfy the energy needs. Crude glycerol production was flooded as the result of increase in biodiesel industries around the world; this crude contains various organic and inorganic impurities such as salt, ash, methanol and free fatty acids. This crude is rich in carbon and energy source, which can support microbial growth thereby producing value added bio products. Several studies have been made for the effective utilization of crude glycerol for the production of value added products. The bioconversion of crude glycerol offers safe and more viable biotechnological processes are imposed to produce a high value chemical such as DHA, ethanol, succinic acid etc.,. DHA is a value added chemical commonly used in cosmetics as an artificial browning agent and is generally produced by glycerol oxidation. In this review, a comprehensive study was carried on various microbial sources which can effectively convert glycerol for the production of DHA.
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    • "The recultivated culture (10 % v/v) was subsequently transferred to 100 mL NB medium (24 hr incubation), third transferred into 500 mL NB medium (18 hr incubation) prior to harvesting the cell. The cells were washed by simple medium (SM) [6], and determined cell dry weight (CDW) before using as seed. "
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    ABSTRACT: Kinetics of ethanol production from glycerol as sole carbon source using Enterobacter aerogenes were evaluated in batch fermentation with initial glycerol range from 10 to 120 g L-1 under 240 hr incubation at 30°C and pH 7. E. aerogenes was able to grow and produce the maximum ethanol concentration of 136.7 mM at the initial glycerol concentration of 20 g L-1. At this glycerol concentration, glycerol was completely utilized after 40 hr fermentation and ethanol yield was 0.7 mol mol-1. Microbial growth appeared to decrease when the initial glycerol concentrations were increased. In the initial glycerol concentration range of 10-45 g L-1, glycerol utilization was approximately 90% after 40 hr fermentation. Minimal amount volatile fatty acids and 1, 3-propanediol were detected.
    Energy Procedia 12/2014; 61:2244-2248. DOI:10.1016/j.egypro.2014.12.118
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    • "However, with increased availability of glycerol, due to biodiesel production, the alternative utilization route needs to be explored otherwise this will lead to its disposal problem and may also affect the economics of biodiesel industry. For large scale production the best option would be to use the by-product as a fuel directly [9] [10]. Unlike methane [11], glycerol is a poor fuel, which does not burn in either petrol or diesel engines [12]. "
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    ABSTRACT: The present paper deals with the study of the combustion of reforming gas in a small size Internal Combustion Engine. Therefore, mathematical models of both reforming process and internal combustion engine were implemented. In particular, steams reforming of glycerol to produce synthesis gas and spark ignition four strokes ICE were studied. The reforming process mathematical model was verified using experimental data. Synthesis gas was used to feed the ICE with different syngas and engine configuration. On the basis of the comparison with the experimental results, it is possible to state that the mathematical model is validated. Engine performance and pollutant emission evaluation was carried out using the integrated mathematical models with reference to the engine running on standard commercial fuel. The results highlight a reduction in engine performance and, at the same time a reduction of pollutant emissions in terms of CO and CO2.
    Energy Procedia 12/2014; 45:899 - 908. DOI:10.1016/j.egypro.2014.01.095
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