Study on the Effect of the Impurities In the Biodiesel-Derived Crude Glycerol on Growth and Fermentation by Clostridium Pasteurianum ATCC™ 6013

The biodiesel industry is growing at a rapid rate in the US. The process of biodiesel production also results in the production of glycerol (10% w/w), a byproduct, which contains methanol, salts and fatty acids. Typically, crude glycerol cannot be used for chemical conversions, therefore requiring purification steps. But unfortunately, the purification costs are three folds higher than the cost of crude glycerol. Thus, the excess glycerol from the biodiesel plants can be used in a manner to convert it into useful chemicals and hence develop processes that result in value-addition to the biodiesel-derived crude glycerol. We had earlier developed an anaerobic fermentation process of the crude glycerol by Clostridium pasteurianum ATCC? 6013 to produce butanol. Butanol has a great potential as an alternate fuel and is also a key chemical compound for other chemical synthesis processes. In this study we show the effects of the impurities in the crude glycerol on bacterial growth and solvent formation. The presence of fatty acids in crude glycerol has an inhibitive effect on the growth of the bacteria. The removal of the fatty acid from the crude glycerol results in faster growth and a shorter fermentation period. In this study we also discuss the study of the membranes of the bacteria exposed to different conditions.