Study of utilizing microalgae residues for butanol production by Clostridium acetobutylicum

Abstract

Since the Industrial Revolution in the eighteenth century world pollutions expanded exponentially because of the dramatic increase of human population Global warming and energy crisis have already been proved as internal issues in recent year The renewable energy become more and more important Current technologies usually remain a large portion in percentages of carbohydrate and COD as residues during microalgae biomass extraction in biodiesel production process In this study we explored the characteristics of Clostridium acetobutylicum to enhance butanol production and the hydrolysis method of microalgae residues for acetone butanol and ethanol fermentation Fermentation biobutanol batch tests in order to exam the effects of pH the addition of butyrate or/and acetate and to figure out a better pretreatment strategies for microalgae residues were conducted in this study Clostridium acetobutylicum grew up and acidogenesis occurred at initial pH > 5 5 The best condition was investigated when initial pH = 6 and maintained at 5 chieving a butanol concentration of 9 78 g/L and yielded 154 mg-butanol/g-glucose The butanol yield under addition of 18 g/L butyrate were 308 9 mg-butanol/g-glucose at the initial concentration of 30 g/L glucose The butanol yield under addition of 4 g/L acetate were 196 mg-butanol/g-glucose at the initial concentration of 60 g/L glucose The maximum butanol production and yield were 2 197 g/L and 21 96 mg-butanol/g-microalgae residues which microalgae residues were pretreated via 2% sulfuric acid followed 2% sodium hydroxide hydrolysis without filtration Results indicate that microalgae residues are also suitable for ABE fermentation but an optimized operational condition is still needed

Date of Award	2014 Aug 18
Original language	English
Supervisor	Liang-Ming Whang (Supervisor)