Biobutanol Production with Hybrid Membrane-Distillation

Although biobutanol has a number of clear-cut advantages over bioethanol as a renewable alternative fuel, biobutanol is not currently produced as a biofuel for economic reasons. The current method of biobutanol production, by acetone-butanol-ethanol (ABE) fermentation and distillation, is too complex and energy-intensive. This project will develop a novel membrane-distillation hybrid process for biobutanol separation and recovery that uses membranes for both butanol removal and dehydration. Compared to conventional biobutanol distillation, the proposed technology could lower the energy consumption of the biobutanol separation steps by 87%. In Phase I, two types of membranes were successfully developed to recover and separate ABE from ABE fermentation solutions. The data obtained were used to conduct process simulations that confirmed the technical performance and economic feasibility of the process. In Phase II, the membranes and process design will be optimized, and a hybrid membrane-distillation separation process will be evaluated. A pilot system will be constructed to evaluate the performance of industrial scale membrane modules with both synthetic ABE solutions and real feedstocks. The pilot system will used in a small field test to demonstrate the technology. Commercial Applications and Other Benefits as described by the awardee: The new membrane technology should enable economic production of butanol, a green fuel alcohol, from renewable resources. Existing and future corn-to-ethanol plants could be retrofitted for butanol production if the technology were proven to be economic. In addition, the technology could be adopted to replace petroleum-derived butanol and acetone.