(736c) Novel Technology for Producing Bio-Butanol

    Butanol is an important organic solvent and industrial intermediate. It is widely used in plastic, organic synthesis, paint and pharmacy industry. Moreover, Butanol’s Brit­ish thermal units (BTU) is almost equal to that of gasoline and higher than ethanol. Therefore, butanol has been recently identified as a good candidate of next-generation clean and renewable biofules to address the concerns for the availability of fossil feed stocks and climate change.

    Recent advances in the field of biotechnology have resulted in a renewed interest in the fermentation production of butanol (coproducts are acetone and ethanol) by using raw materials like starch, sugar and lignocelluloses. However, the traditional acetone butanol ethanol (ABE) fermentation process has many disadvantages such as high energy and material consumption and serious water pollution. For instance, the steam consumption is more than thirteen tons/per ton of solvent.

    In the past few years, our team has developed a series of new technologies to facilitate an effective and energy-efficient product removal in the traditional ABE fermentation process. The multi-effect thermal coupling technique was employed in the distillation unit which consumes the largest amount of energy in the entire process. With the heat integration and optimization, more than 35% energy was saved and the steam consumption was reduced to 6.5 tons/per ton of solvent while the product quality was also improved with the high-efficient distillation process. Based on the whole process modeling and optimization, both the heavy and light enrichment areas were identified for bleeding the impurities respectively. Accordingly, the total product yield was increased by 2% to reach 99%. In the meantime, the water flow was also optimized to minimize the water usage as well as the waste water.

    The production cost was greatly reduced in this improved ABE fermentation process. Currently, a 70,000 MTA bio-butanol plant has been built up using this technology.