Process development and techno-economic analysis of butanol production by IBE (Isopropanol-Butanol-Ethanol) fermentation

Author(s)

Ercília Regina Silva Dantas

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Química
• Defense date: 2018-07-30

Examining board members

Adriano Pinto Mariano; Roberta Ceriani; Daniele Farias

• Advisor: Adriano Pinto Mariano

Abstract

Biobutanol can be produced naturally through ABE (acetone-butanol-ethanol) or IBE (isopropanol-butanol-ethanol) fermentation by strain Clostridium; however, both processes face difficulties in establishing competitiveness for its production. The product inhibition is highlighted as major drawback. In fact, this issue is even more critical in IBE fermentation, whose conversion values of sugars (59%), butanol yield (0.13 g/L?h) and butanol yield (0.17 g/g) are lower than ABE fermentation. To mitigate the inhibition effects of products on cells, the method of in situ product recovery by vacuum separation was applied using flash fermentation design. In addition, a hypothetical case of genetic modification was developed and its developments in the performance of conventional batch fermentation and "flash fermentation" technologies were verified. The main objective was the development and technical-economic evaluation of an advanced technology process to produce n-butanol via IBE fermentation using lignocellulosic biomass. For this, the studies were conducted through computational simulations that allowed to determine optimal operating conditions of the "flash fermentation" for maximum productivity of IBE or minimum rate of vaporization in the flash tank, besides feeding the economic analyzes of different business strategies. Finally, it was observed that the "flash fermentation" technology promoted less diluted broths in products and increased productivity, whose optimum condition of minimizing the amount of vaporized broth in the flash tank demonstrated energy efficiency gains with a productivity increase of ~ 10 times compared to batch technology (2.0 versus 0.2 g /L?h). The isolated use of the "flash fermentation" technique makes butanol production via economically viable IBE fermentation with a net present value of over 90 million dollars, but the association of this technique with a hypothetical case of genetic modification has given the IBE process greater competitiveness, reaching net present value of 146 million dollars and internal rate of return of more than 23% (AU)

• FAPESP's process: 16/08791-5 - Process development and technical-economic evaluation of the butanol production by IBE (isobutanol-butanol-ethanol) fermentation
• Grantee: Ercília Regina Silva Dantas
• Support Opportunities: Scholarships in Brazil - Master