Biobutanol Production from Agro-industrial by-products using ABE Fermentation: Analysis of Feedstock Effect on Biobutanol Yield and Titer

Abstract

This study examined a range of agro-industrial by-products that could be used as potential carbon and nitrogen sources for ABE fermentation. In general, the study examined more than a dozen different by-products from dairy, biodiesel, sugar, agriculture, beverage, food, etc. production industries. The by-products were tested to determine which of them would result in higher biobutanol yield and concentration in the fermentation medium. All by-products were used in the cultivation of three bacteria of the genus Clostridium to observe differences also between the strains’ ability to utilize the respective substrates. The test results demonstrated that the most suitable by-products for ABE fermentation, which served as carbon sources, are biodiesel and sugar production by-products and hydrolysates of agricultural residues. These by-products are available in large quantities. The tests show that they serve as a good energy source for the production of butanol fuel. By-products of dairy processing and specific beverage production residues (yeast residues) showed the best results as the most suitable nitrogen sources; however, these by-products are either limited in availability at scale or their transportation is uncompetitive due to the high water content. This study shows that ABE fermentation can be provided with a range of different agroindustrial by-products. The wider use of these by-products in the future can reduce the negative impact on the environment, reduce the production costs of ABE fermentation products and allow obtaining an efficient biofuel – biobutanol, which can compete with bioethanol and biodiesel.