Butanol production from food waste: a novel process for producing sustainable energy and reducing environmental pollution

Authors: HUANG, HAIBO - University Of Illinois; SINGH, VIJAY - University Of Illinois; Qureshi, Nasib

Submitted to: Biotechnology for Biofuels and Bioproducts
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/30/2015
Publication Date: 9/15/2015
Publication URL: https://handle.nal.usda.gov/10113/5695402
Citation: Huang, H., Singh, V., Qureshi, N. 2015. Butanol production from food waste: a novel process for producing sustainable energy and reducing environmental pollution. Biotechnology for Biofuels. 8:147. doi: 10.1186/s13068-015-0332-x.

Interpretive Summary: Butanol is a superior biofuel than ethanol. It packs 33% more energy (than ethanol), can be used in internal combustion engines without any modifications, can be transported in existing pipelines as it is not corrosive and burns cleaner thus producing less soot. This novel biofuel can be produced from renewable resources including grains, molasses, and agricultural residues. However, use of grains and molasses is prohibitive due to their high cost contribution to produce biobutanol on a commercial level. Hence, we focused to produce butanol from waste streams such as “Food Waste”. In 2012, approximately 33 million tons of food waste was generated in the United States. Being a zero cost substrate, food waste is expected to improve process economics of butanol production dramatically. In these studies we demonstrated that food waste can be effectively used to produce butanol. Additionally, its use would result in reduced environmental pollution. Production of butanol from such a waste stream would benefit the United States public and the transportation industry.

Technical Abstract: Efficient utilization of food waste for fuel and chemical production can positively influence both the energy and environmental sustainability. In these studies we investigated use of food waste to produce butanol by Clostridium beijerinckii P260. In control fermentation, 40.5 g/L of glucose (initial glucose 56.7 g/L) was used to produce 14.2 g/L of ABE with a fermentation productivity and a yield of 0.22 g/L/h and 0.35, respectively. In a similar fermentation 81 g/L of food waste (containing equivalent glucose of 60.1 g/L) was used as substrate, and the culture produced 18.9 g/L ABE with a high ABE productivity of 0.46 g/L/h and a yield of 0.38. Fermentation of food waste at higher concentrations (129, 181 and 228 g/L) did not remarkably increase ABE production but resulted in high residual glucose due to the culture butanol inhibition. An integrated vacuum stripping system was designed and applied to recover butanol from the fermentation broth simultaneously to relieve the culture butanol inhibition, thereby allowing the fermentation of food waste at high concentrations. ABE fermentation integrated with vacuum stripping successfully recovered the ABE from the fermentation broth and controlled the ABE concentrations below 10 g/L during fermentation when 129 g/L food waste was used. The ABE productivity with vacuum fermentation was 0.49 g/L/h, which was 109% higher than the control fermentation (glucose based). More importantly, ABE vacuum recovery and fermentation allowed near complete utilization of the sugars (~98%) in the broth.