Executive Summary : | Microbial electrosynthesis (MES) is a process that produces chemicals from the biocathodic reduction reactions by supplementing small amount of energy. Dark fermentation (DF) is a process that produces hydrogen from the wastewater and leaves volatile fatty acids (VFAs) as byproducts. These VFAs can be reduced by MES to high value chemicals to develop the whole process as part of circular carbon economy and sustainable waste management. In this direction, the present project proposed to utilize the highly biodegradable food waste generated from industries and vegetable markets for the production of ethylene which is one of the platform chemicals having high market value. Dark fermentation (DF) of food waste is gaining attention due to its advantages in producing sustainable hydrogen production and treatment, simultaneously. An efficient DF is leaving about 40-60% organic carbon in effluents as VFAs like acetate, propionate, butyrate and valerate. Among these, acetate is found to be dominant with more than 70% of total VFA. MES process is gaining importance worldwide for production of chemicals from CO2 utilization and chain elongation. Present study is aimed to utilize the acetate (which is the major portion of VFA) to produce ethylene employing selectively enriched ethylene producing microflora. As acetate is found to be a suitable substrate for ethylene production under controlled environmental conditions, the proposed project will address the appropriate utilization of DF effluents. In MES, a biocathode that is enriched with specific bacteria with specific reduction reactions is functioning to produce chemicals from VFAs. In the present case, ethylene forming bacteria (EFB) is acting as a biocatalyst for cathodic reduction reaction. Mild applied potential (0.2 to 0.8 V) is needed to control the reduction reaction. The challenges such as establishing biocathodic reduction environment for ethylene production, enrichment of EFB, biocathode development considered, optimization of cathodic potential, for present project. The outcome of the project will be a breakthrough in generating platform chemicals from waste resources and biological processes. Since petroleum based processes are the major sources for the production of ethylene, MES can be a new process for sustainable energy generation. It also addresses the circular carbon economy for waste management in the renewable hydrogen production process called DF. |