​In-situ Bio-methanation in Food Waste Digesters using CO2 and Catalytically-derived Hydrogen from Biogas

Technology & Investment Solutions LLC (TIS), in partnership with the University of Southern California (USC), was awarded by the California Energy Commission (CEC) with Project Grant No. ARV 18-024 to demonstrate a novel “in-situ” biological upgrading of biogas from the anaerobic digestion (AD) of liquid food waste and/or liquified food substrates. TIS developed the novel in-situ (internal) upgrading technique in order to address the challenges and the high expense associated with traditional upgrading processes for low-quality biogas into high-value fuel. Upgrading biogas to biomethane has many benefits which includes (but not limited to) the following:

• Allows for use as an alternative fuel to pipeline natural gas;
• Creates a renewable source of energy;
• Potential source of additional income to AD plant owners or operators; and
• Prevents methane emission to the atmosphere.

The demonstration of this system has shown that upgrading biogas directly within the AD reactor through biological processes is possible without the need for highly specialized and expensive external upgrading equipment such as membrane filters or PSA. The project also demonstrated that low-quality biogas can be upgraded through a relatively simple and economical manner which is especially important for small-scale AD plant owners and operators or those that produce less than 100,000 standard cubic feet (scf) of biogas daily. Further, TIS believes that with additional optimization of the system, commercial-scale implementation throughout the State of California and beyond can be realized.