Top: George DeRuyter & Sons Dairy’s anaerobic digester (top) generates renewable natural gas. It uses screens/roller presses to separate digested fiber (above).

Keep an eye on Washington State in 2022, as several significant developments are anticipated in the anaerobic digestion space. First is the rulemaking underway by the Washington Department of Ecology to implement the state’s Clean Fuel Standard. The law, signed by Governor Jay Inslee in May 2021, is designed to cut statewide greenhouse gas emissions by 4.3 million metric tons a year by 2038. It requires fuel suppliers to gradually reduce the carbon intensity of transportation fuels to 20% below 2017 levels by 2038. There are several ways for fuel suppliers to achieve these reductions, including: Improving the efficiency of their fuel production processes; Producing and/or blending low-carbon biofuels into the fuel they sell; and Purchasing credits generated by low-carbon fuel providers, including electric vehicle charging providers. Several operating dairy digesters have transitioned to renewable natural gas (RNG) production, including George DeRuyter & Sons Dairy in Outlook, Washington, which has been collaborating with Brightmark Energy to inject RNG into the natural gas pipeline. The rulemaking was announced in July 2021, and the proposed rule is scheduled to be released for public comment this summer. The final rule will be adopted before the end of the year, and the Clean Fuels Program is scheduled to begin in January 2023.

The second development is a new funding initiative for dairy digester bioenergy projects. The Washington State Department of Commerce received $4.9 million in 2021 for a new rural innovation grants program. Within this program is a dedicated carve-out of $1.9 million for the Dairy Digester Bioenergy Program to provide funding for projects that enhance the viability of dairy digester bioenergy projects. This includes nutrient management systems that produce RNG and value-added biofertilizers, generate electricity and heat, reduce greenhouse gas emissions, and improve soil health and air and water quality. The agency is developing a rural energy work group to guide distribution of these funds, with a report due by June 30, 2022. The Department of Commerce is expected to start accepting grant applications in fall 2022 from applicants that own, operate and/or service anaerobic digesters located at dairies in the state.