Modular Biomass Power Systems to Facilitate Forest Fuel Reduction Treatment

This research and development project aimed to evaluate modular gasification for use across California’s forested landscape to promote and support sustainable fire-safe management activities. Research activities were conducted at the Woodland Biomass Research Center in Woodland, California through a collaboration between West Biofuels, University of California San Diego, and University of California Davis with additional support from TSI Consultants on forest resource analysis. The research program included extensive feedstock testing and resource analysis, gasifier system testing and demonstration, and internal combustion engine testing using biomassderived producer gas. The project team used data collected throughout the testing phases to evaluate the techno-economic feasibility of various gasification system schemes, identify opportunities for structural and operational improvements, and define best practices to improve the performance and reduce the cost of community-scale gasification. The results of the research identified critical challenges with the original CircleDraft gasification design when used with traditional forest residue. These challenges are a direct result of the feedstock processing used in fire-safe management activities across the western United States. In addition, the resulting syngas did not meet gas quality targets and was difficult to synchronize with an engine generator system. The team found an alternative gasification approach using rotary processing technology already commonly used in the forest products industry with challenging biomass feedstock. This rotary gasification system coupled with a thermal oil heater and organic rankine cycle turbine generator resulted in a superior approach in terms of overall energy cost and system capacity factor. Coupled with site optimization and biochar marketing, the resulting energy costs are in the range of currently available power purchase prices from California utility companies. These research breakthroughs resulted in process improvements to ready a new technology for commercialization in California forest communities, as well as a deeper understanding of best practices applicable to community-scale forest biomass projects across California.