Biochar: A Solution to Oakland’s Green Waste?

Lawrence Berkeley National Laboratory (LBNL) has been working in conjunction with the Department of Energy on finding new and innovative ways of sequestering atmospheric carbon, and lessening the population's carbon footprint. LBNL is committed to finding interdisciplinary and creative ways to ensure a carbon-neutral future. In the spirit of this commitment, this research project examined the economics of converting Oakland's residential green waste stream to biochar as an alternative waste management solution. Biochar is a charcoal created from biomass by pyrolysis. Carbon in biochar has been found to stay stable for thousands of years, unlike carbon in compost and thus may be a better alternative than compost in reaching a city's carbon sequestration goal. In addition, some biochar's have been found to act as a valuable soil amendment, leading to increased crop yields in many cases. Also, pyrolysis produces by-products, syngas and bio-oil, which can be converted into bioenergy. Through calculations and reference research, the preceding potential benefits were examined in order to determine if a biochar production plant would be an appropriate form of green waste diversion in Oakland. The research found that biochar production from Oakland's residential green waste may be profitable. However, this project is laden with assumptions, so further research is recommended to understand how biochar specifically affects local crops, the ability of pyrolysis to handle heterogeneous feedstocks, and how biochar may fit with Oakland's carbon sequestration goals.