The U.S. is the world's largest emitter of CO2 and other greenhouse gases, primarily from the combustion of fossil fuels, such as coal, for power generation. The utilization of biomass-based fuels offers the advantage of releasing essentially no net CO2 emissions to the atmosphere during power generation, due to the fixation of CO2 during photosynthesis. This project will develop technology for biomass production through cyanobacterial fixation of CO2 generated during power generation and subsequent conversion of the produced biomass through slurry carbonization to a quality coal substitute. In Phase I, feasibility will be determined through bench-scale experiments, computer modeling, and engineering estimates. CO2 fixation mechanisms will be determined for several strains using advanced photobioreactors at the Hawaii National Energy Institute; slurry carbonization performance will be determined with EnerTech's 2.2 gal/hr Process Development Unit; and combustion performance of the upgraded biomass will be characterized using a 100,000 Btu/hr Control Temperature Tower at a subcontractor's site.
Commercial Applications and Other Benefits as described by the awardee: This technology should provide utilities the versatility to economically stabilize greenhouse gas emissions, while maximizing utilization of existing coal handling and power generation infrastructure and technologies. The resulting carbonized biomass fuel not only could be combusted efficiently in traditional suspension boilers but also in advanced coal-based power systems which are currently under development.
