Optimal Utilization of Forestry Biomass in Integrated Gasification Systems for Fueling Zero Emission Vehicles
- Author(s): Shaffer, Brendan
- Advisor(s): Samuelsen, Scott
- et al.
Risk of significant climate change continues to rise while degraded air quality persists in certain regions of the world. Zero emission vehicles provide one technological solution to these environmental issues. In the near term, forestry residue biomass could be a major resource for the production of these fuels (electricity and hydrogen) in the near term. Given that these biomass supplies are limited, their effective utilization is important if the maximum benefits are to be realized. This dissertation seeks to understand the optimal utilization of these forestry resources in California for fueling zero emission vehicles with a focus on the 2030 timeframe. Various biomass energy conversion plant designs were modeled in detail to understand the differences in energy efficiency, cost, and pollutant emissions. The remaining steps in the supply chain were modeled in varying levels of detail depending on the level of detail available in the literature.
The application of stationary fuel cells was observed to be integral to maximizing energy efficiency and minimizing levelized costs for many of the plant designs. The least cost supply chain for producing fuels for zero emission vehicles on a per mile basis is through production of liquid hydrogen that is liquefied using advanced liquefaction processes and stationary fuel cells at larger scale biomass energy conversion plants. However, hydrogen liquefaction significantly degrades the performance of the integrated biomass gasification plant unless advanced liquefaction processes and/or stationary fuel cells are utilized. A conflict between costs and environmental impacts exists where the largest biomass energy conversion plants exhibit the lowest levelized costs but also have the highest emission rates of NOx, PM2.5, and fossil fuel based GHGs with one exception, the integrated biomass gasification combined cycle design at high roadside feedstock costs. Although the highest offset of GHGs from the displacement of gasoline consumption is through the production of electricity from forestry biomass for plug-in electric vehicles, the production of hydrogen for fuel cell electric vehicles provides the lowest cost per unit of offset GHGs from the displacement of gasoline consumption.