2019 Bioenergy Sustainability Conference

Bioenergy Via Char Gasification with Carbon Capture and Storage: An Alternative to Beccs

Authors

Chun, D. - Presenter, The Cooper Union
Zhao, P., Cooper Union
Davis, B., The Cooper Union
Simson, A., The Cooper Union for the Advancement of Science and Art
Antony, A., Pennslyvania State University
IPCC techno-economic models suggest that staying below the 2oC limit set forth by the Paris Agreement will require negative emissions technologies, with a majority of models incorporating bioenergy with carbon capture and storage (BECCS). However, there are several limitations to the most commonly described BECCS approach such as competition for water, land, and energy resources as well as difficulty in separating CO2. We propose a novel BECCS alternative which uses biowaste and pyrolyzes it into biochar. This biochar would then be gasified at a larger power plant in CO2 to generate syngas as a fuel for a solid oxide fuel cell (SOFC). The fuel cell would produce a stream which is almost all H2O and CO2, easily separated through condensation into a CO2 stream for sequestration.


The biochars we have derived experimentally were from food waste (walnut shells, pistachio shells, corn cob, and pumpkin seeds). Several pyrolysis conditions such as ramp rate, moisture content, and purge atmosphere were investigated to understand reactivity in gasification. Chars with high ash content (e.g. corn cob) were most reactive with CO2, perhaps from the inorganics present in ash. Fast pyrolysis yielded a more reactive biochar and biowaste drying before pyrolysis made the biochar less reactive in gasification. We will present both a techno-economic analysis of the alternative BECCS scheme and experimental data on pyrolysis and biochar gasification. We performed ASPEN simulations to compare our data to traditional BECCS models. [Fajardy, M; Dowell, N. Energy Environ. Sci., 2017, 10, 1389-1426].