Life cycle assessment of a biomass based chemical looping combustion

Chemical looping combustion (CLC) is a promising technology that generates energy while inherently separating carbon dioxide from air using oxygen carriers. This allows for an efficient and cost-effective means of carbon capture and storage. Current CLC systems use coal with metal oxides for combustion in the fuel reactor, thus, resulting in some environmental impacts. Recent life cycle assessment (LCA) of CLC studies have indicated the environmental impacts of conventional coal-based CLC, especially on the global warming potential. To mitigate these environmental impacts, this study proposes the use of a biomass-based CLC and evaluates its impacts using LCA. A case study in the Philippines is adopted where rice husks are used as biomass feedstock. A kilowatt-hour of electricity generated from the CLC plant is utilized as the functional unit. A relative comparison of environ-mental impacts was considered between the coal-based power plant, the coal-based CLC plant, and the biomass -based CLC plant. The single score results have shown that the biomass-based CLC has the least environmental impacts relative to the coal-based power plant and the coal-based CLC plant. However, it is noted that water consumption is the main drawback of utilizing rice husks as CLC biomass feedstock. The majority of the envi-ronmental impacts of the coal-based CLC and the coal-based power plant were derived from upstream processes such as coal mining and processing. With the use of rice husks as CLC biomass feedstock, net negative emissions were achieved.

Automated summary

Chemical looping combustion (CLC) is a promising technology for efficient carbon capture and storage. Recent studies have shown that conventional coal-based CLC has significant environmental impacts, especially on global warming potential. This study proposes the use of biomass-based CLC, specifically rice husks, which were found to have the least environmental impacts compared to coal-based power plants and coal-based CLC. However, water consumption remains a drawback in using rice husks as CLC biomass feedstock, despite achieving net negative emissions.