Trade-off between carbon reduction benefits and ecological costs of biomass-based power plants with carbon capture and storage (CCS) in China

Integrating carbon capture and storage into biomass power plants (BioCCS) can reduce carbon emissions, but its ecological performance associated with natural resources consumption remains unexamined. Taking a typical BioCCS project - the Maowusu biomass direct-fired power plant with the CCS of Spirulina cultivation in Inner Mongolia of China - as a case, this study observed the trade-offs between the carbon reduction benefits and ecological performance of adding CCS to the power plant. Life cycle assessment (LCA) revealed that the combination of CCS avoids 1228 metric tons (MT) of CO2 emissions annually, while emergy analysis revealed that it deteriorated the ecological performance of the BioCCS system because considerable nonrenewable resources were required by Spirulina cultivation. The BioCCS system is unsustainable in the long run from the ecological point of view. The sensitivity analyses show that there would be no carbon reduction benefits by adding CCS when 60% of designed CO2 capacity is fixed by Spirulina, and insufficient biomass for electricity generation also affects system performance significantly, which are two main barriers to the BioCCS project. These results indicate that decision-makers should take into account both the carbon reduction benefits and the ecological costs in the development of BioCCS systems.