Comparative life cycle environmental assessment of CCS technologies

Hybrid life cycle assessment is used to assess and compare the life cycle environmental impacts of electricity generation from coal and natural gas with various carbon capture and storage (CCS) technologies consisting of post-combustion, pre-combustion or oxyfuel capture; pipeline CO2 transport and geological storage.The systems with a capture efficiency of 85–96% decrease net greenhouse gas emission by 64–78% depending on the technology used. Calculation of other life cycle impacts shows significant trade-offs with fresh-water eutrophication and toxicity potentials. Human toxicity impact increases by 40–75%, terrestrial ecotoxicity by 60–120%, and freshwater eutrophication by 60–200% for the different technologies. There is a two- to four-fold increase in freshwater ecotoxicity potential in the post-combustion approach. The increase in toxicity for pre-combustion systems is 40–80% for the coal and 50–90% for the gas power plant. The increase in impacts for the oxyfuel approach mainly depends on energy demand for the air separation unit, giving an increase in various toxicity potentials of 35–70% for coal and 60–105% for natural gas system. Most of the increase in impacts with CCS systems is due to the energy penalty and the infrastructure development chain.