The energy demand and environmental impacts of oxy-fuel combustion vs. post-combustion capture in China

Abstract

Oxy-fuel combustion is one of the clean coal combustion technologies for CO2 capture. However, post-combustion capture is studied as a challenged technology against oxy-fuel combustion. This paper presented the life cycle assessment (LCA) of these two CO2 capture technologies used in the 300 MW coal fired power plant. The purpose was to identify and quantify the energy demand and the environmental impacts of oxy-fuel combustion throughout its whole life cycle and compared the results with post-combustion capture by an amine (MEA) absorbent. The results showed an increase in cumulative energy demand in oxy-fuel combustion compared with post-combustion capture. Total life cycle energy consumption of oxy-fuel combustion system was more 0.065 MJ than post-combustion capture system. However, oxy-fuel combustion can reduce 0.00047 mPET2000 of global warming, 0.04084 mPET2000 of acidification, 0.04486 mPET2000 of eutrophication, 0.001 mPET2000 of photochemical ozone formation and 0.35082 mPET2000 of slag and ashes compared with post-combustion capture. The total environmental impact loading (EIL) of oxy-fuel combustion to produce 1 kWh of electric energy was 9.06382 mPET2000, which was less than that of post-combustion capture (9.50181 mPET2000), indicating that the oxy-fuel combustion can play a relatively important role in reducing environmental impacts.

Keywords

• Life cycle assessment
• Oxy-fuel combustion
• Post-combustion capture
• Energy demand
• Environmental impacts