Life cycle CO2 emission estimation of CCS-EOR system using different CO2 sources

Abstract

Balancing sustained economic growth with energy security and environmental and climate change constraints is a common but difficult challenge. China, as the largest energy consumer in the world – 90% of which is fossil fuel-based – faces the enormous task of transforming its energy mix to low-emissions. CO2 has been successfully injected for the purposes of both carbon capture and storage (CCS) and enhanced oil recovery (EOR). This study employs life cycle assessment to quantify the CO2 emissions from the CCS-EOR system to analyze net CO2 emissions. This system includes carbon capture, transportation, EOR, downstream, and consumption. Our model analyzes life cycle CO2 emissions from plants of integrated gasification combined cycle (IGCC) with CCS, pulverized coal plants (PC) with CCS, and oxy-fuel plants with CCS while we use technologies of fractionation, refrigeration, Ryan-Holmes, and membrance in the process of EOR. Total CO2 emissions are 114.69-121.50 Mt CO2 e, 222.95-236.19 Mt CO2 e, and 49.09-51.96 Mt CO2 e from IGCC, PC, and oxy-fuel plants, respectively, based on IGCC with 426 MW, PC with 600 MW, and oxy-fuel with 200 MW in China. Emissions from the combustion of refined petroleum fuel is the most of total emissions – from 66.21% to 71.35%, emissions from EOR are 14.27-19.32%, emissions from downstream are 8.47-9.13%, emissions from capture are 4.12-5.09%, and emissions from transportation are 0.47-1.61%. Based on these results, CCS-EOR (where CO2 is sourced from IGCC, PC and oxy-fuel plants) provides one potential means for producing electricity and oil to meet growing energy demand and reducing CO2 emissions to abate global warming.