Life cycle energy-carbon-water footprint assessment of an existing coal power plant retrofitted with calcium looping (CaL) based CCS system

Abstract

The current study uses a detailed process based LCA model to evaluate the life cycle energy, carbon and water footprint of an existing 660 MWe supercritical coal powerplant in India retrofitted with the calcium looping based CCS system. LCA of the base case is followed by a sensitivity analysis to analyze effect of variation of different input parameters on the output performance metrics such as life cycle energy input, EROI, life cycle GHG emissions and life cycle blue water consumption. Further, the performance of calcium looping is compared with other mature CCS technologies such as MEA and oxycombustion, which are also retrofitted to the same existing coal power plant. Results show that, as compared to the base power plant, the life cycle energy input and life cycle blue water consumption of the integrated system using calcium looping increases by around 31 and 36% respectively, whereas EROI and life cycle GHG emissions decrease by 33–45% and 79–83% respectively. Sensitivity analysis results show that EROI has the largest variation range and change in rail transportation distance of coal leads to maximum variation in life cycle energy input, EROI and life cycle GHG emissions. Comparison of the three CCS technologies clearly shows that the integrated system using calcium looping has the lowest increase in life cycle energy input and life cycle blue water consumption and the lowest decrease in EROI. Thus, in addition to efficiently reducing CO2 emissions and enhancing power generation capacity of existing coal powerplants, use of calcium looping is also favourable from a life cycle sustainability perspective.