SUITABILITY OF CO2 CAPTURING TECHNOLOGIES FOR CARBON CAPTURE & STORAGE

Abstract

Carbon capture and storage (CCS) is the most viable option to reduce CO2 emissions from power plants while continuing the use of fossil fuels required to satisf' the increasing energy demand. CCS is especially attractive for electric power plants burning coal and other fossil fuels, which are a major source of global CO2 emissions. l'his work analyse different types of CO2 capture technologies, including pre-combustion, postcombustion, and oxy-fuel combustion capture systems, along with the outlook for new or improved technology. The advantages and limitations of various carbon capture technologies are discussed. The suitability of various CO2 capture technologies for coal power plants in India is checked on the basis of different parameters such as energy penalty, cost of CO2 capture, efficiency, age and size of the POVCr plants. For calculating energy penalty and cost of capture for the coal power plants in India. Integrated Environmental Control Model (IECM), was used to simulate the power plants. All 5 17 units of 115 coal power plants of India were considered for CCS and they were analyzed using the IECM software. One Integrated Gasification Combined Cycle (IGCC) plant and one ultra-supercritical plant was also simulated using the software. Results shows that the total installed capacity of Indian coal power plants will reduce to 93645.46 MW, 87499.66 MW and 57867.01 MW from 126319.5 MW by the use of amine, ammonia and membrane systems respectively. The average efficiency of Indian coal power plants, which is 29.08% currently, will reduce to 24.39%, 20.65% and 15.37% on using amine, ammonia and membrane systems respectively. Also cost of CO2 capture will be less in case of amine system (38.42 $/ton CO2 captured) as compared to ammonia (68.15 $/ton captured) and membrane (74.25 $/ton CO2 captured). I lence amine technology will be the best technology for Indian coal power plants. It was observed that CO2 capturing technologies will be beneficial on coal power plants which are not more than 20 years old as the energy penalty will be less as compared to their use on old power plants where energy penalty will be comparatively high. The energy penalty of amine on power plants commissioned during 1950-1970, 1991-2000 and 2011-2013 will be 29.77%, 27.22% and 23.49% respectively whereas the use of membrane technology on these plants will result in an energy penalty of 64.36%. 57.43% and 48.63% respectively. Use of amine technology on power plants which are in operation since 1950, 1991 and 2011 will reduce their efficiency by 6.41%. 5.08% and 2.5 1% respectively. Reduction in efficiency on these power plants on use of membrane technology will be 16.28%, 14.16% and 11.26% respectively and ammonia will result in the reduction of 10.5 1%. 8.86% and 5.59% respectively. Also provisions for SO2 control in Indian coal power plants will have to be made prior to the use of CO2 capturing technologies in order to be technologically as well as economically feasible. The main options available in India for storage of captured CO2 are deep saline aquifers, depleted oil and gas fields and deep unminable coal fields but further work is required to confirm the exact capacity for storage of captured CO2 in India.