A Pilot Study of Post Combustion Carbon Capture & Sequestration Pilot Plant Aimed at Feasibility Analysis of Installation of a Carbon Capture, Utilization and Sequestration (CCUS) Plant on a Large Thermal Unit in India

Abstract

CO2 Capture, Sequestration and Production of Multi-purpose fuels – Hydrogen, Methane and Biodiesel through Algae route through Post combustion CCS on a fossil fuel fired Plant has been successfully demonstrated at the DST sponsored CO2 sequestration Pilot Plant at the State Technological University of MP, the ‘RGPV’ at Bhopal in Central India. A CO2 Capture efficiency of over 93% has been achieved using MEA solvent of 18 % concentration and the required heat for stripping captured CO2 in the regeneration tower has been worked out at the level of 3.88 MJ per kg of recovered carbon dioxide, which is provided by the low pressure steam of about 150°C and 2 bar pressure @ 1.5-1.6 tons of steam per ton of CO2. Exergy analysis was carried out to optimize this regeneration energy requirement with multiple fuels including bituminous coal, fuel oil and also bio-mass aiming towards negative emission strategy. Production of multipurpose fuels like hydrogen and bio-diesel have been demonstrated in the pilot plant through lignite gasifier via CO and Algae routes respectively. Hydrogen to the tune of 21.92% by volume has been produced, while selected species of Algae grown in open pond with CO2 and Solar flux input provided Algal oil by using Soxhlet extraction process using petroleum ether. Parallel efforts are made in a Solar Thermal Pilot Unit, a MNRE sponsored project, in collaboration with Rensselaer Polytechnic Institute (RPI), NY, USA at the State Private University, RKDF in near vicinity of RGPV’s CCS pilot plant under joint collaboration. Based on above two pilot studies a feasibility analysis is carried out for installation of Carbon Capture, Utilization & Storage plant on a 500 MW Anpara Thermal Power Plant in Northern Coal Fields of India. The Feasibility Study has revealed that it is possible to implement Carbon Utilization by growing selected species of Algae culture in the Ash pond of the plant for almost doubling the Algae growth for bio-diesel production. The feasibility analysis has further revealed that energy penalty for a 30% CO2 capture for a 500 MW Unit would be around 25% including 10% for compression and pumping in an Enhanced Coal Bed Methane (ECBM) technique in proximity to the CO2 source. In any case, the energy penalty in Indian context, when our power planners are targeting at no-storage options for CCS like Carbon sequestration for conversion to multi-purpose fuels rather than CO2 storage, the energy penalty still remains at level of 15-20%. This can be further reduced to a level of 5-10 % if solar thermal device is used for production of steam for solvent regeneration and stripping of CO2. A specially designed Alkali Halide Salt developed by RPI, USA is used as 24x7 heat storage- materials in the pilot plant and the same is integrated with the CCS pilot plant for solvent regeneration and stripping of CO2. Test results of Solar Thermal pilot plant for Steam production with thermal storage, using solid pathway is given which may pave way for development of the technology of Post Combustion Carbon Capture with least energy penalty in regeneration of solvents used in the CCS process.