Techno-economic study of carbon capture from coal-fired power plant using MEA assisted by solar organic rankine cycle for power generation

Abstract

A carbon capture system applied in coal-fired power plant assisted by solar organic rankine cycle (ORC) for power generation is studied; the ORC system is driven by concentrated solar energy for power generation, the heat of condensation is for carbon capture system using MEA applied in coal-fired power plant, which makes thermal efficiency of ORC 100% theoretically. The system guarantees stable operation and high benefit of the coal-fired power plants via avoiding steam extraction from steam turbine. ORC working fluid candidates are selected based on thermodynamic analysis and parameter design of the system. Toluene, octane, silicone oil MDM and cyclohex are four candidate ORC working fluid. Economic analysis and comparison between different carbon capture systems are conducted based on levelized cost of electricity (LCOE), cost of carbon (COC) and net present value (NPV). When carbon capture rate is less than 90%, LCOE of proposed system is higher than that of traditional carbon capture based on steam extraction. COC of new system is higher than that of traditional one, approximately twice. The new system has higher NPV than that of normal one when subsidy electricity price for concentrated solar power (CSP) is higher than 1.18 CNY/(kW·h), otherwise, if subsidy electricity price for (CSP) is lower than 0.82 CNY/(kW·h), traditional system has higher NPV, and it depends on carbon capture rate to decide which system has better economy when subsidy electricity price is between them.