Thermo-economic evaluation of integrated gasification combined cycle co-generation system with carbon capture: A Pakistan's perspective

Emissions of greenhouse gases such as carbon dioxide are of major apprehension during power generation from coal. Global warming is the main detrimental effect of these emission products, and it becomes essential to mitigate the effect of emissions to the environment. Integrated gasification combined cycle (IGCC) technology operating in flexible mode of co-generation can play a key role in mitigating the air pollution and improving the overall efficiency of the plant. Thermal and economic analysis of the IGCC co-generation system help make fine decision to run the IGCC plant in flexible mode for co-generation of fuel and chemicals along with power. In this work, the IGCC co-generation system has been simulated using dry-coal feed gasifier (i.e., Shell gasifier) under thermochemical equilibrium with the Gibbs free energy approach in Aspen Plus (R). Thermal and economic models for the coal similar to Pakistani coals have been developed. Thermal and economic analysis on the IGCC co-generation system developed for simultaneous production of methane, ammonia and electricity has been performed. Performance indicator like cost of electricity (COE) of co-generation system has been calculated by considering methane and ammonia as a co-product and subtracting revenue credits from the annual operating cost. Results show that, COE for IGCC 100% power is 133.6 S/MWh in comparison to IGCC co-generation with value of 152.4 S/MWh. In the end, change in CO2 emission rate in co-generation system has also been investigated. Annual CO2 emission in IGCC co-generation system is 352,314.4 tons/year in comparison to 433,449.6 tons/year for IGCC 100% power design.