Economic assessment of integrated coal gasification combined cycle with sorbent CO2 capture

Abstract

An integrated gasification combined cycle process with sorbent CO2 capture (IGCC-SCC) using lime (CaO) was developed to assess the application of the gasification process to the power generation industry. Aspen Plus was used to simulate the detailed heat and material balance of the process. The process modeling results, including the composition, flow rate, temperature, pressure and enthalpy of different streams, were used to determine the sizes of the process units and related equipment.A high-level economic model was prepared to evaluate the economic viability of an IGCC-SCC plant and to compare it to GE Energy and Shell Convective gasification plants for converting coal to power. The results show that the proposed process would produce 560MW of power with a net plant efficiency of 46.4% compared to those of the GE Energy and Shell Convective plants, which are 39.2% and 42.0%, respectively. The total capital investment required for an IGCC-SCC facility having a coal capacity of 3000tpd was estimated to be $1082million, which translates to a specific annual capital expenditure (CAPEX) of 1889$/kW. It was estimated that an IGCC-SCC plant could generate an after-tax internal rate of return (IRR) of 14.4%, which is equivalent to a payback period of 9.1years. This represents an improvement over the IRR and payback period of the GE Energy and Shell Convective plants at the same capacity.A sensitivity analysis was also conducted in order to identify the relative importance of key economic variables driving the project returns and to quantify the impact of any changes to the assumptions used in the project economics.