An experimental and modeling study of CO2-selective membranes for IGCC syngas purification

• A 2-stage CO2-selective membrane process for an IGCC plant was proposed.
• Economics of the proposed process was evaluated using membrane data.
• The optimum cost of electricity was identified by varying Stages 1 and 2 feed pressures.
• The increase in the cost of electricity with the proposed process varied from 14% to 18%.

In recent years, integrated gasification combined cycle (IGCC) technology has gained significant attention for large-scale power generation with carbon capture. In an IGCC power plant, the syngas is typically directed to the gas turbine (for power generation) after CO2 and H2S removal. This work describes the transport properties of the CO2-selective polymeric facilitated transport membranes for syngas purification at different pressures (2–15 bar) and 107 °C. These membranes contain amines as CO2-carriers that are dispersed in a crosslinked polyvinylalcohol (PVA) matrix. Furthermore, a two-stage membrane process is proposed for CO2 removal from syngas in an IGCC plant. A process modeling and cost-sensitivity analysis of the proposed two-stage membrane process was performed. The effects of feed pressure, temperature, membrane permeance, and selectivity on the overall increase in the cost of electricity (COE) were analyzed. An increase in the COE of 14–18% was estimated for 90% CO2 removal and >99% H2 recovery using the two-stage membrane process in an IGCC power plant.