Technical economic evaluation of a system for electricity production with CO2 capture using a membrane reformer with permeate side combustion

The paper investigates the application of a novel concept, based on a membrane reactor with permeate side combustion (MRPC), to capture CO2, in a natural gas fuelled power plant. The MRPC combines the steam reforming reaction on the feed side and hydrogen separation through a dense hydrogen selective membrane, with combustion of part of the permeated hydrogen, using a mixture of steam, nitrogen and air as a sweep gas. The remaining hydrogen permeated is used in the gas turbine of the combined cycle. The unconverted fuel in the high pressure CO2 rich stream exiting from the membrane reactor is burned with oxygen to permit carbon dioxide sequestration.

The thermodynamic performance and economic prospects of a power plant incorporating MRPC are investigated, with a sensitivity analysis on several parameters involved. The membrane surface area required is calculated using a membrane reactor model. The final results indicate a carbon capture ratio of 100% and a net overall efficiency close to 50%. If compared to a conventional natural gas fuelled combined cycle without CO2 capture, this technology leads to an increase in cost of electricity of about 30% and a CO2 avoidance cost of about 30 €/tCO2.