CO2-selective membranes for hydrogen production and CO2 capture – Part II: Techno-economic analysis

Abstract

Syngas processing often requires separation of CO2 and hydrogen for hydrogen production, and the resulting CO2-enriched stream presents an opportunity for simultaneous CO2 capture. For example, syngas-based integrated gasification combined cycle (IGCC) power plants are envisioned as an efficient means of producing power from coal where CO2 capture technologies can be applied relatively easily. Membrane technology is an attractive approach for CO2 capture because of inherent process advantages such as simplicity, reliability, compactness and modularity. This paper (Part II of a two-part study) performs techno-economic analysis for CO2-selective membranes in three hydrogen production or utilization applications: methane reformer/pressure swing adsorption processes, oxygen-blown coal-fired IGCC power plants using GE gasification technology, and air-blown coal-fired IGCC power plants using Transport Integrated Gasification (TRIG) technology. These processes require membranes with CO2/H2 selectivities of 10–20, which can be provided using PolarisTM membranes. Hybrid approaches using a combination of membrane and cryogenic processes are evaluated for the production of high-pressure liquid CO2 ready for utilization or sequestration. The optimal membrane CO2/H2 selectivity and influence of CO2 capture rate on the cost of CO2 capture are determined, providing general guidelines for future membrane development. The cost of CO2 capture with these membrane processes depends not only on the feed CO2 partial pressure, but on the feed CO2 concentration as well.