Development of CO2 Molecular Gate Membranes for IGCC Process with CO2 Capture

Abstract

Carbon dioxide (CO2) capture and storage (CCS) is widely accepted as an important option for mitigating climate change. It is very important to reduce the cost of CO2 capture to implement CCS. CO2 capture by membrane is a promising technique because it is energy efficient and simple to operate. One promising means of reducing CO2 emission is the development of integrated coal gasification combined cycle with CO2 capture & storage (IGCC-CCS). We are currently developing CO2 molecular gate membrane, with the goal of producing a new, high-performance separation membrane modules for IGCC-CCS. In the concept of the molecular gate membrane, the pathway for gas molecules is occupied solely by CO2, which acts as a gate to block the passage of other gases. Consequently, the amount of H2 permeating to the permeate side of the membrane is greatly limited and high concentrations of CO2 can be obtained. As the molecular gate membrane, poly(amidoamine) (PAMAM) dendrimer/polymer hybrid membranes and membrane modules were developed in the METI project, “CO2 Separation Membrane Module Research and Development Project” (2011FY-2014FY). The cost target was 1,500 JPY/ton-CO2. We succeeded in improving the separation performance of such membranes through the modification of poly(vinyl alcohol) (PVA)-based materials, and the target CO2 separation performance was obtained under high-pressure conditions of 2.4MPa using laboratory-scale membranes. It was shown that PAMAM dendrimer/polymer hybrid membrane module is suitable for IGCC process with CO2 capture.