Long-term CO2 capture tests of Pd-based composite membranes with module configuration

• CO2 capture was investigated in a Pd–Au alloy membrane.
• CO2 capture tests were carried out using the 40%CO2/60%H2 mixture gas.
• The Pd–Au membrane is a promising way to achieve >90% of CO2.
• SS 310S module was very stable after the long-term test for 3150 h.

In this study, we investigate the configuration of a Pd–Au composite membrane on a porous nickel support and membrane modules for withstanding the capture of CO2 from a coal gasifier for a long time. The hydrogen permeation flux, recovery and CO2 capture were experimentally evaluated using two different modules and two conditions. As in our study, the CO2 capturing and durability tests were performed with a 40% CO2/60% H2 feed gas mixture in stainless steel (SS) 316L and 310S membrane modules. As a result, it is achieved the durability tests for more than 1150, 1100 (SS 316L module) and 3150 h (SS 310S module) with pressure cycles from 100 to 2000 kPa at 673 K. The durability of the membranes and membrane modules was demonstrated under pressure cycles from 100 to 2000 kPa at 673 K and the SS 310S module was very stable after 3150 h. The durability test for more than 3000 h demonstrated that there was no significant intermetallic diffusion between the PNS and Pd–Au layer. The CO2 capturing test performed using a 40% CO2/60% H2 mixture confirmed that the CO2 capturing capacity of the membrane and membrane module was 2.0 L/min for a CO2 concentration in the retentate stream of 92.3% and that the hydrogen recovery ratio increased with increasing pressure and reached 93.4%. Furthermore, we suggest that the SS 310S module configuration, CO2 capturing test using Pd–Au/ZrO2/PNS membrane and membrane module is very suitable for application as an Integrated Gasification Combined Cycle (IGCC) system due to very simple numbering-up stackable module design was successful.