The property of hydrogen separation from CO2 mixture using Pd-based membranes for carbon capture and storage (CCS)

This study investigates the module configuration for upscaling CO₂ capture capacity to a bench-scale in hydrogen selective Pd-based composite membranes. In order to confirm effective upscaling, four plate-type membranes of two inch diameter were stacked in a newly designed plate-and-frame type module, reaching a total membrane surface area of 6.64 × 10⁻³ m² (66.4 cm²). A pure gas test carried out using H₂ and He confirmed that there were no effects of module configuration in gas permeation behavior, indicating that the upscale of the separation capacity by numbering-up of membranes using our module design was successful. The CO₂ enrichment test was conducted using a 40%CO₂ + 60%H₂ mixture (i.e. a similar composition for the coal gasifier after both the shift reaction and H₂O removal), under high feed pressure and flow rate, i.e. 600–2100 kPa and 0.48–0.72 N m³ h⁻¹. The mixture gas test confirmed that the bench-scale membrane module could enrich 40% of the CO₂ at a feed flow rate of 0.48 N m³ h⁻¹ up to 93% with a hydrogen recovery ratio of >90% at 673 K and a total feed pressure of 2100 kPa, i.e. ∼4 times CO₂ enrichment capacity of one membrane.