Ultra-low temperature water-gas shift reaction catalyzed by homogeneous Ru-complexes in a membrane reactor - membrane development and proof of concept

A monolithic membrane reactor combining the supported ionic liquid-phase (SILP) catalyzed ultra-low temperature water-gas shift reaction (WGSR) with in situ product removal is presented. The SILP catalyst consists of the transition metal complex [Ru(CO)(3)Cl-2](2) homogeneously dissolved in 1-butyl-2,3-dimethylimidazolium chloride [C(4)C(1)C(1)Im]Cl and supported on alumina pellets. These Ru-SILP pellets are deposited inside the channels of a silicon carbide monolith. The resulting monolithic catalyst is very active and stable in the WGSR in the temperature range between 120 and 160 degrees C, thereby making full use of the high equilibrium conversion at these conditions. A facilitated transport membrane was coated onto the smooth outside of the SiC monolith to allow preferential removal of CO2 compared to H-2. The proof of this concept has been shown under industrially relevant conditions using a biogas feed. These results demonstrate, for the first time, the combination of homogeneous SILP catalyzed WGSR with enhanced in situ removal of one of the products (here: CO2) via facilitated transport membrane separation.

Automated summary

By combining the supported ionic liquid-phase (SILP) catalyzed ultra-low temperature water-gas shift reaction (WGSR) with in situ product removal, a monolithic membrane reactor has been developed that is highly active and stable in the temperature range of 120 to 160 degrees C. The concept was proven under industrially relevant conditions using biogas feed, demonstrating for the first time the enhanced in situ removal of CO2 via facilitated transport membrane separation in combination with homogeneous SILP catalyzed WGSR.