Syngas to higher alcohols synthesis over 3D printed KMoCo/ZSM5 monolith

Abstract

The catalytic conversion of syngas into high carbon number alcohols (ethanol, propanol, butanol) has opened an avenue for the development of sustainable aviation fuels. The commercial production of higher alcohols from syngas remain challenging because of several constraints including poor selectivity, harsh operating conditions, and unavailability of suitable technology. The present study is based on metal impregnated zeolite-based catalysts for catalytic conversion of syngas into higher alcohols. Following the superior catalytic performance of powdered ZSM5 (Si/Al 100), a structured monolith was engineered via 3D printing (Hyrel 3D – Engine SR). The catalyst precursors (K–Mo–Co) were in situ grown (by hydrothermal treatment) onto channels of zeolite monolith. A comparison between monolithic and powdered structures revealed a similar catalytic performance at lower space velocities (< 3000 h−1). With an increasing space velocity at 6000 h−1 and above, the structured catalyst retained its catalytic performance, whereas, carbon monoxide conversion dropped significantly (~20%) over powdered catalyst. Moreover, the by-products formation (methane and carbon monoxide) were reduced over structured monolith. The development of zeolite-based monolith has provided an opportunity to overcome diffusional limitations for better utilization of intrinsic kinetics of Mo-Co based catalysts for higher alcohols synthesis.