Conditions for the Joint Conversion of CO2 and Syngas in the Direct Synthesis of Light Olefins Using In2O3-ZrO2/SAPO-34 Catalyst

Ander Portillo; Ainara Ateka; Javier Ereña; Andres T Aguayo; Javier Bilbao

doi:10.1021/acs.iecr.1c03556

Conditions for the Joint Conversion of CO₂ and Syngas in the Direct Synthesis of Light Olefins Using In₂O₃-ZrO₂/SAPO-34 Catalyst

Ind Eng Chem Res. 2022 Jul 27;61(29):10365-10376. doi: 10.1021/acs.iecr.1c03556. Epub 2021 Nov 9.

Authors

Ander Portillo¹, Ainara Ateka¹, Javier Ereña¹, Andres T Aguayo¹, Javier Bilbao¹

Affiliation

¹ Department of Chemical Engineering, University of the Basque Country UPV/EHU, P.O. Box 644, Bilbao 48080, Spain.

Abstract

The conditions for promoting the joint conversion of CO₂ and syngas in the direct synthesis of light olefins have been studied. In addition, given the relevance for the viability of the process, the stability of the In₂O₃-ZrO₂/SAPO-34 (InZr/S34) catalyst has also been pursued. The CO+CO₂ (CO _x ) hydrogenation experimental runs were conducted in a packed bed isothermal reactor under the following conditions: 375-425 °C; 20-40 bar; space time, 1.25-20 g_catalyst h mol_C ^-1; H₂/(CO _x ) ratio in the feed, 1-3; CO₂/(CO _x ) ratio in the feed, 0.5; time on stream (TOS), up to 24 h. Analyzing the reaction indices (CO₂ and CO _x conversions, yield and selectivity of olefins and paraffins, and stability), the following have been established as suitable conditions: 400 °C, 30 bar, 5-10 g_cat h mol_C ^-1, CO₂/CO _x = 0.5, and H₂/CO _x = 3. Under these conditions, the catalyst is stable (after an initial period of deactivation by coke), and olefin yield and selectivity surpass 4 and 70%, respectively, with light paraffins as byproducts. Produced olefin yields follow propylene > ethylene > butenes. The conditions of the process (low pressure and low H₂/CO _x ratio) may facilitate the integration of sustainable H₂ production with PEM electrolyzers and the covalorization of CO₂ and syngas obtained from biomass.