Giorgia Lombardelli, Mauro Mureddu, Sarah Lai, Francesca Ferrara, Alberto Pettinau, Luciano Attori, Antonio Conversano, Manuele Gatti. CO₂ hydrogenation to methanol with an innovative Cu/Zn/Al/Zr catalyst: experimental tests and process modeling. Journal of CO₂ Utilization 2022; 65:102240.

Abstract

In this study, an innovative Cu/Zn/Al/Zr catalyst for the conversion of CO₂ and H₂ into methanol is tested at laboratory scale (0.5 g of catalyst into a cylindrical fixed bed reactor, with 9.1 mm internal diameter). Fourteen experimental tests are performed under isothermal conditions (T = 250 °C), covering a range of pressure (3.0–7.0 MPa), Gas Hourly Space Velocity (4000–13,000 h^-1) and H₂/CO₂ molar ratio (between 3 and 6) relevant to industrial applications, with or without CO in the feed mixture, with flow-rates ranging between 200 and 650 NmL min^-1. Based on the established Graaf’s kinetic model, new kinetic parameters are calibrated and a plug-flow model of the isothermal reactor is implemented and simulated in Aspen Plus. A reasonable agreement between experimental data and calibrated model is achieved, with deviations lower than 10% of the measured flow rates for each species in the product stream. CO₂ conversion up to 26% and methanol yields up to 13% are obtained during the test campaign (test run #12). The model represents a valid tool for future research or engineering studies targeting the design and performance assessment of demo/full-scale CO₂-to-methanol synthesis processes based on the Cu/Zn/Al/Zr catalyst introduced in this paper.