A techno-economic and life cycle assessment for the production of green methanol from CO2: catalyst and process bottlenecks

Tomas Cordero-Lanzac,Adrian Ramirez,Alberto Navajas,Lieven Gevers,Sirio Brunialti,Luis M Gandía,Andrés T Aguayo,S Mani Sarathy,Jorge Gascon

doi:10.1016/j.jechem.2021.09.045

Abstract

The success of catalytic schemes for the large-scale valorization of CO2 does not only depend on the development of active, selective and stable catalytic materials but also on the overall process design. Here we present a multidisciplinary study (from catalyst to plant and techno-economic/lifecycle analysis) for the production of green methanol from renewable H2 and CO2. We combine an in-depth kinetic analysis of one of the most promising recently reported methanol-synthesis catalysts (InCo) with a thorough process simulation and techno-economic assessment. We then perform a life cycle assessment of the simulated process to gauge the real environmental impact of green methanol production from CO2. Our results indicate that up to 1.75 ton of CO2 can be abated per ton of produced methanol only if renewable energy is used to run the process, while the sensitivity analysis suggest that either rock-bottom H2 prices (1.5 $ kg−1) or severe CO2 taxation (300 $ per ton) are needed for a profitable methanol plant. Besides, we herein highlight and analyze some critical bottlenecks of the process. Especial attention has been paid to the contribution of H2 to the overall plant costs, CH4 trace formation, and purity and costs of raw gases. In addition to providing important information for policy makers and industrialists, directions for catalyst (and therefore process) improvements are outlined.

Highlights

The high environmental impact of greenhouse gas emissions requires the development of technologies for the capture, storage and valorization of CO2
Without considering the reaction at 250 °C and 3.7 g h molCO2−1, which shows negligible conversion values, methanol selectivity significantly declines as temperature increases
A multidisciplinary study of a methanol production plant from CO2 has been carried out, assessing from the possibilities of a novel catalyst to the economic viability and the main operational issues coupled with a life cycle assessment

Summary

Introduction

The high environmental impact of greenhouse gas emissions requires the development of technologies for the capture, storage and valorization of CO2. In this scenario, the catalytic conversion of captured CO2 has attracted a great deal of attention over the last few decades. Production of methanol, dimethyl ether and other hydrocarbons is amidst the most studied CO2 hydrogenation processes [1,2]. Among these possibilities, methanol stands out [3,4], thanks to its versatility as commodity chemical, potential as a marine fuel, and as feedstock for the manufacture of intermediate chemicals and even more complex road transport fuels [5]. The uncertainty of calculations was highlighted, as well as the high costs associated with these new technologies, mainly caused by electrolizer capital costs and stack life [8]

Methods

Results

Conclusion