Enhanced Methanol Synthesis Process via an Integrated Process Involving CO₂ Hydrogenation under Plasma Conditions

Abstract

An integrated process combining CO 2 reduction with hydrogen under plasma conditions and catalytic methanol synthesis offers an encouraging option for the conversion of CO 2 from exhaust gas marine emissions. The process interconnects a microwave-induced plasma reactor and a methanol synthesis fixed-bed reactor. The paper explores the CO 2 hydrogenation process in the microwave-induced plasma reactor via an unsteady-state, two-dimensional (2-D) axisymmetric, nonisothermal model and the catalytic methanol synthesis in the fixed-bed reactor via an unsteady-state, two-scale, isothermal model, highlighting the impact of key parameters on the integrated process performance. In the microwave-induced plasma reactor, CO 2 conversion reaches 82% when the reactor is supplied with only H 2 and CO 2 and 74% when H 2 is supplied in the diesel engine exhaust (H 2 /CO 2 ratio = 3). However, this enhanced CO 2 conversion at large H 2 /CO 2 ratios is achieved by increasing the power of microwave plasma to compensate for the temperature drop induced by the amplified radial heat transport and radiative wall heat transfer. The specific energy input required to achieve a reasonable CO 2 conversion is close to the specific energy input of the conventional thermal catalytic process for H 2 /CO 2 = 1 and when H 2 is supplied in the diesel engine exhaust. A large specific energy input into plasma reactor allows for high CO 2 conversion and low energy efficiency. Methanol synthesis process in the fixed-bed reactor is improved by the amplification of H 2 /CO x ratio and when CO 2 is progressively substituted by CO, which is easily achieved via the reverse water-gas shift reaction in a microwaveinduced plasma reactor located upstream from the methanol synthesis reactor.

CO2 Capture and Utilization Editorial

“…The conversion of CO 2 from exhaust gas marine emissions via a hydrogenation route was investigated by Iliuta and Larachi . They explored, by process modeling, the combination of CO 2 reduction with hydrogen under microwave-induced plasma conditions and catalytic methanol synthesis in an integrated process.…”

“…44 The conversion of CO 2 from exhaust gas marine emissions via a hydrogenation route was investigated by Iliuta and Larachi. 45 They explored, by process modeling, the combination of CO 2 reduction with hydrogen under microwaveinduced plasma conditions and catalytic methanol synthesis in an integrated process. CO 2 hydrogenation to methanol was also investigated by Geng et al, 46 but their focus was the promotional effect associated with bimetallic phosphide catalysts.…”

Plasma-Catalytic Methanol Synthesis from CO2 Hydrogenation over a Supported Cu Cluster Catalyst: Insights into the Reaction Mechanism

“…In recent years, plasma-assisted heterogeneous catalysis, simply called “plasma catalysis”, has been applied in C1 chemistry and has attracted more and more attention. − Various “plasma effects” have proven to be beneficial for CO 2 conversion and product yields, which makes plasma catalysis an attractive alternative to thermal catalysis. Therefore, in this paper, we want to explore whether a combination of a Cu cluster catalyst and plasma shows a synergistic effect for CO 2 hydrogenation to CH 3 OH.…”

Conversion of CO2from the Energy Systems On-Board Ships via Catalytic Cycloaddition to Styrene Oxide: Modeling and Numerical Simulation

“…17 The heterogeneous kinetic model developed considering that the total catalyst surface coverage incorporates SO, CO 2 , and SC adsorption is 17 (9) where K SO = 1 m 3 /kmol, K COd 2 = 1 m 3 /kmol, K SC = 0 m 3 /kmol, k = 3. are coupled with the hydrodynamic model) were formulated for isothermal reactor conditions, constant catalyst activity over time, fully wet catalyst particles inside, and the cycloaddition reaction exclusively in the catalyst. The unsteady-state continuity equations considering the nonuniform velocities profiles are (10) (11) (12) The corresponding boundary conditions are…”

“…11 Also, the process integrating plasma CO 2 reduction and methanol synthesis can be a stimulating alternative for the conversion of carbon dioxide from marine engine exhaust gas. 12 T h i s c o n t e n t i s The catalytic synthesis of cyclic carbonates via CO 2 cycloaddition to epoxides is an encouraging reaction in terms of sustainability to turn the carbon dioxide into value-added chemicals 13,14 and can be used for the conversion of carbon dioxide from the emissions on-board marine vessels. This chemical reaction is a very interesting green route for carbon dioxide conversion because CO 2 can be incorporated into the epoxy molecule without generating byproducts 14 and is a safer alternative to the obnoxious and corrosive conventional one through diols and poisonous phosgene.…”