Methanol synthesis by CO2 hydrogenation using reactive distillation

Abstract

Methanol is a very versatile product that can be found in a large number of industrial applications such as it’s use as a solvent or as a raw material for the synthesis of methyl ether, methylamine, etc. Due to the current environmental situation, many research projects are starting to focus on the reduction of greenhouse gases pollution, which directly affects fossil fuels and certain industries that have a large CO2 stream as their major waste (cement plants, thermal power plants, etc.). One of the most studied projects nowadays is the synthesis of carbon-based fuels using CO2 as raw material, which could be used to store the surplus energy obtained from renewable sources in chemical products, to be reused later on. This method has great advantages since with renewable energy and a carbon source (such as CO2) "green" fuels could be produced and these could be easily transported with current logistics and used by many facilities, due to their similarity to fossil fuels. One of the carbon-based fuels with the greatest potential is methanol due to its high energy density. Currently there are several plants producing methanol from CO2 and hydrogen, but they are still too unprofitable to be implemented worldwide. This project studies an intensified process, the reactive distillation process, as an alternative to the current methanol synthesis process to make it more cost effective and efficient. Reactive distillation is an intensified process which allows to reduce the number of equipment required to carry out a process, since several unit operations take place simultaneously inside the column. As it is a process that has not been studied yet, in this project a model has been proposed (simulated using Aspen plus technology) and different points have been evaluated: - Proposal for the process using assumptions and calculation bases. - Process parameters: column reflux, total distillation column stages, feed stages and product obtained by column bottom-head flow stream. - Improvement proposals for the process studied: equipment adjacent to the main column. The different stages of the whole process have been simulated with the ASPEN program and it has been demonstrated that this initial study opens the possibility for future studies since the results are optimistic for the viability of the project in the industrial field