Simulation, Optimization and Analysis of a Syngas to Ethanol and other Oxygenates Production Plant Using a Rh-Based Catalyst

Synthesis gas (syngas) is mostly known by its use on ammonia and hydrocarbons (Fischer-Tropsch process) production. However, a less explored route to produce chemical products, among them alcohols and other oxygenates, from syngas is gaining attention over the last few years. In this route, an initial feedstock as biomass is firstly gasified to synthesis gas, which is reformed, cleaned, compressed and finally catalytically converted in a mixture of alcohols and oxygenated products that after separation steps attain sufficient purity to be sold. In this case of study, the commercial simulator ASPEN Plus v7.3 is used to evaluate the application of a Rh-based (Rh-Mn-Li-Fe/SiO2) catalyst in a small scale plant with processing capacity of 100 kmol/h of pure syngas. This plant, besides methane, water, and CO2 produces 8 oxygenated products: methanol, ethanol, propanol, butanol, acetic acid, acetaldehyde, methyl and ethyl acetates, being necessary 9 further separation or concentration steps in order to obtain the products in their desired purity. The main goals of this work were to design and optimize a process so as to produce alcohols and other oxygenates using syngas as feedstock. After conceiving the process, an optimization was performed, which started by evaluating the reactor conversion/selectivity in order to produce more add-value products. Then, the downstream separation processes were optimized searching for less energy consumption and recovering as much as possible add- value products. Lastly, we aimed at possible solutions and improvements concerning sustainability, feedstock and energy integration, and utilities consumption.