A Technoeconomic Model Coupled with HYSYS to Analyze the Electroreduction of Carbon Dioxide to Ethanol

Abstract

This research develops a technoeconomic analysis to study the profitability of ethanol production from CO 2 electroreduction. A HYSYS simulation is used to calculate the separation costs, a challenge in previous models available in literature. The profitability of a 10 000 kg per day CO 2 electroreduction plant to produce ethanol is studied. An optimization of the pressure swing adsorber and distillation tower, which greatly influence the total cost of the plant (≈20% of total cost), is carried out, obtaining a total cost of separation of £1.94 × 10 6 . The study demonstrates that reducing the voltage applied to values around 0.5 V, i.e., by increasing the pH up to 12 makes the process economically feasible with a current density over 15 mA cm −2 . It also shows that the process is economically feasible using a current density of 5 mA cm −2 if the electricity cost from renewable sources drops to 2.0 × 10 −2 £ kWh −1 . Finally, it is proved that if catalyst stability is not considered, some catalysts currently available in the literature can be used with a positive economic income. The results of this research show that the industrial electroreduction of ethanol can be feasible and can attract interest in the industrial adoption of the technology.