Bioethanol recovery and production using a pressure swing adsorption plant: Fault compensation and disturbance rejection by Fault-Tolerant MPC control

Bioethanol is obtained from distillates or processes for separating carbohydrates or compounds present in various organic raw materials (cereals or crops with high sugar content, such as beets); these can be third-generation to avoid affecting food sovereignty. This biofuel obtained from sugarcane bagasse represents 70% fewer emissions than fossil fuels. However, obtaining this biofuel requires advanced technological processes. An advanced process that can be used for this goal is the Pressure Swing Adsorption (PSA) method. This work focuses on producing bioethanol used as a fuel or oxygenating additive, complying with international purity criteria. This work aims to implement robust controllers that can keep the desired purity stable (above 99% wt of ethanol), attenuate disturbances in the feeding, and reduce the effect of faults in the operational valves. The productivity generated by these controllers goes from 59.09 to 59.20 kmol with a bioethanol recovery of 73.62% to 73.79%, using an energy efficiency of 60.10% to 60.30%. These results imply the attenuation of combined disturbances and the reduction of the effect of multiple faults in the supply valve, as well as trajectory changes to achieve a purity of 99.60% wt of ethanol.