Treatment of effluent from methanol synthesis via Methanol Assisted Water Electrolysis

In addition to the reduction in applied potential required to initiate electrolysis compared to the conventional water-only process, Methanol Assisted Water Electrolysis (MAWE) research has increased due to the growing interest in green hydrogen production and reducing electrical costs. This thesis wanted to explore a further application for this innovative electrochemical process by treating a methanol contaminated water stream from methanol synthesis distillation and reduce to minimal COD concentration required by law for safe release to the environment. As well as to propose optimal operating parameters based on the Polarization Curves obtained from the used Proton Exchange Membrane (PEM) zero-gap design cell at low methanol concentrations. Moreover, Tafel approximation was used for kinetic and mass-transfer characterization of the system. Using the given data, experiments were conducted at 100 and 450 mA of applied current for three hours, resulting in a reduction of 23% of the initial COD concentration and 51% of Faradaic efficiency for the anodic reaction at 0.3M methanol concentration and 450 mA. While the production of hydrogen reached 86% of efficiency at the same operating parameters and sample. Low COD removal was attributed to unwanted water electrolysis and the need for long operating periods at low currents that normally used in current literature and processes. It was concluded that this process cannot be considered an improvement or even a substitution for the conventional wastewater treatment process due to the high costs and operating periods required. However, it provides a sustainable option for reusing resources, production of hydrogen and as a CO2 neutral solution.