Sustainably Scaled Electrochemical Synthesis of 3-Propyladipic Acid in Line with Fluctuating Grid Supply

Abstract

Chemical production is a significant contributor to global climate change, which expedites the growing demand for transitioning to more sustainable and climate-friendly methodologies. Ideally this should include high compatibility with the fluctuating electricity supply which results from renewable energy sources in the electrical grid. Here we show an electrochemical path for the 3-propyladipic acid synthesis from 4-propylcyclohexanol implementing a semi-technical electrochemical continuously stirred tank reactor. Following a Design of Experiments approach, we found a strong influence of the biphasic electrolyte mixing and the continuous feeding in of the substrate. By switching to an electrolyte recirculation mode and efficient mixing, the isolated product yield could be increased up to 31 % for a 10 L total reaction volume, indicating the potential for further scale-up into the technical range. This reaction proceeds while forming several by-products, which have not been fully described yet. A proposal for the formation mechanism is included.