Cost-Constrained Design of Electrochemical Hydrogenation Processes

Abstract

During the past decade, there has been a concomitant decrease in the cost of renewable electricity and increase in interest in electrochemical transformations in the chemical industry. Although electrochemical technologies present a number of theoretical advantages for chemical processing, they remain poorly understood compared to their thermochemical analogues, especially at large scales. As a subset of these, electrochemical hydrogenations are poised to be an especially influential electrochemical technology considering the desire to transition from traditional crude-based feedstocks to biomass-based sustainable feedstocks. Indeed, several groups have demonstrated the feasibility of electrochemical hydrogenation for a number of interesting reactions: the saturation of aromatic hydrocarbons,1–3 the hydrogenation of furfural to valuable biofuel additives or platform chemicals,4–6 and the conversion of whole bio-oil streams to their hydrogenated components.7,8 However, to both accelerate the development and deployment of these novel processes, economic analysis which can assess credible pathways to implementation are necessary. Contrary to traditional techno-economic modeling however, we must instead rely on an inverted scheme, wherein the desired system cost metrics can help us to establish the necessary constituent performance metrics and guide further fundamental research questions. Given the necessity of economic modeling to guide these research directions for electrochemical hydrogenation, we have focused on developing a generic techno-economic model that can be used to evaluate a wide variety of electrochemical hydrogenation conditions. From this model, we are able to evaluate the feasibility of three selected electrochemical technologies. First, to establish the accuracy of our model, I will evaluate water electrolysis as a means of hydrogen production comparing our results to established U.S. Department of Energy models. Second, we will evaluate the feasibility of electrochemical hydrogenation of bio-based guaiacol to produce either phenol or cyclohexanol compared to current production methods. Finally, we will investigate the hydrogenation of furfural to methylfuran and furfuryl alcohol. Such inverted techno-economic models can guide research investigations to address the most important deficiencies in the current technology and provide performance benchmarks for these technologies.