SusChem: Sustainable Chemicals Production Using Solid Polymer Electrolyte Reactors

Vanderbilt University, Nashville TN

Investigators

Abstract

Principal Investigator: Peter N. Pintauro Number: 1437384 Nontechnical Description To address concerns related to carbon dioxide emissions and dependence on foreign sources of fossil fuels, the chemical process industry is working to transition its manufacturing methods towards more sustainable raw materials and production schemes. A potentially transformational strategy to improve the environmental and energy sustainability of organic chemical manufacturing would involve the replacement of thermally driven reactions with processes that are driven directly by electricity obtained from renewable resources. A prime example is the reaction of organic chemicals with hydrogen gas to make a variety of new chemicals, a process called hydrogenation, which accounts for up to 20% of all reaction steps in a typical chemical process. Hydrogen gas is typically obtained from the reforming of natural gas, which is an energy-intensive and complicated process requiring fossil fuels. New systems based on electrochemistry offer a sustainable alterative. The overall goal of this study is to develop an electrochemical reactor to carry out the hydrogenation of organic chemicals using electricity, water, and the organic chemical feedstock as the only inputs. In particular, solid polymer electrolyte (SPE) reactors which promote electrochemical reactions are a potentially efficient platform for this purpose. These reactors internally generate hydrogen which feeds the hydrogenation reaction that is occurring at the cathode of the reactor system. The mild temperatures and high hydrogen concentrations at the cathode can promote the production of a variety of commercially relevant hydrogenated organic products. The innovative aspects of the project include the use of electricity, preferably from renewable resources, to drive the chemical reactions under mild conditions of temperature and pressure, the development of novel catalytic cathodes to improve product selectivity, and the use of water as the source of hydrogen. The project will train graduate students in multi-disciplinary science and engineering technologies, including electrochemistry, chemical engineering, and chemical catalysis. Technical Description The overall goal of this study is to develop an electrochemical reactor to carry out the hydrogenation of organic chemicals using electricity, water, and the organic chemical feedstock as the only inputs. The availability of low-cost, renewable electricity could drive a transformation in the chemicals processing industry via a significant expansion in the commercial use of electrochemical reactors that use solid polymer electrolytes (SPE) for driving organic hydrogenation reactions. Expanded use and improved designs for such reactors would benefit from a better understanding of the inter-relationships between cathode composition, reactor operating parameters, product yields, and current efficiencies. Towards this end, this project will investigate the use of new catalytic materials and hybrid electrochemical/chemical mixed catalytic systems as the cathode electrode in SPE reactors, and study the selective hydrogenation of multifunctional organic substrates. Experiments will be performed to correlate reactor operating conditions and feed composition to power consumption and products yield. The mechanistic details of electrochemical organic substrate hydrogenation and hydrogen generation on catalytic cathodes will be elucidated through analysis of kinetic data from batch slurry reactor experiments. The project will train graduate students in multi-disciplinary science and engineering technologies, including electrochemistry, chemical engineering, and chemical catalysis.