Combustion Webinar 06/14/2023, Speakser: Jay Benziger

Water management is a major technological problem with Polymer Electrolyte Membrane (PEM) Fuel Cells. Bad performance is seen with membranes operating at low relative humidity or with liquid water flooding the fuel cell. Employing model fuel cell reactors that elucidate the basic physics of Polymer Electrolyte Membrane (PEM) fuel cell reactors we have been able to demonstrate that the water produced at the cathode can auto-humidify the fuel cell permitting fuel cell operation with dry feeds to 130°C. PEM fuel cells reactors are shown to be conceptually identical to exothermic reactions, e.g. flames! Model fuel cells are employed to elucidate the mechanism of liquid water motion through the PEM fuel cell. Water slugs and drops form in the gas flow channels of fuel cells giving rise to spatial temporal current density fluctuations. The current fluctuations were reduced by redesigning the flow channels to exploit gravity to assist in water drainage. Water emerging from the porous electrode grows into drops that eventually occlude the open area of the channel. Drops detach and move when the force for gas flow through the porous electrode is greater than the force to advance the solid/liquid contact lines of the drop. The shape and surface properties of the flow channel can be engineered to minimize blockage effects of drops and slugs. In this talk we shall demonstrate the use of reaction engineering principles to improve PEM fuel cell design.

Dr. Jay Benziger is a professor of Chemical Engineering at Princeton University. He was educated in Mathematics, Chemistry and Chemical Engineering at Carleton College (BA 1973), Columbia University (MS 1975) and Stanford University (PhD 1979). Professor Benziger is an expert in chemical reaction engineering and chemical process technology. Professor Benziger’s group has developed novel reactor designs for Polymer Electrolyte Membrane Fuel Cells that have provided the physical basis controlling the dynamic behavior of PEM fuel cells. Professor Benziger’s group has also elucidated the coupling of mechanical properties and transport processes in polymer electrolytes. Professor Benziger co-authored over 350 journal papers and holds 7 US patents. He has received the Exxon Award in Solid State Chemistry from the Inorganic Chemistry Division of the American Chemical Society, and the Purdy Award from the American Ceramic Society. He is a fellow of the American Institute of Chemical Engineers. He is on the Editorial Advisory Boards of Industrial Engineering Chemistry and Membranes and is a Senior Editor of Journal of Power Sources.