FuelCell Energy has developed a cost-efficient system to separate pure hydrogen from a gas mixture that then can be sold as fuel for hydrogen vehicles or industrial uses. Fuel Cell Energy is a leader in the development and manufacture of high-temperature direct fuel cells (DFC) for electric power generation, with more than 45 installations worldwide.
The US Department of Defense (DoD) has awarded FuelCell Energy $1.36 Million to advance this Electrochemical Hydrogen Separator (EHS) project for use with the company’s Direct FuelCell (DFC) power plants.
Direct Fuel Cell power plants equipped with such a hydrogen export system could be used by FuelCell Energy’s customers to produce pure hydrogen for industrial uses or for vehicle fuel, in addition to generating electrical power and heat from the fuel cell. (Earlier post.)
The DFC takes in a hydrocarbon fuel (pipeline natural gas, propane, methanol, ethanol, digester gas, coal-derived gases, diesel, and others) and reforms it internally to produce the hydrogen required for use in the fuel-cell reaction. During normal operation, the fuel cell itself only consumes some 70%–80% of the hydrogen feed, leaving 20%–30% available for export. The hydrogen would first need to be separated, cooled, pressurized and purified prior to external use.
Unlike other means of separating hydrogen which rely on compression, FuelCell Energy’s proprietary EHS technology has no moving parts. The company expects EHS to be significantly more reliable and efficient than conventional methods, and to save up to one-half of the energy required when compared to conventional compression based-methods of hydrogen separation.
A subscale prototype EHS unit developed by FuelCell Energy is currently operating at the University of Connecticut Global Fuel Cell Center. This test was made possible through a $600,000 grant provided by the Connecticut Clean Energy Fund under its operational demonstration program.
Work on electrochemical hydrogen separation systems stretches back to the late 1980s and early 1990s. The basic concept is to oxidize hydrogen in the impure stream to H+ ions, transport those ions through a cation transport electrolyte membrane under an applied electric field, and discharge them in a pure hydrogen state on the cathode.
The subscale EHS system currently produces 1,200 liters per hour of pure hydrogen (1.2 Nm3 or 0.1 kg). With the DoD award, the unit will be scaled up by a factor of 25 and will operate in conjunction with a sub-megawatt DFC power plant in Danbury for testing.