|The HES has three outputs: heat, power and hydrogen|
Air Products has awarded a subcontract to FuelCell Energy under a United States Department of Energy (DOE) Cooperative Agreement to evaluate, design and demonstrate a next-generation Hydrogen Energy Station (HES).
The HES (diagram at right, Click to enlarge) is being designed to co-produce electricity and hydrogen for vehicle fueling and electrical power from a single system capable of using a variety of gaseous feedstocks such as natural gas, propane and anaerobic digester gas from municipal and industrial wastewater treatment facilities.
Scheduled to come on-stream in 2007, the HES will integrate FuelCell Energy’s Direct FuelCell (DFC) sub-megawatt power plants with an Air Products’ hydrogen purification system. FuelCell Energy is involved in a similar project with QuestAir (earlier post).
FuelCell Energy is a leader in the development and manufacture of high-temperature fuel cells for electric power generation, with more than 40 installations of its DFC power plants worldwide.
The current generation of DFCs are high-temperature carbonate fuel cells with an operating temperature of some 1,200º F (649º C). Fuel Cell Energy is exploring the use of solid oxide technology for smaller (and even higher temperature) units in the future. This is not the same type of fuel cell as the PEM used in an automobile, which is smaller, runs at lower temperatures, produces less power and requires an external supply of hydrogen.
|Operation of the carbonate Direct Fuel Cell. Some 20%–30% of the hydrogen produced internally is available for export as a fuel.|
The DFC reforms the input gas 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 cooled, pressurized and purified prior to external use—the role of Air Products’s technology. (Thus, the station is actually a combined heat, power and hydrogen station.)
The HES is designed to provide up to 250 kilowatts of electricity daily, sufficient to provide the base load power requirements of a 300-room suburban hotel, and enough hydrogen to fuel 20 cars per day.