|The HES concept. Click to enlarge.|
Air Products, a leader in hydrogen fueling station technology and the world’s largest producer of hydrogen, and FuelCell Energy, Inc., a manufacturer of stationary fuel-cell power systems, have together begun construction of a demonstration hydrogen energy station capable of providing low-cost hydrogen, electric power and heat from one integrated unit.
The tri-generation system (hydrogen, electricity and heat) is designed to operate on renewable fuel sources, such as anaerobic digester gas from industrial or municipal wastewater treatment facilities, as well as readily available fuels, including natural gas and propane.
The overall cost of on-site generation of hydrogen via this process has the potential to be lower than other currently available production options.
The new system will combine FuelCell Energy’s molten carbonate fuel cell (DFC-300) with Air Products’ advanced gas separation technologies. Current process projections put the electrical efficiency at 49%.
The direct fuel cell (DFC) technology is based on internal reforming of fuels inside the fuel cell, integrating the synergistic benefits of the endothermic reforming reaction with the exothermic fuel cell reaction.
Heat generated in the fuel cell drives the reforming process, simultaneously cooling the stack. Steam produced in the anode reaction helps to drive the reforming reaction forward. Hydrogen produced in the reforming reaction is used directly in the anode reaction, which further enhances the reforming reaction.
The baseline electric DFC is designed to operate at 75% fuel utilization in the stack. The remaining 25% offers a possible source for low-cost hydrogen, if it can be recovered from its low-pressure, high-temperature, dilute form (< 15% hydrogen by volume)—the role of the Air Products system.
The system is designed to produce more than 250 kilowatts (kW) of power and more than 135 kilograms (about 300 pounds) of hydrogen per day. The system could provide hydrogen for smaller industrial users who routinely purchase liquid or gaseous hydrogen that currently must be delivered by truck. The DFC system could also be equipped to provide daily hydrogen fueling for approximately 35 fuel cell vehicles.
The project originally received funding in 2001, and the companies completed the design phase of the DOE project in 2006. System construction is expected to be complete in 2007. The unit will be tested at FuelCell Energy and shipped to Air Products for subsequent field demonstrations. Several locations are being evaluated for the field test, which is scheduled to occur before the end of 2008.
|Integrated Hydrogen Energy Station|
|Units||Phase I||Phase II|
(Net power + H2 product)/(Fuel)
(Net power)/(Total Fuel - H2 Product)
(H2 Product - Purification Power)/(H2 Product)
|Net Power without H2||kW||~247||~300|
|Net Power with H2||kW||~207||~243|
|Natural Gas Flow||Nm3/hr||~55||~74|
Globally, Air Products has placed more than 65 fueling stations on stream in 12 countries, most recently for mass transit fueling in Beijing, China for buses to be used to shuttle athletes and visitors for the 2008 Olympic Games.