Fraunhofer Institute for Solar Energy Systems’ (Fraunhofer ISE) researchers have developed an ethanol reformer fuel cell system. The system is suitable for outdoor use and has an electric power output of 250W. The system is fueled with denatured bioethanol, which is inexpensive, non-toxic and commercially available worldwide. The ethanol reformer fuel cell system can be used outdoors and operates at ambient temperatures ranging from -10 to +40 °C.

One potential application of the system is as a power supply for medical equipment in developing and threshold countries.

Along with other products from Fraunhofer ISE, this system will be presented to the public for the first time from April 20 to 24, 2009 in Hall 13/ Stand E 27 at the Hannover Trade Fair.

Using precisely this point, reformer fuel cell systems can demonstrate their great advantage. These systems combine the high energy storage density of the fuel with the high power density of the fuel cell. A further advantage is that with the integration of a reformer, commercially available fuels like bioethanol, propane or gasoline (U.S.) can be used.

At the push of ethanol reformer fuel cell system button, the electric power becomes available. A buffer battery is used during the start-up phase, when hydrogen is not yet flowing to the fuel cell. The system including the tank has a total volume of 200l and a weight of 30kg, respectively. It consists of four modules (fuel cell, reformer with gas purification, electronics and tank). The main system functions are carried out by:

A low-temperature PEM fuel cell from the company Schunk. This was optimized for operation with a reformate gas (product gas of the reformer).

A reformer with gas purification. The latter reduces the amount of carbon monoxide in the reformate gas to a level that is suitable for the following PEM fuel cell.

A tail gas combustor in which the offgas from the anode is oxidized and provides the heat needed for evaporation and overheating the feed streams (ethanol, water and air).

No further heat integration is used in the reformer system in order to maintain a simple system architecture and achieve controllability of the entire system. The four modules are stacked on top of each other within a housing mounted on wheels for easy transport.

The development of the reformer fuel cell system is supported by the Federal German Ministry for Economics and Technology BMWi. The partners in this cooperative project are the companies DMT GmbH, EGO Elektro-Gerätebau GmbH, Elbau GmbH, Intratec GmbH, LIFEBRIDGE Medizintechnik AG, Magnum Automatisierungstechnik GmbH und Umicore AG & Co. KG. The Hahn-Schickard-Gesellschaft e.V. (HSG-IMIT), the second research institute involved in the project, contributes its expertise in the area of liquid dosage.

The core piece of the system to be presented at the trade fair is a commercial PEM fuel cell with an electric power output of 300W. “If fuel cells are to achieve long periods of operation, then it is best if they are combined directly with a reformer. In this case, the use of hydrogen storage, be it either metal hydride storage or pressurized gas cylinders, is neither economical nor practical,” says Dr. Thomas Aicher, head of the group Hydrogen Production at Fraunhofer ISE.

“The goal at the end of the development work was to present a fully functional technology for demonstration purposes. Today, the consortium is able to offer interested manufacturers the technology for series production,” reports Johannes Full, the project leader responsible at Fraunhofer ISE.