Talking About Electricity Generation

Apr 16 - Automotive Design & Production

The first 75-kW fuel cell at Dow's massive Texas Operations. GM and Dow are working on a project that uses the by-product hydrogen produced at the plant in the fuel cell to generate electricity. By 2006 there could be as much as 35 megawatts' worth of fuel cells supplied to Dow. The main objective is not to develop fuel cells for stationary applications but to have real-world testing of the fuel cells that GM plans to install into light vehicles.

One of the issues related to hydrogen-powered fuel cell vehicles is obtaining the hydrogen that's turned into electricity by the fuel cell. After all, while hydrogen is the most abundant element in the known universe, that doesn't mean it's readily available. But that is not a problem at the Dow Chemical Company's Texas Operations in Freeport, which is Dow's largest integrated site in the world for chemical manufacturing: there are three major complexes, encompassing 75 plants, on 37 miles2. One of the offshoots of manufacturing such chemicals as chlorine, ethylene, and styrene is hydrogen. Presently, according to George Kehler, commercial manager- Fuels & Energy, Dow Hydrocarbons and Resources, the hydrogen is sold to industrial gas companies (interestingly, one of the applications it is used for is to remove sulfur from diesel fuel during refining) or it is burned in boilers, which is not the most-efficient use of the gas. So General Motors and Dow are cooperating on a multi-year program wherein GM will supply fuel cells to the Texas Operations so that some of the by-product H^sub 2^ generated will be used to create electricity. In phase one of the program, which was officially initiated February 10, including the ceremo- nial throwing of a switch by Dept. of Energy secretary Spencer Abraham and Texas governor Rick Perry, there is a single 75-kW fuel cell module installed in a truck trailer, the same fuel cell that's used by GM in its hydrogen-powered development vehicles that are running is places ranging from Washington, DC, to Tokyo. In the second phase, which will occur during the next year-and-a-half, there will be additional fuel cells brought to the site so that there will be a 2-megawatt capacity. Then, explains Julie T. Beamer, director, GM Fuel Cell Commercialization, by '06 GM will be providing fuel cells with a combined capacity of 35 megawatts, which would be sufficient to power 400 vehicles.

Although the 35 megawatts is a non-trivial amount of electricity- it could power an estimated 25,000 homes-in the context of Dow Texas Operations, it is only a couple of percent of the 1,100 megawatts used on a daily basis. However, R.W. (Bill) Jewell, business vice president, Energy, Dow Chemical, points out that they perceive the program as a good learning experience. He notes, for example, "Fuel cells prefer perfectly pure hydrogen. A lot of hydrogen in the world is not perfectly pure. The technology of cleaning up hydrogen is of interest to us." On a global basis, Dow makes enough hydrogen for 1,000 megawatts of energy.

The reason why the first fuel cell module (and those that will be part of the second phase) is in a trailer is because of the amount of monitoring and test equipment deployed. Beamer explains that the purpose of the first two phases is to be "a cost-effective, accelerated durability-testing environment for our fuel cell technology." She continues, "They will not be running on a continuous power-generation cycle. We'll be simulating stop-start, acceleration, deceleration-the same test cycles that we're running in the labs in Mainz-Kastel and Honeoye Falls." In fact, these units will be remotely controlled from the Honeoye Falls, NY, GM facility.

Beamer admits that the distributed power setup at the Texas Operations is different than that which is necessary for mobile fuel cells. The packaging requirements and operating environments are completely different. But she points out that this is a unique opportunity that will help CM engineers find the ways and means to reduce the 10x premium that fuel cells currently have for light vehicle applications.-GSV

Copyright Gardner Publications, Inc. Mar 2004