Of course, there are other roadblocks. Sulfur in the hydrocarbon fuel can contaminate the fuel cell and degrade it. GE and others are working on various pre-treatment processes to keep the contaminant out of the fuel cell. For example, researchers at Tufts University have developed a way to use cerium and lanthanum oxides to remove sulfur.
Maria Flytzani-Stephanopoulos, a chemical engineer at Tufts who led development of the scrubber, cautions that while the GE work is impressive, large challenges lie ahead. “I think that the reported numbers represent a significant development,” she says. “Of course, scale-up systems must be shown to be equally efficient in future work.”
The work is part of a Department of Energy clean-coal initiative launched in 2003 that aims to build, within ten years, a highly efficient, multi-megawatt, solid-oxide fuel-cell power plant paired with coal-gasification technology. The United States is thought to have about 250 years’ worth of coal in the ground. But burning coal looms as a major factor in increasing global warming; indeed, coal releases more carbon dioxide for each unit of energy produced than any other fossil fuel does.In coal-gasification plants, the coal is heated and turned into a “syngas,” a mixture of mainly carbon monoxide and hydrogen. This can then be combusted in a type of power plant called Integrated Gasification Combined Cycle. The GE technology would allow hydrogen to be pulled out of the syngas and sent through a solid-oxide fuel cell.