Sulfur causes costly problems for high-temperature fuel cells. Tufts U. researchers may have found an answer.
High-temperature fuel cells promise clean, efficient energy in quantities large enough to power cities. But, so far, they've been too expensive for widespread use. One major problem is the sulfur in fossil fuels, such as coal, oil, and natural gas, which contaminates the hydrogen gas that runs the cells. The sulfur attacks and degrades a part of the fuel cell called the anode, reducing power production -- and eventually shutting down the cell.
Now chemical engineers at Tufts University in Medford MA, led by Maria Flytzani-Stephanopoulos, have found a way to continuously remove sulfur from incoming hydrogen before it feeds these cells. The work, published in the June 9 issue of Science (abstract), could be a significant step in making high-temperature fuel cells practical.
Lanny Schmidt, professor of chemical engineering and materials science at the University of Minnesota, says many operational issues have kept more powerful fuel cells off the market, including long startup times and parts wearing out under high heat. But, he says, sulfur is "one of the major problems." Schmidt predicts that researchers will overcome these obstacles in the next few years, and, if successful, SOFCs "may become the fuel cell of choice." He says that Flytzani-Stephanopoulos has "an innovative, clever new way to remove sulfur."