Of the 3,085 grant proposals submitted to the Coordinating Board, only 416 received funding. In announcing the awards, the board described the competition as "intense."

Rai, the lead principal investigator, is a professor of chemical and natural gas engineering. Pierce, the co-principal investi- gator, is an associate professor of biology.

The new process, which has been patented, adds an acidophil- ic iron oxidizing bacteria to the gas-sweetening process, greatly improving efficiency and reducing costs, Rai says. The standard sweetening method uses only chelated iron catalysts without the bacteria. The microbes in the Rai/Pierce process produce an enzyme which prolongs the life of the expensive catalysts. The sweetening of sour natural gas and recovery of sulfur are gaining importance as EPA regulations tighten and citizens become increasingly concerned about air quality. Rai, whose extensive research on the subject has drawn hundreds of thousands of dollars in grants and outside funding, says his process has the potential for widespread use.

"About 25 percent of all gas processed in the U.S. is sour and requires sweetening to some degree," Rai said. "There are about 100 plants that sweeten natural gas. Our work is an improvement on the current process and will make it a lot cheaper."

Sulfur extracted from the gas can be sold for $50 to $150 per ton, depending on its purity. It is used by industry to make sulfuric acid, fertilizers and a variety of other products.

Wheelabrator Clean Air Systems, Inc. is collaborating in the study along with Radian Corporation, which is testing the new sweetening process at a facility in Kermit, Texas. The Gas Research Institute built the $10 million test facility and also is sponsoring the testing.

-- John R. Kent