July-August 2004

CHP Opportunities at New York State Wastewater Treatment Plants

Most of the northeast water treatment plants were forced to shut down during the blackout of 2003, causing huge operational and environmental problems. As a result, in many cities the water supply was drastically reduced because sewage plants lacked backup power generators.

Catalytica Energy Systems Inc. of Gilbert, AZ, and Mountain View, CA, helps gas-turbine manufacturers design complete systems that include its Xonon Cool Combustion modules.

In addition to Kawasaki, Catalytica is collaborating with Solar Turbines Inc. of San Diego, CA, a subsidiary of Caterpillar Inc. in Peoria, IL; and GE Energy (formerly GE Power Systems), a Houston, TX - based subsidiary of General Electric Company. The Solar Taurus 70 will be a 7-megawatt system. GE is developing a 10-megawatt turbine with a 24-inch-diameter Xonon module that weighs 500 pounds. Both are years away from being commercially available.

Glenn Asher, director of operations at Kawasaki Gas Turbines-Americas, says his firm's 1.4-megawatt model GPB15X gas turbine with Xonon catalytic technology is ideal for hospitals, universities, pharmaceutical manufacturers, pulp and paper plants, and "any manufacturing or institutional process for which there's a significant thermal load. It's a small gas turbine with a high heat rate compared to an internal-combustion engine."

Putting Xonon technology into larger - 5.5-, 6.5-, and 17-megawatt - Kawasaki units would entail "an investment in the millions of dollars to redesign these larger machines," Asher says. "It's feasible, but it would have to be justified based on worldwide sales. It's a good niche technology, but other technologies make sense for the bigger machines.

"The 1.4-megawatt unit has a single can-type combustor, but the larger machines have multiple combustors - six each for the 5.5- and 6.5-megawatt units, eight for the 17-megawatt machine. Would we put in six or eight Xonon modules or redesign those machines to have one or two cans? We would have to evaluate what's cost-effective, what the market is willing to pay. A lot has to go into that decision."

The smaller size range, Asher says, is dominated by internal-combustion engines. "It's difficult to justify a small gas turbine unless you have a significant thermal load, and most facilities that need a 600- or 800-kilowatt generator have small thermal loads. We are looking at some 600-kilowatt applications that will produce about 5,000 pounds per hour of steam, 10 times the thermal energy of an equivalent internal-combustion engine."