Nov 20 - McClatchy-Tribune Regional News - John G. Edwards Las Vegas Review-Journal

Public controversy over coal-fired power plants has focused on carbon dioxide emissions, which scientists say leads to global warming.

Sierra Pacific Resources, however, has helped the industry test technology that reduces coal-plant pollutants such as sulfur dioxide and nitrogen oxide that can cause public health problems and contribute to acid rain and higher levels of mercury, which can damage human brains, kidneys and fetuses.

The company, for example, allowed the Electric Power Research Institute and J-POWER EnTech to conduct a six-month demonstration project at the North Valmy Power Station, which is 30 miles east of Winnemucca.

The regenerative activated coke technology tested at the plant has worked well, slashing pollution from coal-fired power plants in Japan. But the institute wanted to determine whether the technology would be effective with coal burned in power plants in the United States. Power plants in the United States burn different types of coal than those used in Japan.

Sierra Pacific Resources Senior Vice President Roberto Denis said he is encouraged by what he learned during the test at Valmy. He said he expects the institute to release the results of the demonstration project after six months of study and review.

Denis hopes that the Valmy test produces results similar to those found at Japanese power plants. In Japan, plants using the system cut by one third to one half the sulfur dioxide and nitrogen oxide emissions that would come from a coal plant using wet scrubber technology like that often used at U.S. plants.

The United States has abundant coal, and Denis believes the country should focus on technology that will reduce pollution from coal plants so that those reserves can be used for power production.

"We really need to learn how to better use this abundant resource (coal)," Denis said.

Here's how the process works: Pellets of coke are dropped into flue gas being expelled from a coal plant. Ammonia also is injected into the flue gas. The pellets then can absorb sulfur dioxide, nitrogen oxide, mercury and dust being emitted by the plant. The pollutant-saturated coke is then removed and regenerated for reuse.

The next step in testing the technology will be for a larger electric utility to try using it at a large-scale plant, Denis said.

Sierra Pacific Resources is developing a 1,500-megawatt, coal-fired power plant near Ely in eastern Nevada to produce electricity for Nevada Power Co. in Las Vegas and Sierra Pacific Power Co. in Reno. While construction has not started on the Ely Energy Center, rules prevent the company from installing the Japanese technology at Ely.

Sierra Pacific already has requested approval of wet scrubbers and must use wet scrubbers, Denis said. It isn't clear whether it would be feasible to later retrofit the Ely plant with the Japanese pollution control equipment, he said.

Sierra Pacific Resources plans to use wet scrubbing at the Ely center, as suggested by the National Park Service, because wet scrubbers are 30 percent more effective at cleaning sulfur dioxide emissions than dry scrubbers. The Japanese technology, however, has the potential to cut air pollutants even more.

The Valmy test cost $7 million of which $200,000 came from Sierra Pacific Resources.

The Valmy plant is half-owned by Idaho Power Co. and half-owned by Sierra Pacific Power, but the Nevada company operates the plant. The 250-megawatt plant was completed in stages in 1981 and 1985.