EPRI develops economical NOx reduction process
29 Apr 2002
A new NOx reduction process developed by EPRI provides coal-fired generating units with a cost-effective means of complying with NOx regulations.
The process, called Rich Reagent Injection (RRI), reduces NOx formation by injecting amine-based compounds into the fuel-rich region of a cyclone furnace. The combustion process is then completed with another EPRI innovation, cyclone overfire air.
Overfire air has been fitted to over 70% of the cyclone furnace market, and is responsible for reducing over 1 million tons of NOx from the atmosphere, says Dave O'Connor, EPRI's manager for combustion performance.
The first demonstration of RRI was completed at Conectiv's B. L. England Unit 1, in Beesley's Point, New Jersey. 'In our tests, we were able to lower our NOx an additional 28%, and the low capital cost of this process makes it even more valuable,' said station manager, William Gibson.
Conectiv's senior engineer, V.N. Bhamidipati, explained that the RRI system produces no ammonia slip and virtually eliminates flyash disposal difficulties and air heater pluggage problems. He said that Conectiv used RRI in combination with commercially offered Selective Non Catalytic Reduction Processes to lower NOx as much as 60% beyond overfire alone at B.L. England station.
Additional tests recently completed at AmerenUE's Sioux Unit 1 achieved NOx reductions of over 30%. 'These test results are very encouraging and offer us another technology to consider in our system's NOx control strategy,' said AmerenUE's Consulting Project Engineer, Dave Boll.
EPRI has licensed the RRI technology to Reaction Engineering International of Salt Lake City, UT, and implementation licenses have been issued to FuelTech NV and RJM Corporation.
EPRI is currently evaluating RRI for use with pulverized coal boilers.
