The technology is based on excitation of gas molecules by electron beam. SO₂ and NO_x are oxidized and react with water vapor to form acids which are neutralized by ammonia. The obtained solid product is a commercial fertilizer used in vast quantities as a blending stock for NPK fertilizers. Both pollutants are removed in dry one step process.
The process has been investigated in Japan, the USA, Germany and in Poland. A large industrial pilot plant has been built in the EPS Kaweczyn in Warsaw.
New solutions which have been applied in the Polish pilot plant are presented in fig. 1.
They lead to 20-30% decrease in energy consumption. The achieved removal efficiencies of acidic pollutants are as high as 98% for SO₂ and 70-90% for NO_x, depending on the process conditions. High SO₂ removal can be achieved with very low power consumption (ca 1% of the block). Most of the energy is consumed for NO_x reduction. The SO₂ removal increases sharply with temperature decrease while for NO_x this effect is positive. These phenomena allow adjusting of the process conditions in dependence on the target removal efficiency (due to existing emission/imission limits). The outlet temperature can be varied from 65-90ºC according to requirements. The process is easy to control. VOC are removed in the process as well.
Intensive studies at the EPS Kaweczyn pilot plant performed in cooperation with IAEA, JAERI (Japan), FK Karlsruhe etc. were a basis for designing an industrial installation to be built at EPS Pomorzany (Dolna Odra PS Group). The installation will treat flue gases from two boilers 60 MWe each.
Investment and operational costs are by about 20% lower for as compared with a conventional processes and space requirements are by about 20% lower which is important for retrofit installations.
Tests performed at the pilot plant and in the laboratory on the orders of Berkeley Research Association (USA) and CChEN (Chile) have been proved that the process is technically feasible for treatment of flue gas from combustion of coal with high sulfur content (ca 3000 ppm) SO₂ and from copper smelters (up to 15% vol. SO₂). The combined microwave electron beam process has been patented, and Ebara Co., Japan has bought 30% of the patent ownership.
The Polish pilot plant was awarded a gold medal with jury mention at the 44 World Exhibition of Inventions and Innovations "Eureka" at Brussels 1995.

in Polish