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Fresh air is a luxury around Poland's northern industrial city of Szczecin, near the port of Gdansk. Heavy use of low grade coal for power generation pollutes the atmosphere with large quantities of sulphur dioxide (SO2) and nitrogen oxide (NOx). As a direct consequence, the surrounding forests are damaged and the incidence of many respiratory system diseases is alarmingly high.
When fossil fuels (especially coal and oil) are burned, "acid rain" is produced as SO2 aerosols become sulphuric acid and NOx aerosols change into nitric acid by photochemical conversion in the atmosphere. Not only does acid rain destroy vegetation and buildings, the gases are also believed to contribute to "global warming." Most nations around the world are now committed to containing them, and recent global treaties require all countries to pass and implement laws limiting national SO2 emissions.
One way is to switch from coal to other primary energy sources such as hydropower, natural gas or nuclear. But for Poland these are not currently options: It has no viable hydro source; it cannot afford to pay hard currency to import natural gas from Russia; and its nuclear power programme is postponed indefinitely. For the foreseeable future, Poland must rely on its huge reserves of brown coal (estimated at over 14 billion tons). Indeed, the livelihoods of hundreds of thousands depend on the industry.
The key question is how to ensure that new industrial production is not as environmentally damaging as in the past and that gas emissions are in line with EU standards. Polish legislation enacted in the early 1990s requires utilities to progressively reduce SO2 emissions, beginning in 1997. Technologies are readily available for removing either SO2 or NOx from the flue gases of individual coal-fired power plants before they are emitted into the atmosphere, but to date there was none that could extract both in one single-stage process.
A coal-fired power plant in Szczecin is now the site of a four-year IAEA technical co-operation Model Project to demonstrate, on an industrial scale, a 'novel' technology that can do just that. Electron beam dry scrubbing (EBDS) works by recycling the flue gases through a chamber, before they escape from the chimney, and exposing them to low-energy electron radiation from an accelerator. As a result the toxic SO2 and NOx are transformed to other chemical forms. By adding ammonia to the chamber, the resulting by-product, a dry powder, can be used as fertiliser. Other cleaning systems do not have this beneficial effect and produce a lot of waste. Although it is a radiation process, no radioactivity is produced in the operation and there is no residual radiation.
EBDS was developed some 20 years ago, principally in Germany and Japan. It is novel only in that it has not been used on an industrial scale, except in demonstration plants in Germany, Japan and the United States. By the time it came out of the laboratory and became available for industrial scale use in the mid-80s, utilities in these heavily regulated countries had already fitted most older coal-fired power plants with other proven scrubbing techniques, or had committed to installing more efficient boilers that would produce less emissions.
Studies carried out in Germany, Japan, USA, as well as in Poland - where an earlier Agency technical co-operation project helped set up a pilot EBDS plant near Warsaw in 1988 - have shown that the technique is 25-30% less costly to install and to operate than conventional systems. When NOx removal also becomes compulsory, the advantages of EBDS will be greater. The value of the agricultural by-product and the relatively much smaller waste disposal problem make it additionally attractive.
There is a strong interest in EBDS across the energy sector in Poland, among its neighbours and in developing countries that are industrialising fast and have large coal reserves. Ukraine has an ongoing programme and the Agency has just launched a new technical co-operation project to assess the option in Bulgaria.
Poland has opened the doors to the Szczecin plant, allowing the IAEA to bring visitors from other countries who are keen to see it operating. Of these, China which plans to install cleaning systems in some 60 power plants has recently contracted with a Japanese company to fit a power plant with EBDS. Further down the road are India, Indonesia, Malaysia, the Republic of Korea, Singapore and Thailand. In Latin America, Brazil, Chile and Mexico already have pilot projects and are closely watching progress in Szczecin.
The Polish Government is investing 60% of the $20 million needed to set up the EBDS system, and all the personnel and operation costs. The remaining 40% is shared between Japan, the Republic of Korea and the IAEA. Sweden and the US may also contribute. The project plant is scheduled to be fully operational by the end of 1998. Hopefully, it will show Poland a way to attain European emission standards without having to compromise industrial growth and demonstrate to the energy sector a cost efficient and environment friendly technology. Currently industrial restructuring and privatisation are influencing the energy sector and, at the end of the day, the economics and efficacy of EBDS itself may also decide its future in Poland and in many other developing countries.
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