Читать книгу Encyclopedia of Renewable Energy - James Speight G., James G. Speight - Страница 35

Acid rain reduction can be done either fuel switching or scrubbing. Fuel switching includes limiting the use of Sulphur-containing fuels such as coal or switching to low sulphur–containing coal or oil, switching to alternative energy sources such as using gas boilers instead of coal or oil boilers, nuclear power generation, using renewable energy sources such as wind, air, wave and geothermal energy.

Gas cleaning (gas scrubbing) includes use of electrostatic precipitators where positively charged sulphur particles are attracted by negatively charged plate or chemical means either wet scrubbing such as injecting water or chemical solution such as flue gas desulphurization (FGS) which has the sulfur dioxide removal rate between 80-95% or dry scrubbers such as lime injection multi stage burning (LIMB) or fluidized bed combustion (FBC or circulation dry scrubber) that react with sulphur in the absence of water medium.

To reduce nitrogen oxides (NOx), methods such as selective catalytic reduction process (SCR) which has the NOx reduction rate up to 80% where injection of reactive chemicals such as ammonia reacts with NOx and convert into nitrogen and oxygen, changing air to fuel ratio and changing the combustion temperature. In automobile NOx reduction, catalytic converters are used, e.g., three-way catalytic converters: (i) conversion of nitrogen oxides into nitrogen and oxygen, (ii) conversion of carbon monoxide into carbon dioxide, and (iii) conversion of hydrocarbon derivatives into carbon dioxide and water.

See also: Acid Rain, Gas Cleaning, Gas Processing, Gas Treating.