Читать книгу Encyclopedia of Renewable Energy - James Speight G., James G. Speight - Страница 154

In addition, the BioDeNOx process is a biological process removes nitrogen oxides from flue gases. An iron chelate selectively absorbs the nitrogen oxides which are reduced to nitrogen with ethanol in the presence of microorganisms. Then, a wet gas scrubber is used to contact the circulation liquid with flue gas feed and absorb the nitrogen oxides (NOx).

In the sump underneath the scrubber, the absorbed nitrogen oxides are biologically reduced to nitrogen and ethanol is also consumed and, thus, the iron chelate solution is regenerated. The presence of oxygen and acid compounds in the flue gas, such as hydrogen chloride and hydrogen fluoride, oxidizes a part of iron chelate to the ferric (Fe³⁺) state. Therefore, a purge and makeup of iron chelate is necessary to eliminate this oxidized ferric material. To minimize iron chelate consumption, a nano-filtration can be installed and bleed from the unit is passed through the filter and the chelate is recovered.

See also: THIOPAQ DeSOx Process.