| 摘要 |
For the purification of waste gas containing nitrogen oxides in combination with CO, VOCs or nitrous oxide, in particular waste gas resulting from the production of cement clinker, nitric acid, adipic acid, fertilizers and uranium trioxide, a regenerative thermal post-combustion system with at least two regenerators (A, B) is used by means of which the CO, VOCs and nitrous oxide are thermally purified in the combustion chamber (1) at a temperature of 800 to 1000° C. and the nitrogen oxides are thermally reduced with the SCR catalyst (6) by adding a nitrogen-hydrogen compound, wherein the waste gas already thermally purified is removed from the respective two-part regenerator (A or B) at a suitable place at a temperature of approx. 300° C., guided via the SCR catalyst (6) in a constant direction of flow and subsequently fed back to the remaining section (A′, B′) of the regenerator (A or B). |
| 主权项 |
1. Process for the purification of waste gas containing thermally purifiable compounds oxidizable with the oxygen in the waste gas as well as nitrogen oxides and/or compounds forming nitrogen oxides during the thermal purification in a post-combustion system having at least two regenerators (A, B. . . ) filled with heat-accumulator bodies (3) and connected to a common combustion chamber (1), wherein the waste gas is alternately supplied to a raw gas inlet regenerator (A or B), the heat-accumulator bodies (3) of which have been preheated, and the thermally purified waste gas emerging from the combustion chamber (1) is supplied to a clean gas outlet regenerator (B or A) for the heating of its heat-accumulator bodies (3) and the selective catalytic reduction of the nitrogen oxides to nitrogen by means of a reducing agent, characterized in that at least two regenerators (A, B . . . ) are each divided into two parts in the direction of flow, namely into a section of the regenerator (A′, A″; B′, B″) facing away from the combustion chamber (1) and facing the combustion chamber (1) and that the at least two regenerators (A, B) have a common catalyst (6) for the selective catalytic reduction, wherein, after cooling down to the temperature required for the selective catalytic reduction in the section (A″, B″) of the clean gas outlet regenerator (A, B) adjacent to the combustion chamber (1) and mixing with the reducing agent, the waste gas thermally purified in the combustion chamber (1) is supplied to the common catalyst (6) for forming clean gas, which is directed to the outside after it has conveyed heat to the heat-accumulator bodies (3) of the section (A′, B′) of the clean gas outlet regenerator (A, B . . . ) facing away from the combustion chamber (1). |
