| 摘要 |
<p>In the process, nitrogen oxides and sulphur oxides are removed from off-gases, in particular flue gases from power stations, by a modified nitric oxide process for the manufacture of sulphuric acid with the production of utilisable nitric and sulphur compounds by absorption of more than half the nitric oxide content of the off-gas introduced into the process and desorption of the nitric oxide-containing liquid, wherein a) the released nitric oxide is mixed with an oxygen-containing gas to give a gas relatively rich in nitric oxide and oxygen, in which the nitrogen monoxide is oxidised to nitrogen dioxide, and feeding the resulting nitrogen dioxide and/or nitric acid produced from it and a residual nitrogen monoxide content into the main stream of the off-gas to be treated, the molar quantities of tetra- and penta-valent nitrogen-oxygen compounds introduced into the system being greater than the molar quantity of nitrogen monoxide introduced in parallel and b) the liquid at least partially freed of nitrogen oxides or their main quantity is, after passing through the desorption unit, recycled into one or more of the gas treatment towers of the main off-gas stream. <IMAGE></p> |
