Methane(CH4) catalytic oxidation can effectively deal with CH4 slip from liquefied natural gas(LNG) ships, but it also catalyzes the oxidation of NO in the exhaust gas. In order to study the impact of CH4 oxidation unit on the selective catalytic reduction(SCR) system of LNG ships, a joint catalytic reaction system based on Mn-Ce-Ox catalyst and commercial vanadium based catalyst was constructed on a self-built denitrification experimental platform. The effects of reaction temperature, catalyst type, space velocity and impurity gas interference on the catalytic oxidation of NO and catalytic reduction of NOx by Mn-Ce-Ox were studied. The results indicate that, when the NO volume fraction is elevated from 0.05% to 0.20% and the O2 volume fraction is decreased from 17.00% to 5.00%, the oxidation efficiency of NO slightly declines. Under the same conditions, Mn-Ce-Ox significantly enhances the denitration efficiency of SCR. Under conditions of a reaction temperature of 180℃, a space velocity of 21356h-1 and a mole ratio n(NO)/n(NH3) of 1.0∶1.1, the denitration efficiency can reach 86.80%, and the overall catalyst volume can be reduced by 50.7%, thereby reducing the occupied space of the SCR system.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |