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2021

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Deactivation of Catalysts in Catalytic Combustion Equipment and Causes of Oil Leakage

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Deactivation of Catalysts in Catalytic Combustion Equipment and Causes of Oil Leakage

Catalyst is very important in catalytic combustion equipment. It is not only related to the treatment effect of exhaust gas, but also related to the operating cost of the equipment. Sometimes the catalyst in the catalytic combustion apparatus is deactivated. What is the reason?


Sintering of 1. catalysts at high temperatures


The catalyst reaction temperature is too high will lead to the catalyst surface active component sintering (particles become larger), the catalyst specific surface area is reduced, the transition metal oxide between the solid phase reaction, phase change, all of which will lead to the catalytic combustion equipment to reduce the activity of the catalyst, so in the use of the process should avoid the high temperature impact of the catalyst.


2. catalyst surface carbon


Catalytic combustion equipment model reactions, such as toluene, ethyl acetate, propanone, etc., It is usually used to evaluate the performance of the catalyst in the laboratory, and the mixed solvent can also be used to test the performance of the catalyst. It is generally difficult to observe the surface carbon. However, in actual use, the composition of VOCs is very complex, including large molecules, small molecules, high boiling point and low boiling point, and the properties of volatile organic compounds are very different. Also contains a small amount of paint mist, dust and other substances. In particular, the presence of paint mist and high boiling point organic matter leads to the formation of carbon deposits on the surface of the catalyst, resulting in a decrease in catalyst activity.


Dust in 3. volatile organic compound exhaust gases


If VOCs exhaust gas contains more dust, dust and catalyst surface friction, resulting in the loss of catalyst surface active substances, on the other hand may be deposited on the surface of the catalyst. Both of these factors can lead to a decrease in catalyst activity. Therefore, for high dust organic waste gas, dust removal equipment should be added at the front end of the equipment.


Sulfur oxides and nitrogen oxides in 4. volatile organic compound exhaust gases


Many catalytic combustion equipment coating lines are heated by natural gas combustion, which will produce a small amount of SOx and NOx. Practice has proved that a small amount of SOx and NOx have no effect on catalyst performance and can be used with confidence. Usually called s, it has an impact on precious metal catalysts. I think it is organic sulfur. In fact, noble metals are industrial catalysts for the oxidation of SO2 to SO3 and NO to NO2, so there is no SOx and NOx poisoning.