Nanjing Chemical Plant Waste Gas Treatment Equipment RTO Catalytic Combustion Production

The combustion method can be either direct combustion or thermal combustion depending on the concentration of combustible organic compounds in the exhaust gas. (1) Direct combustion method can be used to treat exhaust gas when the concentration of organic matter in the exhaust gas or waste gas is high enough to maintain continuous combustion through the heat released by the combustion of organic matter in the waste gas. In the direct combustion method, organic matter in the exhaust gas is treated as fuel, and the final products of combustion are CO2, H2O, and N2. The combustion equipment used in the direct combustion method can be industrial and civilian combustion furnaces, such as boilers or household stoves; It can also be a torch burner. When using exhaust gas as fuel for civilian stoves, an exhaust gas holder must be installed to maintain a balance between the amount of exhaust gas generated and the amount of treatment. When using a torch burner to treat organic waste gas, the torch burner should be specially designed to ensure that the torch burner can basically burn the organic matter in the gas when there are fluctuations in the amount of organic waste gas or organic matter. (2) When the content of organic matter in the exhaust gas is low, the exhaust gas itself cannot be burned, or the heat released during the combustion of combustible components in the exhaust gas cannot maintain continuous combustion, and additional fuel needs to be added to maintain combustion, it is called thermal combustion. During thermal combustion, the organic matter in the exhaust gas serves as auxiliary fuel and is also the object of treatment. In the thermal combustion method, the first step is to burn additional fuel to provide heat, and then the waste gas containing organic matter is mixed with high-temperature gas to reach the combustion temperature of organic matter, causing the combustion of organic matter in the waste gas. At this temperature, the waste gas is maintained for sufficient residence time to fully burn and decompose the organic matter in the waste gas, producing harmless CO2 and H2O. Thermal combustion can be carried out in ordinary boilers or combustion furnaces, or in thermal combustion furnaces.

When using ordinary boilers or combustion furnaces for thermal combustion, the following conditions should be noted: ① The exhaust gas should not contain non combustible components such as inorganic smoke and dust, which may deposit on the heat transfer surface, thereby reducing efficiency and increasing power consumption. 2) The gas content in the exhaust gas should be adapted to the hydrogen required for boiler combustion to ensure full combustion. Otherwise, high molecular weight organic compounds such as tar that are not formed during combustion will adhere to the heat transfer surface and reduce thermal efficiency

The thermal combustion furnace should ensure a temperature of 760 ℃ or above and a contact time of about 0.5s to ensure the combustion of organic pollutants. The thermal combustion furnace consists of a burner and a combustion chamber, and can be divided into a flame combustion furnace and an off flame combustion furnace according to the type of burner.

Catalytic combustion method is the hydrogenation of organic pollutants * in exhaust gas into CO2 and H2O under the action of a catalyst. The catalytic combustion method has a low ignition temperature, good safety performance, and small concentration restrictions on the organic matter to be purified, which makes it more commonly used for treating low concentration organic pollutants. However, the dust particles and droplets in the exhaust gas may reduce the lifespan of the catalyst, so the catalytic combustion method is not suitable for treating organic exhaust gas containing dust particles and droplets.

(1) Catalytic combustion catalysts include precious metal catalysts, non precious metal catalysts, and rare earth metal catalysts. The active components of the catalyst are usually loaded onto a carrier and used in granular or honeycomb form.

(2) Process and equipment of catalytic combustion method

The process of catalytic combustion method has the following characteristics:

① The gas entering the catalytic combustion device must first undergo pretreatment to remove dust, droplets, and harmful components, avoiding blockage and poisoning of the catalyst bed. ②) The temperature of the gas entering the catalyst bed must reach the ignition temperature of the catalyst used before the catalytic reaction can proceed. Therefore, for intake air below the ignition temperature, preheating must be carried out to reach the ignition temperature. Especially when driving, preheating is required for cold intake air, so catalytic combustion method is suitable for treating continuously discharged organic waste gas. ③ Catalytic combustion of organic waste gas generates a certain amount of reaction heat, and when the heat is generated, attention should be paid to recovering the reaction heat. Adsorption method can effectively purify organic waste gas. Suitable for purifying low concentration organic waste gas, it can also enrich and recover valuable organic compounds in the waste gas.