26

2020

-

11

Detailed Explanation of Structural Features of Desorption Catalytic Combustion Equipment

Source:


Detailed Explanation of Structural Features of Desorption Catalytic Combustion Equipment

Desorption catalytic combustion equipment is mainly composed of heat exchanger, combustion chamber, catalytic reactor, heat recovery system and exhaust stack for flue gas purification. The principle of purification is that the raw gas is pre-prepared before entering the combustion chamber. Heated and sent to the combustion chamber. The desired reaction temperature is reached in the combustion chamber and the oxidation reaction is carried out in the catalytic reactor. Catalytic combustion is a purification method that oxidizes and decomposes combustible substances in exhaust gas at a relatively low temperature. Therefore, catalytic combustion is also called catalytic chemical conversion. Since the catalyst accelerates the oxidation and decomposition process, most hydrocarbons can be oxidized by the catalyst at a temperature of 300 to 450°C.


The desorption type catalytic combustion equipment first uses the activated carbon fiber to adsorb the organic waste gas, and stops the adsorption when it is close to saturation, and then uses the hot air to desorb the organic matter from the activated carbon fiber to regenerate the activated carbon fiber. The desorbed organic matter has been concentrated (the amount of desorbed hot gas is about 1/10 to 1/15 of the original exhaust gas, that is, the concentration of VOCs gas increases to 10 to 15 times of the original exhaust gas) and is sent to the catalytic combustion chamber to catalytically burn it into carbon dioxide and water vapor for discharge. When the concentration of the organic off-gas reaches 2000ppm or more, the organic off-gas can be maintained self-igniting in the catalytic bed without external heating. A portion of the combusted tail gas is vented to the atmosphere and most of it is sent to the adsorbent bed for activated carbon regeneration. Compared with thermal combustion methods, catalytic combustion equipment requires less auxiliary fuel, lower energy consumption and smaller equipment and facilities. However, due to the poisoning of the catalyst used and the high cost of replacement and cleaning of the catalyst bed, the promotion and application of this method in industrial production processes are affected.


In the process of chemical reaction, the method of using catalytic combustion equipment to reduce the combustion temperature and accelerate the oxidation of toxic and harmful gases is called catalytic combustion. Since the catalyst carrier is a porous material, the specific surface area is large, and the pore diameter is suitable. When heated to 300-450°C, oxygen and organic gases are adsorbed on the surface catalyst of the porous material. This increases the chances of contact and collision of oxygen and organic gases and improves the activity of the catalyst. The organic gas reacts strongly with oxygen to produce carbon dioxide and hydrogen peroxide and heat, thereby converting the organic gas into a harmless gas.