1. The adsorption efficiency of organic waste gas is up to 90% by using active carbon adsorption method.
(1) adsorption principle of activated carbon
Activated carbon is a kind of microcrystalline carbon material, which is mainly made of carbon material with black appearance, with developed internal pore structure, large specific surface area and strong adsorption capacity. There are a lot of invisible micropores in the activated carbon material, and the surface area of the micropores can be as high as 800-1500 square meters, especially high. In other words, the internal surface area of a rice sized activated carbon particle may be the size of a living room. It is these highly developed pore structures, such as human capillaries, that make the activated carbon have good adsorption performance. The combination of molecules is called van der Waals force. Although the velocity of the molecule is affected by temperature and substance, it is always in a constant state in the micro environment. Due to the mutual attraction between molecules, when a molecule is adsorbed into the inner hole of the activated carbon by the inner hole of the activated carbon, more molecules will be attracted until the inner hole of the activated carbon is filled due to the mutual attraction between the molecules.
(2) activated carbon desorption
When the gap of activated carbon is filled with organic waste gas and reaches saturation, pollutants begin to release. This phenomenon is called infiltration. The saturated activated carbon adsorption bed needs regeneration. The adsorption bed is usually desorbed by heating gas. On the one hand, regeneration of the adsorption bed is reactivated; on the other hand, pollutants are released for recycling or decomposition. This desorption method is called temperature desorption. The adsorption capacity decreased with the increase of temperature. By increasing the temperature of the adsorbent, the adsorbed components can be desorbed. This method is also called variable temperature desorption.
2. The adsorption efficiency of inorganic waste gas can reach more than 90% by liquid adsorption. Liquid absorption is a common treatment technology to purify inorganic gas. With the liquid as the adsorbent, the harmful components in the waste gas are absorbed into the liquid through the washing collection device to achieve the purpose of purification. The absorption system belongs to the process of gas film control absorption. When working, the liquid is sprayed onto the top of the uniform packing layer by spraying the top packaging layer, and the flow is like a film packaging layer, while the exhaust gas enters the bottom of the tower and discharge through the packing layer from the top of the tower. In this process, the exhaust gas is forced to change its direction and speed for many times, and constantly collide with the absorption liquid. Therefore, the reaction time of the exhaust gas and the absorption liquid is in full contact with the packaging layer, so that the harmful component absorption liquid in the exhaust gas can be completely absorbed and purified. The purified gas can be discharged after defrosting in the tower.
3. According to the type of waste gas produced in the laboratory, the treatment scheme adopts activated carbon adsorption and combination. Organic pollutants were adsorbed by activated carbon, and inorganic pollutants were absorbed by packed tower.
The reasons are:
The inorganic waste gas in laboratory is mainly acid waste gas, and alkaline waste gas is common in industrial production. The influence of pH value on the adsorption efficiency of activated carbon generally decreases with the increase of pH value of solution. When pH value is greater than 9.0, adsorption is not easy. Therefore, the activated carbon was first adsorbed and then filled with spray.