Activated Carbon Filter Factory Share: Why activated carbon has a large specific surface area but the effect of formaldehyde removal is generally

Customers often ask questions about activated carbon deformaldehyde removal when customizing deformaldehyde air filters: why some activated carbon has a large specific surface area and high CTC and iodine adsorption values, but its adsorption performance of formaldehyde, ammonia, acetaldehyde in cigarettes and other gases is very poor. You can refer to the following activated carbon filter factory sharing: why activated carbon has a large specific surface area but the effect of removing formaldehyde is general.
Generally we think that activated carbon adsorption of formaldehyde, the physical adsorption performance of activated carbon and the specific surface area and the size of the microporous activated carbon has a great relationship. If the microporous size of activated carbon is very close to the diameter of a certain gas, then its adsorption of this gas is very strong, and it is not easy to desorb after adsorption. However, for gases such as formaldehyde, acetaldehyde, ammonia, due to its low boiling point and less obvious polarity, it is necessary to increase the specific size of the microporous to adsorb them, but this technology is more difficult to control. Therefore, the physical adsorption effect of activated carbon on formaldehyde and other gases is often not very satisfactory. Especially when coexisting with other gases, activated carbon will preferentially adsorb other gases that are better adsorbed, but seldom adsorb formaldehyde, etc., and it will be easier to desorb, and once desorbed, it will cause secondary pollution.
Therefore, the adsorption of organic gases such as formaldehyde has no significant relationship with the size of the specific surface area, and Henkaes activated carbon filters are now mostly modified by the principle of chemical adsorption. Commonly, the activated carbon is loaded with chemicals or catalysts, and can also be modified by chemical process conditions. This makes it possible to completely disintegrate gases and convert them into formic acid, and also avoids secondary contamination.
Suitable and good activated carbon additives and modification methods can increase the adsorption efficiency of activated carbon for specific gases by several to tens of times.