Carbon molecular sieves use screening characteristics to separate oxygen nitrogen. When the carbon molecular sieve adsorbs the residue vapor, the pore the vertical pore are only used as safety channels, the adsorbed molecular structure is transported to the microporous plate the sub microporous plate, which are the specific volumes to give full play to the adsorption effect. Carbon molecular sieves consist of many microporous plates. This kind of microplate can make the molecular structure with small size of kinetic model rapidly diffuse into the pore, restrict the entry of large-diameter molecular structure. Because of the different size of the vapor molecular structure of the relative external diffusion rate is the same, so the composition of the vapor compounds can be well separated. Therefore, in the production of carbon molecular sieve, according to the size of molecular structure specification, the distribution of microporous plates in carbon molecular sieve should be 0.28 ~ 0.38 nm. Within the scope of this microplate specification, CO2 can be rapidly diffused into the pores according to the micropores, but N2 cannot be separated oxygen nitrogen according to the micropores. The diameter of the microplate is the basis for separating oxygen nitrogen carbon molecular sieve. If the diameter is very large, CO2 N2 carbon molecular sieves are very easy to enter into the microporous plate can have the effect of separation; when the diameter is too long, neither oxygen nor nitrogen can enter into the microporous plate have no separation effect.
Because of the limitation of the standard, the domestic carbon molecular sieves can be well manipulated by the diameter. The carbon diameter of carbon molecular sieves on the market is 0.3 ~ 1nm, while that of yangu carbon molecular sieve is 0.28 ~ 0.36nm. The raw materials of carbon molecular sieve are coconut shell, coal, epoxy resin, etc., which are pre molded with basic raw materials after processing crushing. The main purpose of the plate is to improve the compressive strength avoid damage delamination. The second step is to stimulate skin pores. The active agent was introduced at 600 to 1000 ℃. Common active agents include water vapor, carbon dioxide, carbon dioxide compounds. They conduct thermochemical changes with relatively active amorphous carbon molecules to slowly expand the specific surface to produce pores. The three steps are to adjust the porosity structure by applying the vapor of the compound: for example, benzene in carbon accumulates the pore edge of carbon molecular sieve to adjust the diameter to meet the requirements.
