Thread Content
Adsorbent selection determines the separation effect. Commonly used adsorbents in industry include: Adsorbents such as silica gel, alumina, activated carbon, and molecular sieves ； In addition, there are special adsorption materials developed for selective adsorption of certain components. The adsorption performance of the adsorbent for various gas components is evaluated by experimentally measuring the isothermal adsorption line under static conditions and the breakthrough curve under dynamic conditions. The good adsorption performance of the adsorbent is the basic condition for the adsorption separation process. In the pressure swing adsorption process, the choice of adsorbent should also consider resolving the contradiction between adsorption and desorption. On the one hand, the adsorbent should have a large adsorption capacity for impurities, and at the same time, the adsorbed impurities should be easy to desorb, so that the adsorption-desorption equilibrium can be reached in a short period, so that the separation and purification process can be maintained. Another important point in selecting an adsorbent is to have as large a separation coefficient as possible between the components. The greater the separation coefficient of the gas components, the easier the separation and the higher the purity of the product gas obtained. At the same time, the recovery rate is also higher. During the adsorption process, due to the periodic changes in the pressure in the bed, gas enters or exits the adsorption bed in a short period of time. The adsorbent must withstand frequent erosion by air flow. It is required that the adsorbent used should have sufficient strength to reduce breakage and wear. To separate gas mixtures with complex components and many types, it is often necessary to select several adsorbents. These adsorbents can be layered and loaded in the same adsorption bed according to their adsorption and separation performance. In some cases, they can also be loaded in each adsorption bed separately. It is precisely because of the above reasons that the pressure swing adsorption process has special requirements for adsorbents, so the adsorbents used in the pressure swing adsorption process are called special adsorbents.