I would like to ask about the methods for hydrogen removal in methanol synthesis! ! !

Pressure swing adsorption is likely to be used more often

1. The basic working principle relies on the fact that adsorbents have different adsorption capacities, adsorption rates, and adsorption forces for adsorbates at various partial pressures. Moreover, they possess the ability to selectively adsorb the various components of a gas mixture to be separated under certain pressures. By applying pressure, impurity components in the feed gas are removed through adsorption, and these impurities are desorbed by reducing the pressure, thereby regenerating the adsorbent. 2. Adsorption: When gas molecules move to the solid surface, due to the residual attractive force of the atoms on the solid surface, some of the molecules in the gas remain temporarily on that surface. The concentration of these molecules on the solid surface increases, and this phenomenon is known as the adsorption of gas molecules on a solid surface. The solid that adsorbs substances is called an adsorbent, while the substance that is adsorbed is called the adsorbate. Based on the nature of the gravitational field between the adsorbate and the adsorbent, adsorption can be divided into chemical adsorption and physical adsorption. 3. Physical adsorption: Also known as van der Waals adsorption, it is caused by the attractive forces between the adsorbate molecules and the surface molecules of the adsorbent; these forces are also referred to as van der Waals forces. Since the molecules on the solid surface differ from those inside the solid, a residual surface free energy field exists. When gas molecules come into contact with the solid surface, some of them get adsorbed, releasing adsorption heat in the process. Among the adsorbed molecules, only those whose kinetic energy from thermal motion is sufficient to overcome the potential energy of the adsorbent’s gravitational field can return to the gas phase; therefore, many adsorbed molecules remain on the solid surface in contact with the gas. The adsorption caused by intermolecular attractions results in a low adsorption heat, which is close to the vaporization or condensation heat of the adsorbate; moreover, both the adsorption and desorption rates are fast. The adsorbed gas can also be desorbed from the solid surface relatively easily; therefore, physical adsorption is reversible. Physical adsorption is usually divided into temperature-dependent adsorption and pressure-dependent adsorption. 4. The pressure swing adsorption process for separating gas mixtures is a pure physical adsorption process, with no chemical reactions occurring throughout it. 5. Common adsorbents used in pressure swing adsorption include silica gel, activated alumina, activated carbon, molecular sieves, etc.; in addition, there are also adsorbent materials developed for the selective adsorption of specific components. The success of gas adsorption separation depends to a large extent on the properties of the adsorbent; therefore, selecting an appropriate adsorbent is the primary issue in determining the adsorption process. Is his cost high? ? ? How effective is it? ? ? After hydrogen is removed, do the remaining components remain intact? ? Please don’t mind me; I don’t quite understand. I humbly ask for your guidance! ! ! !

Are there any other ways? ? ? I would be grateful for your advice! ! !

Reply to 4# Longhua Worker: There are currently two common methods for hydrogen recovery. 1. Hydrogen is recovered using Prisen hollow fiber membrane separation; the advantages of this method include A. lower investment requirements and a smaller footprint for the equipment. B. The gas handling capacity of single-membrane systems is low. The gas handling capacity for single-membrane systems generally does not exceed 1500 NM3/h. C. The hydrogen recovery rate is relatively low. 2. Hydrogen recovery by pressure swing adsorption; the characteristics of this hydrogen recovery method are A: relatively high investment costs and a large footprint for the equipment. B. A single unit has a high processing capacity; the minimum gas handling volume is generally 5000 NM3/h. C. The hydrogen recovery rate is relatively high.

Pressure swing adsorption has a large treatment capacity and fewer impurities in the hydrogen.

There are generally three methods for hydrogen separation: membrane separation, PSA, and cryogenic separation. Membrane separation is mainly used in systems where the gas composition is relatively simple and the gas pressure is high, and where high performance from the hydrogen separation element is not required ； PSA is generally used in situations where the gas composition is complex, high purity of the hydrogen product is required, the pressure of the system exhaust gases is low, and it is difficult to recover the hydrogen using other methods ； Deep cryogenic separation is used in situations where a large volume of material needs to be processed, the components of the feedstock are relatively simple, and the hydrogen and other components obtained after separation can be utilized effectively