Firstly, Suzhou SAIPEI editors briefly introduce the principle of the packed absorption tower. The principle primarily involves selecting an appropriate solvent during the absorption process to dissolve one or more gases in the solvent from the gas mixture, achieving the separation of the mixed gases. It also utilizes the packing inside the tower to increase the contact area between the absorbent and the off-gas, serving as a solvent recovery unit. This is a gas-liquid exchange device that operates through gas-liquid contact.
Process Flow of the Filling Absorption Tower:
1. Counter-current Operation Process: Most packed absorption towers use a gas-liquid counter-current operation process. This operation typically results in an average driving force for the gas-liquid phases throughout the tower, leading to high mass transfer efficiency. However, in certain special chemical absorption processes, when the reaction between the dissolved solute and the absorbent is irreversible, there is little difference in the average driving forces between co-current and counter-current operations. The packing serves as a catalyst for the liquid-phase reaction, and in such cases, co-current operation can be employed, such as in the hydrocracking process in the petroleum industry.
2. Absorption Liquid Recirculation Process: When the absorption liquid level in the absorption tower is low and cannot meet the moisture content requirement of the packing material; or when a large amount of dissolved heat is released during the absorption process, requiring the recirculation of the absorption liquid to remove the heat, the absorption liquid recirculation process can be adopted.
3. Multi-tower Countercurrent Series Process: When a larger mass transfer area is required for the absorption process, a single absorption tower would be tall. Instead, the tower can be divided into several smaller towers, adopting a multi-tower countercurrent series process. Additionally, depending on the need, the gas phase can be in series while the absorbent liquid is in parallel flow. For example, an逆流串联process is used in the production of formaldehyde from the oxidation of dimethyl ether.
4. Segmented Absorption and Regeneration Process: To enhance the driving force of the absorption process and improve mass transfer efficiency within the absorption-regeneration operating system, a segmented absorption and regeneration process can be employed, such as the thermal potassium alkali process for carbon dioxide removal.
5. Absorption and Distillation Process: In the absorption of multi-component gases, to increase the concentration of solutes in the absorbent liquid, a distillation process can be adopted, such as using oil to absorb and separate cracked gas. The upper part of the tower is the absorption tower, and the lower part is the stripping tower. The cracked gas enters from the middle of the tower to achieve the oil separation goal.
The above is a simplified description of the filling tower's process flow. For more in-depth knowledge on the professional aspects, a detailed explanation is available!
What kind of packing is commonly used in an absorption tower? Main options include Pall rings, spherical packing, Haldor Top spheres, and other structured packings. Suzhou SAIPE is a professional manufacturer of various types of packing and tower internals. Welcome to visit and guide us!
