Study On The Recovery Of Isopropanol From Gas By Hypergravity Absorption

Isopropanol as an excellent organic solvent and an important chemical raw material,is widely used in the production processes of medicine,pesticides and organic chemicals.This article takes the characteristic pollutant,isopropanol gas,emitted by a fine chemical company in Ningxia as the research object,aiming at the poor mass transfer effect and effective gas-liquid effect of the synthetic tail gas absorption tower?mainly containing isopropanol tail gas?in its current production process.The contact area is small,and multiple absorption towers are required to be connected in series,which leads to a large area and low isopropanol absorption rate,high energy consumption and production costs.At the same time,because isopropyl alcohol has a large saturated vapor pressure,it is easy to get out of water.Escape again,resulting in a large circulating volume of the absorption liquid and a low concentration of rich liquid,and subsequent recovery operations are costly and difficult.To solve the above production problems,this article comprehensively considered the influence of absorbent and absorption equipment on the absorption process,established a supergravity absorption method to treat isopropanol,and developed an organic solvent co-solvent in water to develop a solution for isopropanol gas.The high-efficiency water-based absorbent has important practical significance in order to reduce the vapor phase saturated vapor pressure of isopropanol,improve the purification efficiency and the rich liquid concentration,and reduce the circulating flow rate and production cost of the absorbent liquid.Based on the principle of similar miscibility and the comparison of physicochemical properties of isopropanol-ethylene glycol-water,and considering the problem of isopropyl alcohol recovery and reuse later,the value of ethylene glycol as a potential good organic co-solvent was explored.The experimental results show that Ethylene glycol can affect the gas-liquid distribution behavior of isopropyl alcohol in aqueous solution,can effectively reduce the vapor pressure of isopropyl alcohol in aqueous solution,and increase the concentration of rich liquid isopropyl alcohol,and 1wt%ethylene glycol absorption the absorption performance of EGW is obviously better than that of pure water.The absorption rate is increased by about 15%,and the rich liquid concentration is increased by about 44%,which effectively increases the solubility of isopropanol in water and reduces the absorption liquid circulation flow.Using countercurrent rotating packed bed as absorption equipment and 1wt%EGW as absorbent,the parameters such as high gravity factor,gas velocities,liquid spray densities and isopropyl alcohol gas inlet concentration were investigated for isopropyl alcohol absorption rate and gas volumetric mass transfer the influence law of quality coefficient.The results show that the isopropyl alcohol gas K_Ga increases with the increase of?,u,and q,and the effect of the concentration of isopropyl alcohol is small.Absorptance E increases with increasing?and q,and decreases with increasing u.Suitable conditions for the absorption process:?=60,u=0.9 m/s,q=15.92 m³/?m²·h?,when the isopropyl alcohol gas inlet concentration is 10000 ppm,the absorption rate is 96%,and K_Ga reaches 21.7 s^-1.In the counter-current rotating packed bed,the influence of rotors with different structures on E and K_Ga was investigated.The results show that:the optimization of the rotor structure does not affect the change of E and K_Ga by the operating parameters,but the absorption The rate and the gas-phase volumetric mass transfer coefficient are improved by about 1.9 times and 1.34 times compared to the ordinary counter-current rotating packed bed,respectively,the dynamic and static rotor structure breaks the inherent flow pattern of gas and liquid in the rotating bed,and further strengthens the mass transfer process between gas and liquid.In this paper,through the investigation of absorbent and absorbent equipment,using rotating packed bed as absorbent equipment,1wt%EGW as absorbent,increased the solubility of isopropyl alcohol in water,and reduced the vapor pressure of isopropyl alcohol in water,improves the rich liquid concentration and absorption rate,and reduces the circulating flow rate and operating cost of the absorbent.