Absorption treatment of trichloroethylene waste gas

Polyethylene glycol has different surface activities depending on its degree of polymerization, and can change the surface properties of aqueous solutions to varying degrees. It has been extensively studied in the treatment of exhaust gas absorption, especially in the treatment of toluene waste gas, which is remarkable. effect.Peregals O-25 is a fatty alcohol polyoxyethylene ether with good hydrophilic properties.

Trichloroethylene is an important raw material for production and organic solvents in chemical production, and is widely used in electronics, electroplating, coatings and other industries. Due to its volatile and difficult to degrade characteristics, trichloroethylene discharged through exhaust gas easily accumulates in the air, causing serious harm to the environment and the human body. Countries around the world attach great importance to the discharge of trichloroethylene and have successively enacted various environmental laws and environmental standards to limit them. Finding efficient and economical trichloroethylene waste gas treatment technology is of great significance. At present, the treatment technologies of trichloroethylene waste gas mainly include adsorption method, photocatalysis method and catalytic combustion method. The adsorption method faces the problems of large adsorption dose, difficult recovery, high cost, etc. Catalyst poisoning and short service life in the catalytic process are the main reasons why the technology cannot be industrialized. Absorption is currently the most common method of industrial waste gas treatment. The absorption method is simple, easy to operate, and low in cost, and is an ideal technology for industrial waste gas treatment. Due to the poor water solubility of organic waste gas, oily solvents are often used in engineering applications, such as waste vegetable oil, biodiesel, and activated motor oil. The absorbing liquid is liable to cause secondary pollution and is costly. Water is the safest, cheapest absorbent. In recent years, aqueous composite absorbents have been favored, such as microemulsion systems, surfactant systems, and the like.

The ether bond in the polyethylene glycol 600 and the flattened O-25 molecule is hydrophilic, and the carbon-carbon bond is lipophilic. Above the critical micelle concentration, the flat addition of O-25 has a longer alkyl chain, which facilitates the solubilization of weakly polar trichloroethylene. On the other hand, the flattening plus O-25 has a higher degree of polymerization and a longer molecular chain. The more carbon-carbon bonds, the easier it is to form a micelle, which makes the flattening O-25 have a higher processing efficiency than the polyethylene glycol 600. And the flat addition O-25 has a very low critical micelle mass concentration of 0. 014 mg / mL, the critical micelle mass concentration of sodium dodecyl sulfate is 1. 6 mg / mL, polyethylene glycol 600 critical micelle mass concentration of 15 mg / mL. When the critical micelle mass concentration is reached, the amount is less, the cost is lower, and the industrial promotion is facilitated. The flattening addition of O-25 as a trichloroethylene absorption liquid has a higher absorption efficiency. The mass concentration of the trichloroethylene inlet is 5. 36 g / m3, flat plus O-25 absorbent mass concentration is 0. 07 mg / mL ( 5 CMC), the temperature is 25 ° C, the dosage is 50 mL, the absorption efficiency of trichloroethylene is 80%, and the absorption liquid is subjected to saturated absorption measurement, and 50 mL is found. 07 mg /mL ( 5 CMC) of flat and O-25 absorbent absorption flow rate of 300 mL / min, mass concentration of 5. 36 g / m3 of trichloroethylene, the treatment efficiency is stable at about 80%, sustainable use for 46 h, that is, every g of flat plus O-25 can absorb 22 g of trichloroethylene. This has important economic and environmental significance in engineering.