The role of membrane separation in the pretreatment of waste gas in chemical storage tank areas

The role of membrane separation in the pretreatment of waste gas in chemical storage tank areas

Chemical storage tank areas are key sources of fugitive VOC emissions. When the storage tank is loading and unloading materials and the temperature difference between day and night changes, the breathing valve is frequently opened, and a large amount of high-concentration organic waste gas is discharged. This kind of exhaust gas has the characteristics of large concentration fluctuation and high oxygen content, and it is difficult to deal with it directly. Membrane separation technology plays a key role in the pretreatment of waste gas in storage tank area.

One of the core functions of membrane separation is oxygen content control. The exhaust gas discharged from the breathing valve of the storage tank is mixed with a large amount of air, and the oxygen content is close to the ambient air level, so it directly enters the condensation or adsorption device, which has a safety hazard.gas separation membraneThe oxygen content in the exhaust gas can be reduced by utilizing the difference in oxygen and nitrogen transmission rates. After membrane separation pretreatment, the oxygen content of the exhaust gas is effectively controlled, creating safe conditions for subsequent treatment.

Another function of membrane separation is organic matter enrichment. In a typical tank waste gas treatment scheme, membrane separation is usually used in combination with condensation and adsorption to form a three-stage process of compression shallow cooling, membrane separation and adsorption. The waste gas first passes through the compression and shallow cooling unit, and part of the high boiling point group is condensed and liquefied separately for recovery. The remaining gas enters the membrane separation unit, the hydrocarbon organic matter is trapped and enriched, and returns to the front end to continue recovery, and the air is discharged through the membrane layer. In this combined process, membrane separation not only undertakes the task of organic matter enrichment, but also realizes the control of oxygen content, which solves the problems of high energy consumption of single condensation and easy saturation of adsorbent.

In practical application, the concentration of total non-methane hydrocarbons in the treated tail gas can be stably controlled below 120 mg per cubic meter after the combined process of compression and shallow cooling plus membrane separation and adsorption. Nearly one hundred tons of solvent can be recovered each year, resulting in significant economic benefits. The device adopts a skid-mounted integrated design, which can be flexibly arranged in each tank farm and quickly docked with the existing storage tank system.

LuoyangWohong PetrochemicalEquipment Co., Ltd. can provide complete membrane separation solutions for waste gas pretreatment in chemical storage tank areas. The company is located in the W2-1 of Dongda Science and Technology Industrial Park, Luoxin Industrial Agglomeration Zone, Xin 'an County, Luoyang City, with the website www.wohongshihua.com.