There are many types of pollutants in ethylene oxide waste gas with different characteristics. Oil pollution may come from residual grease of sterilized items, equipment lubricating oil or other oily substances in the operation process; impurities may include metal debris, fibers, dust, etc.; particulate matter covers a wide range from tiny particles to larger agglomerates. These pollutants are not only diverse in physical form, but also in chemical properties, so they are extremely challenging to handle.

To make it more complicated, the content and distribution of these pollutants in the waste gas are often unstable. The type of sterilized items, changes in sterilization conditions, and the operating conditions of the equipment may affect the generation and emission of pollutants. This uncertainty requires the pretreatment system to be highly adaptable and flexible to ensure that pollutants can be effectively removed under various working conditions.

Faced with the challenge of pollutants in ethylene oxide waste gas, oil removal and impurity removal technology has become the core of the pretreatment stage. This technology mainly separates and removes oil, impurities and particulate matter in the waste gas through physical and chemical methods.

1. Physical separation method
The physical separation method mainly uses physical principles such as gravity, inertia, and centrifugation to separate particles and larger impurities in the exhaust gas. For example, the gravity settling chamber slows down the exhaust gas flow rate so that the heavier particles settle to the bottom under the action of gravity; the cyclone separator uses the centrifugal force to throw the particles to the wall and fall into the collection bucket. Although these methods are simple and effective, they have limited effects on the removal of tiny particles and oil.

2. Chemical adsorption and filtration method
In order to remove oil and tiny particles more efficiently, chemical adsorption and filtration methods are widely used. Chemical adsorbents such as activated carbon and molecular sieves have a high specific surface area and pore structure, which can adsorb oil and certain impurities in the exhaust gas. High-efficiency filter materials such as glass fiber and polytetrafluoroethylene (PTFE) membrane can intercept tiny particles and oil droplets. The selection and design of these materials need to be optimized according to the characteristics and treatment requirements of the exhaust gas.

3. Combined process and intelligent control
In order to further improve the efficiency of oil removal and impurity removal, combined processes have become a trend. For example, a gravity settling chamber is combined with a cyclone separator to form a multi-stage separation system; or chemical adsorption is combined with filtration to form a composite filtration unit. In addition, the introduction of an intelligent control system can automatically adjust the treatment parameters according to the changes in the exhaust gas composition to ensure the stability and optimization of the treatment effect.

In the residual gas treatment system of the ethylene oxide sterilization workshop, the application of oil removal and impurity removal technology has achieved remarkable results. Through the combination of physical separation and chemical adsorption and filtration, the oil, impurities and particulate matter in the exhaust gas are effectively removed. This not only avoids the blockage and damage of subsequent treatment equipment, but also improves the overall treatment efficiency and treatment quality.

Specifically, the combination of a gravity settling chamber and a cyclone separator effectively separates large particle impurities and heavier oil in the exhaust gas; while the combination of chemical adsorption and high-efficiency filtration materials further removes tiny particles and residual oil. The introduction of an intelligent control system has realized the automation and intelligence of the treatment process, and improved the treatment efficiency and stability.

Although the oil removal and impurity removal technology has achieved remarkable results in the residual gas treatment system of the ethylene oxide sterilization workshop, it still faces some challenges. For example, with the improvement of sterilization process and the increase of environmental protection requirements, the types and contents of pollutants in waste gas may change, which will put forward higher requirements for pretreatment system. In addition, the balance between treatment efficiency, energy consumption and cost is also a problem that needs to be solved in the future.

In order to meet these challenges, the development of oil removal and impurity removal technology in the future will pay more attention to innovation and sustainability. For example, research and development of more efficient and environmentally friendly chemical adsorbents and filter materials; optimization of combined processes and intelligent control systems to improve treatment efficiency and stability; strengthening synergy with other environmental protection technologies to form a comprehensive treatment plan.