In many fields such as medical, pharmaceutical, and food processing, ethylene oxide (EO) sterilizers are favored for their efficient sterilization effect and wide applicability. However, as a toxic, flammable and explosive gas, the treatment of the tail gas produced after sterilization has become a key link to ensure environmental safety and personnel health. In the tail gas treatment system, adsorption technology is an efficient purification method, especially in removing trace harmful substances.

Ethylene oxide sterilizers achieve sterilization by injecting ethylene oxide gas into a confined space and using its killing effect on microorganisms. However, the tail gas generated during the sterilization process contains ethylene oxide and its reaction products, such as organic matter such as aldehydes and ketones, as well as possible acidic gases and particulate matter. If these harmful substances are directly discharged without proper treatment, they will pollute the atmospheric environment and threaten the health of surrounding residents and workers. Therefore, it is a necessary measure to ensure environmental safety and personnel health to efficiently purify the tail gas of ethylene oxide sterilizer to ensure compliance with national or regional environmental protection standards.

Adsorption technology is a purification method based on physical or chemical forces. Through the microporous structure on the surface of the adsorbent, harmful substances in the tail gas are adsorbed and fixed inside the adsorbent. Commonly used adsorbents include activated carbon, molecular sieves, zeolites, etc. They have a large specific surface area and rich microporous structure, which provides sufficient contact area and adsorption sites for the adsorption process.

Activated carbon is a porous carbonaceous material with rich microporous and mesoporous structures. The surface area can reach hundreds to thousands of square meters/gram, and it has good adsorption performance for organic matter, acidic gases, etc. Molecular sieve is an inorganic crystalline material with a regular pore structure. It selectively adsorbs specific molecules or ions through screening effect and adsorption. Zeolite is a natural or synthetic silicate mineral with rich microporous structure and high ion exchange capacity. It has good adsorption effect on organic matter, heavy metal ions, etc.

Adsorption technology has the advantages of high efficiency, economy and easy operation. First, the adsorbent has a high adsorption capacity and selectivity for harmful substances in the tail gas, which can achieve efficient purification. Secondly, the adsorption process usually does not require additional energy input and has low operating costs. In addition, adsorption technology is also easy to operate and maintain, and is suitable for tail gas treatment systems of various sizes.

In the tail gas treatment system of ethylene oxide sterilizer, the selection of adsorbents should be considered comprehensively based on factors such as tail gas composition, treatment requirements, and operating costs. Activated carbon is one of the commonly used adsorbents because of its good adsorption performance for organic matter and acidic gases. However, the adsorption capacity of activated carbon is limited and needs to be replaced or regenerated regularly. The regeneration process usually includes methods such as heating desorption and chemical washing to restore the adsorption performance of the adsorbent.

Adsorbents such as molecular sieves and zeolites have higher selectivity and stability and are suitable for deep purification of specific harmful substances. However, the cost of these adsorbents is high, and the regeneration process is relatively complex, requiring professional equipment and operating techniques. Therefore, in practical applications, appropriate adsorbents should be selected according to the tail gas composition and treatment requirements, and the regeneration process should be optimized to improve treatment efficiency and reduce operating costs.

In the tail gas treatment system of ethylene oxide sterilizer, the design of the adsorption system should fully consider the tail gas flow, concentration, temperature and other parameters, as well as the characteristics and regeneration method of the adsorbent. Reasonable system design can ensure that the tail gas is evenly distributed in the adsorption bed, improve the adsorption efficiency and purification effect.

The size and number of the adsorption bed should be determined according to the tail gas flow and concentration. A larger bed can provide more adsorption sites, but it will also increase the investment cost and operating energy consumption. Therefore, the design should be weighed according to actual needs.

The appropriate adsorbent filling method and bed structure should be selected. Common filling methods include fixed bed, moving bed and fluidized bed. The fixed bed has a simple structure and is easy to operate, but the regeneration process requires shutdown. Moving bed and fluidized bed can achieve continuous operation and online regeneration, but the structure is complex and the maintenance cost is high. Therefore, the appropriate filling method and bed structure should be selected according to actual needs during design.

The temperature and pressure control of the adsorption system should also be considered. Appropriate temperature and pressure conditions can improve the adsorption efficiency and regeneration effect. In practical applications, it should be optimized and adjusted according to the characteristics of the adsorbent and the tail gas composition.

Although adsorption technology performs well in the treatment of tail gas from ethylene oxide sterilizers, it still has some limitations. First, the adsorption capacity of the adsorbent is limited and needs to be replaced or regenerated regularly, which increases the operating cost and maintenance difficulty. Some harmful substances may be difficult to be effectively removed by the adsorbent and need to be supplemented by other purification methods.

In view of these limitations, future research should focus on developing new and efficient adsorbents, optimizing the regeneration process, and improving adsorption efficiency and stability. For example, by modifying activated carbon, synthesizing new molecular sieves and zeolites and other materials, the adsorption performance and selectivity of adsorbents for specific harmful substances can be improved. More efficient and energy-saving regeneration methods can be studied to reduce operating costs and maintenance difficulties. It is also possible to explore the combined application of adsorption technology with other purification methods, such as catalytic oxidation and biodegradation, to achieve more efficient and comprehensive tail gas purification.

As an efficient tail gas purification method, adsorption technology plays an important role in the residual gas treatment system of ethylene oxide sterilizers. By selecting suitable adsorbents, optimizing system design, and improving adsorption efficiency and stability, efficient tail gas purification can be achieved to ensure compliance with national or regional environmental protection standards. Future research should continue to explore the development of new and efficient adsorbents, the optimization of the regeneration process, and the combined application with other purification methods to promote the continuous development and progress of ethylene oxide sterilizer tail gas treatment technology.

Adsorption technology has broad application prospects and important environmental significance in industrial ethylene oxide sterilizer residual gas treatment systems. Through continuous technological innovation and optimization and improvement, we can provide safer and more efficient environmental protection solutions for the sustainable development of medical, pharmaceutical, food processing and other fields.