Dichloromethane Waste Gas Treatment

Current situation of dichloromethane waste gas treatment

In recent years, while the pharmaceutical and chemical industries have flourished, air pollution has become increasingly severe. Among them, dichloromethane waste gas is widely used in pharmaceutical production due to its low flammability and high solubility. However, dichloromethane is highly toxic and difficult to degrade, posing great harm to the atmospheric environment and human health. It has been listed as one of the 129 priority controlled toxic pollutants by the US EPA, making rapid and effective treatment of dichloromethane waste gas even more urgent. Now let's take a look at some methods for treating dichloromethane waste gas.

Partial methods for dichloromethane treatment

At present, the main methods for treating exhaust gas include condensation, absorption, incineration, biodegradation, and adsorption. The condensation method is suitable for low air volume, high concentration dichloromethane exhaust gas, and the condensation temperature is 70 ° C, which is not economical. The absorption method is suitable for substances with high water solubility, while dichloromethane is a pollutant with extremely poor water solubility and strong volatility, and the treatment efficiency of the absorption method is very low; If other organic solvents are used for absorption treatment, the consumption of absorbent is high, the separation of absorbed components is difficult, and the overall cost is extremely high. Incineration method is currently a promising treatment method for organic waste gas, but the chlorine element in dichloromethane and high-temperature incineration process are likely to produce substances such as dioxins that are more harmful than dichloromethane. Due to the non degradable nature of dichloromethane, biodegradation methods are also not applicable. The adsorption method mainly selects suitable adsorbents for different substances, with high removal efficiency and applicability. It is currently the most suitable technology for treating dichloromethane waste gas. Commonly used adsorbents include activated carbon and molecular sieve, among which activated carbon has a short service life, poor regeneration effect, low recovery rate, and is prone to secondary pollution; However, molecular sieves have poor adsorption performance for substances with poor polarity. Therefore, although there are many mature technologies for exhaust gas treatment, there are significant limitations in the treatment of dichloromethane. Therefore, it is necessary to develop a treatment method suitable for dichloromethane. In practical cases of treating organic waste gas, the treatment of dichloromethane in the pharmaceutical and chemical industries usually has high concentration and recovery value. Conventional adsorbents for adsorption methods include activated carbon and molecular sieves, but activated carbon has a short service life, a relatively small specific surface area compared to resin, low treatment effect, poor regeneration effect, low recovery rate, and is prone to secondary pollution; Molecular sieves have poor adsorption performance for substances with poor polarity (such as dichloromethane).

Haipu customized treatment of dichloromethane process

Jiangsu Haipu Functional Materials Co., Ltd. is committed to the research and industrialization of high-performance adsorbents and catalysts. In 2018, it was approved as the Suzhou Adsorption and Catalytic Functional Nanomaterials Engineering Technology Research Center. Through years of independent research and development, it has achieved international leading levels in ion exchange technology and adsorption technology, nano inorganic material hybridization technology, etc., realizing the serialization of adsorption and catalytic products and successfully applying them in the fields of environmental protection and resource recycling. With a series of independently developed high-performance adsorbents and catalysts as the core, combined with self-developed process technology, Haipu has become a professional supplier of green and environmental protection solutions.

The adsorption process developed by Jiangsu Haipu Functional Materials Co., Ltd. utilizes special adsorption functional material resins for deep adsorption treatment of dichloromethane, providing an effective solution for the standard treatment of dichloromethane waste gas.

When using Haipu's adsorption process to treat dichloromethane waste gas, the dichloroethane waste gas is collected through pipelines and first enters a spray tower. It is then extracted and pressurized by a fan before being sent to an adsorption tower containing adsorbent resin to adsorb and enrich the dichloroethane components in the waste gas. The concentration of the treated waste gas can meet the design requirements. When the adsorbent approaches adsorption saturation, steam is used as a desorption agent to desorb the adsorbent. After desorption, the organic vapor is condensed and separated, and dichloroethane can be recycled. The wastewater enters the sewage treatment plant for treatment. The adsorbent undergoes high-temperature steam desorption in the adsorption tower and is then cooled by blowing with water and cold air for re adsorption.

Case analysis

After a project in Zhejiang is put into operation, dichloroethane in the exhaust gas is concentrated and recovered: if the emission concentration is calculated as an average of 10000mg/m3, 600kg of dichloroethane is discharged per day, and the recovery rate is calculated as 98%, the daily recovery amount is about 588kg, and the annual recovery amount is about 194t. The implementation of this project can simultaneously improve the economic and environmental benefits of customers.

Figure 1: Implementation Project for Resource Recycling and Treatment of 2000m³/h Dichloroethane Waste Gas in Our Company