Tail chlorine liquefaction recovery

In chemical production, the recovery of chlorine from off-gases is a crucial step, as it can significantly reduce production costs and minimize environmental pollution. Currently, several techniques can be used to recover chlorine from exhaust gases: 1. **Condensation method**: – Chlorine is separated from the exhaust gases by using low-temperature condensation. This usually requires cooling the exhaust gases below the liquefaction temperature of chlorine (–34.04°C at 1 atm pressure) in order to liquefy the chlorine through condensation. - This method requires high energy consumption and specialized low-temperature equipment. 2. **Adsorption method**: - Adsorbants such as activated carbon or molecular sieves are used to absorb chlorine gas from exhaust gases. After becoming saturated, the adsorbent can be regenerated by heating or depressurization, releasing pure chlorine gas. - This method allows for the reuse of the adsorbent, but it requires regular replacement or regeneration of the adsorbent. 3. **Membrane separation technology**: – Specific gas separation membranes, such as polymer membranes or metal membranes, are used to separate chlorine gas. Chlorine molecules pass through the membrane at a higher rate than other gas molecules, thereby enabling separation. - Membrane separation technology is easy to operate, but the selection and maintenance of membranes are crucial. 4. **Chemical absorption method**: - Although you mentioned that the cost of alkaline absorption is high, it is possible to consider optimizing the recycling of chemical absorbents or finding more economical alternatives. In your case, considering the costs and the feasibility of equipment, the condensation method might be a straightforward and effective option—especially if you already have low-temperature equipment available. At the same time, adsorption methods and membrane separation technologies are also worth considering; the specific choice needs to be evaluated based on your specific operating conditions and economic benefits. It is recommended to collaborate with professional chemical equipment suppliers or engineering companies to conduct a detailed technical and economic analysis as well as process design, in order to ensure the feasibility of the technology and its economic viability. .

Sodium hypochlorite is cheap, while liquid caustic is expensive; for every ton of liquid caustic consumed, a loss of around 500 yuan occurs