I. Overview

N-Methylpyrrolidone (NMP for short) is an important chemical raw material, widely used in petroleum processing, fine chemicals, pharmaceuticals, pesticides, electronic products and other fields. It has a pivotal position in the chemical industry and is essential for the manufacture of lithium batteries. It is one of the raw materials, and our country vigorously advocates the policy of energy saving and emission reduction. At present, new power battery companies have sprung up all over the motherland. As a result, a large amount of nitrogen methyl pyrrolidone needs to be consumed, and the used nitrogen methyl pyrrolidone Will be discharged into the atmosphere in the form of organic waste gas, which not only causes great pollution to the local environment, but also causes huge economic losses and energy waste. Therefore, according to the country’s energy and environmental protection development strategies, our company organizes research Developed the "recycling technology of organic matter in the organic waste gas of lithium battery plant" and its complete set of equipment, which solved this problem excellently for lithium power plants. This device has a simple structure and is easy to install. It can achieve green and safe emissions without any changes to the production equipment, which not only solves the environmental protection problem, but also brings considerable economic benefits to the enterprise.

2. Product technical features

1. Recovery performance: The average recovery rate of recovery equipment is as high as 99%, and the average recovery purity is as high as 80%.

2. Energy-saving performance: reasonable equipment design, low operating energy consumption.

3. Operation performance: The equipment can be linked with the coating machine to realize fully automatic operation and fault alarm.

4. Safety performance: In the exhaust pipe before entering the recovery equipment, a fault handling device is specially installed, even if the alarm is issued, it will not affect the normal production of the enterprise.

5. Process performance: reasonable structure layout, beautiful appearance, no leakage in the sealed connection.

3. Structure and working principle

N-Methylpyrrolidone (NMP) is a highly efficient polar solvent of Guangpu. It is 100% miscible with water at room temperature and has a boiling point of 202°C at room pressure. Based on the unique physical characteristics of NMP, our company uses a low-energy condensing method, through a special process design, and manufactures a complete set of equipment for efficient recovery of NMP in organic waste gas. Its structure and working principle diagram are as follows: NMP recovery principle diagram

(1) Pre-cooler: The temperature of the hot exhaust gas discharged from the coating machine is about 120°C. It is cooled by an outdoor air pipe, generally around 80°C. After the four-stage heat exchange of the equipment, the exhaust air temperature drops to about 20°C. , Using its low temperature gas, make the hot exhaust gas discharged from the coating machine into the recovery device through the pre-cooler to achieve the first-stage cooling, and the cooling range can reach about 15 ℃.

(2) Heat exchangers 1, 2, and 3: Use the cooling tower to dissipate heat, and circulate the waste heat gas flowing into the heat exchangers 1, 2, and 3 through the second, third, and fourth stages of cooling. The cooling range is up to At around 35°C, NMP gas reaches the recovery equipment and is condensed into liquid after three-stage cooling; after passing through the gas-liquid separator, the exhaust gas with an NMP content of less than 300ppm is discharged into the spray tower to reduce the emission to 50mg/m3 and then emptied to meet the emission standard.