Preparation method of nitrile butadiene rubber monomer recovery unit

- Aug 03, 2019-

Technical field:

The utility model relates to a nitrile butadiene rubber monomer recovery device, which belongs to the field of nitrile butadiene rubber production equipment.

Background technology:

Butadiene and acrylonitrile are copolymerized monomers of nitrile butadiene rubber.The monomer conversion rate of continuous low-temperature emulsion polynitrile butadiene rubber is 68% and 89%, which contains a lot of unreactive monomers. The recovery and recycling of these monomers can reduce the consumption of raw materials and increase the economic benefit of the unit.At present, the main recovery methods of NBR monomer include decompression, humidification and preheating of latex after polymerization, positive pressure flash and vacuum flash to extract butadiene, and the extracted butadiene gas is then compressed, cooled and liquefied for recycling.Butadiene-free latex is sent to the degassing tower, and the saturated steam from the lower part of the tower is used for stripping. The negative pressure inside the tower is maintained by steam injection pump.The steam phase of the tower is condensed into nitrile water containing acrylonitrile, which is returned to the polymerization system for recycling.The monomer butadiene liquid recovered by this process still contains a small amount of acrylonitrile, which will cause losses when the monomer butadiene is recycled by alkaline washing.Besides propylene, the recycled nitrile water also contains other impurities, such as additives, which will affect the quality of NBR.

Invention content according to the shortage of the existing technology, the utility model to solve the technical problem is to provide a kind of nitrile rubber monomer recovery unit, reduce the wastage of the monomers in the process of recycling,Improve the quality of recycled monomer and reduce the influence of monomer recycling on the quality of nitrile butadiene rubber.The utility model solve the problem of its technology adopted by the technical solution is to provide a kind of nitrile rubber monomer recovery unit, its characteristic is that including crude acrylonitrile condenser, low period of the compressor, compressor, butadiene washing tower in middle and high segment compressor, butadiene flash tank, condenser, butadiene recovery tank, nitrile butadiene tank, tail gas absorption tower and desorption cans and acrylonitrile butadiene stripper, crude acrylonitrile condenser, low period of the compressor, compressor, the middle water tower, high period of the compressor and acrylonitrile butadiene stripping tower through the pipeline connection, in turnLow section compressor, middle section compressor and high section compressor are connected to the butadiene flash tank through pipelines respectively. The flash tank, butadiene condenser, butadiene recovery tank, tail gas absorption tower and butadiene desorption tank are connected successively through pipelines.The butadiene recycling tank is connected with a high-section compressor through a pipeline.The bottom of the butadiene washing tower is connected to the nitrile water pump through pipelines, the nitrile water pump is connected to the inlet and outlet heat exchanger of the stripper through pipelines, the inlet and outlet heat exchanger of the stripper is connected to the acrylonitrile stripper through pipelines, and the inlet and outlet heat exchanger of the stripper is connected to the inlet and outlet nitrile water tank through pipelines.The butadiene desorption tank is connected with the compressor in the middle section through a pipeline.The acrylonitrile stripper is connected to the acrylonitrile condenser through pipelines, the acrylonitrile condenser is connected to the acrylonitrile separation tank through pipelines, and the acrylonitrile separation tank is connected to the acrylonitrile water tank and the compressor in the middle section respectively through pipelines.This device consists of butadiene washing, butadiene condensate recovery and compression and butadiene acrylonitrile recovered three parts (I) compression and washed with water ring type low period of compressor maintain latex suction pressure of the vacuum degassing tower, tower steam after crude acrylonitrile condenser cooling, non-condensable gas into the lower section of compressor, compressed gas phase separation into middle compressor, the compressor system overflow the seal water into butadiene flash tank, flash off overhead steam condensate into nitrile butadiene liquid and water tank.From the lower section of the compressor, vacuum flash tank, butadiene flash tank, the tail gas absorption system and acrylonitrile butadiene separation tank together into the middle gas compressor, the compressor system of seal water into butadiene flash tank, compressed gas and isolated from positive pressure flash trough of butadiene gas mixture to butadiene washing tower.Deoxidized water is added to the upper part of the butadiene washing tower and countercurrent contact with the butadiene gas entering the lower part of the tower to wash away the acrylonitrile contained in the butadiene gas.The nitrile-containing washing water at the bottom of the tower is fed into the acrylonitrile stripper through the nitrile pump, and the butadiene gas at the top of the tower enters into the high-section compressor.Butadiene gas enters the high stage compressor for compression, and the sealed water discharged from the compressor system enters the butadiene flash tank.The separated gas enters the condensation recovery system.In order to prevent the production of end-polymerization in the compressor system, the end-polymerization inhibitor for sealing water should be continuously added to each stage of the compressor.(2) the three-stage compressed butadiene gas after condensation recovery is cooled by the butadiene condenser and enters the recycling butadiene tank. Liquid butadiene returns to the polymerization system for recycling, and non-condensable gas enters the tail gas absorption tower.In the absorption tower, non-condensing gas and the solvent sprayed from the top of the tower are in countercurrent contact. After butadiene is removed, it is discharged from the top of the tower to the torch. The solvent absorbed by butadiene is heated, desorbed and cooled, and then returned to the absorption tower for recycling.The desorption of butadiene gas into the compressor in the middle section.(3) nitrile-containing water from crude acrylonitrile condenser, butadiene flash tank and acrylonitrile separation tank is collected in acrylonitrile recovery nitrile water tank. The nitrile water from the bottom of the butadiene washing tower and the nitrile water from the acrylonitrile washing tower enter the feed heat exchanger of the stripping tower and the acrylonitrile stripping tower bottom waste water for heat exchange and heat recovery, and is sent to the top of the stripping tower.Low pressure steam from the stripper tower kettle, and the top-down nitrile countercurrent contact with water, the top steamed out of acrylonitrile after acrylonitrile condenser cooling gas into the acrylonitrile separating tank, return to the middle of non-condensable gas compressor was isolated entrance, water phase into nitrile pitcher, recycled acrylonitrile liquid recycle by pump to polymerization unit.Beneficial effects of this utility model is recycled recycling butadiene and acrylonitrile monomers, reduces the production cost of nitrile rubber, increase the economic efficiency of the plant.The utility model reduces the loss of monomer in the recycling process, improves the quality of monomer recovered, and reduces the influence of monomer recycling on the product quality of nitrile butadiene rubber.


Claim:1. A kind of nitrile rubber monomer recovery unit, its characteristic is that including crude acrylonitrile condenser, low period of the compressor, compressor, butadiene washing tower in middle and high segment compressor, butadiene flash tank, condenser, butadiene recovery tank, nitrile butadiene tank, tail gas absorption tower and desorption cans and acrylonitrile butadiene stripper, crude acrylonitrile, low period of the compressor and condenser middle compressor, water tower, high period of the compressor and acrylonitrile butadiene stripping tower by pipeline connection, in turn, low high section of the compressor, the compressor and the middle section of the compressor through the pipeline connection butadiene flash tank respectively,Butadiene flash tank, butadiene condenser, butadiene recovery tank, tail gas absorption tower and butadiene desorption tank are connected successively through pipelines.

2. According to the nitrile rubber monomer recovery device mentioned in claim 1, its feature lies in that the butadiene recovery tank is connected to the high-section compressor through pipelines.

3. According to claim 1 nitrile rubber monomer recovery unit, its characteristics is described in butadiene nitrile pump water to wash the bottom through the pipeline connections, nitrile pump through a pipeline connecting the stripper front-rear heat exchanger, stripping tower front-rear heat exchanger through pipeline connection acrylonitrile stripper, stripping tower in and out of the tank via pipeline connection nitrile material heat exchanger.

4. According to the nitrile rubber monomer recovery device mentioned in claim 1, its characteristics are that the butadiene desorption tank is connected with the compressor in the middle section through pipelines.

5. The nitrile rubber monomer recovery device mentioned in claim 1 is characterized by the acrylonitrile stripper connected to acrylonitrile condenser through pipelines, acrylonitrile condenser connected to acrylonitrile separation tank through pipelines, and acrylonitrile separation tank connected to acrylonitrile water tank through pipelines, respectively, and the compressor in the middle section.

Patent abstract: the utility model relates to a kind of nitrile rubber monomer recovery unit, belong to the nitrile rubber production equipment, its characteristic is that crude acrylonitrile, low period of the compressor and condenser middle compressor, water tower, high period of the compressor and acrylonitrile butadiene stripping tower by pipeline connection, in turn, low high section of the compressor, the compressor and the middle section of the compressor through the pipeline connection butadiene flash tank respectively, butadiene flash tank, butadiene condenser, butadiene, tail gas recovery tank absorption tower and desorption butadiene tank through a pipeline connected in turn.The recycling of butadiene and acrylonitrile monomers reduces the production cost of nitrile butadiene rubber and increases the economic benefit of the unit.The utility model reduces the loss of monomer in the recycling process, improves the quality of monomer recovered, and reduces the influence of monomer recycling on the product quality of nitrile butadiene rubber.

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