Polyacrylamide production technology and process

Polyacrylamide (PAM) is a linear organic polymer.It's widely used in water treatment, pulp & paper,oil exploitation,Mining industry.

Usually the production process of polyacrylamide is "pre-prepared raw material ratio - mixing reaction - granulation - drying - crushing - packaging - warehousing".

Yangzhou Zoomri Co., Ltd. is a professional polyacrylamide supplier.

production technology

2x 104t/a polyacrylamide industrial development research includes two main process units: microbiological AM unit and PAM unit. The AM unit process mainly includes AN raw material preparation, air purification, biological fermentation, catalytic reaction and AM refining. The PAM unit mainly includes AM liquid preparation, AM polymerization, PAM granulation, PAM drying, grinding, screening, packaging, etc. process.

Production process

(1) AN raw material preparation

The purpose of this process is to remove the polymerization inhibitor (hydroquinone monomethyl ether) added during the storage and transportation of raw material AN. The AN from the storage tank is heated and then enters the flash tank, where it is flashed in a vacuum state. The gas phase is condensed and cooled before entering the AN intermediate storage tank.

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(2) Air purification

The purpose of this process is to produce oil-free, sterile air for bacterial culture. Compressed air (0.35MPa) is cooled to separate part of the moisture, and the dew point of the air is controlled below 20°C. After reheating, it enters the main filter to eliminate bacteria in the air and is sent to the fermentation process.

(3) Biological fermentation

The purpose of this process is to cultivate bacteria that produce nitrile hydratase. The first step of the operation is to send the culture medium into the seed tank, propagation tank, and fermentation tank; the second step is to use steam to strictly sterilize the equipment and culture solution; the third step is to transplant, propagate, and ferment to produce a relatively high quality product. Fermentation broth with high enzyme activity. This process operation is intermittent operation.

(4) Catalytic reaction

The purpose of this process is to complete the reaction of AN and H2O into AM under the action of biological enzyme catalysts. The fermentation broth uses immobilized cell technology to produce granular biological enzyme catalysts, which are mixed with water into the catalytic reactor in a certain ratio. The refined AN is measured and added dropwise to the catalytic reactor, and the concentration of AN in the solution in the reactor is controlled. 3-4%, and control the temperature of the reactor at the same time. When AM reaches the predetermined concentration and the AN concentration is ≤500 mg/l, enter the AM intermediate tank. The effective activity of the biological enzyme catalyst is three cycles. After three cycles, the catalyst is filtered and separated and sent for incineration.

(5) AM refined

The purpose of this process is to separate light component impurities in AM brought by raw materials, as well as impurities brought by culture media, catalysts, and equipment, including biological cells, organic matter, metal ions, etc. The AM aqueous solution is flashed under high vacuum to remove the light components brought by the AN raw material, and is filtered through an ultrafiltration membrane filter to remove biological cells, organic matter, etc., and then is demetalized by an ion exchange resin to obtain a solution that meets the requirements of the subsequent polymerization process. AM aqueous solution products on request.

(6) AM liquid preparation

The purpose of this process is to prepare AM, H2O, and alkali in a certain proportion into a mixed solution with a predetermined concentration, while controlling the solution temperature within the set range.

(7) Polymerization and hydrolysis

The purpose of this process is to polymerize AM into a high molecular weight PAM colloid under the action of an initiator, and to perform a hydrolysis reaction in the same polymerization kettle to achieve the required degree of hydrolysis. After the AM solution enters the polymerization tank, pure N2 (99.99%) is used to remove O2 in the solution, and then various initiators are added according to predetermined procedures and amounts to carry out the polymerization reaction. The reaction process does not require temperature control. After the polymerization reaction is completed, hot water is introduced into the jacket of the polymerization kettle for heat preservation to carry out the hydrolysis reaction.

(8) PAM colloidal granulation

The purpose of this process is to cut the rubber block PAM into 3-6mm rubber particles. The PAM colloid is pressed from the polymerization kettle into the storage box with air, and then into the granulator from the storage box. The screw in the granulator transports the colloid from the feeding port to the knife hole. At the same time, the pressure of the screw causes the colloid to be extruded from the knife hole to form a thin strip. The rubber strip is then cut into thin strips by the rotating TJ knife that cooperates with the knife hole. Particles. Colloidal particles with a particle size of about 3-6mm can be obtained through the granulator, and then the colloidal particles are fed into the dryer by pneumatic conveying.

(9) PAM drying

The purpose of this process is to turn PAM colloid into solid granular PAM, and its water content is reduced from 75% of the colloid to 10% of the solid PAM. The dryer is divided into 2 sections, and the first section is dried with hot air at 110-120°C , dry until the PAM moisture content is about 25%, and in the second stage, use 90-70°C hot air drying to dry until the PAM moisture content is 10%, and then cool to 55°C. The drying is divided into two production lines, one line has a scale of 6500t/a and uses domestically developed products; the other line has a scale of 13500t/a and uses imported equipment. The NH3 and H2O vapor generated during the drying process are discharged into high altitude together with the air.

(10) Grinding and packaging

The purpose of this process is to grind solid large granular PAM into small granular powder, sieve 0.15-1.Omm granular PAM dry powder, and package it into bags. The products from the vibrating screen are transported to the cyclone separator through negative pressure pneumatic. The material at the bottom of the cyclone separator enters the double-layer screener and is divided into three parts by the double-layer screener. The fine powder is fed into the hopper and bagged; the coarse particles are fed into the bag. The grinder grinds again and then sends it to the cyclone separator; the particles that meet the requirements are transported to the mixing hopper, so that the products from different reactors are mixed to obtain a uniform product, which is then measured and bagged through the packaging machine.

If you want to know more about the application of polyacrylamide in water treatment, pulp and paper, oil extraction, and mining, please contact Zoomri.