Study On The Production Process Of Polyacrylamide

Polyacrylamide(PAM) products are widely used in the industrial field,such as tertiary oil recovery,water treatment,paper making,mineral separation and so on.With the development of economy,sewage treatment capacity,paper and demand for crude oil increase sharply,resulting in a rapid increase in demand for polyacrylamide products.The thesis study the copolymerization with acrylamide(AM)and sodium acrylate in aqueous solution to produce polyacrylamide.Its main raw material include acrylate,acrylic acid and sodium hydroxide.Acrylic acid,sodium hydroxide purchased from changeless manufactures,acrylamide is produced by ourselves,mainly contain the product of acrylic acid in excessive hydration reaction and amino acid,protein,inorganic sail in bacteria.We have studied very carefully impurity removal in the acrylamide monomer and refining process,test conditions of copolymerization with acrylamide and sodium acrylate,production process in workshop.The following results are obtained:1.Optimizing cell culture conditions,obtained cell with biomass in10mg/ml and enzyme activity in 9 million μg/ml · h to react with acrylonitrile(AN)through microbial method,adjusting reaction p H 7.0,reaction temperature in 20 deg.c,AN residual in bellow 0.5 per thousand in reaction process,AN feeding mode with gradient,reduced the amino acid,protein,acroleic acid(AA)and inorganic salts in acrylamide filtrate.Then changed the resin to purity,with 732 strong acid cation exchange resin and D311 macroporous weakly basic anion exchange resin,refined acrylamide filtrate,removed various impurities,include protein,inhibitor,AA,N-3 propanamide and so on,further acrylamide solution are purified,obtained acrylamide solution of high quality.2.Based on the theory of free radical polymerization,analyzed the influencing factors of acrylamide polymerization.To adopt copolymerization of acrylamide and sodium acrylate in aqueous solution with ammonium persulfate,ferrous sulfate and azobisisobutyronitrile as composite inhibitor to prepare PAM.Through many experiments,to research the effects of reaction temperature,concentration of initiator and monomer concentration on the polymerization,determined the optimum polymerization conditions:material concentration of 23-25 %,ionic degree of 28%,reaction temperature 0-2 deg.c,redox agent concentration of 0.003 per thousand,azobisisobutyronitrile concentration of 0.15%,urea concentration of 2-3%,p H value in the 7.5,the complexant concentration of 0.012 per thousand,the chain transfer agent concentration of 0.06 per thousand.Based on the above conditions,obtained the polymer with high solubility and molecular weight of 20-21 millions.3.Using experimental data to expand pre-production trial,by changing the mode with initiator to join polymerizer,the initiator at the bottom of polymerizer to join,adjusted emulsifier’s ratio to 2:8 with S-20 and light oil,the injected amount to 6000 ml,reduced the rubber block wall sticking phenomenon,changed the granulating machine template to2.8mm,reduced particle size of rubber block into the dry bed,slowed granulation speed,reduced baffle plate’s height of ⅠandⅡ section in dry bed and drying temperature,used the way of low temperature and slow drying,improved the solubility of the product,obtained industrial product with the good solubility and molecular weight of 18 million,its performance index is better than the other domestic manufactures.