Research On Corrosion Inhibitor Of Pharmaceutical Circulating Water System

Nowadays the water resources are more and more scare. Government is raising the charges on water usage and disposal charge. This trend makes almost every industry company to improve the operation of circulation infrastructure, improving the water recirculation efficiency, in order to reduce the new water supply amount and waste water discharge amount. Water recirculation cooling system is the most complicated water system in medicine production process. The stability of the system has great influence on the safety operation of medicine production.The most commonly used monomer inhibitors in China are 2 - phosphono butane -1, 2,4 - tricarboxylic acid (PBTCA), Hydroxy ethylidene diphosphonic acid (HEDP), 2 - hydroxy phosphono acetic acid (HPAA), Amino trimethylene phosphonic acid (ATMP) Acrylic acid / Acrylate(HB-901),Acrylic acid / Acrylate /AMPS Copolymer(HB-903). Based on the Calcium carbonate static scale preventing experiment and comparison with dispersed iron oxide, scale inhibitor ability selection research on PBTCA,HEDP,HPAA,ATMP was carried out. On the bases of this research, Orthogonal Experiment method was adopted to prepare the sample using four selected monomer inhibitors, PBTCA, HEDP, HPAA, ATMP. Using limit carbonate method and rotary coupon method respectively,experiments were carried out feathering on the scale preventing ability of 1#～9# compound pharmacy. At last, the optimized formula of the scale preventing solution for the plant is finally found out. It was applied to real world.The experimental results show that:(1) The water supply of this pharmaceutical plant is high alkalinity, high hardness quality. Through the discrimination of water property stability, the scale effect is more severe as the increase of concentration multiple. When the concentration multiple is larger than 2.0, the scale effect tends to be very severe.(2) Among those 6 monomer inhibitors, PBTCA,HB-901,HB-903,HEDP,ATMP,HPAA, under the same concentration, the scale inhibition abilities of the first selected six monomer inhibitors are: PBTCA>HB-901>HEDP≈ATMP>HPAA>HB903; The scale preventing ability of samples is decreasing with the increase of temperatures. Among all the samples, PBTCA and HB-901 are the best. The ability of disperse iron dioxide of the samples are: PBTCA≈HPAA >HEDP≈ATMP.(3) Inhibitor ability selection research on PBTCA,HEDP,HPAA,ATMP was carried out. The inhibitor ability of samples is creasing with the increase of concentration. The corrosion prevention effect: PBTCA≈HPAA>HEDP≈ATMP>EDTMP.(4) Considering the scale preventing effect and the corrosion prevention effect of the inhibitors, the final compound of the inhibitors are composed of PBTCA, HPAA, HB-901 and HB-903.(5) By the optimization of compound effect research, the test results show that: 2# sample has the best scale and corrosion prevention effect. Its limit concentration multiple is 3.094, the corrosion rate is 0.0246 mm/a, the corrosion prevention rate is 93%.The final ingredients ratio should be PBTCA:HB-901:HB-903:HPAA equals to 10:25:10:10.