Synthesis Of High Efficient And Environmental Scale Inhibitor For Circulated Cooling Water

It is stated in the paper that the current research and development of water treatment agent used in circulated cooling water in China and other countries. The synthesizing process of polymer is simplified in order to be convenient for industrial production. So the research breaks through the traditional method in the synthesis of polyepoxysuccinicate (PESA). NaOH acted as initiator, substituted rare earth and Ca(OH)2, is used in the research. The synthesizing method of PESA, its multi-property of scale inhibition, and the influence of synthesizing condition and water-quality on the scale inhibition, are tested by IR and scale static beaker test.Maleic anhydride as raw material, sodium tungstate as catalyst, hydrogen peroxide as oxidation agent, sodium hydroxide as initiator, are applied in the synthesis of PESA though solution polymerizing. In order to seek for the optimum synthesis technology, amount of oxidation agent and initiator, as well as duration and temperature is studied in the research by orthogonal experiment. IR spectrum and qualitative test of hydroxy indicated that the polymer has the characteristic cluster of PESA, such as carboxyl and hydroxyl, etc. meanwhile the characteristic parameters are concluded: the content of polymer is 81.9%, the content of hydroxy compound is 0.2%, density is 1.322 g/cm3, and characteristic viscosity is 1.358cm3/g.The concentration of polymer, alkalinity and hardness of water are discussed in the research. Those factors influence the scale inhibition property of polymer. Several conclusions have been drawn: PESA is fit to high hardness water system with alkalinity value 1000mg/L and hardness value 2600mg/L, to high alkalinity water system with hardness value 1000mg/L and alkalinity value 1500mg/L (hardness and alkalinity value is accounted by the mass of calcium carbonate without specification in thepaper). In addition, appropriately increasing amount of PESA can improveproperty of scale inhibition and be applied to worst circulating cooling water system.At last, the inhibition performance of PESA on inorganic scale is evaluated by scale static beaker test of calcium carbonate and calcium phosphate, stability test of zinc salt, diffusion test of ferric oxide in the paper. The experimental results show that PESA has excellent scale inhibition on calcium carbonate and calcium phosphate, stability on zinc salt and diffusion on ferric oxide. Under the condition of hardness 1250mg/L and alkalinity 1000mg/L, while amount of PESA is 20.8mg/L, inhibiting scale ratio on calcium carbonate is more than 90%. While amount of PESA is 36mg/L, inhibiting scale ratio on calcium phosphate is 48.0%; while amount of PESA is 7.8mg/L, stabilizing zinc salt ratio is more than 80.0%; while amount of PESA is 5.7mg/L, PESA has excellent diffusion on ferric oxide. So PESA is a soluble, high effective and versatile scale inhibitor.