Comparative study of a low phosphorous co‐polymer inhibitor with commercial scale inhibitors used in cooling water systems

Abstract

AbstractTo reduce the economic loss caused by scale formation and corrosion of equipment and pipelines, a low phosphorus polymer scale inhibitor is synthesized and characterized, the ability of the polymer to mitigate the calcium scale and the influences of operating conditions on CaCO3 scale are investigated by static tests. X‐ray diffraction (XRD) and scanning electron microscope (SEM) studies are performed to understand the morphological changes of the scales in the presence of the polymer. The interaction between polymer molecules and calcite crystal surface is studied by molecular dynamics simulation. The synthesized polymer is compared with the commercial product such as hydrolysis polymaleic acid (HPMA), polyacrylic acid (PAA), and 1‐hydroxy ethylidene‐1,1‐diphosphonic acid (HEDP). The experimental results show that the polymer shows better inhibition of calcium scale than the commercial product. The scale inhibition efficiency of the polymer is 92% at 10 mg/L for CaCO3 scale, 83% at 14 mg/L for Ca3(PO4)2 scale, and 98% at 6 mg/L for CaSO4 scale. SEM and XRD analysis show that the polymer induces the conversion of CaCO3 from calcite to arachite and crystal. The interaction of the polymer with both 104 and 1–10 calcite crystal surfaces are more stable than that of commercial product. The experimental results are in good agreement with those of molecular dynamics simulation.