Synergistic effect of some antiscalants as corrosion inhibitor for industrial cooling water system

Abstract

In order to study synergistic effect, various combinations of antiscalants 1-hydroxyethane-1,1-diphosphonic acid (HEDP), sodium hexametaphosphate (SHMP), sodium tripolyphosphate (STPP), and trisodium phosphate (TSP), were investigated as corrosion inhibitors for carbon steel. Corrosion rate and percentage inhibition efficiency of various combinations of antiscalants as corrosion inhibitors (20/80, 40/60, 60/40, 50/50, 80/20, and 100 ppm of different combinations of HEDP, SHMP, STPP, and TSP) in synthetic cooling water VI (692 ppm of Cl -ions) was determined by weight loss, electrochemical polarization technique, and metallurgical microscopy technique. It was observed that a 50/50 ppm combination of HEDP and SHMP gave 98% corrosion inhibition efficiency and maximum synergistic effect. The percentage inhibition efficiency of HEDP when mixed with other antiscalants as corrosion inhibitors at 50/50 ppm concentration was found in the following order HEDP/SHMP [ HEDP/STPP [ HEDP/TSP. The synergistic effect of HEDP/SHMP combination is due to intermolecular hydrogen bonding between the molecules of HEDP and SHMP, which results in the adsorption of uniform multilayered two-dimensional film of -HEDP-SHMP-molecules on carbon steel surface.

Double‐hydrophilic polyether antiscalant used as a crystal growth modifier of calcium scales in cooling‐water systems

“…Meanwhile, the peaks at d 5 4.20 ppm proved the existence of carbonyl groups. All of these suggested that the AOH groups in PEG 8 were entirely transformed into AOC(@O)CH@CHCOOH and PEG 8 The double-bond adsorption peaks at d 5 6.37 ppm in Figure 1(b) completely disappeared in Figure 1(c); we concluded that free-radical polymerization between PEG 8 DMA and AA occurred.…”

“…To gain a better understanding of the stand or fall of the PEG 8 DMA/AA inhibition power, the effects of PEG 8 Figure 3.…”

“…PEG 8 DMA/AA contained many ACOO 2 groups in its molecules; this guaranteed the source of negative ions, so that the crystal growth processing was almost ruined completely. The great amounts of PEG 8 DMA/AA at the scale surface formed a dense adsorption layer with electronegative ACOO 2 groups, which were able to adsorb calcium ions continuously. The leading result was the formation of a multiadsorption layer, and calcium ions (Ca 21 ) were dissociated between the layers far away from the negative ions (CO 3 22 and SO 4 22 ).…”

Synthesis, characterization and electrochemical performance of a new imidazoline derivative as an environmentally friendly corrosion and scale inhibitor

“…Phosphonate groups were inserted into 2-aminobenzimidazole to develop such inhibitor with an improved corrosion inhibition as well as a high scaling inhibition efficiency. In fact, phosphonate is known as an anti-scaling group [30][31][32]. This threshold inhibitor is added to aquatic media even with high calcium ion concentration and disrupts the formation of precipitates by means of adsorption onto crystal growth sites [33].…”

Estudo da atuação e sinergismo de inibidores de corrosão para o aço inoxidável austenítico 304 em meio de ácido peracético comercial 0,2%

“…No entanto, íons fosfato vêm sendo empregados há mais de um século como meio para proteger superfícies metálicas dos efeitos da corrosão, seja na forma de banhos fosfatizantes [40], como na forma de sais aplicados como inibidores de corrosão para diversos meios e materiais metálicos [41] [42] [43].…”