Studies on corrosion of carbon steel in deaerated saline solutions in presence of scale inhibitor

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

“…The inhibition efficiency also remained constant after it attained the ultimate inhibition efficiency values for HEDP, PESA, HPMA, PAA, and PBTC (93.6, 90.6, 88.8, 81.6, and 68.8%, respectively) at dosage levels of 3, 5, 4, 4, and 6 mg/L. It is worth noting that the most effective CaCO 3 water additive, PBTC, had a relatively poor antiscaling function on CaSO 4 ; this suggested that function of some of the inhibitors were not perfect. Meanwhile, PBTC had phosphorus in its structure, and this is not desirable in water additives.…”

“…Meanwhile, PBTC had phosphorus in its structure, and this is not desirable in water additives. In this study, the newly synthesized PEG-based PEG 8 DMA/AA was a versatile, nonphosphorus, and environmentally friendly scale inhibitor, not only for CaCO 3 but also for CaSO 4 , with the potential to be applied in industrial water systems, not only to solve the water eutrophication problems caused by phosphorus but because of its economic efficiency. …”

“…1,2 In the long-cycle operation, severe phenomena of scale deposition, metal pipeline corrosion, microbial propagation occurred spontaneously; this caused security issues and technical and economic problems such as decreased system heat-transfer efficiency, increased cleaning frequency, and even unexpected system shutdowns. 3,4 To alleviate and prevent the aforementioned phenomena from occurring, the most common and effective control method is to apply water-treatment agents, which consist of strong chelating functional groups and pose superior affinity and dispersion power toward Ca 21 , Fe 31 , Mg 21 , Ba 21 , and the like in industrial water systems. 5 Polycarboxylate and polyphosphonate antiscalants are the most commonly used inhibitors for retarding the growth of calcium salts, such as poly(acrylic acid) (PAA), hydrolytic poly(maleic anhydride) (HPMA), 2-phosphonobutane 1,2,4-tricarboxylic acid (PBTC), 1-hydroxyethylidine 1,1-diphosphonic acid (HEDP), and poly(hydric alcohol phosphate ester), together with the nonphosphorus environmentally friendly inhibitor poly(epoxysuccinic acid) (PESA).…”

“…20 CaSO 4 crystallizes out of water in three forms: dihydrate (CaSO 4 Á2H 2 O, gypsum), hemihydrate (CaSO 4 Á0.5H 2 O, Plaster of Paris), and anhydrite (CaSO 4 ), among which the former type is widely occurring on the heat-transfer surface. The relation between the solubility of CaCO 3 , CaSO 4 , and temperature is inverse; that is, the higher the temperature is, the easier of the formation of CaCO 3 and CaSO 4 scales is. Traditional chelating agents and naturally occurring polymers are also limited because they are unstable in high-temperature conditions and a higher minimum inhibitor concentration requirement.…”

Novel polydentate phosphonic acids: Protonation and stability constants of complexes with Fe(III) and Cu(II) in aqueous medium

“…Their high chemical stability and their high solubility in water allow their use in detergents [1][2][3], industrial water treatment [4,5], industrial cleaners, enhanced oil recovery operations, and in corrosion control [6][7][8][9][10][11]. They also find applications in medicinal chemistry as antiviral agents, acting as analogues of natural pyrophosphates [12,13].…”