Design of Polymeric Antiscalants Based on Functional Vinyl Monomers for (Fe, Mg) Silicates

Abstract

Silica/silicate scaling is one of a few detrimental problems that cause high economical loss in the geothermal and petroleum fields. The prevention of silica/silicate has been attempted using antiscalants with functional groups, particularly −NH 2 ; however, metal silicates are commonly found in the fields, and the antiscalants developed thus far are not effective against these compounds. In this work, polymeric antiscalants have been developed by merging two or more functional comonomers consisting of various chelating groups for metal cations. Homo-and copolymers of acrylamide (AM), the sodium salt of vinyl sulfonic acid (VSA), and vinyl phosphonic acid (VPA) were synthesized to examine their antiscaling performance against metal silicate scaling. Lab-scale metal silicates were obtained in a pressured autoclave reactor. The antiscalants were tested at various dosages (25, 50, and 100 ppm), and their effects were investigated from the leftover decantates after isolation of the solid precipitates. The polymeric antiscalants were found to be particularly effective against metal silicates and ineffective against simple silica precipitates. Acidic groups may be coordinating the metal cations, which prevents the formation of precipitates. Among these acidic comonomers, VSA-containing polymers, in particular, increased the solubility of metal silicates.

Increasing solubility of metal silicates by mixed polymeric antiscalants

“…For this purpose, the effect of metal-chelating agents (PAM, PVSA, and PVPA) in the presence of PEG 1500 was examined. These agents were chosen because they were found to be active in the reduction of metal silicate scaling in our previous work (Topçu et al, 2017). The concentration of molybdatereactive silica for mixed antiscalants was examined.…”

“…These compounds include protonated primary, secondary or tertiary amines (Danilovtseva et al, 2011;Demadis et al, 2008;Spinde et al, 2011); amide moieties (Demadis and Neofotistou, 2007); and phosphonium (Demadis et al, 2012a, b), while the functional groups are reactive silica species. The polymers reported so far are molecules intended merely for the improvement of silica solubility; however, similar attempts for the metal-silicates aiming at metal solubility have not been examined (Topçu et al, 2017). The effect of metal cations, known as catalysts for silica polycondensation (Demadis et al, 2012a, b), on metal-silicate formation was reduced by using polymers with pendant groups that are capable of chelating metals.…”

“…The various molecular weights of PEG (Mw: 0.4, 1.5, and 6.0 kg/mol) and PVA (Mw: 40, 50, and 92 kg/mol) were supplied by Sigma-Aldrich. PAM, PVSA, and PVPA were synthesized in our lab to employ as co-antiscalants and detailed information regarding the synthesis was given in a previous study (Topçu et al, 2017). All the antiscalants were dissolved in 50 mL dH 2 O and their dosage was fixed to 25, 50, and 100 mg/L.…”

SHMP as Antiscalant for Treating Brackish Water using Reverse Osmosis

“…Thus the growth of the crystal from the cores is known as scale arrangement. (Topçu et al 2017) have categorized the silica-based scaling as metal scaling and silica scaling. The process of silica-based scale faces limitations due to silica polymerization and the aggregation of shapeless colloidal silica.…”

Evaluating efficiency and stability of calcite scaling inhibitors at high pressure and high temperature in laboratory scale

“…Environmental concerns of the governmental authorities are increasing and enforce the usage of "green" inhibitors that are non-toxic and biodegradable (Chaussemier et al 2015;Popov et al 2016). New scaling inhibitors meeting these requirements were lately tested with regard to their inhibitory efficiency (Reddy and Hoch 2001;Baraka-Lokmane et al 2008;Kavitha et al 2011;Choi et al 2002) but scarcely at elevated temperatures such as occurring in geothermal fluids (Topçu et al 2017;Ketrane et al 2009).…”