US 12,146,099 B2
Inhibition of silica scale using a chelating agent blended with acid and alkylene oxide derived polymer dispersants
Puspendu Deo, Pearland, TX (US); Maria Simon, Rosharon, TX (US); Pramod Akhade, Houston, TX (US); Graham P. Abramo, Penllyn, PA (US); Kaylie L. Young, Sugar Land, TX (US); and Somil Chandrakant Mehta, Mumbai (IN)
Assigned to Dow Global Technologies LLC, Midland, MI (US); and Rohm and Haas Company, Collegeville, PA (US)
Appl. No. 15/734,058
Filed by Dow Global Technologies LLC, Midland, MI (US); and Rohm and Haas Company, Collegeville, PA (US)
PCT Filed May 29, 2019, PCT No. PCT/US2019/034349
§ 371(c)(1), (2) Date Dec. 1, 2020,
PCT Pub. No. WO2019/232019, PCT Pub. Date Dec. 5, 2019.
Claims priority of application No. 201841020598 (IN), filed on Jun. 1, 2018; application No. 201841020613 (IN), filed on Jun. 1, 2018; application No. 201841029480 (IN), filed on Aug. 6, 2018; and application No. 201941002455 (IN), filed on Jan. 21, 2019.
Prior Publication US 2021/0221723 A1, Jul. 22, 2021
Int. Cl. C09K 8/528 (2006.01); C02F 5/12 (2023.01); C08F 220/06 (2006.01); C08F 220/28 (2006.01); C08F 283/06 (2006.01); C02F 101/10 (2006.01)
CPC C09K 8/528 (2013.01) [C02F 5/12 (2013.01); C08F 220/06 (2013.01); C08F 220/286 (2020.02); C08F 283/06 (2013.01); C02F 2101/10 (2013.01); C02F 2303/22 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method of inhibiting silica and metal silicate scale formation, said method comprising the steps of:
treating an aqueous system comprising silica and at least one metal ion selected from the group consisting of Fe3+ and Al3+, with an effective amount of a mixture of a chelating agent and an acid and alkylene oxide derived polymer dispersant which is a polymerizable-acid graft polymer comprising from 5% to 25% by weight of an unsaturated grafting acid and an alkylene oxide polymer backbone;
wherein said chelating agent is ethylenediaminetetraacetic acid (EDTA) or diethylene triamine pentaacetic acid (DTPA);
wherein said acid and alkylene oxide derived polymer dispersant has a number average molecular weight from 500 Daltons to 40,000 Daltons; and
wherein said chelating agent is mixed with said acid and alkylene oxide derived polymer dispersant in a weight ratio from greater than 1.0:3.0 to less than 1.0:0.5, agent to dispersant.