Research Article

A Comparative Performance Evaluation of Some Novel “Green” and Traditional Antiscalants in Calcium Sulfate Scaling

Table 3

Scale inhibitors ranking reports for calcium sulfate.

Experiment detailsDosage, mg·dm−3RankingReference

Static method. Brine composition: CaCl2·2H2O 6,8 g·dm−3 (0,097 mol·dm−3); Na2SO4 7,1 g·dm−3 (0.074 mol·dm−3); pH = 7; 6 hours at 70°C5PA (3500 Da) > HMP > PA (10000 Da) > PBTC > HEDP > PA (50000 Da)[12]
Dynamic method: induction period and crystal growth velocity. Brine composition: CaSO4 0,0497 mol·dm−3; NaCl 0.4 mol·dm−3; pH = 7; 25°C0.5PA (3500 Da) > HMP > PA (10000 Da) > PBTC > HEDP > PA (50000 Da)[13]
Static method. Brine composition: [Ca2+] 2,0 g·dm−3 (0,097 mol·dm−3), [] 4,8 g·dm−3 (0,05 mol·dm−3) pH 7; 18 hours at 60°C5 PASP (1–5 kDa) > PESA (0,4–1,5 kDa)[15]
Static method. Brine composition: [Ca2+] 0,097 mol·dm−3, [] 0.074 mol·dm−3; pH = 7; 10 hours at 60°C 1PMA (600 Da) > PA (1800 Da) > PESA (1500 Da);[9] 
5 (1800 Da) > PESA (1500 Da)
Static method. Brine composition: [Ca2+] 6,8 g·dm−3 (0.17 mol·dm−3), [] 7,1 g·dm−3 (0.07 mol·dm−3), pH = 7; 10 hours at 60°C2PBTC > PAA (1800 Da) > PESA (1500 Da) > HEDP[18]
Static method. Brine composition: CaSO4 0,045 mol·dm−3, pH = 7; 24 hours at 66°C1PA (2000 Da) > ATMP > PBTC > HEDP[14]
Static method. Brine composition: CaSO4 0,0045 mol·dm−3, pH = 7; 20 hours at 66°C2ATMP > PA (6 kDa) > PBTC > HEDP[17]
Static method. Brine composition: [Ca2+] 0,097 mol·dm−3, [] 0.074 mol·dm−3; pH = 7; 6 hours at 80°C2PMA (600 Da) > PA (1800 Da)[16]
Static method. Brine composition: [Ca2+] 0,097 mol·dm−3, [] 0.074 mol·dm−3; pH = 7; 6 hours at 80°C2PA (2000 Da) > PMA (1000 Da) > PA (6000 Da)[20]
Dynamic method: crystal growth velocity at 55°C. Brine composition: 0.045 mol·dm−3 CaCl2 and 0.045 mol·dm−3 Na2SO41PASP efficacy is comparable with industrial phosphonates [7]
Static method. Brine composition: CaCl2·2H2O 6,8 g·dm−3 (0,097 mol·dm−3); Na2SO4 7,1 g·dm−3 (0.074 mol·dm−3); pH = 7; 10 hours at 60°C 3PA (1800 Da) > PMA (600 Da) > PESA (1500 Da)[21]  
9PESA (1500 Da) ≥ PA (1800 Da) ≥ PMA (600 Da)
Static method. Brine composition: [Ca2+] 0,051 mol·dm−3, [] 0.021 mol·dm−3; 10 hours at 80°C5PASP > PESA > HEDP[22]
Static method. Brine composition: CaCl2·2H2O 5,55 g·dm−3 (0,038 mol·dm−3), Na2SO4 5,33 g·dm−3 (0.038 mol·dm−3); NaCl 7,50 g·dm−3 (0.11 mol·dm−3) pH = 6-7; 24 hours at 71°C0.5 (400–1500 Da) > PASP (1000–5000 Da) > Our data
3.0PAAS (3000–5000 Da) > HEDP > PBTC

For static methods, an antiscaling effect was estimated by calcium titration with EDTA before and after deposition.