ACUMER polymers are a series of Low Molecular Weight (LMW) Polyacrylic Acids and their corresponding sodium salts.
These products have weight average molecular weights of approximately 2000 and 4500. ACUMER polymers contain no phosphorus,making their use acceptable where legislation requires thatdischarge waters contain low or no phosphorus.
ACUMER polymers are highly effective scale inhibitors that can be used industrial water treatment and oil production applications to inhibit the deposition of calcium carbonate,
calcium sulfate, barium sulfate, and other low solubility salts on surfaces. These polymers show good activity over a wide range of pH, water hardness, and temperature conditions.
The choice among the members of the series depends on the application, formulation, use conditions, and required performance characteristics. These materials show excellent
Applications ACUMER polymers can be used to inhibit scale buildup on surfaces through at least three mechanisms:
• Solubility enhancement or threshold effect, which reduces precipitation of low solubility inorganic salts.
• Crystal modification, which deforms the growing inorganic salt crystal to give small,irregular, readily fractured crystals that do not adhere well to surfaces.
• Dispersing activity, which prevents precipitated crystals or other inorganic particulates from agglomerating and depositing on surfaces.
Low molecular weight polyacrylic acids are widely used to inhibit scaling in industrial water treatment and in oil production applications.
The activity of the ACUMER polymers in cooling tower, boiler, and oil field applications is illustrated by the following data.
ACUMER 1000, 1020, 1100, and 1110 Scale Inhibitors
Scale Inhibition at
In evaluating scale inhibition at heat transfer surfaces, the ACUMER™ polymers were used alone under stressed conditions.
Note that their relative effectiveness may change in formulated water treatment systems or under less stressed conditions.
1. Laboratory Test on Immersion Heater (Table 4, Figures 4 and 5)
Test water was recirculated past an immersion heater and over baffles exposed to upward air flow; Table 4 lists the test parameters.
During the 3-hour run, the calcium ions remaining in solution as evaporation proceeded and the rate of heat transfer (time the heater was on) were monitored.
The amount of scale deposited on the heater at the end of the test was also measured.
ACUMER 1000/ACUMER 1020 (Mw 2000) were the most effective under these conditions by all three measurements of scaling tendency.
The highest molecular weight analogs ACUMER 1100/ACUMER 1110 (Mw 4500) and a competitive sodium polyacrylate (Mw 2800) were less effective
The relative performance of the ACUMER™ polymers was evaluated in simulated
cooling tower devices under stressed conditions. Water containing 625 mg/l hardness
(as CaCO3) and 150 mg/l alkalinity was circulated past a copper heat transfer coupon at
0.4 to 2 ft./sec. in an apparatus designed to give a range of flow rates over a single heat
transfer surface; Table 5 lists the test parameters. Heat transfer coefficients were
monitored daily for 5 days; the polymer levels were 2.5, 7.5, and 15 ppm. Table 6 lists
the average retained heat transfer coefficient at each polymer concentration. Like the
immersion heater study, ACUMER 1000/ACUMER 1020 were the most effective
polymers in maintaining a constant, high heat transfer coefficient and
ACUMER 1100/ACUMER 1110 were almost as good.
Most oil-field waters are brines, containing large amounts of divalent cations which
commonly form mineral scales. Scale can be encountered on the formation face, in the
production tubing, on surface vessels, injection pumps, lines, etc.
The scales of greatest concern in oil production are calcium sulfate, calcium carbonate, and
barium sulfate. Laboratory screening tests are useful for comparing the effectiveness of
inhibitor candidates. Details of the test procedures are given in the Appendix.
1. Inhibitor of CaSO4 Precipitation (Figure 7)
ACUMER™ polymers are all highly effective inhibitors of CaSO4 precipitation. Virtually
complete inhibition is achieved with 0.5 ppm polymer under the NACE test conditions.
No significant difference in activity among the polymers in the ACUMER series is noted
during this test.
2. Inhibition of CaCO3 Precipitation (Figure 8)
ACUMER 1100/ACUMER 1110 (M� R
w 4500) and ACUMER 1000/ACUMER 1020
polymers (M� R
w 2000) are equally effective inhibitors of CaCO3 precipitation.
Inhibition by Blends of ACUMER™ Polymers and Phosphonates (Figure 9)
In some instances, blends of phosphonates or phosphate esters with ACUMER
polymers are better anti-precipitants than either alone. Figure 9 demonstrates the
synergistic behavior of ACUMER 1100/ACUMER 1110 and phosphonate for calcium
carbonate inhibition; the dotted lines plot the additive effects and the solid lines the
actual effects of the blends.
4. Inhibition of BaSO4 Precipitation (Figure 10)
BaSO4 scale is particularly difficult to remove and consequently prevention is critically
important, especially in off-shore oil wells and papermaking applications.
ACUMER 1000/ACUMER 1020 polymers (Mw 2000) are particularly effective in a typical 16-hour duration test and show more efficient inhibition than ACUMER 1100/
ACUMER 1110 (Mw 4500) polymers.
ACUMER 1000/ACUMER 1020 polymers also show better inhibiting activity than a competitive sodium polyacrylate, a phosphonate, or a phosphate ester.
If longer times (64 hours) are allowed for precipitation, ACUMER 1100/ACUMER 1110
(Mw 4500) are more effective than ACUMER 1000/ACUMER 1020 (Mw 2000).
5. Overall Anti-Precipitation Performance
The actual choice between the two molecular weight polymers depends on the test conditions, although generally ACUMER 1000/ACUMER 1020 (Mw 2000) are the most
effective polymers. At high Ca+2 concentration and high temperature,ACUMER 1000/ACUMER 1020 would be expected to perform better than ACUMER 1100/ ACUMER 1110 considering the comparative solubilities versus Ca+2
concentration and temperature in Figure 3.
ACUMER™ 1000, 1020, 1100, and 1110 Scale Inhibitors
MODIFICATION OF CaSO4 AND CaCO3 CRYSTALS (Figures 11 and 12)
The photomicrographs in Figures 11 and 12 show the dramatic crystal distortion effects of
ACUMER 1000/ ACUMER 1020 and ACUMER 1100/ACUMER 1110 on CaSO4 and
CaCO3. The normally long and regular CaSO4 crystals are fractured and distorted when
formed in the presence of ACUMER 1000/ACUMER 1020 polymers. CaCO3 crystals are
normally large and well formed, but are smaller and more irregular when formed in the
presence of ACUMER 1100/ACUMER 1110.
ACUMER™ polymers 1000, 1020, 1100 and 1110 are very stable at high pressures and
temperatures typical of boilers up to at least 1200 psig/298°C. The chart below contains
data on the hydrothermal stability of ACUMER 1000.