Scale control performance

Belclene® 494 is a highly effective scale inhibitor and dispersant. It effectively controls calcium carbonate, calcium phosphate and iron oxide scales, which results in reduced inorganic deposition in cooling systems and maximising heat transfer.

Mechanism
Belclene 494 is a medium molecular weight acrylic-based polymer containing both sulphonate and phosphonate groups. It gives calcium carbonate threshold inhibition and dispersancy as a result of the phosphonate functionality and molecular weight range respectively. The inclusion of sulphonate groups imparts phosphate and iron control to the product.

The multifunctional scale control activity of Belclene 494 has been shown in laboratory evaluations.

Laboratory evaluation of Belclene 494

Calcium carbonate scale control
Belclene 494 was compared with PBTC, a sulphonated terpolymer and a 2000 molecular weight polyacrylate in bottle tests and dynamic testing.

In standard bottle tests to evaluate threshold inhibition, Belclene 494, was shown to match the performance of PBTC while far outperforming both the sulphonated terpolymer and the 2000 molecular weight polyacrylate (see figure 1).

Figure 1: Inhibition of calcium carbonate

Conditions
Ca²⁺: 375 mg/l as CaO₃
HCO₃^-: 220 mg/l as CaCO₃
CO₃^2-: 85 mg/l as CaCO₃
Mg²⁺: 185 mg/l as CaCO₃
pH 8.2
30 minutes at 70°C

This result was repeated in dynamic tests as shown in figure 2. In this test, where calcium loss from a pilot cooling system is measured, Belclene 494 controls calcium carbonate as effectively as PBTC, and again outperforms the sulphonated terpolymer and the polyacrylate.

Figure 2: Inhibition of calcium carbonate in the recirculation rig

Calcium phosphate scale control
The performance of Belclene 494 as a calcium phosphate inhibitor and dispersant was compared with that of a polyacrylate and a sulphonated terpolymer.

The results are shown in figures 3 and 4.

Belclene 494 outperforms the polyacrylate and shows similar performance to the sulphonated terpolymer in both tests.

Figure 3: Inhibition of calcium phosphate at pH 8

Figure 4: Dispersion of calcium phosphate

The ability of Belclene 494 to disperse iron oxide was evaluated against the polyacrylate and the sulphonated terpolymer. The results are shown in figure 5.

Figure 5: Dispersion of iron oxide

In this severe test with 100 mg/l of iron, Belclene 494 outperformed the polyacrylate and compared favourably with the sulphonated terpolymer.

Performance against other scales
Your FMC representative can provide data which shows that Belclene 494 also performs well as a calcium sulphate scale inhibitor and a kaolin dispersant.

The multifunctional scale control properties of Belclene 494 make it a flexible and wide-ranging additive for the control of inorganic cooling water deposits. Combining scale and corrosion control in one product, Belclene 494 is a new building block for the next generation of cooling water treatment formulations.

Process Additives Division

Warranty - Patent Position
The information contained herein is, to our knowledge, true and accurate. Because conditions of use are beyond our control, we make no warranty or representation, express or implied. except that the products discussed herein conform to the chemical descriptions shown on the labels. Nothing contained herein should be construed as permission or recommendation to infringe any patent. No agent, representative or employee of this company is authorised to vary any terms of this notice.