At what temperature can PASP be used?

PASP is a biodegradable, non-phosphorus scale inhibitor widely used in water treatment. Its effectiveness depends on temperature, with key thresholds as follows:

1. Optimal Temperature Range

Application Temp. Range Performance Characteristics

Cooling Water 5–80°C Stable scale inhibition (CaCO₃, CaSO₄)

RO Systems 10–45°C Effective silica dispersion

Boiler Water ≤100°C Short-term use; gradual degradation above 100°C

Oilfield Injection 20–120°C Tolerates high TDS & moderate temps

2. Thermal Stability Limits

≤80°C: Full functionality (no significant decomposition).

80–100°C: Partial degradation after prolonged exposure (e.g., >48 hrs).

>100°C: Rapid loss of efficacy; not recommended for high-pressure boilers.

Comparative Data:

Polymer Max. Temp. (Continuous) Degradation Byproduct

PASP 100°C Aspartic acid monomers

PBTC 120°C Phosphates

HEDP 200°C Orthophosphates

3. High-Temperature Alternatives

For systems >100°C, consider:

POCA (Phosphinocarboxylic acid): Stable up to 150°C.

Sulfonated copolymers (e.g., VS-Co-AA): Tolerates 130°C.

4. Field Recommendations

Cooling Towers: Ideal for open/closed loops (<80°C).

Geothermal Systems: Use PASP + polyacrylate blends (max 90°C).

Boiler Blowdown: Limit exposure to <30 mins at 105°C.

Note: PASP’s biodegradability makes it unsuitable for prolonged >100°C applications – monitor residual polymer levels monthly in high-heat systems.

For exact dosing at elevated temperatures, conduct dynamic loop tests with site water.