Seeking Highly Selective Calcium Phosphate Formation Inhibitor for Thermal Management Fluids

A very large oil company is looking for a technology preventing calcium phosphate formation and precipitation in thermal management fluids without increasing corrosiveness.

The SpecialChem Client, a leading oil company, is facing calcium phosphate formation problems when a solution containing sodium phosphate is mixed with a calcium chloride solution. The formation of deposits is due to hard water or water contamination and influences stability of the thermal management system and corrosion inhibitors.

These deposits are detrimental to the functionality of the product (heat transfer and corrosion protection) and affect key performances requirements or result in blockages within the system or reduced flow through of the thermal management fluids.

Chemicals currently used by the SpecialChem Client to solve this challenge are not specific enough (increasing corrosion rate of some materials), so he is looking for an efficient alternative.

The minimum opportunity for an efficient technology is 200 tons/year.

The conditions in use will be the following:

• pH = 8,0 – 8,5, obtained by neutralizing phosphoric acid with sodium hydroxide
• Sodium phosphate concentration is (asPO43-): 1400 mg/l
• Calcium chloride concentration (as Ca2+): 240 mg/l
• Temperature: 90°C
• Solvent: ½ mixture monoethylene glycol / water

The proposed technology must not increase corrosion rate of all the following materials: Brass, copper, solder, cast iron, carbon steel and aluminum.

The proposed technology must not affect key performances requirements. When used in the thermal management fluids, the technology should:

• Prevent the formation of insoluble calcium phosphate in the presence of hard water
• Pass standardized stability test (remain stable for 3 days at above mentioned conditions)
• Have limited or no effect on the general physic-chemical characteristic of a water-based / Water-glycol solution
• Be compatible with currently used additives
• Be soluble in water and glycol (from 5% for concentrate to 70% water)
• Be easy to manipulate in a production environment (safe for employees and transportable).

Tailored polyanionic polymers, co-polymer or telopolymers, which are capable of sequestering calcium and magnesium ions in solution, but have little or no affinity for other metal ions - E.g. by steric hindrance or more selective functional groups – could be a solution.

Alternatively polymers that are highly effective in preventing the growth and propagation of calcium phosphate nuclei to actual calcium phosphate precipitate, without have stoichiometric chelating capability could also be of interest.

The SpecialChem Client is open to highly efficient innovative technologies.

Substances either non-registered in (or non-exempt from) mayor chemical inventories: substances should at least be evaluated for eco-tox activity and should be able to get chemical inventory registration.

Technologies that are not calcium specific are not of interest for the SpecialChem Client. Polyacrylates additives for instance have affinity with too many metals.

An efficient solution would be adopted within 6 months, or even faster.

The substance identity should be known and the substances should be commercially available in Europe and ideally also in Asia.

The SpecialChem Client would prefer a ready to be used technology, but could also consider co-developing a promising technology for longer term adoption.