What is a Low Dosage Hydrate Inhibitor?

Low Dosage Hydrate Inhibitors (LDHI) can be divided in two categories; Anti-Agglomerants (AA) and Kinetic Inhibitors (KI).

Anti-Agglomerants allow gas hydrates to form, but these are then dispersed in the hydrocarbon phase, thus preventing larger aggregates to form and give blockage. Kinetic Inhibitors, on the other hand, delay the first appearance of stable hydrate crystals.

First generation AA

Akzo Nobel participated in the development of the first generation of Anti-Agglomerants in the mid 90s. These products were based on quarternary ammonium chemistry and are now being phased out in environmentally sensitive markets as the North Sea. Akzo Nobel has now developed a second generation of Anti-Agglomerants which gives high performance linked with improved environmental data.

Applications

The AA concept is highly interesting for the future in deep-sea applications where traditional thermodynamic inhibitors have limitations.

Performance evaluation by multicell technology

For the performance evaluation during our development work we have used the multicell technology, developed by SINTEF in Trondheim, Norway. The multicell test system consists of a high pressure vessel containing the multicell test unit, a cooling unit, stirrer drive, sensor interface unit and a computer system.