Investigation of Hydrate Formation Kinetics and Mechanism of Effect of Inhibitors on it, a Review

Gaseous hydrates are ice-like compounds of water and gas that are usually formed at high pressures and low temperatures in such a way that in each of their constituent units a gas molecule is enclosed in a cage of water molecules. Gas hydrate was introduced by Hamrasmith in 1934 as one of the problems of the gas industry in transmission pipelines because by reducing the internal cross section of the pipe, it increases the pressure drop and sometimes may lead to complete blockage of the pipe. Hydrate formation can also lead to the destruction of tools in the process, including valves and sensors, or accumulate in storage tanks, increasing labor costs for cleaning. In industry, one of the thermal, mechanical, thermodynamic and kinetic methods is usually used to prevent the formation or elimination of hydrate. Thermal methods try to keep the gas away from the formation of hydrates by insulating the pipe, using rotating water or hot oil, or by electrically heating the pipe. The use of pigs is a mechanical method to remove clogged tubes due to hydrate formation. It is also possible to change the gas mixture by adding a third material to the fuzzy diagram and eliminate the possibility of hydrate formation at the temperature and operating pressure of the system. Kinetic methods help to improve the working conditions of the gas transmission system by increasing the latency or by reducing the growth rate or adhesion of hydrate crystals.