Characterization of CO2 hydrate formation and dissociation kinetics in a flow loop
Caractérisation des cinétiques de formation et de dissociation des hydrates de CO2 dans une boucle de circulation
Abstract
The objective of this work is to investigate CO2 hydrate formation and dissociation kinetics in the aim of designing a circulation loop with heat exchangers for secondary refrigeration applications. The formation of gas hydrates is a crystallization process which requires a supersaturated environment. The majority of the experimental formation data from the literature were obtained in semi-batch stirred tank. It was found that the hydrate growth for CO2 hydrate formation was approximately 1.8 × 10−3 %hydrate.s−1 for a stirring velocity about 450 rpm. The study reveals that for our system, an isothermal circulation loop, the kinetic varied from 4.3 × 10−3 to 8.3 × 10−3 %hydrate s−1, respectively for two protocols with water and water-additives selected for their dispersive and promoter properties. The first results of CO2 hydrate dissociation kinetics with or without additives were equivalent with various systems (semi-batch stirred tank reactor or loop) with approximately 5 × 10−3 %hydrate s−1.