CHARACTERIZATION OF CO_2 HYDRATE FORMATION

摘要

This work is an investigation about CO_2-hydrate formation kinetics in the aim of designing a circulation loop with heat exchangers for secondary refrigeration applications. The formation of gas hydrates is a phase change which requires a supersaturated environment. It is a crystallization process. The majority of the experimental formation data from the literature were obtained in a semi-batch stirred tank. It was found that the hydrate growth for CO_2 hydrate formation was 1.45 × 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 5.45 × 10~(-3) and 8.37 × 10~(-3) %hydrate·s~(-1), respectively with water and water-additives selected for their dispersive and promoter properties.