Kinetic Investigation of Propane Gas Hydrate Formation by Tracking Particle Size Evolution in the Presence of THF

The significant applications of gas hydrates in sustainable technologies are considerably dependent on solving the main existing challenges, including the low kinetics of hydrate formation. In this study, the particle size distribution (PSD) of propane hydrate in the presence of tetrahydrofuran (THF) was measured during the early stages of formation to investigate the kinetics of growth and agglomeration. The experiments were conducted at 500 kPa and 273.65 K at three different stirring rates and a THF concentration of 2 vol %. A kinetic model based on population balance modeling (PBM) is applied to predict the mean diameter of hydrates considering growth and agglomeration mechanisms. The results demonstrate that as the shear rate increases, the growth rate is increased to 1.69 X 10(-11) m/s, which seems to be approximate for the intrinsic growth rate of hydrate crystals. Three different scenarios are assumed in modeling to predict the size evolution of hydrate particles under test conditions. The results demonstrate that orthokinetic agglomeration provides better prediction for the mean diameter of the hydrate particles that increased from 800 nm at 650 rpm to 1000 nm at 750 rpm. The collision efficiency increases from 0.19933 in 650 rpm to 0.31667 in 750 rpm. It is also confirmed that agglomeration does not play a significant role under test conditions and the increase of collision efficiency with the shear rate could be attributed to the increase of growth rate.