Heat Transfer During CO2 Hydrate Formation in a Continuous Flow Reactor

Abstract

Mixtures of CO2 and argon, or helium, were used to continuously produce CO2 hydrate slurries at high linear fluid velocities and high gas volume fractions. The impact of gas carrier, fluid velocity, and slurry loading on heat transfer processes were investigated using a tubular continuous flow reactor. Due to the high gas volume fraction, the thermal conductivity of the carrier gas was found to significantly impact the heat transfer rate on the process fluid side. The overall heat transfer coefficient from a He/CO2 gas mixture was found to be at least 50% higher than that obtained from a comparable Ar/CO2 mixture. High fluid velocity in the hydrate formation reactor resulted in effective interphase mixing and, thus, enhanced both mass and heat transfer between the gas, liquid, and solid phases. With vigorous mixing, hydrate formation kinetics were very favorable and hydrate formation became heat-transfer limited.