INVESTIGATION OF THERMO-PHYSICAL AND FLOW PROPERTIES OF CO2 HYDRATE SLURRY

Abstract

A pilot CO2 hydrate slurry production system was built and tested. The density of CO2 hydrate slurry was experimentally investigated and the relation between the density and the solid fraction has been established. The apparent viscosity of water, CO2 solution and CO2 hydrate slurry was investigated with a XL7-100 online resonant viscometer. We find that when the solid mass fraction in slurry increases, the density and apparent viscosity of CO2 slurry also increase. CO2 hydrate solid particles contribute only slightly to the viscosity increase when the solid mass fraction increased from 1.59% to 28% from our experimental results. Higher solid mass fraction can be achieved when more CO2 gas is injected into the loop under suitable hydrate formation conditions. The pure hydrate's dissociation enthalpy was evaluated by Micro Differential Scanning Calorimetry system. The enthalpy of CO2 hydrate slurry mainly depends on solid mass fraction. Real-time coupled multielectrode array sensor probes were applied to measure the maximal localized corrosion rate of three different materials subjected to CO2 hydrate slurry and saturated CO2 solution in the temperature range of 274.15–291.15 K and pressure range of 2.5–3.0 MPa. For a long-term usage in a mixture of CO2 saturated aqueous solution and hydrate slurry environment, carbon steel materials are to be unacceptable from the corrosion resistance point of view. In contrast, stainless steel type 304L and copper 110 have presented very low corrosion rates.