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

Abstract

A pilot CO 2 hydrate slurry production system was built and tested. The density of CO 2 hydrate slurry was experimentally investigated and the relation between the density and the solid fraction has been established. The apparent viscosity of water, CO 2 solution and CO 2 hydrate slurry was investigated with a XL7-100 online resonant viscometer. We¯nd that when the solid mass fraction in slurry increases, the density and apparent viscosity of CO 2 slurry also increase. CO 2 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 CO 2 gas is injected into the loop under suitable hydrate formation conditions. The pure hydrate's dissociation enthalpy was evaluated by Micro Di®erential Scanning Calorimetry system. The enthalpy of CO 2 hydrate slurry mainly depends on solid mass fraction. Realtime coupled multielectrode array sensor probes were applied to measure the maximal localized corrosion rate of three di®erent materials subjected to CO 2 hydrate slurry and saturated CO 2 solution in the temperature range of 274.15À291.15 K and pressure range of 2.5À3.0 MPa. For a long-term usage in a mixture of CO 2 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.