Diffusion coefficient of oleic acid in supercritical carbon dioxide (SC-CO2) is measured at 200 bar and...

 

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Diffusion coefficient of oleic acid in supercritical carbon dioxide (SC-CO2) is measured at 200 bar and 40°C using a diffusion cell between parallel plates. The length and the width of the plates can be considered as infinite. Pure SC-CO2 (gas phase) is pumped through the oleic acid rich phase (liquid phase, oleic acid saturated with between SC-CO₂). The liquid phase is in a pool which is enclosed in the diffusion cell. There are diffusers after the pipe entrance in order to distribute the gas phase flow evenly between the parallel plates. When steady-state is reached oleic acid concentration of SC-CO2 leaving the diffusion cell is measured. Write the differential equation (by simplifying the equation of continuity) and boundary conditions to determine the steady state concentration profile of oleic acid in SC-CO2. The solubility of oleic acid in SC-CO₂ is low at measurement pressure and temperature. The side view of the diffusion cell showing the phases contacted between parallel plates (excluding the diffusers at the entrance), is given in the figure below. The contact length is L. Take the coordinate system (x, y, z) at the interface as shown below. Assume the thickness of the gas phase is constant and can be taken as H. Flowing gas phase Liquid phase pool Diffusion coefficient of oleic acid in supercritical carbon dioxide (SC-CO2) is measured at 200 bar and 40°C using a diffusion cell between parallel plates. The length and the width of the plates can be considered as infinite. Pure SC-CO2 (gas phase) is pumped through the oleic acid rich phase (liquid phase, oleic acid saturated with between SC-CO₂). The liquid phase is in a pool which is enclosed in the diffusion cell. There are diffusers after the pipe entrance in order to distribute the gas phase flow evenly between the parallel plates. When steady-state is reached oleic acid concentration of SC-CO2 leaving the diffusion cell is measured. Write the differential equation (by simplifying the equation of continuity) and boundary conditions to determine the steady state concentration profile of oleic acid in SC-CO2. The solubility of oleic acid in SC-CO₂ is low at measurement pressure and temperature. The side view of the diffusion cell showing the phases contacted between parallel plates (excluding the diffusers at the entrance), is given in the figure below. The contact length is L. Take the coordinate system (x, y, z) at the interface as shown below. Assume the thickness of the gas phase is constant and can be taken as H. Flowing gas phase Liquid phase pool