Measurements of Binary Diffusion Coefficients of Organic Compounds in n-Hexane, n-Dodecane and Cyclohexane at 16.0 MPa

Abstract

Binary diffusion coefficients (D₁₂) of some organic compounds were measured in n-hexane at 303.2K333.2K and 16.0 MPa, and in n-dodecane and cyclohexane, separately, at 313.2 K and 16.0 MPa by the Taylor-Aris tracer response technique. As compared with the correlations based on the Stokes-Einstein equation, the following freevolume equation :
D₁₂/√T=α₁ (v-1.358 v₀)
was found to represent well the measured D₁₂, where D₁₂ is the binary diffusion coefficient, T is temperature, α is constant, ν is solvent molar volume and v₀=Nσ³/√2; N is Avogadro's number ; σ is effective hard-sphere diameter. The values of α₁ were almost proportional to V_b^-0.6 for all the solvents.