Concentration dependency of dispersion coefficient of aqueous solutions of urea and ethyl acetate in porous media

We report new measurements of the concentration‐dependent longitudinal dispersion coefficient of aqueous urea and ethyl acetate solutions in a porous medium at a wide range of concentrations. The longitudinal dispersion coefficient was obtained by injection of a pulse of an aqueous solution of urea (or ethyl acetate) into a carrier phase flowing through a porous column and analysis of the effluent peak using the Taylor dispersion theory. The measured longitudinal dispersion coefficients for different velocities and concentrations showed an increasing trend with concentration and pore velocity. The longitudinal dispersion coefficient measurements show a power‐law relationship with the Peclet number KL∝αlPemβl. The results are compared with experimental data and empirical formulas available in the literature, and a reasonable agreement is achieved over the range of Peclet numbers studied.