Estimation of mass transfer coefficient in ozone absorption by linear least square fitting and Simplex search methods

Abstract

For physical ozone absorption without reaction, two parametric estimation methods, i. e. the common linear least square fitting and non-linear Simplex search methods, were applied, respectively, to determine the ozone mass transfer coefficient during absorption and both methods give almost the same mass transfer coefficient. While for chemical absorption with ozone decomposition reaction, the common linear least square fitting method is not applicable for the evaluation of ozone mass transfer coefficient due to the difficulty of model linearization for describing ozone concentration dissolved in water. The nonlinear Simplex method obtains the mass transfer coefficient by minimizing the sum of the differences between the simulated and experimental ozone concentration during the whole absorption process, without the limitation of linear relationship between the dissolved ozone concentration and absorption time during the initial stage of absorption. Comparison of the ozone concentration profiles between the simulation and experimental data demonstrates that Simplex method may determine ozone mass transfer coefficient during absorption in an accurate and high efficiency way with wide applicability.