THE ENHANCEMENT OF THE RATE OF ABSORPTION OF CO2 IN AMINE SOLUTIONS DUE TO THE MARANGONI EFFECT

Results of the experimental and theoretical investigations of the occu rrence of cellular convection during absorption of CO2 in amine soluti ons (Marangoni effect) are presented. Experiments in CO2-aqueous solut ions of MEA and CO2-aqueous Solutions of DEA systems show that cellula r convection indeed occurs during chemisorption and that it can increa se mass transfer rate significantly enough to lower the absorber heigh t. The influence of certain parameters characterizing mass transfer (e .g. mass transfer coefficient in the liquid phase, initial concentrati ons of reactants, presence of surface-active agents) on the intensity of cellular convection is analyzed. Theoretical considerations confirm the possibility of the occurrence of cellular convection in the syste ms investigated. Experimental correlations are given which describe th e influence of the effect in terms of the mass transfer enhancement fa ctor. The results can be directly employed in the design of absorbers for CO2 capture. (C) 1997 Elsevier Science Ltd.