Removal of Dissolved Aromatics from Water: Comparison of a High Intensity Contactor with a Packed Column

Abstract

An experimental comparison of the performances of a new high intensity contactor and a conventional packed column in stripping dissolved aromatics from water is described. The contactor gives significantly lower values of HOL. These, combined with the much higher liquid fluxes, give volumetric mass transfer coefficients, KLa, several hundred times higher than those for the packed column and substantially higher than those in the literature for bubble columns. Performance is particularly good on saline water due to suppression of bubble coalescence. That characteristic would be beneficial in the removal of aromatics from produced water in oil and gas production. The contactor utilizes enhanced acceleration fields achieved by water injection and so should be insensitive to the marine motion and tilt experienced on offshore floating production systems, as well as being compact. At constant water rate, KLa ∝ Gn with n ranging from 0.50 to 0.92. Some preliminary results on the effects of liquid feed rate and initial bubble size are included, the latter confirming the importance of bubble size on performance. Pressure drop and consequent energy requirements are also considered.