Extractive desulfurization in microchannels with polyethylene glycol 400: An experimental study and mass transfer evaluation

Abstract

Conventional methods for removing sulfur compounds show unsatisfactory performance, especially when treating aromatic compounds. Current studies have directed efforts to investigate extraction desulfurization (EDS) using microdevices to overcome this difficulty. These units are designed with micrometer-sized channels responsible for intensifying heat and mass transfer phenomena. When using EDS, an adequate choice of extraction solvent is essential and among the possibilities, an excellent candidate for extraction solvent is polyethylene glycol (PEG). The present work studied the extractive performance offered by microdevices and the aspects related to mass transfer intensification by adopting PEG 400 as an extraction solvent in the removal of dibenzothiophene. The identification of flow patterns was performed by digital image colorimetry, making it possible to estimate the specific interfacial area (as) and the overall mass transfer coefficient (KLas) more accurately. DBT decontamination behavior was investigated under different volumetric flow rates (71.74–326.58 μL/min), different microchannel lengths (1.0–2.0 m), and a fixed diameter of 0.5 mm. The best result achieved an extractive efficiency of 94.06%, corresponding to a volumetric flow rate of 107.30 μL/min, whose interfacial area and overall mass transfer coefficients related to the slug flow pattern were calculated as 453.69 m−1 and 0.0229 s−1, respectively.