Dynamic adsorption-desorption of methyl ethyl ketone on MCM-41 and SBA-15 decorated with thermally activated polymers

Three series of mesoporous adsorbents designed for removal of methyl ethyl ketone vapor (MEK) were synthesized: MCM-41 was decorated with various amounts of novolac resin (Nov) and polyacrylonitrile (PAN), while SBA-15 was modified with PAN. The composites were thermally activated towards an enhancement of MEK adsorption capacity and tested in a fixed bed adsorber. Structural features of parent silicas were investigated by XRD, while textural parameters of the composites were studied by low temperature nitrogen adsorption. A surface composition was examined by DRIFT and XPS. It was found that decoration of the silica surface with small amounts of PAN improved the monolayer adsorption capacity. The MEK breakthrough curves and desorption profiles were employed for calculation of the monolayer capacity and total pore volume (V-totalMEK). The V-totalMEK for the materials with smaller pores (MCM-41) were comparable to those determined by nitrogen adsorption, whereas respective values for the solids with larger pores (SBA-15) were underestimated. The mechanism of adsorption of MEK onto the adsorbents was elucidated. The MEK molecules were adsorbed solely in the form of keto tautomer. The enhanced MEK adsorption capacity came from the beneficial textural features of the support and the presence of a ladder-type PAN structure containing O-groups. (C) 2018 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.