Elaboration of composite hollow fiber membranes with selective layer from poly[1-(trimethylsylil)1-propyne] for regeneration of aqueous alkanolamine solutions

Abstract

The results of research on elaboration of the hollow fiber composite membranes for regeneration of aqueous solutions of alkanolamines in membrane gas-liquid contactor are presented in this work. Asymmetric polysulfone (PSF) hollow fiber UF membranes were used as a porous support, poly[1-(trimethylsylil)-1-propyne] (PTMSP) was employed as a diffusion layer. The influence of PSF hollow fiber casting conditions on hydraulic permeability was studied. Samples of composite membranes were obtained with a defectfree layer of PTMSP and carbon dioxide permeance of 0.26 m3 (STP) (m2 h bar)−1. It was revealed by SEM that the thickness of the PTMSP separation layer is 2.5 microns, where in X-ray spectrometry analysis data and calculations according to resistance-in-series model discovered that the selective layer penetration depth to the pores of the support was 1.4 microns. Calculation by resistance-in-series model showed that 98.6% of resistance to the gas transport is attributed to PTMSP, partially intruded in the pores of the support. Chemical stability of materials which comprise composite membrane makes promising their using for regeneration of aqueous solutions of alkanolamines (pH > 11) from carbon dioxide at a temperature of 100°C and a pressure drop of 10 bar in the membrane gas-liquid contactors.