Effect of coagulant bath on the gas permeation properties of cellulose acetate asymmetric membrane

Abstract

Abstract. Membrane based gas separation process technology has been recognized as one of the most efficient and advanced unit operation for gas separation. One of the problems in membrane gas separation is membrane performance. This paper explores the application of cellulose acetate (CA) membrane for natural gas purification and separation by improving its permeability and selectivity. The main interest in this research is to study the effect of quench medium on the gas separation performance towards its physical characteristics and gas separation performance of CA membrane. Cellulose acetate polymer was dissolved in nmethyl-2-pyrrolidone solvent and casted onto a glass plate using a pneumatically controlled casting system with fixed shear rate and solvent evaporation times. The parameter varied was the non-solvent used as quench medium during membrane post treatment that were methanol and n-hexane. The different quench media as post treatment affected the O 2 and N 2 gas permeation and O 2 /N 2 selectivity as well as the tensile strength of the flat sheet asymmetric membrane. Combination of methanol and n-hexane as quench media gave the best result than the other steps. This solvent exchange step influenced the morphology by producing thin skin layer and thus gives better gas separation performance than other steps

Comparison of Regenerated Cellulose Membrane Coagulated in Sulphate Based Coagulant

“…RCM with lower crystallinity imply lower percentage of bonding. This is because the crystalline region in the native cellulose had been destroying during the dissoution process (Mohamed et al, 2016).…”

Preparation and Characterisation of Blend Cellulose Acetate Membrane for CO2/N2 Separation

“…The dense skin layer formed by the molecular orientation concentrated on the upper surface of the membrane. 32 As displayed in the SEM images, shown in Figures 2(b, d, f and h), the dense skin layer was observed with reducing thickness from 6.16 ± 0.07 μm (M1) to 3.97 ± 0.11 μm (M4) when the polymer concentration of CA-39 increased from 1 wt% (M1) to 5 wt% (M4).…”