Microstructure Control of Tubular Micro-Channelled Supports Fabricated by the Phase Inversion Casting Method

Yuliang Liu,Martin Van Sint Annaland,Fausto Gallucci,Arash Rahimalimamaghani

doi:10.3390/pr7060322

Abstract

Thin-film membrane layers coated onto porous supports is widely considered as an efficient way to obtain high-performance oxygen transport membranes with both good permeability and high mechanical strength. However, conventional preparation methods of membrane supports usually result in highly tortuous channels with high mass transfer resistance. Tubular porous MgO and MgO/CGO supports were fabricated with a simple phase inversion casting method. Long finger-like channels were obtained inside the dual-phase supports by adjusting the ceramic loading, polymer concentration and particle surface area, as well as by introducing ethanol inside the casting slurries. Slurries that exhibit lower viscosity in the zero-shear viscosity region resulted in more pronounced channel growth. These supports were used to produce thin supported CGO membranes for possible application in O2 separation. Similar shrinkage speeds for the different layers during the sintering process are crucial for obtaining dense asymmetric membranes. The shrinkage of the support tube at a high temperature was greatly affected by the polymer/ceramic ratio and compatible shrinkage behaviours of the two layers were realized with polymer/ceramic weight ratios between 0.175 and 0.225.

Highlights

Ceramic-based membrane separation is widely accepted as a clean and cost-effective way to produce high purity oxygen from air [1,2,3,4,5]
Partial delamination of the sintered Ce0.9 Gd0.1 O1.95-δ (CGO) layer from the support tube can be observed from surface and cross section of the asymmetric membrane
CGO membrane layer with a thickness of ~20 μm was obtained on the dual-phase support and strong attachment was achieved between the two layers (Figure 3b)

Summary

Introduction

Ceramic-based membrane separation is widely accepted as a clean and cost-effective way to produce high purity oxygen from air [1,2,3,4,5]. These membranes can be integrated in reactors for partial oxidations, making these membrane reactors more efficient in terms of operational expenditures (OPEX) and capital expenditures (CAPEX). The oxygen permeability could be improved by increasing the partial pressure difference across the membrane, improving the operating temperature, choosing material with high conductivity or reducing the membrane thickness. As a simple way to achieve high oxygen fluxes, thin-film membranes are preferred for separation processes

Methods

Results

Conclusion