Asymmetric LSCF Membranes Utilizing Commercial Powders

Abstract

Powders of constant morphology and quality are indispensable for reproducible ceramic manufacturing. In this study, commercially available powders were characterized regarding their microstructural properties and screened for a reproducible membrane manufacturing process, which was done by sequential tape casting. Basing on this, the slurry composition and ratio of ingredients were systematically varied in order to obtain flat, crack-free green tapes suitable for upscaling of the manufacturing process. Debinding and sintering parameters were adjusted to obtain defect-free membranes with diminished bending. The crucial parameters are the heating ramp, sintering temperature, and dwell time. The microstructure of the asymmetric membranes was investigated, leading to a support porosity of approximately 35% and a membrane layer thickness of around 20 µm. Microstructure and oxygen flux are comparable to asymmetric La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) membranes manufactured from custom-made powder, showing an oxygen flux of > 1 mL⋅cm−2⋅min at 900 °C in air/Ar gradient.

Development of a Membrane Module Prototype for Oxygen Separation in Industrial Applications

“…The different layers of the membrane components were manufactured by tape casting. LSCF powders, with nominal composition La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ , were purchased from Praxair Inc. (Danbury, CT, USA) and fully characterized, as described in [4]. Slurries suitable for tape casting were prepared by dispersing the powders in a mixture of solvents and by adding appropriate amounts of organic binder and plasticizers.…”

“…Two different slurries were prepared for casting thin dense layers and thick, porous supports, respectively, following the procedure schematized in Figure S1. Further details on slurry composition and preparation route can be found in [4].…”

“…Membranes 2022, 12, 167 2 of 28 Based on the experience gained in the FP7 EU project GREEN-CC [3,4], we oriented our efforts toward oxygen transport membranes (OTMs), with the aim of developing a planar membrane module for oxygen separation at high temperature for integration in industrial processes. Such a technology has the potential to perform oxygen separation from air more efficiently than standard technologies [5][6][7][8][9][10][11].…”

“…The membrane preparation based on the use of commercial powders, which allows for large-scale production, was already demonstrated [4], and the scalability of the manufacturing process was already reported in the literature for several ceramic membrane materials [3,[18][19][20]. Nevertheless, some technical barriers in the membrane module construction are still present, making difficult its development and reliable utilization for oxygen production in industrial applications.…”

Processing Ceramic Proton Conductor Membranes for Use in Steam Electrolysis

“…This advanced casting technique involves the inversion of the traditional tape casting approach’s necessary manufacturing steps and produces homogeneous, large-area, flat ceramic films. This method has been used for the fabrication of solid oxide-oxygen ions conducting fuel and electrolysis cell (O-SOFC/O-SOEC) [ 21 , 23 ] as well as hydrogen [ 31 , 32 ] and oxygen separation membranes [ 33 , 34 , 35 ]. Another great advantage of this technique is its potential to minimize manufacturing cost since multi-layer components are laminated and co-sintered in a single step [ 23 , 35 ].…”