The effect of porous support composition and operating parameters on the performance of supported liquid membranes

Journal Article · Sun Mar 01 00:00:00 EST 1992 · Separation Science and Technology; (United States)

DOI:https://doi.org/10.1080/01496399208018883· OSTI ID:5251928

Takigawa, D Y ^[1]

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1. Los Alamos National Lab., NM (United States)

Supported liquid membranes (SLMs) of varying porous support compositions and structures were studied for the transport of metal ions. A microporous polybenzimidazole support was synthesized and prepared in the form of an SLM. This SLM, containing the selective extractant di-(2-ethylhexyl) phosphoric acid, was evaluated for the transport of copper and neodymium. Metal ion transport reaches near completion in less than 3 h, whereas Celgard-polypropylene and Nucleopore-polycarbonate reaches only 50% completion even after 15 h. The transport driving force for acidic extractants is a pH gradient between the feed and strip solutions. Polybenzimidazole, an acid-and radiation-resistant polymer, has two protonatable tertiary nitrogens per repeat unit that may help sustain the pH driving force. Another factor may be the ability of the polybenzimidazole to hydrogen bond with the extractant. Transport through the flat-sheet SLMs was tested by using a unique cell design. Countercurrent flow of the feed and strip solutions was established through machined channels in half-cell face plates that are in a spiral, mirror-image pattern with respect to each other, with the flat-sheet SLM interposed between the two channeled solutions. Advantages comprised in the design of the two clamped half-cells (tangential entry, zero primary pressure, zero pressure differential, controlled flow regimes, no sharp turns, and channeled flow) give operating parameters that will not physically dislodge the liquid membrane from the porous support; consequently, the lifetime of the support is increased. Permeability coefficients remained unchanged after a month of daily use versus 20 to 100% declines for membranes in other cell configurations.

• OSTI ID: 5251928
• Journal Information: Separation Science and Technology; (United States), Vol. 27:3; ISSN 0149-6395
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
COPPER
MEMBRANE TRANSPORT
NEODYMIUM
SUPPORTED LIQUID MEMBRANES
PERFORMANCE
CHEMICAL PREPARATION
COMPARATIVE EVALUATIONS
EXPERIMENTAL DATA
FLOW RATE
MEASURING METHODS
METALS
MICROSTRUCTURE
OPERATION
PERMEABILITY
PH VALUE
POLYMERS
POROUS MATERIALS
RADIOACTIVE WASTE PROCESSING
SEPARATION EQUIPMENT
SERVICE LIFE
SUPPORTS
TIME DEPENDENCE
CRYSTAL STRUCTURE
DATA
ELEMENTS
EVALUATION
INFORMATION
MANAGEMENT
MATERIALS
MECHANICAL STRUCTURES
MEMBRANES
NUMERICAL DATA
PROCESSING
RADIOACTIVE WASTE MANAGEMENT
RARE EARTHS
SYNTHESIS
TRANSITION ELEMENTS
WASTE MANAGEMENT
WASTE PROCESSING
052001* - Nuclear Fuels- Waste Processing