Advanced Ceramic Membrane Technology

CeraMem® ceramic membrane element in housing

Membrane element in stainless-steel housing with simple compressive seal design

Veolia Water Solutions & Technologies' (VWS) new ceramic membrane modules, utilizing the CeraMem technology platform, can be supplied with a variety of inorganic microfiltration (MF) and ultrafiltration (UF) membranes. Nanofiltration (NF) and pervaporation (PV) membranes are currently under development.

Silicon carbide ceramic membranes are now available as an extension of the current CeraMem offering. These membranes feature a resistance to high pH conditions and operate in a range of 0-14 as well as an increased membrane permeability to provide a high degree of flexibility in cleaning an regeneration.

Key features of these innovative membrane modules include:

  • Robust large-diameter monoliths as membrane supports

  • New, chemically-durable, highly abrasion-resistant ceramic MF & UF membranes

  • Very high packing density with large membrane area in a single membrane module (10.7 m2)

  • Life-cycle costs competitive with most polymeric membranes

  • Available in both 2mm and 5mm channel sizes

Large Diameter Elements with Permeate Conduits

membrane operationZoom

Large diameter monolith membrane element with permeate conduits

A typical multi-channel ceramic membrane has multiple parallel passageways that run from a feed inlet end face to an opposing outlet end face. The surfaces of the passageways are coated withpermselective membrane.

A feed stream is introduced under pressure at the inlet end face, flows through the passageways over the membrane, and is withdrawn at the downstream end face as retentate.Material that passes through the membrane (permeate) flows into the porous monolith material.

Under an applied transmembrane pressure, the combined permeate from all the passageways flows through the porous monolith support to the periphery of the monolith and is removed at the monolith exterior surface.

CeraMem® Technology Overcomes Conventional Limitations

monolith wall structure

SEM of CeraMem monolith wall structure

There is a technical limitation to the use of monolith supports as described above. The long and tortuous path through which the permeate must flow to get to the outside of the monolith can lead to a large pressure drop for permeate flow within the porous membrane support. The pressure drop reduces the trans-membrane pressure for the interior passageways. This limitation generally restricts the diameter of monoliths than can be used, at least for microfiltration (MF) and ultrafiltration (UF), to approximately 40 mm.

Mechanical modifications to the monoliths have effectively overcome this limitation. The modifications form permeate "conduits" within the monolith that conduct permeate from interior feed passageways to the permeate collection zone external to the monolith.

One of these modified monolith structures has been produced in membrane elements of 142 mm diameter by 864 mm length, and sold commercially for more than sixty (60) membrane systems.