Membrane Technologies

Targeted separation technology makes the difference 

KMS offers one of the world’s largest membrane portfolios. Over the years, we have expanded and tailored our products to the specific requirements of different market applications and finished product specifications. We have a wide range of pore sizes that suit numerous applications, from removing salt to filtering large particulates. Reverse osmosis offers the finest degree of separation, followed by nanofiltration, ultrafiltration and microfiltration, which has the largest pore size. Membrane technologies can be used in combination, such as ultrafiltration followed by reverse osmosis for seawater desalination processes, and microfiltration followed by nanofiltration for clarification of fermentation broth and product concentration.

Our technologies are made to handle a wide range of process fluids, water and wastewaters. We would appreciate the opportunity to help you select an optimal solution for your separation challenges.


Low-pressure membrane technology for separation of large solids

The most common application of microfiltration (MF) is clarification, or removal of suspended solids to produce a clear liquid. Examples include clarification of whole cell broths; purification processes in which macromolecules must be separated from other large molecules, enzymes or cell debris; clarification of dextrose and highly colored fruit juices, wine and beer; whey de-fatting and casein removal.

MF systems operate at relatively low pressures and come in a variety of configurations. They are characterized by pore size, ranging from 0.05 micron to 1 micron.


Low-pressure membrane technology for separation, concentration and purification of dissolved molecules

A versatile and economical solution for clarification, concentration and purification of liquids, ultrafiltration (UF) is a process that removes emulsified oils, metal hydroxides, colloids, bacteria and viruses, emulsions, dispersed material, suspended solids, and other large molecular weight materials from water and other solutions.

UF also serves in critical parts of the production processes of fruit juice, milk and whey, electrocoat paints, pharmaceuticals, poly-vinyl alcohol and indigo dye. It is key to surface water treatment for potable uses and wastewater treatment for reuse. UF membranes are characterized by their molecular weight cut-off (MWCO), ranging from 3,000 to 500,000 Daltons.


Medium-pressure membrane technology for separation, concentration and demineralization of liquids

Nanofiltration (NF) is generally targeted to remove divalent salts and ions and low molecular weight organic materials from water and other process liquids. Monovalent ions such as sodium and chloride will pass through a nanofiltration membrane, so many of its uses involve de-salting (demineralization) of the process stream.

In the production of lactose from cheese whey, NF concentrates lactose molecules while passing salts, a procedure that purifies and concentrates the lactose stream. In water treatment, NF is used for hardness removal (in place of water softeners), pesticide elimination and color reduction. It can also reclaim spent acids and caustic solutions, in which case the permeate stream is purified acid or caustic for chemical recovery and reuse.  NF membranes are characterized by their molecular weight cut-off (MWCO), ranging from 150 to 2,000 Daltons.

Reverse Osmosis

Medium- and high-pressure membrane technology for water purification and product concentration

Reverse osmosis (RO) membranes feature the smallest pores and involve the reversal of osmotic pressure to drive water through the membrane, away from dissolved molecules. RO is not a size exclusion process based on pore size; it depends on ionic diffusion to affect separation. One of its common applications is seawater and brackish water desalination, in which pure water is produced from a saline feed stream, with far better economy than evaporation.

RO technology is also used in cheese whey concentration, fruit juice concentration, ice making, car wash water reclamation, wastewater volume reduction and other industrial processes, with the goal of producing a pure filtrate (typically water) or concentrating valuable components. Because the osmotic pressure of many process streams is quite high, RO membranes must operate at pressures of 400 to 1,200 psi (29 to 83 bars).