Filtration Equipment

Membrane Filtration (MF / UF / NF / RO)

Membrane filtration is a pressure-driven separation technology that passes a liquid across a semi-permeable membrane, retaining species larger than the membrane's cut-off while smaller molecules and solvent permeate. The range runs from microfiltration (MF) through ultrafiltration (UF) and nanofiltration (NF) to reverse osmosis (RO), each retaining progressively smaller species. In an extraction or process line these systems can clarify crude extract, concentrate or purify actives and remove salts, using pressure rather than heat or a phase change, which suits heat-sensitive compounds. Mechotech designs and manufactures turnkey membrane filtration systems as engineered skids for pharmaceutical, nutraceutical, food and botanical extraction lines. The membrane type, area and staging are configured to the feed and the separation required.

Pressure drives the feed across a semi-permeable membrane and splits it into a permeate that passes through and a retentate that is held back. The skid is usually run in cross-flow, with the feed sweeping along the membrane surface to limit fouling. MF separates suspended solids and microbes, UF retains macromolecules and colloids, NF rejects multivalent ions and small organics, and RO rejects most dissolved species, including salts. A typical skid combines a pre-filter, a feed pump, membrane housings, a CIP system and permeate and concentrate outlets under PLC-based control. Wetted parts are built in SS 304 or SS 316L with sanitary membrane elements and a hygienic, GMP-oriented design. Which membrane stages are used, the element format, the membrane area and the capacity are configured to the client's feed and established by pilot trials; no fixed flux, rejection or recovery values are quoted on this page.

Technical Specifications

Technology	Pressure-driven membrane separation (MF / UF / NF / RO)
Working Principle	Feed driven across a semi-permeable membrane is split into permeate and retentate by size and charge selectivity
Separation Range	MF retains suspended solids and microbes; UF retains macromolecules and colloids; NF rejects multivalent ions and small organics; RO rejects most dissolved species, including salts
Flow Configuration	Cross-flow (tangential) with recirculation and diafiltration options
Membrane Stages	One or more of MF, UF, NF and RO, selected for the feed and the separation required
Membrane Elements	Element format (for example spiral-wound, hollow-fibre, tubular or ceramic) selected for the application and confirmed during design
Pre-filtration	Pre-filter ahead of the feed pump to protect the membranes
Product-contact Material	SS 304 / SS 316L with sanitary membrane element types
Cleaning	CIP system for the membrane circuit
Automation	PLC-based control (SCADA configurable)
Capacity	Configured to requirement
Utilities	Electrical power, feed pumping, CIP and rinse water as applicable
Compliance	GMP hygienic design; full documentation for qualification
Output	Clarified, concentrated, desalted or purified permeate and retentate streams

Plant Capacities

Scale	Typical Duty	Configuration
Pilot	Membrane selection and process trials on the actual feed	Small skid with one or more membrane stages and a CIP circuit
Production	Plant-scale clarification, concentration or desalting	Skid with membrane area and staging configured to the feed and throughput
Large commercial	Higher throughput	Larger membrane area and additional stages, with modular expansion

Membrane area, staging and capacity are configured to the feed characteristics and throughput rather than a fixed model; pilot trials are recommended to confirm flux, rejection and cleaning parameters before scaling.

Manufacturing Process

Feed Pretreatment

The incoming stream is pre-filtered and conditioned to remove coarse solids and protect the membrane elements from premature fouling.

Pressurised Feed Delivery

A feed pump raises the stream to the pressure required for the selected MF, UF, NF or RO stage.

Cross-Flow Membrane Separation

Feed flows tangentially across the membrane so that permeate passes through while retained species are swept along, limiting build-up on the surface.

Permeate Collection

The permeate is collected for downstream use or for a further membrane stage.

Retentate Concentration or Recirculation

The retentate, carrying the concentrated actives or the retained species, is recirculated to raise its concentration or discharged through the concentrate outlet.

Diafiltration and Desalting

Where required, fresh water or buffer is added to the retentate loop to displace salts and small molecules from the retained product.

Membrane Cleaning

CIP cycles clean the membranes between production runs; the cleaning agents and cycle are configured to the feed and the membrane type.

Major Plant Equipment

Pre-filter
Feed pump(s)
Membrane housings with MF, UF, NF and/or RO elements, as configured
Pressure gauges and instrumentation
CIP system
Permeate outlet and concentrate (retentate) outlet
Stainless-steel skid frame and interconnecting piping
PLC-based control panel

Plant Output

Permeate streamRetentate (concentrate) stream

Applications

Clarification of crude botanical and herbal extracts (MF / UF)
Concentration of actives without a heat load (UF / NF / RO)
Desalting and buffer exchange by diafiltration (UF / NF)
Fractionation of dissolved species by molecular size (UF)
Removal of small coloured impurities (NF)
Dewatering and recovery of extract streams (RO)
Microbial reduction and fine clarification (MF)
Water purification and process-water polishing (RO)

Key Features

MF, UF, NF and RO Stages
Skids can be configured with one or more stages so that a suitable cut-off is used for clarification, concentration, desalting or purification.
Cross-Flow Operation
Tangential flow sweeps the membrane surface to limit fouling on difficult feeds.
No Heat Load
Separation is driven by pressure rather than heat, which suits heat-sensitive actives.
Hygienic Construction
SS 304 or SS 316L wetted parts with sanitary membrane elements and a CIP system, with documentation to support GMP qualification.
PLC-Based Control
PLC-based control of pressure, flow, diafiltration and cleaning sequences.
Turnkey Engineering
Design, fabrication, installation and commissioning are delivered as one accountable scope.

Frequently Asked Questions

What is membrane filtration (MF / UF / NF / RO)?

Membrane filtration is a pressure-driven separation in which a liquid is passed across a semi-permeable membrane that retains species larger than its cut-off and lets smaller molecules and solvent permeate. MF, UF, NF and RO form a range that retains progressively smaller species, from suspended solids down to dissolved salts.

How does membrane filtration work?

Pressure drives the feed across the membrane, usually in cross-flow, splitting it into a permeate that passes through and a retentate that is held back. Microfiltration retains solids and microbes, ultrafiltration retains macromolecules, nanofiltration rejects multivalent ions and small organics, and reverse osmosis rejects most dissolved species, including salts.

Where does membrane filtration fit in an extraction or purification line?

It can follow extraction or primary clarification: MF and UF can clarify crude extract, UF and NF can concentrate and desalt actives, and RO can dewater streams, all without heating the product. Mechotech's article Turnkey Phytochemical Extraction Plant lists membrane separation among the purification options used alongside resin columns, chromatography and crystallisation, depending on the product.

How do I choose between MF, UF, NF and RO?

The choice follows what must be retained and what must pass: suspended solids and microbes (MF), macromolecules (UF), multivalent ions and small organics (NF) or dissolved salts (RO). The cut-off, element format and staging are confirmed with trials on the actual feed, because feed composition strongly affects fouling and flux.

How does membrane filtration compare with evaporation for concentration?

Membrane concentration uses pressure and involves no phase change, so there is no evaporative heat load, but the concentration it can reach and the permeate quality depend on the membrane and the feed. Where a higher final concentration is needed, the retentate can be taken on to a Falling Film Evaporator or other evaporator. The selection is made against the actual feed.

Which Mechotech filtration and purification pages work with a membrane skid?

Upstream clarification can use a Filter Press, a Cartridge Filter or a Centrifuge. Purification can also use Resin Adsorption / Desorption, Activated Carbon Purification, Chromatography Systems or Crystallisation Systems. The hub is Filtration Equipment Plants.

Where are UF and RO used outside extraction lines?

Mechotech's article on zero liquid discharge (ZLD) systems describes ultrafiltration and reverse osmosis as stages in the water-treatment train ahead of evaporation. A membrane skid for that duty is configured to the effluent and the water quality required.

What capacity of membrane system can Mechotech supply?

Membrane area, staging and capacity are configured to the client's feed characteristics and throughput rather than a fixed model. Mechotech recommends pilot trials to confirm flux, rejection and cleaning parameters before scaling.

What materials and compliance standards apply?

Wetted parts are built in SS 304 or SS 316L with sanitary membrane elements and a hygienic, GMP-oriented design with a CIP system, and documentation to support qualification. The membrane material and element format are confirmed against the feed and the cleaning chemicals.

Does Mechotech supply the membrane filtration plant as a turnkey system?

Yes. Mechotech designs, fabricates, installs and commissions the complete membrane filtration skid as a single accountable turnkey scope, integrated with the surrounding extraction or process line.

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Membrane Filtration (MF / UF / NF / RO)