Ultrafiltration vs Nanofiltration

At a glance

Scope1-100 kDa MWCO

CAPEX$100k-$600k

Best forProtein concentration & buffer exchange

vs

Scope200-1000 Da

CAPEX$150k-$800k

Best forSalt/sugar separation, desalting

Criterion	Ultrafiltration	Nanofiltration	Verdict
Separation principle	Protein concentration & buffer exchange	Salt/sugar separation, desalting	Size cutoff range
Throughput / scale	100-50,000 L/hr	100-20,000 L/hr	UF slightly higher
Capital cost	$100k-$600k	$150k-$800k	UF lower
Operating cost	Low (~$0.5-2/m3)	Moderate (higher TMP)	UF cheaper
Product purity ceiling	Protein 95-99% recovery	Salt/sugar 90-99%	Application-dependent

UF and NF differ by an order of magnitude in cutoff. Pick by what you want to retain: proteins go in UF, salts and sugars get separated by NF.

Rule of thumb: If your target is >1 kDa, you probably want UF. If it's <1 kDa and you need to separate it from something even smaller, NF.

When should I choose Ultrafiltration over Nanofiltration?

Use UF (1-100 kDa MWCO) for protein concentration and buffer exchange, or for retaining macromolecules while letting small solutes pass.

When should I choose Nanofiltration over Ultrafiltration?

Use NF (200-1000 Da) for separating salts from sugars, demineralizing fermentation broths, or recovering small charged molecules.

Can these two techniques be used together?

Yes — UF first to remove proteins, then NF to demineralise the filtrate. This sequence appears in lactic acid and amino acid production trains.

Which has lower OPEX at scale?

UF has lower TMP (1-3 bar vs 5-25 bar for NF) so pumping energy is much smaller, but NF can avoid a downstream evaporation step in dilute streams.