Petro Sep
Membrane distillation modules in an industrial enclosure.

MD · Technology

Membrane Distillation

Membrane distillation is the thermal cousin of VMD. A temperature gradient across a hydrophobic membrane drives water vapor from a hot feed to a cooler permeate side. No vacuum required. Used where waste heat is plentiful and the feed cannot tolerate the energy of true evaporation.

What it solves

Performance you can size against.

The outcomes below come from commissioned systems and verified pilots, not theoretical limits. Every number is independently testable on your own feed.

Thermally driven, no vacuum
Suits sites with available waste heat and tight space envelopes.
Recovery on high-TDS feeds
Up to 95%
Comparable to VMD on most feeds.
Operating temperature
60 to 90°C
Pairs with low-grade heat sources.
Distillate quality
<10 mg/L TDS
Boiler-quality water from highly impaired feeds.

How it works

The working principle.

Hot feed flows on one side of a hydrophobic membrane. Cool distillate flows on the other side. The temperature differential creates a vapor pressure gradient that drives water vapor through the membrane pores. The membrane stays liquid-tight; only vapor crosses. Distillate condenses on the cool side and is collected.

Process diagram
Custom SVG to be added in design phase

Performance envelope

Specs and operating range.

For preliminary sizing only. Production sizing is always validated against your specific feed.

Recovery
85 to 95%
Maximum feed TDS
200,000mg/L
Distillate quality
<10mg/L TDS
Hot side temperature
60 to 90°C
Cold side temperature
20 to 40°C
Specific thermal energy
300 to 600kWh thermal/m³

Where it's deployed

Industries that use this process.

Membrane Distillation fits some sectors better than others. The industries below are where we have shipped multiple systems.

Have a feed that MD
might fit?

We will pilot before we promise. Send us a sample and a target outcome. If the technology fits, we will tell you what to expect; if it does not, we will tell you that too.