Sistemas de Pervaporación
Pervaporacion y permeación de vapores son procesos de purificación de líquidos volátiles con membranas.- Separación de azeótropos
- Secado de solventes y otras sustancias orgánicas volátiles - remoción de agua.
- Separación de mezclas orgánicas - remoción de metanol y etanol.
General characteristics of pervaporation:
- Uses semi-permeable membrane
- Permeate leaves membrane in vapor state
- Permeate must be volatile at operating condition
- Functions irrespective of vapor/liquid equlibrium
- Used to purify volatile chemicals
- Permeates water, methanol, ethanol or organics
- Separates mixtures that form azeotropes
- Replaces traditional separation methods
- Low energy consumption
- No entrainer required, no contamination
Sulzer Chemtech has the following pervaporation technologies and skid-built equipment available:
1. Continuous pervaporation- Lowest energy consumption
- Best with low impurity level feeds
- Effective for large capacities
- Simple system
- Maximum flexibility
- Requires buffer tanks
- For impure feeds
- Can be fed directly from distillation column
- Dissolved solids removed by evaporation
Typical Pervaporation Plants
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Plants from a few kg per hour up to thousands of tons per year.  |
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Bench and pilot test your lab or ours?
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Most applications can be evaluated from our experience. For new applications,
tests are required:
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Products separated or purified by pervaporation
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Solvents routinely dehydrated in SULZER CHEMTECH pervap units
Isopropanol, ethanol: Standard applications for pervaporation, typically dehydrated from their azeotropes to fractions of a percent of water. Debottlenecking of entrainer plants.
Ethyl acetate, butyl acetate: Form azeotropes in the miscibility gap. Pervaporation or vapour permeation is easily the best technique for dehydration.
Acetone: Does not form an azeotrope with water but when distilled, a large reflux is required. Pervaporation is ideal for final dehydration or for debottlenecking existing distillation systems.
Acetonitrile: Forms azeotrope with water, fully miscible with water. Can easily be dehydrated to low water concentrations. Avoid messing with contaminated salt solution and redistillation of salt contaminated organic phase.
Pyridine: Forms fully miscible, water rich azeotrope, easily split by pervaporation or vapor permeation. Final dehydration feasible. Avoids entrainers and messy salt/alkali solutions.
THF: Easily dehydrated by pervaporation down to a few hundred ppm of water. No messy chemicals.
MEK: Distillation is only possible with an entrainer because the azeotropic composition is nearly identical to the miscibility limit. Pervaporation is far superior.
N-butanol, n-propanol: Form azeotropes with high water content so the distillation/phase separation process involves massive recycle streams. Pervaporation plants are less costly to build and easier to operate.
Reaction mixtures: Remove by-product water to shift equilibrium, increase yield, simplify product purification. Pervaporation or vapor permeation.
Acetic Acid: Difficult to remove pure water by distillation. Pervaporation can remove water from acetic acid of any concentration.
Methanol, ethanol: Can be separated out of its mixture with organics. Pervaporation ideal tool for splitting of azeotropes of organics with these alcohols. No water wash, no messy salts