Deep Drying and Purification of Industrial Gases
Application Background
Industrial gases almost always contain moisture — even trace amounts can cause pipeline corrosion, equipment freeze-plugging, product-quality degradation, and catalyst poisoning. Granular molecular sieve desiccants and activated alumina can lower the gas dew point to -40 °C to -100 °C, making them the deepest and most reliable means of industrial gas drying.
|
Gas Type |
Moisture-Related Hazards |
|
Natural Gas |
Pipeline corrosion, hydrate freeze-plugging |
|
Compressed Air |
Pneumatic equipment corrosion, condensate freezing |
|
Petroleum Cracking Gas |
Poisoning of polymerization catalysts |
|
Refrigerant |
Ice plugging and corrosion in HVAC / refrigeration systems |
|
Hydrogen |
Poisoning of fuel cells / chemical reactions |
|
Inert Gases (N₂ / Ar) |
Oxidation and defects in electronics / metallurgy |
Molecular Sieve Grade Selection
|
Gas to Be Dried |
Selection Rationale |
|
Natural Gas (Deep Dehydration) |
Atmospheric dew point down to -70 °C |
|
Petroleum Cracking Gas (Containing Olefins) |
Adsorbs water only, does not co-adsorb ethylene / propylene, avoiding olefin loss and polymerization |
|
Ethylene / Propylene / Butadiene |
First choice for unsaturated-hydrocarbon drying, strongest selectivity |
|
Fuel Ethanol Dehydration |
Adsorbs water only, no ethanol uptake |
|
Compressed Air |
General-purpose drying, high cost-performance |
|
Refrigerant (R-12 / 22 / 134a) |
Dedicated JZ-ZRF series molecular sieve, does not co-adsorb refrigerants |
|
Hydrogen |
Deep drying with simultaneous removal of impurity gases |
|
Argon Purification |
Removes trace H₂O and N₂ from argon |
Typical Process Units
|
Unit Type |
Working Principle |
Molecular Sieve Configuration |
|
Fixed-Bed Drying Tower (TSA) |
Temperature-swing adsorption: adsorption at ambient temperature → regeneration at 200-350 °C |
Dual / multi-tower switching, 4A / 13X beads |
|
Pressure-Swing Adsorption Dryer (PSA) |
Pressure-swing adsorption: adsorption at high pressure → regeneration by depressurization |
Beads, requires high crushing strength |
|
Compressed-Air Desiccant Dryer |
Compressed air flows through the sieve bed for dehydration |
Beads, often used together with activated alumina |
|
Natural-Gas Dehydration Station |
Deep dehydration of pipeline natural gas to prevent freeze-plugging |
Beads, large-scale units |
Technical Advantages
- ♦ Deep dehydration: dew point down to -100 °C, far superior to silica gel (-20 to -60 °C) and activated alumina (-20 to -70 °C)
- ♦ Selective adsorption: 3A adsorbs water molecules only and does not co-adsorb other components — zero product loss
- ♦ Excellent performance at high temperature and low humidity: water uptake far exceeds other adsorbents under these conditions
- ♦ Regenerable and reusable: TSA/PSA regeneration, service life up to 3-5 years