Introduction
Chlorine impurities, especially hydrogen chloride (HCl), cause severe corrosion and catalyst poisoning in refineries, gas processing, and petrochemical plants. Activated alumina chlorine removal agent is an efficient dry purification technology that removes HCl and other chlorides from gases and liquids.
What Is It?
Activated alumina chlorine removal agent consists of activated alumina as the carrier, impregnated with alkaline active components such as Na₂O, K₂O, CaO, or ZnO. Unlike ordinary adsorbents, it combines physical adsorption and chemical reaction to achieve deep chlorine removal down to <0.1 ppm.
How It Works
The dechlorination process follows two mechanisms:
Chemical adsorption (dominant) : Alkaline sites react with HCl through acid-base neutralization, forming stable metal chlorides fixed inside the pores (e.g., Na₂O + 2HCl → 2NaCl + H₂O). This reaction is irreversible.
Physical adsorption (supplementary) : The high surface area and mesoporous structure (3–6 nm pores) capture HCl molecules and provide diffusion channels.
Key Performance Indicators
Parameter Typical Value
Surface area ≥130 m²/g
Crushing strength ≥120 N/piece
Bulk density 0.75–0.8 g/ml
Penetration Cl capacity ≥22%
Outlet Cl concentration ≤0.1 ppm
Penetration chlorine capacity is the most important economic indicator.
Main Applications
Application Description
Reformer hydrogen Removes HCl from hydrogen to protect downstream catalysts
Natural gas / syngas Purifies acidic gases before liquefaction or synthesis
Liquid hydrocarbons Removes inorganic and organic chlorides from naphtha, LPG
Blast furnace gas Prevents acid corrosion in power generation systems
Technical Advantages
High chlorine capacity (up to 25%)
High precision (≤0.1 ppm outlet)
Wide operating range (5–400°C, 0–10 MPa)
Good water resistance (no swelling or caking)
Some grades also remove organic chlorides
Certain types can be regenerated 1–8 times
Recent Developments
Water resistance: Na₂O-based formulations replace CaO to avoid hydration, swelling, and bed consolidation.
Bimetallic systems: Adding ZnO increases chlorine capacity from 12.5% to 25.6%.
Organic chloride removal: New agents break C–Cl bonds at moderate temperatures, converting organic chlorides into adsordable inorganic forms.
Best Practices
Store in dry environment
Sieve before loading to remove fines
Load uniformly to avoid channeling
Maintain bed height-to-diameter ratio > 3:1
Install support screens (8–10 mesh) above and below the bed
Conclusion
Activated alumina chlorine removal agent is essential for protecting equipment and catalysts from chlorine damage. Its high capacity, strength, and flexibility make it the preferred choice across refining, gas processing, and steelmaking industries. Selecting the right product for specific conditions ensures safe, reliable, and long-term operation.