What is Deiodination Adsorbent for Acetic Acid Purification

ZC-DIO-1 is a silver-exchanged zeolite adsorbent purpose-built for removing trace iodine contaminants from acetic acid and related organic streams. It addresses a critical purification step in the methanol carbonylation process, where iodine-containing catalyst promoter residues must be reduced to parts-per-billion levels to meet product specifications and protect downstream equipment.

How It Works

The adsorbent consists of silver cations dispersed on a binder-free zeolite support with hierarchical porosity. When iodine-bearing acetic acid passes through the adsorbent bed, multiple capture mechanisms act in concert:

• Chemisorption: Silver ions form stable silver iodide (AgI) species with iodide ions
• Complexation: Molecular iodine complexes with the zeolite framework and silver sites
• Catalytic conversion: Organic iodides are catalytically decomposed to release iodide for capture
• Physical adsorption: The hierarchical pore system provides additional retention through physisorption

This multi-mechanism approach ensures that both inorganic iodine (I⁻, I₂) and organic iodine (iodomethane, iodoethane, etc.) are effectively captured in a single pass.

Key Performance Characteristics

The binder-free zeolite structure provides high mechanical strength and acid resistance essential for acetic acid service, while the high silver capacity (up to 10 wt%+) enables deep removal even under challenging feed conditions.

Advantages Over Alternatives

Compared to activated carbon or ion-exchange resins commonly used for iodine removal, ZC-DIO-1 offers superior acid stability, higher operating temperature tolerance, and longer service life in aggressive chemical environments. The zeolite support does not swell, leach, or degrade in acetic acid service, and the adsorbent can be regenerated multiple times without significant performance loss.