What is Isomer Separation Adsorbent for Xylene and Dichlorobenzene

ZC-ISO-1 is a binder-free MFI-type zeolite adsorbent with engineered hydrophobicity designed for the selective separation of aromatic isomers and hydrophobic adsorption of organic molecules.

Binder-Free Technology

Conventional zeolite adsorbents contain amorphous binder material (typically 10-20 wt%) that dilutes the active zeolite content and can block access to micropores. ZC-ISO-1 uses a proprietary process that converts the binder phase into crystalline MFI zeolite with the same framework topology as the primary zeolite crystals. This yields three advantages:

• Maximum active surface: Every gram of adsorbent is active MFI zeolite
• Full pore accessibility: No binder blocking access to micropores
• Superior mechanical strength: The intergrown crystalline network is stronger than amorphous binder

Hydrophobicity

The post-synthesis treatment imparts exceptional hydrophobicity, achieving a hydrophobicity index (Hn) greater than 7. For comparison, conventional binder-containing zeolite adsorbents typically have an Hn of approximately 2. This means ZC-ISO-1 can preferentially adsorb organic molecules from humid gas streams without competitive water adsorption — a critical advantage for both isomer separation in wet feeds and VOC treatment where humidity varies.

Selectivity Mechanism

Separation selectivity is derived from the MFI framework’s 10-membered ring channel system (5.1-5.6 A). Linear and slightly branched aromatic isomers such as para-xylene can enter the pore system while bulkier ortho- and meta-isomers are excluded or diffuse much more slowly. This kinetic and equilibrium selectivity enables the preferential capture of target isomers from equilibrium mixtures.