HY for FCC

HY zeolite is the proton-exchanged acidic form of Y zeolite (FAU framework). Replacing Na⁺ with H⁺ generates strong Brønsted acid sites that deliver higher cracking activity per unit mass than USY, making HY a useful high-activity component in FCC catalyst formulations where maximum conversion is the priority.

HY vs USY in FCC

The trade-off is hydrothermal stability. HY’s framework — with a Si/Al ratio of 2.5-5 and no dealumination — is significantly less stable under FCC regenerator conditions than USY (Si/Al 20-50, dealuminated). For units with mild regenerator temperatures or shorter catalyst residence times, HY can provide an activity boost without the stability penalty becoming prohibitive.

When to Choose HY for FCC

HY is most commonly used in:

• Older FCC units operating at moderate regenerator severity
• Moderate-severity operations where the target is maximum conversion from a smaller catalyst inventory
• Formulations dominated by USY, where a 5-15 wt% HY component adds incremental acidity
• Fresh-catalyst activity staging during start-up or unit turnarounds

For most modern FCC units operating at 700-800 °C regenerator temperatures with steam, USY remains the preferred FAU zeolite. See HY vs USY for the complete trade-off analysis, or the FCC solution hub for the full zeolite selection matrix. When requesting a sample, specify your regenerator temperature, target conversion, and desired SiO₂/Al₂O₃ for the HY grade.