What is FCC Catalyst?

FCC (Fluid Catalytic Cracking) is the largest-volume conversion process in petroleum refining. It converts heavy gas oil into gasoline, LPG, and light olefins by cracking large hydrocarbon molecules over a solid zeolite catalyst in a fluidized bed at 500-550 °C. The catalyst continuously circulates between the reactor and a regenerator, where coke deposited during cracking is burned off at 700-800 °C in steam.

What is an FCC Catalyst Made Of?

A modern FCC catalyst is an engineered composite, not a single material. The active zeolite — most commonly USY zeolite — is embedded in a matrix of alumina and silica that provides physical strength, binds the catalyst particles, and contributes secondary cracking activity. The zeolite fraction (15-35 wt%) determines the chemical activity; the matrix determines attrition resistance and particle size distribution.

The zeolite component is what refiners specify most carefully, because it directly determines conversion, gasoline yield, coke selectivity, and metals tolerance.

The Role of Zeolites in FCC

FCC Process Fundamentals

Reactor: Vaporised feed contacts hot catalyst in a riser at 500-550 °C. Cracking is nearly instantaneous; residence time is measured in seconds. The reaction is endothermic, with heat supplied by the hot regenerated catalyst.

Regenerator: Spent catalyst carries coke (typically 0.5-1.5 wt% of catalyst) to the regenerator, where it burns at 700-800 °C in air with steam present. This is the most severe environment the zeolite sees — the reason hydrothermal stability is the primary selection criterion for FCC zeolites.

Products: Gasoline (40-50 wt%), LPG/light olefins (15-25 wt%), light cycle oil, and coke. The product slate is tuned by zeolite selection — for example, adding ZSM-5 increases propylene yield by 2-6 percentage points.

For zeolite selection guidance, see best zeolite for FCC. When requesting a sample, specify your FCC unit configuration, feedstock, and target product slate.