Picture 7.1. Old and New FCCU

The world's first commercial Fluid Catalytic Cracking Unit (FCCU) was commissioned in 1942 at Standard Oil of New Jersey's Baton Rouge refinery.

During the early 20th century, refineries relied primarily on distillation to separate crude oil into products such as kerosene and gasoline. As engine technology advanced—especially in the years leading up to and during World War II—the demand for higher-quality, higher-octane fuels increased dramatically. One of the main drivers behind the development of catalytic cracking was the urgent need to produce large volumes of high-octane aviation gasoline (avgas) to support military aircraft operations.

Catalytic cracking was developed to meet this need by using catalysts to convert heavy oil fractions into lighter, high-octane gasoline. In this process, heavy hydrocarbons pass over a catalyst—such as silica, alumina, and later zeolites—which promotes the breakdown of large hydrocarbon molecules into smaller, more branched products. These branched hydrocarbons have superior combustion characteristics and became essential for high-performance aircraft engines and, later, modern automotive engines.

This technology also played an important role in the global economy, as fuel demand rose sharply with the rapid growth in automobile use following World War II.

Compared with earlier thermal cracking methods, catalytic cracking operates at lower temperatures and pressures. A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. In catalytic cracking, the catalyst provides active sites where large hydrocarbon molecules can break apart more readily, allowing refineries to efficiently produce greater volumes of gasoline and other valuable light products.