Process/catalyst development cracking reactions

Cracking is an endothermic reaction, implying that the temperature must be rather high (500 °C), with the consequence that catalysts deactivate rapidly by carbon deposition. The fluidized catalytic cracking (FCC) process, developed by Standard Oil Company of New Jersey (1940) (better known as ESSO and nowadays EXXON), offers a solution for the short lifetime of the catalyst. Although cracking is... 

The inherent variability of the raw mineral, particularly with respect to minor constituents which in certain cases were known to have major effects on the cracking reaction, led to the development by the Houdry Process Corp. of a synthetic silica-alumina catalyst of controlled chemical composition and more stable catalytic properties. Full scale manufacture of synthetic catalyst was started in 1939. 

Catalysis and reaction engineering became entwined in the late 1930s with the realization that the cracking of petroleum could be achieved most effectively using silica-alumina catalysts. With time, the connection between these two areas grew stronger as more and more catalytic processes were developed for the refining of petroleum, the production of petrochemicals, and the synthesis of polymers. 

Platinum (metal)- and acid (oxide)-catalyzed processes were developed to convert petroleum to high-octane fuels. Hydrodesulfurization catalysis removed sulfur from the crude to prevent catalyst deactivation. The discovery of microporous crystalline alumina silicates (zeolites) provided more selective and active catalysts for many reactions, including cracking, hydrocracking, alkylation, isomerization, and oligomerization. Catalysts that polymerize ethylene, propylene, and other molecules were discovered. A new generation of bimetallic catalysts that were dispersed on high-surface-area (100-400 m /g) oxides was synthesized. 

The first step in the direction of a continuous process utilized buckets and conveyers to transfer spent catalyst from the reactor to a Thermofor kiln. The Thermofor kiln was in use at that time for burning coke off the Fullers earth used in the filtration of lube oils. The idea of transferring catalyst between a reaction and regeneration zone led to the eventual development of the early bucket elevator TCC, the Houdriflow, the airlift TCC, and eventually the Fluid Catalytic Cracking unit. 

Using a series of bench-top units, Houdry attempted to find a catalyst that would enhance the cracking process. He also needed to develop a procedure to burn off the carbon that formed on the catalyst during the reaction (Figure 1-5). Three years after the experiment started, Houdry found one of his reactors operating within design specifications. The reactor was filled with aluminum silicate. 

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