Therefore, ebullated bed reactors have the characteristics of stirred reactor type operation with a fluidized catalyst.

Feed is injected onto hot, fluidized catalyst where large gasoil molecules are broken into smaller gasoline molecules and olefins.

The fluidized catalyst particles are shuttled between the fluidized bed reactor and a fluidized bed burner where the coke deposits are burned off, generating heat for the endothermic cracking reaction.

They developed the process into fluid catalytic cracking, which solved the problem of having to shut down the process to burn the coke off the catalyst by using a continuously circulating fluidized catalyst made of a fine zeolite powder.

Focused on that idea of a fluidized catalyst, researchers Donald Campbell, Homer Martin, Eger Murphree and Charles Tyson of the Standard Oil of New Jersey (now Exxon-Mobil Company) developed the first fluidized catalytic cracking unit.