"[In] the history of fluid beds, the... Speed of certain developments signal their intrinsic rightness."
A. M. Squires, M. Kwauk, and A. A. Avidan
In 1925 Fritz Winkler (1888-1950) patented a chemical reactor in which large particles could be "fluidized" by forcing an upward current of gas through the solid. Winkler used his reactor to extract gas from lignite, which was then piped directly to engines for compressing ammonia.
Catalytic cracking is a process in which the heavier molecules, obtained from petroleum deposits are broken down into the more useful lighter molecules, such as gasoline, by heating them in the presence of a catalyst. The catalyst remains active for a short time and then becomes inactive as a layer known as coke is deposited on the surface. Catalysts can be removed and regenerated by heating them in air. This takes a relatively long time and there is the problem of removing them without disturbing the products of the reaction.
Fluidized bed reactors were the ideal solution. A gas is forced up through the catalyst, enabling it to take on liquid properties, including running off for regeneration before being put back into the reaction mixture. Adapting Winkler's design to work with fine powders, the first U.S. reactor was installed in Baton Rouge's Standard Oil Refinery in 1940. Fluidized beds are still in use in the fuel industry and are also commonly used in the manufacture of polymers such as PVC and rubber.
