Thermofor Catalytic Cracking reactor

Some of the principles used in Thermofor catalytic cracking have been applied to a coking operation. Coke itself, instead of catalyst, is the solid circulated. The coke is heated in the regenerator of the unit and more coke is deposited on the hot moving solid in the reactor of the unit. Appropriate proportions of the coke are removed continuously as the process proceeds (84). 

In a typical thermofor catalytic cracking unit, the preheated feedstock flows by gravity through the catalytic reactor bed. The vapors are separated from the catalyst and sent to a fractionating tower. The spent catalyst is regenerated, cooled, and recycled. The flue gas from regeneration is sent to a carbon monoxide boiler for heat recovery. 

Socony-Vacuum utilized Thermofor kilns to bum off coke deposited on Fuller s earth during the filtration of lube oils (57). They adapted one of these kilns to introduce the first moving bed catalytic cracking process. The first semi-commercial 500 BPD (barrel per day) Thermofor Catalytic Cracking (TCC) unit went on stream in the Paulsboro refinery in 1941. It utilized bucket elevators to transport catalyst from the reactor to the regenerator. In 1943, Socony-Vacuum installed a 10,000 BPD TCC unit (52) at a subsidiary refinery. 

Thermofor catalytic cracking (TCC) introduced by Mobil in 1943, fluid catalytic cracking (FCC) introduced by Exxon, and several other similar processes used moving or fluidized beds of strong catalyst particles. Catalyst was withdrawn continuously from the bottom of the reactor and lifted in buckets or by an air stream to the top of a regenerator, or kiln, after the residual hydrocarbons had been stripped out with steam. Catalyst vyas then returned to the reactor after regeneration. There was a limit to the capacity of moving bed processes... 

THERMOFOR PROCESS. A moving-bed catalytic cracking process in which petroleum vapor is passed up through a reactor countercurrent to a flow of small beads or catalyst. The deactivated catalyst then passes through a regenerator and is recirculated. 

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. 

---