Thermofor

The first Thermofor cracking unit came on line in late 1942. By March of 1943, twenty Thermofor units had been completed or were under construction. The larger Thermofor plants could circulate 100-150 tons of catalyst per hour and could process up to 20,000 barrels of petroleum per day. 

An improved design undertaken by Sacony used high-velocity gases to replace the mechanical elevator systems as catalyst carriers. These so-called air-lift units improved upon the Thermofor process both in terms of economies and octane numbers. It was, however, only with the fluid cracking process that catalytic technology realized fully continuous production. 

Fluid catalytic cracking rapidly overtook its competitors as both a source of fuel and of critical organic intermediates. Prior to 1942, the Houdry Process controlled 90 percent of the catalytic fuel market. But only three years later, in 1945, fluid cracking led all other catalytic cracking processes in market share (40 percent). At this time Thermofor technology stood at 31 percent, and Houdry at less chan 30 percent. 

Fig. 8-51 Bonding two coextruded thermofor-med parts to produce a gasoline fuel tank.

For the purposes of this illustrative example, we wish to calculate the combined and effective diffusivities of cumene in a mixture of benzene and cumene at 1 atm total pressure and 510 °C within the pores of a typical TCC (Thermofor Catalytic Cracking) catalyst bead. For our present purposes, the approximation to the combined diffusivity given by equation 12.2.8 will be sufficient because we will see that the Knudsen diffusion term is the dominant factor in determining the combined diffusivity. 

Airlift Thermofor Catalytic Cracking Also called Airlift TCC. A continuous catalytic process for converting heavy petroleum fractions to lighter ones. The catalyst granules are moved continuously by a stream of air. Developed by Mobil Oil Corp., United States, and first operated in 1950. See also Thermofor. 

TPC [Thermofor pyrolytic cracking] A continuous process for thermally cracking petroleum fractions on a moving bed of hot pebbles. Developed by the Socony Vacuum Oil Company (now a part of Mobil Corporation). See also Thermofor. 

Thermofor catalytic cracker (TCC), 11 819 Thermoformed acrylic sheet, 20 116 Thermoformed food packaging, 18 48-49 Thermoforming, 10 179, 19 555 ABS, 1 427-428... 

A REACTION ENGINEERING CASE HISTORY COKE BURNING IN THERMOFOR CATALYTIC CRACKING REGENERATORS... 

C. D. Prater, J. Wei, V. W. Weekman, Jr., and B. Gross, A Reaction Engineering Case History Coke Burning in Thermofor Catalytic Cracking Regenerators Costei D. Denson, Stripping Operations in Polymer Processing Robert C. Reid, Rapid Phase Transitions from Liquid to Vapor John H. Seinfeld, Atmospheric Diffusion Theory... 

The gas lift unit represents a further improvement over the Thermofor in the elimination of complex internals in the kiln and the mechanical catalyst elevators. These mechanical simplifications in combination with the greatly improved unit heat balance effected an appreciable reduction in investment cost and in unit operating cost. The elimination of so many mechanical components of the unit further resulted in a saving in maintenance, which at the very least would correspond to the reduction in investment. 

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). 

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