1326a. HALL, C. C., AND CRUMLEY, P. Observations on Fluidization as Applied to Fischer-Tropsch Process. Conf. Fluidization Technol., June, 1952; Jour. Appl. Chem. (U.S.S.R.), vol. 2, 1952, Suppl. 1, pp. S47-S45; Fuel Abs., vol. 12, No. 3, 1952, abs. 2,600.

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Literature Abstracts

Fischer-Tropsch process has been studied in beds of fluidized Fe catalyst in baffled tubes of small diameter; various fluidization phenomena peculiar to such a system and/or to the Fischer-Tropsch process are reported. The presence of baffles does not affect the validity of the normally acceptable criteria of fluidization but tends to promote segregation of the particles by hindering solids circulation. By use of a mechanical stirrer, a turbulent fluid condition can be obtained at about ½ the linear gas velocity otherwise necessary. Fischer-Tropsch Fe catalysts suffer little mechanical attrition as a direct result of fluidization but C formation within the particles causes rapid disintegration and reduction in particle size. In the presence of small amounts of wax formed in the synthesis the resulting small particles form fragile agglomerates approximating in shape to true spheres and greater in size than the largest particles in the original catalyst. Under conditions which favor C formation, the catalyst in a synthesis reactor is composed of particles of a wide range of densities and sizes. In narrow baffled beds the particles become distributed at various levels in the bed such that the height of a particle above the gas inlet is proportional to the product of the particle density and the square of its effective diameter. The largest particles, therefore, are not necessarily found at the bottom of the bed, nor those of lowest density at the top. The advantages and limitations of the use of fluidized catalysts in the Fischer-Tropsch process are reviewed.