Feed stock boiling range

Table II. Effect of Feed Stock Boiling Range in Fluid Catalytic Cracking Using...

A highly aromatic product boiling above 400° F. (the yield of which depends on the feed stock boiling range and on the process conditions)... 

Considerable flexibility with regard to feed stock boiling range and composition. It is possible to handle both cracked and virgin heavy stocks without difficulty. 

Feed stock boiling range, ° F. Aromatics in product, vol. % Benzene 200-275 250-350... 

Temperature and pressure are not considered as primary operating variables temperature is set sufficiendy high to achieve rapid mass-transfer rates, and pressure is sufficiendy high to avoid vaporization. In Hquid-phase operation, as contrasted to vapor-phase operation, the required bed temperature bears no relation to the boiling range of the feed, an advantage when heat-sensitive stocks are being treated. 

A number of mechanistic modeling studies to explain the fluid catalytic cracking process and to predict the yields of valuable products of the FCC unit have been performed in the past. Weekman and Nace (1970) presented a reaction network model based on the assumption that the catalytic cracking kinetics are second order with respect to the feed concentration and on a three-lump scheme. The first lump corresponds to the entire charge stock above the gasoline boiling range, the second... 

This paper discusses developments in solvent extraction with emphasis on applications to petroleum fractions in the kerosene and heavier boiling range. Many of these techniques have been extended to the refining of gasoline, Diesel fuels, catalytic cracker feed and cycle stocks, and butadiene. 

The Puertollano plant illustrates a mode of operation for a hydrocracking unit in that each feedstock yields several waxy base stocks after vacuum fractionation. This requires feeds with wide boiling ranges. In such cases, when severity is increased to obtain higher Vis, it is still possible to produce overhead and bottoms base stocks of the same viscosity, but cut point adjustments are required. This will affect base stock yields, particularly of the heaviest base stocks. 

As is true with all naturally occurring feed stocks, the composition or boiling range of crude oil varies greatly from production field to production field. This variability results in a very significant dynamic control problem in a refinery that feeds crude oil from a variety of sources, which is often the case. 

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