Catalytic cracker bottoms fractionated

Aromatic Pitches from the Asphaltene-Free Distillate Fraction of Catalytic Cracker Bottoms... 

This chapter describes the preparations and characteristics of highly aromatic and highly anisotropic pitches from the distillate fraction of catalytic cracker bottoms (CCB). CCB is the aromatic residue from a catalytic cracking process. 

Figure 3 Crude fractionation (crude distillation, three stages). An atmospheric fractionating stage produces lighter oils. An initial vacuum stage produces lube oils. A second vacuum stage fractionates bottoms from the other stages to produce asphalt and catalytic cracker feed. (From Ref. 5.)...

The design vs r rate in the slurry section of a catalytic cracker fractionator did not allow for vaporization which occurs when a bottom feed with 300°F superheat contacts column liqtiid. Column therefore prematurely flooded. Problem solved by iqiecting subcooled quench liquid to desuperheat the feed. At a later stage, subcooled quench was replaced by a lifter liqtiid that vaporized, and premature flooding reoccurred. 

Refinery sour water originates largely from delayed coker, hydrode-sulferizer reactor effluents, and catalytic cracker and visbreaker fractionators. The main contaminants are NHj and H S. Sour water stripper bottoms are reused in two places ... 

Figure 3.35 shows a process flow diagram of Phillips MTBE/ETBE/TAME process. This process is often called the Phillips Etherification Process. The reaction section (1,2) which receives methanol and isobutene concentrate, contains an ion exchange resin. The isobutene concentrate may be mixed olefins from a Fluid Catalytic Cracking Unit (FCCU) or steam cracker or from the on-purpose dehydration of isobutene (Phillips STAR process). High purity MTBE (99 wt%) is removed as a bottoms product from the MTBE fractionator (3). AH of the unreacted methanol is taken overhead, sent to a methanol... 

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