Blown Coke Residue

Table 4-65 Means. r of the coke residue for blown bitumens...

The total colloids (petroleum resins and asphaltenes) can be correlated quite well with the coke residues R600 and RSOO (Fig. 4-54 and 4-55). There is no difference between the distillation and the blown bitumens. Correlation of the maxima of the reaction rate DTG with the colloid content gives two straight lines for the distillation bitumens (independent of the origin of the samples) and a third line for the blown bitumens (Fig. 4-56). No other correlations with the colloid content were found, nor were any expected. 

The asphaltenes are responsible for the formation of coke residue due to their high content of condensed aromatic ring systems. This is shown by the correlation of the coke residues / 600 or RSOO with the contents of asphaltenes (Fig. 4-60). Independent of the origin of the samples, two straight lines result for the distillation bitumens, whereas the data of the blown bitumens fit a third line with a steeper slope. Correlation of the maxima of the reaction rate DTG upon the concentration of asphaltenes presents a similar picture (Fig. 4-61). 

When compared to the delayed coking process, higher yields of liquid products are typically produced by fluid coking. This continuous process utilizes a fluidized reaction zone of hot coke particles held in motion by steam. The coke particles are first heated in a burner to temperatures ranging from 1,100°F to 1,200°F (593.3°C to 648.9°C). The hot coke particles then are blown into the reactor by steam. The residual fuel is fed into the reactor and cracks on the hot surface of the fluidized coke particles. 

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