Characterization factor, Watson

If the boiling temperature is not known, it is somewhat risky to estimate it. One could, if the Watson characterization factor is known, use the following... 

Watson characterization factor log = common logarithm (base 10)... 

K y = Watson characterization factor 5 = standard specific gravity... 

Watson characterization factor Tu = normal boiling point... 

The Watson characterization factor has also been used as a measure of the chemical character of a cmde oil or its fractions ... 

Another relationship used to indicate the crude type is the Watson characterization factor. The factor also relates the mid-boiling point of the crude or a fraction to the specific gravity. 

Ranges from 12.5 for paraffinic stocks to 10.0 for the highly aromatic stocks also called the Watson characterization factor. 

The yields for the various products were given as a function of the properties of the feedstocks and the volume percent conversion. The feedstock properties are the feed sulfur content expressed as a weight percent, the feed API and Watson characterization factor, K. The API is related to specific gravity by the following equation ... 

A characterization factor was introduced by Watson and Nelson to use an index of the chemical character of crude oil or its fractions.6 The Watson characterization factor is defined as... 

Other factors, such as the Watson characterization factor, are also used. A highly paraffinic crude oil can have a characterization factor as high as 13, whereas a highly naphthenic crude oil can be as low as 10.5, and the breakpoint between the two types of crude oil is approximately 12. Sulfur content, the carbon residue, and distillation data are also valuable in petroleum evaluation (Speight, 2001). 

If only the average specihc gravity of the mixture is available, the individual pseudocomponent gravities can be estimated. One method involves the Watson characterization factor, Kyf, dehned as... 

The TBP curve is plotted from the data provided (Figure 1.22). The cut points are set at 50, 100, 150, 200, 250, 300, 350, 400, 500, and 600°C. The TBP and volume percent of each cut are determined graphically from the plot. The Watson characterization factor is calculated from the mixture average boiling point and the overall specific gravity ... 

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