Hydrogen Consumption during Catalytic Hydrotreating

FIGURE 12.5 Residual values of CCR content obtained with the exponential correlation (Equation 12.23) for feedstocks B, E, and F. ( ) Replacing the parameters of derived correlations into the original exponential equation, (o) with parameters values as function of feedstock properties (Table 12.8). 

FIGURE 12.6 Comparison between experimental and predicted total metals content for feedstock B. ( ) with original values of parameters, (x) with predicted values of parameters. 

A particular commercial HDT unit regularly operates with catalyst and feed having more or less similar properties thus, the required amount of hydrogen does not vary significantly. However, when notorious changes in the properties of catalyst and feed are experienced, a more accurate knowledge of hydrogen consumption 

Ramachandran and Menon (1998) presented a brief review on the various uses of hydrogen in the industry. They pointed out that in modern refineries, hydrogen requirement is commonly about lwt% of the crude processed. Typical hydrogen consumption data for various refinery processes are presented in Table 12.9. Hydrocracking of vacuum distillates requires a large amount of hydrogen, not only for desulfurization but also for the increase in the hydrogen/carbon ratio of the products relative to the feed (Aitani, 1996). 

In the near future, practically all fractions of sour crudes will be subjected to catalytic processes that involve hydrogen. The total qnantity of fractions directed to hydrotreating and hydrocracking will amount to 90% of the total crude run (Aitani, 1996). It is therefore mandatory to determine the hydrogen consumption with high accuracy. 

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