Modeling of Processes and Reactors for Upgrading of Heavy Petroleum

13Heavy Petroleum

asphaltenes recovered from light crude oils (21 and 33°API) possess higher concen-

tration of this metal compared with heavier oils (13 and 16°API) (Reynolds, 1990).

Table 1.3 also shows the calculation of percentage of asphaltenic metals. These

values were determined by mass balance using the characterization of crude oils

and asphaltenes. Heavier crude oils exhibit a higher content of asphaltenic nickel,

while in the case of vanadium, the lighter crude oil also presents elevated amount

of asphaltenic vanadium. This fact could be explained taking into account that,

although the asphaltene content in the 33°API crude oil is low, in this crude the

vanadium present is concentrated in the asphaltenes. It can be noticed that as ...