Crude Oil Properties:
Crude petroleum is very complex and, except for the low-boiling components, no attempt is made by the refiner to analyze for the pure components contained in the crude oil. Relatively simple analytical tests are run on the crude and the
results of these are used with empirical correlations to evaluate the crude oils asfeedstocks for the particular refinery.
Each crude is compared with the other feedstocksavailable and, based upon the operating cost and product realization, is
assigned a value. The more useful properties are discussed.
API Gravity
The density of petroleum oils is expressed in the United States in terms of API gravity rather than specific gravity; it is related to specific gravity in such a fashion that an increase in API gravity corresponds to a decrease in specific gravity.
The units of API gravity are °API and can be calculated from specific gravity by the following:
In this equation, specific gravity and API gravity refer to the weight perunit volume at 60°F as compared to water at 60°F.
API gravitiesare not linear and, therefore, cannot be averaged. For example, a gallon of30°API gravity hydrocarbons when mixed with a gallon of 40°API hydrocarbonswill not yield two gallons of 35°API hydrocarbons, but will give two gallons of
hydrocarbons with an API gravity different from 35°API. Specific gravities canbe averaged.
?Using the following formula, API gravity can also be used to
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
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