Types of distillation curves:
1. TBP (True Boiling Point) distillation curve.
2. ASTM (D86/D1160) distillation curve.
3. EFV (Equilibrium Flash Vaporization)
TBP Curve: is the most useful.
- However, no standard test exists for measuring the TBP.
- Most common TBP test is Hempel & D-285.
(Neither specifies # of stages or reflex ratio used).
- Trend is toward 15/5 distillation (D-2892).
ASTM Curve: is more common because it is simple to determine in the laboratory.
TBP/ASTM distillation curves: are the most important characterization properties of the crude/intermediate/product streams.
Both TBP, ASTM distillation curves are measured at 1 atm pressure. In both these cases, the boiling points of various volume fractions are being measured.
The basic difference between TBP curve and ASTM distillation curve is that while TBP curve is measured using batch distillation apparatus consisting of no less than 100 trays and very high reflux ratio, the ASTM distillation is measured in a single stage apparatus without any reflux.
Therefore, the ASTM does not indicate a good separation of various components.
Construction of the TBP & API Curves:
When a refining company evaluates its own crude oils to determine the most desirable processing sequence to obtain the required products, its own laboratories will provide data concerning the distillation and processing of the oil and its fractions.
In many cases, information not readily available is desired concerning the processing qualities of crude oils. In such instances, true boiling point (TBP) and gravity-midpercent curves can be developed from U.S. Bureau of Mines crude petroleum analysis data sheets (Fig. 3.5).
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 .
|