Video: FSC 432 Lesson 5 (3:29)
This section will continue to discuss the separation processes that are carried out on the distillate products obtained from the atmospheric and vacuum distillation units, and the residue from the vacuum distillation unit, as introduced in Section 4. Light Ends Unit (LEU) fractionates the lightest fraction of crude oil obtained as overhead distillate from the atmospheric column in a series of distillation towers to produce LPG as a refinery product and straight-run light, and heavy naphtha for further processing in finishing and conversion units to produce gasoline streams for the blending pool (Section 3). Vacuum distillation residue (VDR) can be fractionated using solvent extraction (deasphalting) to produce an insoluble (asphalt) and a soluble fraction, deasphalted oil (DAO). DAO can be further processed by freezing point separation in a suitable solvent to separate wax. The remaining dewaxed oil is used as base stock for producing lubricating oil. Heavy vacuum gas oil (HVGO) can also be used as a feedstock for dewaxing.
By the end of this lesson, you should be able to:
- analyze the vapor-liquid equilibrium and evaluate the application of Fenske Equation to distillation in Light Ends Unit;
- describe the principles of solvent fractionation as a separation technique;
- place the Deasphalting Process in the refinery and interpret the significance of this process for refining;
- interpret the gradient solubility model that explains the solution of asphaltenes in resin and oil fractions and analyze the structure of asphaltenes;
- analyze the process parameters for deasphalting and assess the anti-solvent effect;
- evaluate the unit operations of deasphalting and assemble the process flow diagram;
- explain the purpose of dewaxing and examine the physical and chemical dewaxing processes.
What is due for Lesson 5?
This lesson will take us one week to complete. Please refer to the Course Syllabus for specific time frames and due dates. Specific directions for the assignments below can be found on the Assignments page within this lesson.
|Readings||J. H. Gary and G. E. Handwerk, Mark J. Kaiser, Chapter 15 (Lubricating Oil Feedstocks)|
|Assignments||Exam 1 will cover the material in Lessons 1-5. Exam 1 is found in the Exam 1 Module.
If you have any questions, please post them to our Help Discussion Forum (not email), located in Canvas. I will check that discussion forum daily to respond. While you are there, feel free to post your own responses if you, too, are able to help out a classmate.