Summary and Final Tasks

Summary

Petroleum, the most important crude oil, consists of a mixture of hydrocarbon compounds including paraffinic, naphthenic, and aromatic hydrocarbons with small amounts of impurities including sulfur, nitrogen, oxygen, and metals. The first process in petroleum refining operations is the separation of crude oil into its major constituents, using distillation to separate the crude oil constituents into common boiling-point fractions. Other separation processes include deasphalting to remove the heaviest fraction of crude oil, asphalt, and dewaxing to remove long-chain n-paraffins called wax.

To meet the demands for high-octane gasoline, jet fuel, and diesel fuel, heavier components of crude oils are converted to gasolines and other distillate fuels. Among the conversion processes are cracking, coking, and visbreaking that are used to break large petroleum molecules into smaller ones. Polymerization and alkylation processes are used to combine molecules smaller than those in gasoline into larger ones to make more gasoline in the refinery. Isomerization and reforming processes are applied to rearrange and reform the structure of hydrocarbons to produce higher-value gasoline components of a similar molecular size.

Finishing processes in a refinery processes stabilize and upgrade petroleum products by hydrogenation and remove undesirable elements, such as sulfur and nitrogen, by hydrotreating processes. Blending of many product streams, to come up with commercial refinery products with the required specifications, also belong to the category of finishing processes.

Lesson Objectives

You should now be able to:

• recognize the significance of petroleum fuels in the U.S. energy supply;
• express the overall objectives of petroleum refining;
• identify the economic and environmental drivers of petroleum refining;
• describe the overall approach to petroleum refining and categorize refinery processes and products;
• portray chemical constitution of petroleum.

Reminder - Complete all of the Lesson 1 tasks!

You have reached the end of Lesson 1! Double-check the to-do list below to make sure you have completed all of the activities listed there before you begin Lesson 2. Please refer to the Course Syllabus for specific time frames and due dates. Specific directions for the assignment below can be found within this lesson.

Questions?

If you have any questions, please post them to our Help Discussion (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.