Chemistry Of Petroleum four: Remedy Of Hydrocarbons
To introduce how petroleum fractions are chemically handled in the refinery process to supply helpful materials.
This lesson is a part of the Vitality in a Excessive-Tech World Challenge, which examines the science behind energy. Power in a High-Tech World is developed by AAAS and funded by the American Petroleum Institute. For extra classes, actions, and interactives that take a better look on the science behind vitality, be sure to take a look at the Vitality in a Excessive-Tech World Undertaking page.
This lesson is the fourth in a collection of lessons about the chemistry of petroleum which are supposed for higher-level chemistry students in the eleventh and twelfth grades. You ought to be an experienced chemistry instructor to show these classes. The goal of those lessons is to introduce excessive-faculty college students to the usage of oil as an vitality source in as we speak’s excessive-tech world. In the Chemistry of Petroleum 1: What are Hydrocarbons college students will discover hydrocarbons, the molecular basis of petroleum, and be taught to tell apart between natural and inorganic compounds.
Within the Chemistry of Petroleum 2: What Happens to Hydrocarbons Once they Burn students will look at the varying quantities of vitality produced by the combustion of various hydrocarbons.
Within the Chemistry of Petroleum three: Distillation of Hydrocarbons, students can be launched to the distillation processes by which petroleum is refined to produce useful petroleum fractions.
The Chemistry of Petroleum 4: Therapy of Hydrocarbons will assist students discover the chemical therapy processes by which distilled petroleum fractions are converted to supply useful gas oils.
This particular lesson is a continuation of lesson 3, which taken together complete the crude oil refining course of. Lesson three concludes with the crude oil being separated into petroleum fractions, based on the relative boiling points of the hydrocarbons in the unique crude oil. In this lesson, college students explore how those petroleum fractions are handled chemically to produce useful fuels that are acquainted to them, resembling diesel, jet gas, and gasoline.
As college students explore the interactive, they could also be overwhelmed with the quantity of terminology and reactions related to the therapy process. College students don’t must know or memorize the small print of those reactions; moderately, they should obtain a basic understanding that a series of chemical reactions are important in producing the fuels which can be used on an on a regular basis foundation.
As in lesson 3, this activity provides a possibility to make clear the frequent misconception that crude oil is composed of particular person molecules of diesel, kerosene, and the other refined products. By the top of those lessons, students ought to understand that there isn’t a single molecule referred to as diesel, or kerosene, or mild gases, with a selected chemical components, like H2O. Gasoline oils, like diesel, are a mixture of various molecules that share related properties. The two major properties shared in a petroleum fraction are the variety of carbons in a molecule and the boiling point.
So as for students to do this lesson, in addition to the other classes on this sequence, they should have prerequisite data of the fundamentals of atoms and their construction. Fundamental information about atoms might be found at the Atom. College students also should know basic organic chemistry, including an understanding of what hydrocarbons are and the way they’re named (i.e. nomenclature).
Begin by asking college students: “We all know that petroleum is used to make gasoline. But what different merchandise are made from petroleum ” Ask college students to brainstorm in teams, every group producing an inventory of at the least ten items that they have seen or used up to now 24 hours which might be petroleum merchandise. A listing of gadgets can be discovered at: A number of Products Made from Petroleum.
As pupil teams share their product items, generate a class list. Level out that this stuff and lots of more are all made with fuels derived from crude oil or petroleum. Ask students:
– How do you assume our use of petroleum merchandise has changed over time
– Given the excessive customer demand and the fact that crude oil is a limited useful resource, how do you suppose refineries take advantage of out of the crude oil they’ve
Assessment with college students the primary phases of crude oil refinement and treatment by making a flowchart. Initially of the flowchart, write the words “crude oil.” At the end of the flowchart, place the record of products generated by the students. Begin to fill within the flowchart by asking students what happens to crude oil once it is located in the earth. Subsequent steps ought to embrace extraction and taking the crude oil to a petroleum refinery. As soon as at the refinery, the crude oil undergoes the distillation course of. The outcomes of distillation are petroleum fractions. Ask college students, “Describe what has happened to the hydrocarbons in the distillation course of.”
Now students should assessment the Oil Refining: A closer Look interactive by watching the introductory video and going via the distillation course of. The film has an accompanying script which you could chemical solvent storage tank yihai kerry print out. The narrator speaks quickly, so it’s a good idea to read the script after watching the movie the primary time. After reading the script, students can watch the film a second time, which is able to facilitate understanding.
– What chemical property was used to separate the hydrocarbons within the distillation process
Undergo the seven fractions, emphasizing that the fractions are composed of a mixture of hydrocarbons, and are not composed of a single molecule. For example, kerosene is a mixture of hydrocarbon molecules from the unique crude oil that contain between 10-sixteen carbons. Because of this there are hydrocarbons in the kerosene fraction that contain 10 carbons and others that comprise 11, and so on via 16.
Level out that by means of the distillation course of, the hydrocarbons have not been altered or modified in any way; they have merely been separated by size utilizing the chemical property of boiling point variations. This can be a bodily change. On the flowchart after distillation and us oil refineries earlier than the scholars’ record of on a regular basis merchandise and oils, write the phrase “treatment.” Define for students that treatment is the series of chemical reactions and technologies to switch the distilled fractions to make useful and marketable oils.
Permit students to explore the treatment part of the interactive on their own using the Treatment of Hydrocarbons pupil esheet. Students can answer the questions using the Therapy of Hydrocarbons student sheet. Solutions are available on the Therapy of Hydrocarbons trainer sheet. Overview the questions together as a class. Via dialogue and evaluate of the guiding questions, clarify that there are three completely different treatment processes, normally. These are:
1. Eradicating impurities within the hydrocarbons, corresponding to metals and sulfur
2. Breaking down giant, heavy hydrocarbons
3. Reshaping or constructing hydrocarbons from smaller ones
The aim of these processes is to make helpful merchandise, akin to diesel, gasoline, jet gas, and asphalt. In the end, these last products aren’t individual molecules, but blends of handled hydrocarbons of varied lengths and buildings.
Go through examples of each of the three processes. Begin with the first process (Removing impurities in the hydrocarbons) by asking college students:
– What are the two processes that are used to remove sulfur
Inform students that the general thought behind hydrotreating is to add hydrogen gas at high pressure and temperature to the petroleum fractions. The oil and hydrogen then enter a reactor loaded with a catalyst.
Ask college students:
– What is a catalyst
In hydrotreating, a steel floor is normally used as a catalyst. These metals embody palladium, nickel, platinum, cobalt, and iron. Draw a normal response formula for college students to know hydrotreating.
S + H2 (g) → H2S (g)
(Catalyst, heat, and strain)
If potential, project the therapy web page of the interactive for the category. Click on on one of the fuels and then on the hydrotreating box to point out students an instance of one of the types of reactions that happen in the hydrotreating unit. Solid sulfur is transformed to hydrogen sulfide fuel, which is then eliminated.
S8 (s) + 8H2 (g) → 8H2S (g)
(Catalyst, heat, and strain)
Inform college students that the hydrotreating course of additionally removes nitrogen compounds, which if not eliminated, would react with the oxygen in the air and produce nitric acid (HNO3).
Begin describing an instance of the second course of (Breaking down giant, heavy hydrocarbons) by asking college students:
– Do massive hydrocarbons have excessive or low boiling factors Why
Write the formula for docosane on the board: C22H46, and inform college students that this giant hydrocarbon is found in the gasoline oil fraction after distillation. The gasoline oil fraction is composed of a mixture of hydrocarbons with 20-70 carbons. If doable, undertaking the therapy web page of the interactive in front of the classroom and click on the purple circle next to “gas oil.” Then click on the throbbing yellow circle within the fuel oil pipe to display the chemical construction of docosane. Ask college students:
– What is the primary remedy course of for the fuel oil fraction
Tell college students that cracking processes break down heavy hydrocarbons (you may want to use the term large hydrocarbon molecules) into lighter products (smaller hydrocarbon molecules). Different types of cracking processes are used. Focus on catalytic cracking, telling college students that this course of makes use of excessive heat and a catalyst to break larger molecules into smaller, extra useful ones. Draw the following response to point out college students how catalytic cracking works:
C22H46 + heat + catalyst → C12H26 + C6H12 + C4H8
The catalyst used is usually silica or alumina. In the above response, docosane is transformed to dodecane, cyclohexane, and butene. The smaller hexane and butene may be mixed with other smaller compounds to make gasoline stock. The larger dodecane is a element of diesel inventory, which can be used to fuel ships and factories.
Describe an example of the third process (Reshaping or constructing hydrocarbons from smaller ones) by clicking the purple circle next to “gentle naphtha” on the treatment page of the interactive. Doing so will present two treatment processes: hydrotreating and isomerization. Ask us oil refineries students:
– Are the hydrocarbons in light naphtha massive or small comparatively
Inform college students that light naphtha is a mixture of mostly pentane and hexane. Have students draw the chemical structures of pentane and hexane. If attainable, present fashions of each construction. Ask college students:
– What’s an isomer
Write the next response on the board:
C5H12 → C5H12
Tell students that this is the reaction for pentane to isopentane. Ask students to attract the chemical structure of isopentane. Utilizing the mannequin for pentane, take away the fifth carbon from the chain and transfer it to the second carbon. This new construction is isopentane (also known as methylbutane or 2-methylbutane), which has the same chemical formula as straight-chained pentane. Inform students that this isomerization is vital within the petroleum therapy process as a result of isomers improve the standard of gasoline versus the straight-chained molecules. In truth, isomers enhance the octane ranking for gasoline.
Have students work in groups to decide on considered one of the end products of the crude oil distillation and treatment course of: diesel, kerosene, gasoline, jet fuel, or asphalt. Ask every group to develop a presentation that discusses how their final product is formed. As they’re doing this exercise, they should make sure to classify each step as a physical or chemical change. Their data ought to draw upon all points of the interactive, together with the film. Their shows ought to start with the tiny sea plants residing millions of years in the past and transfer by means of the process of forming kerogen, and in the end petroleum. Remind students to include drilling before transferring into the distillation and treatment process. College students should embody a move chart of their displays. Encourage students to make use of different strategies of displaying their information. For example, students may select to present a storyboard, comic guide, PowerPoint, essay, or a brief movie. Assess students primarily based on their holistic understanding of how useful gasoline oils are made from crude oil by way of a collection of important chemical processes.
Have students discover what octane scores for gasoline signify in regards to the product. There are various misconceptions that students may have. After a lesson, encourage college students to survey their mother and father, teachers, and other drivers about what they learn about octane rankings of gasoline. You and your students can overview Discovering the Science of Petrol to be taught more about octane.