Petroleum Products
Petroleum products, such as gasoline, kerosene, home heating oil, residual fuel oil and lubricating oil come from one source – crude oil found below the earth’s surface, as well as under large bodies of water, from a few hundred feet below the surface to as deep as 25,000 feet into the earth’s interior. Sometimes crude oil is secured by drilling a hole through the earth, but more dry holes are drilled than those producing oil. Pressure at the source or pumping forces crude oil to the surface.
Crude oil wells flow at varying rates, from ten to thousands of barrels per hour. Petroleum products vary greatly in physical appearance: thin, thick, transparent, or opaque. Their chemical composition is made up of only two elements: carbon and hydrogen, which form compounds called hydrocarbons. Other chemical elements found in union with the hydrocarbons are few and are classified as impurities. Trace elements are also found, but these are of such minute quantities that they are disregarded. The combination of carbon and hydrogen forms many thousands of compounds which are possible because of the various positions and varied joining of these two atoms in the hydrocarbon molecule.
The various petroleum products are refined from the crude oil by heating and condensing the vapours. These products are the so-called light oils, such as gasoline, kerosene and distillate oil. The residue remaining after the light oils are distilled is known as heavy or residual fuel oil and is used mostly for burning under boilers. Additional complicated refining processes rearrange the chemical structure of the hydrocarbons to produce other products, some of which are used to upgrade and increase the octane rating of various types of gasoline.
Adapted from: Cliff TOEFL Preparation Guide
Answer these questions based on the text above.
1. Where do petroleum products come from?
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2. Where can we find crude oil?
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3. How can crude oil brought up to the surface?
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4. What are the main elements of crude oil?
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5. What is the compound produced from the union of the main elements of crude oil?
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6. How can various petroleum products be produced from the crude oil in refinery?
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7. Mention the petroleum products stated in the text!
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8. What is the residual fuel oil mostly for?
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