From Crude Oil to Plastics
In this topic you will:
- Explain how fossil fuels are formed and their role in modern energy
- Describe the environmental impacts of burning fossil fuels
- Understand how crude oil is processed and used in everyday life
- Interpret data about oil discovery and consumption trends
- Explore the process of fractional distillation and polymer formation
- Evaluate the challenges of plastic pollution and carbon emissions
Key Words
- fossil fuels
- crude oil
- carbon dioxide
- polymer
- distillation
- hydrocarbon
- ethene
Fossil Fuels and Climate Impact
Fossil fuels such as coal, crude oil, and natural gas are formed over millions of years through very slow geological processes. These fuels are rich in carbon, and when burned, they release large amounts of carbon dioxide ($\text{CO}_2$) into the atmosphere. One major consequence is the increased concentration of carbon dioxide in the air, which contributes to global warming. As Earth's temperature rises, polar ice caps begin to melt, leading to noticeable changes in seasonal patterns.
Crude Oil and Modern Life
Crude oil is a thick, dark liquid. At first, humans were fascinated by this substance, but over time, they learned to use it in increasingly widespread ways. As people harnessed its power, it became central to modern life, transforming transport, industry, agriculture, and medicine. Cars, airplanes, and energy production all came to rely on oil, while other industries like food, health, and farming also benefited from its applications. This led to improved global health, population growth, and technological advancement.
🧪 Did you know?
It is predicted that if current carbon dioxide production continues unchecked, by the year 2050, nearly one-third of all animal species will become extinct. To prevent this crisis, many countries have signed international agreements to limit their CO₂ emissions.
Oil Consumption and Efficiency
Research shows that on average, about 90% of global oil use goes toward fuel and energy supply — in sectors like residential heating, transportation, and electricity generation. Only about 10% is used for creating refined, non-fuel products such as plastics, medicines, or synthetic materials.
🧪 Did you know?
Russian chemist Mendeleev warned in the late 19th century that burning oil for energy was like using banknotes to keep a stove lit — wasteful and shortsighted.
📊 Oil Discovery vs. Consumption
Access to crude oil has expanded to meet the growing global demand for energy, especially as the human population rises. However, data shows that oil discovery peaked decades ago, while consumption has continued to climb. This trend suggests an eventual shortfall if alternative resources are not developed.
🧪 Did you know?
Global daily crude oil consumption exceeded 100 million barrels for the first time in 2018. Each barrel holds about 159 liters of oil.
❓ QUESTIONS
1. According to the graph, during which decade was crude oil discovery at its peak?
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2. In which decade are crude oil reserves predicted to reach a minimum?
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3. In which year did oil consumption equal the amount of oil being discovered?
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4. In which year did oil consumption exceed discovery?
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🛢️ Hydrocarbons in Crude Oil
Crude oil is a mixture of substances known as hydrocarbons. These compounds are made from only two elements: carbon and hydrogen. The simplest hydrocarbon is methane, which has the chemical formula CH₄. As the number of carbon atoms increases in a hydrocarbon molecule, the size of the molecule and its boiling point also increase. Hydrocarbons can vary from gases like methane to thick, sticky liquids and even solids.
| Hydrocarbon Name | Molecular Formula | Boiling Point (°C) |
|---|---|---|
| Methane | CH₄ | –168 |
| Butane | C₄H₁₀ | –0.5 |
| Octane | C₈H₁₈ | 125 |
| Eicosane | C₂₀H₄₂ | 343 |
❓QUESTIONS
1. What is the relationship between boiling point and the number of carbon atoms in hydrocarbons?
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2. Which compound has the higher boiling point: C12H26 or C8H18? Why?
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🌡️ Boiling Point and Intermolecular Forces
The boiling point of a substance is one of its physical properties and depends on the strength of intermolecular forces. The stronger the forces between particles in a liquid, the higher its boiling point. In hydrocarbons, as the number of carbon atoms increases, the intermolecular forces between the molecules also increase, resulting in a higher boiling point.
❓ QUESTIONS
1. Based on the image, which hydrocarbon flows more easily? Why?
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2. Match each formula with the hydrocarbon shown in the image, based on viscosity.
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- Sample (2): C17H36
- Sample (3): C20H42
- Sample (4): C24H50
💧 Simple Distillation of Hydrocarbons
A simple distillation setup can be used to separate a mixture of two hydrocarbon liquids based on their boiling points. The liquid with the lower boiling point evaporates first and its vapor passes through a condenser, where it cools and turns back into a liquid, separating it from the mixture. This method works best when the boiling point difference between the two liquids is large.
🏭 Fractional Distillation in Refineries
In oil refineries, crude oil is separated into different components using a process called fractional distillation. Crude oil is heated until it vaporizes, and the vapors enter a tall column called a fractionating tower. The tower is cooler at the top and hotter at the bottom. As the vapor rises, it condenses at different levels depending on its boiling point, allowing hydrocarbons with similar boiling points to be collected together. These collections are known as fractions and are the basis for many useful products such as fuels and raw materials for manufacturing.
🍌 Petroleum as a Resource for Making Products
About 150 years ago, people relied entirely on natural materials like wood, stone, and metal. Even fibers came from natural sources like cotton and wool. But today, thanks to our understanding of crude oil and its components, scientists have developed many new materials and products. One example is ethene (C₂H₄), a colorless gas derived from crude oil that is used in industry and also occurs naturally in fruits like tomatoes and bananas, helping them ripen.
Future of Oil Supply
Scientists and engineers are actively researching ways to address the global energy challenge. As conventional oil reserves decline, there is increasing pressure to identify alternative energy sources and more efficient extraction methods. Sustainability and environmental impact are also central concerns in future energy planning.
Oil Products in Daily Life
Petroleum by-products are used in a wide range of everyday materials and objects. These include synthetic fibers for clothing, plastics, rubber, detergents, and even fertilizers. Many consumer goods rely on refined oil compounds, linking modern lifestyles to fossil fuel use even beyond fuel consumption.
Energy Use and Modern Industry
The industrial revolution marked a turning point where coal and later oil allowed machines to replace human and animal power. This increased productivity and efficiency in manufacturing, agriculture, and transportation. The dependence on fossil fuels became deeply embedded in industrial economies.
Climate Change and the Energy Crisis
As countries seek to reduce emissions and combat climate change, the transition from fossil fuels to renewable energy sources becomes more urgent. Global agreements and national policies are increasingly aimed at limiting carbon output, investing in clean energy, and improving energy efficiency.
The Search for Balance
Balancing human progress with environmental responsibility is one of the great challenges of our time. Reducing reliance on fossil fuels while ensuring access to reliable, affordable energy for all remains a key goal for scientists, governments, and future generations.
Making New Products from Ethene
Experiments show that ethene can be used to make new products. For example, if we place a sample of ethene gas in a container and heat it, it undergoes a chemical transformation and forms a synthetic material called plastic. The image shows different types of plastic products (such as synthetic fibers), all made from this basic raw material separated from crude oil.
How Polymers Are Formed
Polyethene is a product that results from a chemical transformation of ethene. During this process, small molecules (monomers) bond together to form long chains called polymers. These polymers consist of many repeating units. The visual below helps illustrate this concept by showing how simple rings link to form a long chain structure.
Ethene Polymerization and Its Impact
As shown in the diagram, placing many ethene units next to each other forms a long chain with repeated structural units. In this polymerization process, the double bonds between carbon atoms are broken, allowing new single bonds to form between the molecules. The resulting long polymer is called polyethene, a widely used synthetic plastic. This chemical transformation is called polymerization and can be represented using structural formulas.
Oil’s Environmental and Industrial Impact
Crude oil is one of the most widely used chemical substances in industry. It provides a large volume of fuel and raw materials for factories and energy plants. Burning oil and fossil fuels generates a significant volume of carbon dioxide, contributing to air pollution and global warming. The chemical reaction of fuel combustion releases both water and carbon dioxide.
Combustion of methane gas: CH₄ + O₂ → H₂O + CO₂
Tackling Carbon Emissions
The rise in carbon dioxide levels contributes to problems such as global warming, melting ice caps, and shifting weather patterns. Reducing carbon emissions has become a key challenge for modern society. We must take steps to limit the combustion of fossil fuels and switch to cleaner forms of energy. Understanding how carbon dioxide is produced helps us design strategies to control emissions.
Durable Plastics and the Environment
Plastics made from oil are inexpensive, long-lasting, and highly durable. These characteristics make them useful for many products, but also lead to environmental problems. Most everyday objects are made from or contain plastic components. However, plastic waste remains in nature for a long time and does not degrade easily, raising concerns about pollution and sustainability.