Fuels And Earth Science Flashcards
(20 cards)
What are hydrocarbons?
Hydrocarbons are compounds made up of hydrogen and carbon atoms only. They are the primary components of crude oil and natural gas.
What is crude oil and how is it formed?
Crude oil is a finite resource formed from the remains of ancient marine organisms buried under layers of sediment and subjected to heat and pressure over millions of years.
How is crude oil separated into fractions?
Crude oil is separated by fractional distillation, where it’s heated, and its components are separated based on their boiling points.
What are the main fractions obtained from crude oil and their uses?
• Refinery gases: Used for bottled gas.
• Gasoline (petrol): Fuel for cars.
• Kerosene: Fuel for aircraft.
• Diesel oil: Fuel for cars and lorries.
• Fuel oil: Fuel for ships and power stations.
• Bitumen: Used for road surfacing.
What is the trend in boiling points and viscosity in fractions?
As the size of hydrocarbon molecules increases:
• Boiling points increase.
• Viscosity increases.
• Flammability decreases.
What is complete combustion of hydrocarbons?
Complete combustion occurs when hydrocarbons burn in excess oxygen, producing carbon dioxide and water, and releasing energy.
What is incomplete combustion and its dangers?
Incomplete combustion happens when there isn’t enough oxygen, producing carbon monoxide (a toxic gas) and water. It can also produce soot (carbon particles), which can cause respiratory problems.
What pollutants are produced from burning hydrocarbons and their environmental impacts?
• Carbon monoxide: Toxic gas that reduces oxygen transport in the blood.
• Nitrogen oxides: Contribute to acid rain and respiratory problems.
• Sulfur dioxide: Causes acid rain, harming ecosystems.
• Particulates: Cause global dimming and respiratory issues.
• Carbon dioxide: Greenhouse gas contributing to global warming.
How can sulfur be removed from fuels?
Sulfur can be removed by desulfurization processes, such as hydrodesulfurization, where sulfur compounds are converted to hydrogen sulfide and then removed.
What are biofuels and their advantages?
Biofuels are renewable fuels derived from biological materials like plants. Advantages include:
• Renewable source.
• Can reduce greenhouse gas emissions.
• Biodegradable and less toxic.
What are the disadvantages of biofuels?
• Can compete with food production for land.
• May not be carbon-neutral due to production processes.
• Deforestation for biofuel crops can harm biodiversity.
What are the stages of the Earth’s atmosphere evolution?
- Volcanic activity released gases like CO₂, water vapor, and nitrogen.
- Cooling led to condensation of water vapor, forming oceans.
- Photosynthetic organisms evolved, producing oxygen.
- Oxygen levels increased, allowing for the evolution of animals.
How has human activity affected the Earth’s atmosphere?
Human activities like burning fossil fuels and deforestation have increased greenhouse gas concentrations, leading to global warming and climate change.
What is the greenhouse effect?
The greenhouse effect is the process where greenhouse gases trap heat in the Earth’s atmosphere, keeping the planet warm enough to sustain life.
What are the main greenhouse gases?
Carbon dioxide (CO₂), methane (CH₄), and water vapor (H₂O).
How can individuals reduce their carbon footprint?
• Using energy-efficient appliances.
• Reducing car travel and using public transport.
• Recycling and reducing waste.
• Using renewable energy sources.
What are the challenges in reducing carbon emissions?
• Economic costs of transitioning to renewable energy.
• Political and social resistance.
• Technological limitations.
• Need for international cooperation.
What is carbon capture and storage (CCS)?
CCS is a technology that captures carbon dioxide emissions from sources like power plants and stores it underground to prevent it from entering the atmosphere.
How does acid rain form and what are its effects?
Acid rain forms when sulfur dioxide and nitrogen oxides react with water in the atmosphere to form acids. Effects include:
• Damage to aquatic ecosystems.
• Harm to vegetation and forests.
• Corrosion of buildings and monuments.
What are alternative fuels and their benefits?
• Hydrogen: Produces only water when burned; renewable.
• Electricity: Can be generated from renewable sources; reduces emissions.
• Biofuels: Renewable and can reduce dependence on fossil fuels.
