In-Depth Notes from PHYS 1149 Environmental Physics Midterm Review

Chapter 5: Fossil Energy

• Fossil Fuels Overview
  • Fossil fuels account for over 80% of the world's primary energy.
  • Three types of conventional fossil fuels: coal, oil, and natural gas.
• Formation of Fossil Fuels
  • Origin: Photosynthesis by plants (and plankton in oceans) captures sunlight energy, which eventually becomes fossil fuels.
  • Formation process stages:
  1. Dead organic matter escapes decay.
  2. Sedimentation.
  3. Geothermal chemical processing.
• Coal Formation
  • Mainly formed during the Carboniferous period (360-300 million years ago).
  • Various forms include peat (precursor), lignite (low quality), bituminous, and anthracite (high quality).
  • Primarily composed of carbon, but also includes impurities like sulfur, mercury, and uranium.
• Oil and Natural Gas Formation
  • Formed mainly during the Permian (250 million years ago), Jurassic (180-140 million years ago), and Cretaceous (140-65 million years ago) periods.
  • Kerogen is a precursor to oil, and hydrocarbons form during fractional distillation.
  • Geological structures called anticlines trap oil and natural gas by allowing migration through porous rock.
• Refining and By-Products
  • The refining process uses fractional distillation to separate crude oil into various products such as gasoline.
  • Combustion of fossil fuels produces carbon dioxide and other pollutant gases.
  • Carbon dioxide is a greenhouse gas and contributes to climate change.
• Energy Efficiency in Fossil Fuels
  • Gasoline engines are inefficient, often delivering only around 15% of fuel energy to the wheels.
  • Hybrid engines improve efficiency through systems such as regenerative braking, which converts kinetic energy back into electrical energy.

Chapter 6: Environmental Impacts of Fossil Fuels

• Air Pollution
  • Major pollutants include particulate matter, sulfur oxides, nitrogen oxides, carbon monoxide, and heavy metals (e.g., mercury).
  • Acid rain formed from sulfur dioxide (SO2) and nitrogen oxides (NOx) contributes to environmental degradation.
• Pollutants vs. Greenhouse Gases
  • Pollutants are toxic by-products of combustion.
  • Greenhouse gases, such as carbon dioxide, are essential in the atmosphere but also contribute to climate change.
• Particulate Matter
  • Significant sources of particulate matter include fuel combustion.
  • Various control techniques such as filters, cyclones, and electrostatic precipitators are used to reduce emissions.
• Clean Air Act
  • Established to regulate air quality.
  • Identifies six criteria pollutants including CO, lead, NOx, particulates, ozone, and sulfur oxides.

Chapter 7: Nuclear Energy

• Primary Energy Contribution
  • Nuclear energy contributes about 4% of the world’s primary energy and about 11% of electricity generation.
• Nuclear Fission vs. Fusion
  • Fission: Splitting a heavy nucleus into lighter nuclei releases energy (e.g., occurs in nuclear reactors).
  • Fusion: Combining lighter nuclei into heavier ones releases energy (occurs in stars like the sun).
• Nuclear Reactor Components
  • Control rods: Absorb neutrons, controlling the chain reaction.
  • Moderators: Slow down neutrons to sustain reactions.
  • Coolants: Remove heat from reactions, essential for safe reactor operation.
• Environmental Considerations
  • Fusion yields clean energy, primarily emitting helium as a by-product.
  • Potential for nuclear energy to provide a large-scale energy source with minimal environmental impacts if properly managed.

Resource Management and Technology

• Resource vs. Reserve
  • Resources: Total amount of fossil fuel underground, both discovered and undiscovered.
  • Reserves: Known amounts that can be economically recovered.
• Hydraulic Fracturing (Fracking)
  • Technique that enhances oil and gas recovery by injecting fluid into the ground to fracture rock formations.
• Future Outlook
  • Ongoing debates about fossil fuel reliance vs. renewable resources and technological influences on energy production.