Energy Sources and Hydrocarbons

Study Notes

Hydrocarbons are energy sources found in Earth’s crust, derived from ancient plants and animals millions of years ago.
Main types of hydrocarbons include Natural Gas, Oil, and Coal.

Crude oil and natural gas originate from phytoplankton and zooplankton.
When these microorganisms die, they sink to the ocean floor, creating organic-rich sediment piles.
Optimal conditions for hydrocarbon formation include high primary production, stagnant and stratified water columns, lack of decomposers, and low oxygen levels (anoxic conditions).

Organic sediments undergo burial by additional layers over time.
Increasing heat and pressure transform organic material into petroleum.
The type and quantity of hydrocarbons produced are influenced by temperature and burial depth.

Oil and gas migrate upwards from source rocks into reservoir rocks, typically capped by impermeable seals.
Extraction can involve drilling into trapped deposits or using hydraulic fracking to access natural gas.

Crude oil is refined via fractional distillation into various fuels such as kerosene, petrol, and diesel.
Oil extraction is relatively inexpensive, providing energy and income for local communities, notably in places like Aberdeen, Scotland.
Natural gas can be transformed into a liquid state for easier transportation.

Burning oil and gas emits carbon dioxide, contributing to atmospheric pollution.
Oil spills, such as the 2010 BP Mexico spill, result in significant environmental damage to marine ecosystems.

Most coal on Earth formed during the Carboniferous period (360 – 299 million years ago) in tropical, swampy conditions.
Coal is created from layers of compressed plant material over time; deeper burial and higher temperatures increase coal efficiency.
Coal is abundant and inexpensive, but its combustion releases carbon dioxide, sulfur dioxide, and nitrogen dioxide, contributing to global warming and acid rain.

Coal mining poses environmental risks and hazards to workers, including toxic dust, cave-ins, and explosions.

Uranium and plutonium serve as nuclear fuels, relying on fission reactions.
Nuclear power is efficient and does not emit greenhouse gases but generates dangerous radioactive waste requiring secure long-term storage.
Nuclear power plants face risks of meltdowns, exemplified by the Fukushima Daiichi incident in 2011.

Oil spills lead to ocean and land contamination, impacting marine life and ecosystems.
Air pollution arises from volatile organic compounds (VOCs) and greenhouse gas emissions.
Land degradation and water pollution occur from drilling and pipeline operations, affecting freshwater sources.
Oil extraction contributes significantly to climate change through carbon emissions.

Fugitive methane emissions during extraction and transport are potent greenhouse gases.
Air quality can deteriorate due to emissions near extraction sites, leading to health issues.
Hydraulic fracking raises concerns regarding water use and potential groundwater contamination.
Natural gas, while cleaner than coal, still contributes to global warming.

Significant emissions from coal-burning, including sulfur dioxide (SO2) and nitrogen oxides (NOx), affect public health.
Mining, especially surface techniques like mountaintop removal, leads to extensive land disturbance.
Coal ash and runoff from mining operations can contaminate nearby water resources.
Among fossil fuels, coal is one of the highest contributors of greenhouse gas emissions, also causing biodiversity loss through habitat destruction.