Fuel Types and Uses

This section provides an in-depth look at various fuel types, their formation processes, and their uses in energy production.

Subsistence Fuels: • Found or gathered by hand, commonly used in developing countries • Examples: Wood and charcoal

Highlight: Wood is free or cheap but causes deforestation and habitat loss. Charcoal is made by heating wood under low oxygen conditions.

Coal Formation and Types: • Peat: Partially decomposed organic matter found in bogs and moors • Coal types (in order of increasing energy density): Lignite → Bituminous → Anthracite

Vocabulary: Lignite - A soft, brown coal that is an early stage in coal formation.

Natural Gas: • Formed from decaying remains buried under layers of rock • Mostly composed of methane (CH4) • Considered the "cleanest" fossil fuel, producing fewer air pollutants and CO2 when burned

Crude Oil (Petroleum): • Formed from decaying organic matter trapped under rocks • Extracted by drilling wells through overlying rock layers • Can be recovered from tar sands (mixture of clay, sand, water, and bitumen)

Definition: Bitumen is a thick, sticky semi-solid form of petroleum found in tar sands.

Fossil Fuel Products: • Crude oil is converted to different products through fractional distillation • Products range from lighter (e.g., petroleum gas) to heavier (e.g., bitumen for asphalt)

Renewable vs Nonrenewable Energy Sources

This section introduces the fundamental concepts of renewable and nonrenewable energy sources, providing clear definitions and examples of each.

Definition: Renewable energy sources can be replenished naturally at or near the rate of consumption, while nonrenewable sources exist in fixed amounts on Earth and cannot be replaced within human timescales.

Renewable Energy Sources: • Depleted renewables: Can run out if overused (e.g., biomass like wood, charcoal, and ethanol) • Nondepletable renewables: Do not run out (e.g., solar, wind, hydroelectric, and geothermal)

Nonrenewable Energy Sources: • Fossil fuels: Formed from fossilized remains of ancient biomass over millions of years (e.g., coal, oil, and natural gas) • Nuclear energy: Generated from uranium or other radioactive fuels

Highlight: The key difference between renewable and nonrenewable resources lies in their rate of regeneration compared to their rate of use. Renewable resources must be used at or below their rate of regeneration to remain sustainable.

Example: Fossil fuels will eventually run out because they take far longer to regenerate than the rate at which we use them.