Energy Sources and Fuels Overview

Introduction

• Energy is crucial for all aspects of life, including bodily functions, technological advancements, and production.
• Energy sources and consumption are frequently discussed due to their importance, supply, cost, and environmental impact.
• This chapter covers energy consumption, characteristics, transformation, and storage.

Energy Consumption

• Maintaining bodily functions (heart, lungs, digestion) consumes energy at a rate of approximately 100 J/s (100 W).
• Physical activities, like climbing stairs, also require energy expenditure.
• Average daily energy consumption is around 125W, equating to approximately 10 megajoules (MJ).
• Energy comes from the chemical energy in food.
• Daily energy consumption per person in the UK is about 450 MJ (125 kWh).

Annual Global Energy Consumption

• Annual global energy consumption has increased significantly since 1840.
• Technological advancements, population growth, and economic development contributed to this increase.
• The early development of the steam engine unlocked fossil fuels, leading to an increase in energy consumption.

Energy Sources

• Most energy, directly or indirectly, originates from the Sun.
• Solar energy drives photosynthesis, and fuels like fossil fuels (coal, oil, natural gas) are decayed organic matter.
• Hydropower, wind power, and wave power are indirectly solar-driven.
• Geothermal energy comes from the Earth's internal heat.
• Nuclear energy comes from nuclear fusion in the Sun, or nuclear fission in reactors.

Energy Sources Summary

• Fossil fuels: Coal, Oil, Natural gas
• Hydropower and Ocean Energy
• Nuclear Energy
• Solar Energy
• Wind Energy
• Transportation Energy

Energy Sources

• Most energy comes directly or indirectly from the sun.
• Sunlight delivers enormous solar power.
• Photosynthesis converts sunlight into organic compounds.
• Fossil fuels are fossilized plant and animal matter.
• Renewable energy sources include hydroelectric power, wind and wave power, bioenergy (wood, etc.), and geothermal energy.
• Nuclear energy utilizes nuclear reactions (fission or fusion).

Fuel

• Fuel is a substance that produces heat when reacted with oxygen.
• Common combustible elements include carbon, hydrogen, and sulfur.
• Fuel transformation (solid, liquid, gas) is needed for efficient use.

Fuel Classification

• Fuels can be categorized based on their physical state (solid, liquid, gaseous) or origin (natural, manufactured).

Renewable and Non-Renewable Energy Sources

• Renewable energy sources come from natural, continuous flows of energy (e.g., solar, wind, geothermal).
• Non-renewable energy sources are finite resources (e.g., fossil fuels, nuclear fission).
• Renewables are more compatible with sustainable development.

Solid Fuels

• Solid fuels include natural sources (wood, coal) and manufactured ones (charcoal, coke).
• Advantages include ease of transport, relatively low cost of production and moderate ignition temperature.
• Disadvantages include high ash content, significant heat loss, and potential for clinker formation.

Liquid Fuels

• Liquid fuels include petroleum and other derivatives (e.g., kerosene).
• Advantages include higher calorific value compared to solids, ease of transport, and clean combustion characteristics.
• Disadvantages include higher cost, potential risks during handling and use.

Gaseous Fuels

• Gaseous fuels (e.g., natural gas) are convenient for various applications and use due to transportation flexibility.
• Advantages include ease of transport, clean combustion, and controlled combustion.
• Disadvantages include the need for large storage tanks and higher risk of fire.

Energy Conversion

• Sources are categorized into thermal, mechanical, and photovoltaic.
• Energy conversion is the change from one form of energy into another, often for practical use.

Liquid Fuels (Petroleum)

• Petroleum is a mixture of hydrocarbons. It is extracted from sedimentary rocks.
• It's a major energy source due to its high energy content and ease of use.
• Different theories explain the origin of petroleum, one being biogenic, where plants and animals decompose over time.

Coal and Characteristics

• Coal is a combustible sedimentary rock.
• Proximate and ultimate analysis of coal determine its composition.
• Proximate analysis assesses moisture, volatile matter, ash, and fixed carbon content
• Ultimate analysis gives a detailed breakdown of the chemical elements (carbon, hydrogen, etc.) in the coal.

Heating Value of Gaseous Fuels

• Heating value calculation methods exist for more accurate determination of the calorific value from gas.
• Common gases have specific heating values.