Introduction to Energy Systems: Fuels & Combustion

Introduction to Energy Systems - Fuels and Combustion

• This course, MECE3260U, is an introduction to energy systems, focusing on fuels and combustion.
• The professor is Dr. Ibrahim Dincer, a professor of Mechanical Engineering at OntarioTech University.

Fuels and Combustion - Outline

• Historical Perspectives
• Impacts of Fossil Fuels
  • Coal
  • Crude oil
  • Natural Gas
• Fuels Combustion
• Thermodynamic Analysis
• Closing Points

Fossil Fuel Era

• Fossil fuels are a significant source of energy.
• The use of fossil fuels began significantly with the Industrial Revolution.
• A graph displays the global primary energy consumption through the years.
• Different fuels like coal, oil, and natural gas have seen different adoption rates over time.
• The consumption rate of fossil fuels increased rapidly from the 1800s to the 1900s.

Historical Perspective on Fossil Fuels

• Fossil fuels formed hundreds of millions of years ago, during the Carboniferous Period (360-286 million years ago).
• Fossil fuel usage started with the Industrial Revolution (1760-1840).

Challenges with Fossil Fuels

• Global CO2 emissions by world region are shown in a graph.
• Emissions have significantly increased since the mid-1800s.
• Various regions like China, India, and the United States show high emission rates, particularly in the past few decades

Heating Values

• Higher Heating Value (HHV) or Gross Calorific Value (GCV) is measured by bringing combustion products to the pre-combustion temperature.
• Lower Heating Value (LHV) or Net Calorific Value (NCV) subtracts the heat of vaporization of water in the products.
• The given values in the table of MJ/kg show higher and lower heating values for different fuels.

How Coal Was Formed

• Coal formed from dead plants buried underground millions of years ago and subjected to heat and pressure.
• Coal varies in quality and heating value (ranks), ranging from lignite to anthracite.
• Coal is primarily used for electricity generation and industrial processes, such as iron and steel production.

Crude Oil

• Crude oil is a complex mixture of hydrocarbons.
• Different fractions of hydrocarbons are separated via distillation at various boiling points in refineries.
• A table presents the quantities of different fractions in a barrel of crude oil.

Natural Gas

• Natural gas primarily consists of methane (CH4), but also contains other hydrocarbons, gases, and impurities.
• Sources include sedimentary rocks (wet or dry, associated/non-associated).
• Natural gas composition variation varies by deposit type.

Fuels and Combustion - Introduction

• Combustion is a chemical reaction releasing a large amount of energy.
• Dry air (79% N2, 21% O2) is commonly used for oxidation.
• Combustion reactions are often illustrated depicting reactants and products. The mass balance is not conserved for the number of moles during a combustion reaction.
• Fuels are materials that release thermal energy when burned.
• Hydrocarbon fuels (mostly hydrogen and carbon) are common.

Theoretical and Actual Combustion Processes

• Complete combustion consumes all fuel and components.
• Incomplete combustion produces unburned fuel or materials such as carbon (C), hydrogen (H2), carbon monoxide (CO), or hydroxyl (OH).
• Stoichiometric air is the minimum needed to burn fuel completely.
• Theoretical air involves complete combustion with stoichiometric air.
• Methane (CH4) is used as an example to show the complete combustion equation.

Excess and Deficiency of Air

• Excess air represents the amount greater than stoichiometric for a reaction.
• Deficiency of air is an amount less than stoichiometric air.
• These values are often expressed as percentages of the ideal (stoichiometric) amount.

Enthalpy of Formation and Enthalpy of Combustion

• The change in enthalpy during a chemical reaction is dependent on the energy state of the system.
• Important properties include higher heating values (HHV) and lower heating values (LHV).

Thermodynamic Analysis of Combustion

• The equations introduced here are essential for a detailed thermodynamic analysis of a combustion chamber.
• The analysis focuses on heat and work transfer, and mass within the system.

Adiabatic Flame Temperature

• Temperature of products at maximum in a closed system without heat loss.
• Maximum temperatures in combustion devices are typically lower than the adiabatic value due to incomplete combustion, heat loss and dissociation of combustion gases at high temperatures.

Summary of Fuel Combustion Analysis

• A summary of different combustion analysis methods (open, closed and adiabatic systems) is provided.
• The relationships between energy, enthalpy, entropy, and exergy during different systems of combustion.

Explore the fundamentals of energy systems, focusing specifically on fuels and combustion in this quiz. Learn about the historical perspectives of fossil fuels, their impacts, and thermodynamic analysis. Perfect for those studying energy engineering or related fields.