(16998) Combustion & Incomplete Combustion | Environmental Chemistry | FuseSchool

Combustion Overview

• Combustion is the process of burning, typically in the presence of air (oxygen).

• It is an exothermic reaction, meaning it releases heat.

• Fuels store potential energy that gets released as heat when burned.

• Example of a fuel: Natural gas (Methane) used for heating food.

Types of Combustion

Complete Combustion

• Occurs with a plentiful supply of air.

• Products: Carbon dioxide (CO2) and water (H2O).

• Chemical equation:

  • CH4 (gas) + 2 O2 (gas) → CO2 (gas) + 2 H2O (gas)

Incomplete Combustion

• Occurs with a limited supply of air.

• Can produce:

  • Carbon monoxide (CO) and water (H2O) or

  • Carbon (C) and water (H2O).

• Chemical equations:

  • 2 CH4 (gas) + 3 O2 (gas) → 2 CO (gas) + 4 H2O (gas)

  • CH4 (gas) + O2 (gas) → C (solid) + 2 H2O (gas)

Effects of Combustion Products

• Water vapor: Harmless byproduct.

• Carbon dioxide (CO2): Greenhouse gas that contributes to global warming.

• Carbon monoxide (CO):

  • Toxic and dangerous, referred to as the silent killer (colorless, odorless, tasteless).

  • Often produced by faulty gas appliances; regular servicing of gas appliances is essential.

• Unburnt carbon: A particulate matter that acts as an air pollutant.

Recap

• Combustion is the burning process in air or oxygen.

• Complete combustion of hydrocarbons results in carbon dioxide and water.

• Incomplete combustion results in dangerous products such as carbon monoxide or unburnt carbon, which have significant health and environmental impacts.