Combustion Reactions Reference Page

Author

DOFPro group

  • Video links go directly to the YouTube video.
  • JTF (Just the Facts) videos are the streamlined versions: greenscreen LaTeX equations, clean graphics, minimal narrative. Think efficient and to the point. Each has a companion TFS video.
  • TFS (The Full Story) videos include interviews, additional explanation, and equations written on whiteboards. Same math, more context, more personality. Each has a matching JTF version.
  • Info Page links lead to definitions, expanded explanations, and related material—because sometimes you really do need to explain it.
  • Visuals links contain the greenscreen or whiteboard materials used in the video, for those who like to see the scaffolding.
  • Wondering about the titles? See Appendix B: If you have to explain it, it’s no longer funny.
  • Videos marked This is NOT a DOFPro video were not produced by DOFPro but are included because they are relevant to the topic. They are shown in red so no one calls the academic integrity police.

Intro to Combustion Reactions

Combustion reactions are among the most common reactions encountered in engineering practice. They are used in power generation, engines, furnaces, and many industrial processes.

Combustion calculations combine stoichiometry, material balances, and gas composition analysis to determine quantities such as required air, excess air, and stack gas composition. The videos on this page introduce combustion reactions and demonstrate how to analyze them.

Flame On, Torch!

This video introduces the basics of combustion reactions and shows how to write balanced combustion equations and determine the theoretical air required for complete combustion.

Visuals

A Combustible Mixture!

This video works through a complete combustion calculation, including determining stack gas composition and interpreting combustion data.

Visuals

Examples and Definitions

Definitions

Combustion Reaction
A reaction in which a fuel reacts with oxygen to produce heat and reaction products. For hydrocarbon fuels the main products are typically carbon dioxide and water.
Stack or Flue Gas
The gaseous products leaving a combustion process. These typically include carbon dioxide, water vapor, nitrogen, oxygen, and sometimes carbon monoxide or other pollutants.
Incomplete Combustion
Combustion in which the fuel is not fully oxidized, producing carbon monoxide, unburned hydrocarbons, or soot in addition to carbon dioxide and water.
Complete Combustion
Combustion in which the fuel is fully oxidized, producing carbon dioxide and water for hydrocarbon fuels.
Fuel
A substance that releases energy when oxidized. Fuels may be solid (coal), liquid (gasoline), or gaseous (natural gas, hydrogen).
Fuel–Air Ratio
The ratio of fuel to air supplied to a combustion process. It may be expressed as a mass ratio or molar ratio.
Dry Basis
A way of reporting gas composition excluding water vapor. Dry-basis compositions are often used when analyzing stack gas measurements.
Wet Basis
A way of reporting gas composition including water vapor.
Orsat Analysis
A classical method for determining the composition of stack gases by absorbing components such as CO₂, O₂, and CO in chemical solutions. Modern methods typically use gas chromatography or infrared analyzers.
Theoretical Air
The exact amount of air required for complete combustion of a given fuel based on stoichiometry.
Excess Air
Air supplied beyond the theoretical requirement. Excess air helps ensure complete combustion but can reduce efficiency.
Burning Lean
A combustion condition in which more air than the stoichiometric amount is present.
Burning Rich
A combustion condition in which less air than the stoichiometric amount is present.