What Is the Heat of Combustion?
The heat of combustion refers to the amount of heat that is released when a substance performs a complete combustion reaction with oxygen. It is generally measured by the amount of unit substance, unit mass, or energy emitted when the fuel is burned. The combustion reaction is usually a reaction in which hydrocarbons burn in oxygen to generate carbon dioxide, water, and exotherm. The combustion heat can be measured with a bomb calorimeter, or it can be obtained by directly substituting the table to obtain the enthalpy of formation of the reactants and products.
- At 25 ° C and 100kPa, (the old standard pressure is 1 atm = 101 kPa, which is 1 standard atmosphere, and the new standard pressure is changed to 1 bar = 100 kPa. Peking University Press, "General Principles of Chemistry (Fourth Edition) "Notes on page 85 1) 1 mol of pure material completely burned to produce stable compounds
- Sometimes the heat of combustion of a fuel can be expressed as HHV (high calorific value), LHV (low calorific value), or GHV (total calorific value).
- Low calorific value is related to water discharged in gaseous form, so the energy used to vaporize water cannot be considered as heat.
- The total calorific value is related to the water being discharged in gaseous form and includes the water present in the fuel before combustion. This value is very important for fuels such as wood or coal, because these fuels usually contain a certain amount of water before burning.
- High heating value is equal to the heat of combustion because
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