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The flames caused as a result of a fuel undergoing combustion (burning) Air pollution abatement equipment provides combustion control for industrial processes.. Combustion, or burning, [1] is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke.
In real world applications, complete combustion does not typically occur. Chemistry dictates that dissociation and kinetics will change the composition of the products. There are a number of programs available that can calculate the adiabatic flame temperature taking into account dissociation through equilibrium constants (Stanjan, NASA CEA, AFTP).
Some multistep reactions can also have apparent negative activation energies. For example, the overall rate constant k for a two-step reaction A ⇌ B, B → C is given by k = k 2 K 1, where k 2 is the rate constant of the rate-limiting slow second step and K 1 is the equilibrium constant of the rapid
A large compost pile can spontaneously combust if not properly managed. Spontaneous combustion or spontaneous ignition is a type of combustion which occurs by self-heating (increase in temperature due to exothermic internal reactions), followed by thermal runaway (self heating which rapidly accelerates to high temperatures) and finally, autoignition. [1]
As an example in everyday life, hand warmers make use of the oxidation of iron to achieve an exothermic reaction: 4Fe + 3O 2 → 2Fe 2 O 3 ΔH⚬ = - 1648 kJ/mol. A particularly important class of exothermic reactions is combustion of a hydrocarbon fuel, e.g. the burning of natural gas:
The combustion of a stoichiometric mixture of fuel and oxidizer (e.g. two moles of hydrogen and one mole of oxygen) in a steel container at 25 °C (77 °F) is initiated by an ignition device and the reactions allowed to complete. When hydrogen and oxygen react during combustion, water vapor is produced.
The combustion reaction can be approximated as follows, with the molecular formula C 12 H 26 : 2 C 12 H 26 (l) + 37 O 2 (g) → 24 CO 2 (g) + 26 H 2 O(g); ∆H˚ = -7513 kJ. In the initial phase of liftoff, the Saturn V launch vehicle was powered by the reaction of liquid oxygen with RP-1. [53]
An exothermic thermite reaction using iron(III) oxide. The sparks flying outwards are globules of molten iron trailing smoke in their wake. Some examples of exothermic processes are: [14] Combustion of fuels such as wood, coal and oil/petroleum; The thermite reaction [15] The reaction of alkali metals and other highly electropositive metals ...