Example 1
15 lbs of propane are burned stoichiometrically with air. For the total fuel provided, determine how many lbs of air are required to complete the reaction.
Per equation C1-3 the combustion equations can be assumed to be:
where
For propane, with a chemical composition of C3H8, this works out to be:
This balanced equation tells us that for every mole of propane that gets burned, 5 moles of oxygen are used. The problem asks for lbs of air though, not oxygen, so the nitrogen in the equation must be taken into account as well. Total moles of air (oxygen and nitrogen combined) per mole of propane is calculated by considering the mole weight of each constituent in air and multiplying by how many moles there are:
15 lbs of propane are burned, therefore the total amount of air combusted is:
