How Much Natural Gas Is Needed to Produce One Tonne of Ammonia?

[ABR124]

Homework Statement

Ammonia NH₃ is made by the haber process: N₂ + 3H₂ --> 2NH₃

The nitrogen required for this process is obtained from air by using the air to burn natural gas CH4 , thereby removing the oxygen from the air, leaving behind only nitrogen. The hydrogen required is obtained by steam reforming natural gas to carbon monoxide and hydrogen, followed by a shift conversion reaction to increase the yeild of hydrogen:

CH₄(g) + H₂O(g) --> CO(g) + 3H₂(g) Steam Reforming

CO(g) + H₂O(g) --> CO₂(g) + H₂(g) Shift Conversion

How many cubic meters of natural gas at STP is required to produce one tonne of ammonia? Air may be assumed to consist of 80% mol nitrogen and 20 % mol oxygen. For the purpose of calculation, you may assume the complete stoichometric of methane in air to produce carbon dioxide and water and that no nitrogen oxides are formed.

Homework Equations

Not to sure

The Attempt at a Solution

Don't know where to start with this one, I just want to get on the right track

 

[morrobay]

Determine how many moles of ammonia are in one ton
Then: moles NH₃ (3H₂/2NH₃) = moles H₂ required.
Determine how many moles of CH₄ are contained in 1 M³
Note that 1 mole of CH₄ yields 4 moles H₂
And 22.4 liters at STP contains 1 mole of gas