Acetylene is hydrogenated to form ethane. The feed to the reactor contains 2.25
ID: 1056058 • Letter: A
Question
Acetylene is hydrogenated to form ethane. The feed to the reactor contains 2.25 moles of H2 for every mole of C2H2.
a) Write the balanced chemical reaction for this process.
b) Calculate the stoichiometric ratio between the reactants (mol H2 / mol C2H2) and the stoichiometric ratio between ethane and hydrogen (mol C2H6 / mol H2).
c) Determine the limiting reactant and the percent excess of the other reactant.
d) Determine the required amount of C2H2 in kg/second if we wish to produce 1.5 million metric tons of C2H6 per year assuming the reaction goes to completion and that the process operates 24 hours per day, 345 days per year.
Please answer step by step, Thank You
Explanation / Answer
a) the balanced reaction is
C2H2 + 2 H2 -------------> C2H6
b) the stoichiometric ratio between the reactants (mol H2 / mol C2H2) = 2 mol / 1 mol = 2.0
the stoichiometric ratio between the reactants (mol C2H6 / mol H2) = 1 mol / 2 mol = 0.5
c) there is requirement of 2 mol of H2 for every 1 mol of C2H2
but there is 2.5 mol of H2 for every 1 mol of C2H2
thus
the limiting reagent is C2H2
and excess of the reactant is = 2.5 mol -2.0 mol / 2.0 mol = 0.25 * 100 = 25 %
d) mass of CEH6 = 1.5 million metric tons
= 1.5 x 10^9 kg / year
moles of C2H6 = 1.5 x 10^9 kg / year / 30.07 g/mol
= 4.99 x 10^10 mol /year
and
therefore
mass of C2H2 = 4.99 x 10^10 mol /year x 26.04 g/mol
= 1.298 x 10^9 Kg / year
= 1.298 x 10^9 kg / ( 345 x 24 x 60 x 60 s)
= 1.298 x 10^9 kg / 2.98 x 10^7 s
= 43.59 Kg/second