This is the problem that I'm attempting to solve:
Calculate for the energy density and carbon footprint of a reformate manufactured via continuous catalytic regenerative reformer (Benzene, C6H6 – 17%; Toluene, C6H5CH3 – 39%; Xylene, (CH3)2C6H4 – 44%)
ΔHf C6H6(l) = 49.03 kJ/mol
ΔHf CO2(g) = -393.5 kJ/mol
ΔHf C6H5CH3(l) = 12.0 kJ/mol
ΔHf H2O(l) = -285.8 kJ/mol
ΔHf (CH3)2C6H4(l) = -24.4 kJ/mol
What I did first is to compute for the equivalent moles from the percentages that are given assuming that they all constitute to 100 g.
Benzene = 78.11 g/mol, Toluene = 92.14 g/mol, Xylene = 106.16 g/mol
For benzene, I multiplied 17 g C6H6 to 1/78.11 g. This gave me 1700/7811 mol. Doing the same thing for the others resulted to 1950/4607 mol for toluene and 550/1327 mol for xylene.
Now, I looked for the heat of reaction by obtaining the summation of the energy produced by these chemicals. From the given, I disregarded the CO2 and H2O, since they are not involved in catalytic reformation anyway, and proceeded with my calculation:
(1700/7881 mol)(49.03 kJ/1 mol) + (1950/4607 mol)(12.0 kJ/1 mol) + (550/1327 mol)(-24.4 kJ/1 mol) = 5.637167165 kJ
To arrive at the energy density, I divided the newly-attained value for energy to 100 g. Then, I converted the value to MJ/kg. My answer is 0.56 MJ/kg. However, I feel that I did something wrong along the way.
I am clueless about the carbon footprint. Upon searching, I did not see a standard formula for it.
Heeeeelp.