3 replies to this topic

[geo123]

I just want to ask question about this as I'm not sure what I to do next:

The product gas from a combustion reaction has the following dry basis molar composition:

CO2 80.35%

CO 4.73%

SO2 0.03%

O2 14.89% 

Pure oxygen is fed to the furnace in 10% excess of that required for complete combustion. There is no oxygen in the fuel (fixed or gaseous). Calculate the elemental composition of the fuel (mole % of elements C,H & S). Base calculations on 100 moles of dry outlet gas.

 

Take SO2 to be the fully combusted form of S. 

Here is my working so far:

'O'in='O'out

2*'O2'in=2*'CO2'out+1*'CO'out+2*'SO2'out+2*'O2'out+1*'H2O'out

 

2*'O2'in=2*80.35+1*4.73+2*0.03+2*14.89+1*'H2O'out

 

'C'in='C'out

'C'in='CO2'out+'CO'out=80.35+4.73=85.08mols

 

'S'in='S'out

'S'in=1*'SO2'out=1*0.03=0.03mols

 

0.1=(O2feed-O2theoretical)/(O2theoretical)

 

Complete combustion

S+O2->SO2              0.03mols O2

C+O2->CO2             85.08mols O2

H2+1/2O2->H2O     x mols       O2

 

Incomplete Combustion

C+1/2O2->CO

 

The answer is 

2. C 34.63%

   H 65.36%

3. S 0.0122% 

4. But the problem is that I do not know how to get to this answer. Please explain it to me step by step and/or the solution(maths/algebra behind it)

Thanks.

Edited by geo123, 15 April 2015 - 04:23 PM.

[Bobby Strain]

Even though I loathe spreadsheets, your work would be better presented with one.

 

Bobby

[breizh]

Hi ,

Let you work with the numbers and the equations .

Good luck

Breizh

[Napo]

Dear Geo123,

 

The solution of Breizh is excellent!!.

 

Maybe if you want a manual form, I send you the information.

 

Regards,

 

Napo.

Attached Files

•  Problem001.pdf   1.53MB   31 downloads