Estimating Flame Temperature: A Basic Guide

[samblohm]

How could someone roughly calculate flame temperature? Let's say that a chemical reaction occurs at 1000F and the specific heat capacity of the reactants averages to 8 J/(mol x K). And the energy released in the reaction was 1000 KJ and the specific heat capacity of the products in 3 J/(mol x K). I really don't see anything else necessary to calculate flame temperature, but I could definitely be wrong. Is is a simple equation or does it require some hardcore computer program?

 

[Borek]

For a rough estimate heat balance should be sufficient. For a precise result there is nothing like an experiment. I guess engineers do have specialized formulas for such calculations.

 

[samblohm]

I only looking for a rough estimate. What do you mean by heat balance? How could it be used for a rough calculation?

 

[Borek]

What do you mean by heat balance?

This is a very basic concept, see for example

http://www.chem.latech.edu/~deddy/chem104/L5Calorie.htm

There are plenty of materials explaining these things on the web.

Same approach used to calculation of the flame temperature:

http://www.et.byu.edu/~rowley/ChEn273/Topics/Energy_Balances/Reacting_Systems/Adiabatic_Flame_Temp.htm

 

[Topher925]

It looks like you're after the adiabatic flame temperature, i.e. temperature with no heat transfer. As Borek stated you can determine the adiabatic flame temperature with a simple first law analysis within an accuracy of maybe 30%ish. To calculate a more realistic flame temperature you need to take into account variations in heat capacity, dissociation, radiative heat transfer, etc. This requires some complex code and I think some I think you can download for free. Of course the most accurate method is just to perform an experiment.