Combustion Reactions in a Furnace
Prepared by H. Binous, A. Bellagi, and B. G. Higgins

Fuel is fed to a furnace at 25°C and a molar flow rate of 100 moles/hr. This fuel is one of these hydrocarbons: methane, ethane, acetylene, propane, or butane. The fuel is subject to a combustion reaction in the furnace: , where  is the stoichiometric coefficient of the chemical species. An excess of oxygen entering at 150°C is used for the combustion reaction, so that the conversion of the fuel is total. You can select the value of the inlet molar flow rate of oxygen and nitrogen. We apply the energy balance for reacting systems using the heat of reaction method [1]. The Demonstration determines:

1. the heat duty in kJ/hr (labeled  in the process flowchart) for user-set values of exit temperature of the exhaust gases


2. the adiabatic flame temperature (i.e., for ) labeled Tad in the process flowchart.

By specifying the exit temperature of the furnace, the enthalpy balance at steady operation requires that excess heat (denoted by ) from the exothermic reaction has to be removed. By specifying adiabatic operations, the heat released by the reaction raises the temperature of the exhaust gases. You can change the inlet molar flow rate of nitrogen and observe its effect on both on  and Tad.

Download the CDF file to view the simulation using the free Wolfram CDF player.