Adiabatic Converter for Sulfur Trioxide Production

A furnace is necessary for the combustion of liquid sulfur in air: .

The sulfur dioxide then undergoes a catalytic conversion into sulfur trioxide, , in an adiabatic reactor: .

Sulfur trioxide is prepared on a massive scale as a precursor to sulfuric acid.

This Demonstration computes the extent of reaction, , the exit temperature, , and the composition of the effluent for the adiabatic converter used for production. To do so, one has to write: (1) the chemical equilibrium using the equilibrium constant , obtained by fitting the free energy data versus temperature for SO₂ and SO₃, and (2) the energy balance: , which exploits the fact that the converter is adiabatic.

Finally, the temperature at the entrance of the converter is chosen equal to =700 Kelvin, a value that depends on the energy produced in the furnace, , used to generate live or superheated steam.

The user-specified values of the mole fraction of SO₂ are in the range typically used in the industry.