Editing Sulfur dioxide (section)

===Combustion routes===
Sulfur dioxide is the product of the burning of [[sulfur]] or of burning materials that contain sulfur:

:{{chem2|S8}} + 8 {{chem2|O2}} → 8 {{chem2|SO2}}, ΔH = −297 kJ/mol

To aid combustion, liquified sulfur ({{convert|140|–|150|C|F}} is sprayed through an atomizing nozzle to generate fine drops of sulfur with a large surface area. The reaction is [[exothermic]], and the combustion produces temperatures of {{convert|1000|–|1600|C|F}}. The significant amount of heat produced is recovered by steam generation that can subsequently be converted to electricity.<ref name = Ullmann/>

The combustion of [[hydrogen sulfide]] and organosulfur compounds proceeds similarly. For example:

:2 {{chem2|H2S}} + 3 {{chem2|O2}} → 2 {{chem2|SO2}} + 2 {{chem2|H2O}}

The [[Roasting (metallurgy)|roasting]] of sulfide ores such as [[pyrite]], [[sphalerite]], and [[cinnabar]] (mercury sulfide) also releases SO<sub>2</sub>:<ref>Shriver, Atkins. Inorganic Chemistry, Fifth Edition. W. H. Freeman and Company; New York, 2010; p. 414.</ref>

:4 {{chem2|FeS2}} + 11 {{chem2|O2}} → 2 {{chem2|Fe2O3}} + 8 {{chem2|SO2}}
:2 {{chem2|ZnS}} + 3 {{chem2|O2}} → 2 {{chem2|ZnO}} + 2 {{chem2|SO2}}
:{{chem2|HgS + O2 -> Hg + SO2}}
:4 FeS + 7 {{chem2|O2}} → 2 {{chem2|Fe2O3}} + 4 {{chem2|SO2}}

A combination of these reactions is responsible for the largest source of sulfur dioxide, volcanic eruptions. These events can release millions of tons of SO<sub>2</sub>.