# Sulphur dioxide (SO2) from burning sour gas

Download the sulphur dioxide (SO2) from burning sour gas calculator to help you estimate the releases of National Pollutant Release Inventory (NPRI) substances.

This calculator will help you estimate the releases of sulphur dioxide (converted from hydrogen sulfide) from the burning of sour natural gas.

The NPRI toolbox contains a number of natural gas combustion calculators (external combustion boilers, internal combustion engines and biogas flaring for natural gas with less than 80% methane) which will also calculate values for sulphur dioxide releases. For the burning of sour gas, the value generated by this calculator will more accurately reflect the actual release of sulphur dioxide than the values from the other tools.

Since NPRI reporting thresholds are for the facility as a whole, you may need to combine the air releases you calculate with releases from other sources at your facility.

The following sections explain how the spreadsheet calculator works.

## Suggested estimation methodology: mass balance

Mass balance and stoichiometric information was used to develop the relationship between the concentration of hydrogen sulfide (H2S) in the natural gas being burned and the amount of sulphur dioxide (SO2) released to the air.

## Input data

A = activity (in this case the mass of H2S burned) [kilograms]
B = volume of H2S burned [cubic meters]
C = percentage of H2S in the gas by volume
D = destruction efficiency [%]
H = heating value [gigajoules/cubic meter]
J = volume of sour gas burned [cubic meters]
K = amount of sour gas burned [gigajoules]

If the volume of sour gas burned is not known you can use this equation to derive the amount:

J = K/H

The conversion above is based on a default heating value (H) of 0.0386. If a site-specific heating value is available, use that instead.

The volume of H2S burned is given by the equation:

B = J x C x D

The mass of H2S burned is calculated by:

A = B x 1.44114915367

## Equation to calculate the amount of sulphur dioxide released:

E = A x (64.0588/34.07588)/1000

Where: E = emission of sulphur dioxide (CAS 7446-09-5Footnote 1 ) [tonnes]