Work out sox nox emission instantly with clear inputs, formula shown and shareable results.
Sulphur in fuel converts almost entirely to sulphur dioxide, so uncontrolled emissions are fuel mass times sulphur fraction times two — the molecular mass ratio of SO2 to S. Nitrogen oxides come from both fuel nitrogen and thermal fixation of air nitrogen, so they are estimated from an emission factor rather than fuel composition.
Sulphur dioxide
SO2 (t) = fuel (t) x sulphur % x 2, reduced by control efficiency
Nitrogen oxides
NOx (t) = fuel (t) x NOx factor (kg/t) / 1000
Sulphur dioxide and nitrogen oxide emissions are subject to statutory limits and continuous monitoring requirements. Use the prescribed measurement and reporting methodology for compliance.
Sulphur has atomic mass 32 and sulphur dioxide 64, so every tonne of sulphur burnt yields two tonnes of sulphur dioxide.
Combustion measures first — low-NOx burners, staged air, flue gas recirculation — then post-combustion selective catalytic or non-catalytic reduction, which can achieve 80-90% removal.