Q & A > Question Details
How to calculate the SOx and NOx emission rate in a heater stack?
17/03/2016 A: Prakash Pimparkar, Environmental Consulting Services , prakash.pimparkar@yahoo.in
SOX formation is pure chemistry for each go of sulfur you have two grams of SO2 and most of sulfur is converted to SOX. The concentration is obtained by devising thsee grams by the M 3 of stack gas .The quantity of stack gas is excess air,residual Nitrogen,residual oxygen,water vapour formed due to Hydrogen in fuel, CO2 formed out of carbon in fuel, the quantity of other components can be neglected.Thus by deviding gm by Mr , gm/ m3 is obtained multiplying by 1000 one can get mg/me. As per requirement of units.
Best way to estimate NOX is to use US EPA Emission factors as formation of NOX is a complex function of furnace configuration, excess air,flame temperature, turbulence in furnace,flame temperature profile and other complex parameters, though predictive models are available needs to be used by experienced hands or else garbage in garbage out.
Another way is to measure directly by simple analytical tools of stack sampling again available as standard tools.
19/11/2011 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
If it is an existing operation, to calculate the SOx, simply analyze the stack gases for sulfur content and calculate the stack gas flow rate using the fuel consumption rate and a calculated sulfur balance. If it is not an existing unit, perform a sulfur component balance based on the sulfur content of the fuel, duty and efficiency, taking into account the expected or calculated excess air and formation of COx.
I don’t know how to calculate the NOx, as it depends to some extent on flame pattern.