Flue Gas De-Suphurisation (FGD) simply requires that SO2-laden exhaust gases to come into intimate contact with water (H2O) and typically Limestone (CaCO3). The reactions that take place are:

CaCO3 + 2SO2 + H2O = Ca(HSO3)2 + CO2

Secondary oxidation with Limestone converts the resultant Calcium Sulphite to the more useable Gypsum:

Ca(HSO3)2 + CaCO3 + O2 + H2O = 2CaSO4•2H2O + CO2

There are many FGD processes used – some with separate reaction chambers – others with combined reaction chambers. They are predominantly fitted after waste heat has been recovered and the solids have been removed. They typically use spray chambers to maximise contact between the flue gas and the reactant.

Where the exhaust gas is reheated before release to atmosphere, CODEL GCEM-40 direct in-situ analysers provide the most convenient solution for both pre- and post-FGD gas analysis. Without re-heat, it may be necessary to use a CODEL GCEM-40E hot-extractive system post-FGD to eliminate liquid droplets prior to analysis.

CODEL’s range of stack emissions gas analysers are suitable for a wide variety of processes offering measurements of CO, NO, SO2, CO2, NO2, CH4, HCL and H2O. Our multi-channel stack emission monitors operate as fully integrated and automated CEMs systems or as stand-alone process control gas monitors.

Our range of dust monitors, particulate and opacity monitors are installed on a variety of applications. From burst bag detection, monitoring of small boilers through to large combustion plant processes our dust monitors have a proven track record throughout the world.

The CODEL flow monitor utilises a correlation technique that provides direct measurement with no contact with the flue gas. These ultra-reliable sensors which require zero maintenance and operate at gas temperatures upto 1000 Deg Celsius are available as either a stand-alone monitor or as part of a fully integrated emission monitoring system.