Tip of the Week
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Predicting
Sulfur Dioxide Emissions from Coal Analysis |
The following Tip comes courtesy of Jack
Bionda.
When
measuring SO2 emissions either with electronic instrumentation or by
a wet chemical method, it is often useful to compare the measured values to
expected values based on the sulfur content of the fuel being burned. This comparison indicates whether the
measurements are in reasonable agreement with the levels one would anticipate. A simple Excel workbook allows the computation of
the volumetric concentration of SO2 (ppmvd) based on the fuel
ultimate analysis and the excess O2 concentration in the flue gas.
The result
from this spreadsheet is the theoretical estimate of the SO2 in the
flue gas assuming all of the fuel bound sulfur is converted to SO2. However, not all of the sulfur is converted
to SO2. A small amount (approximately 1%), is converted to SO3
and H2S. Generally speaking,
if your measurement shows agreement within 2-3% of this calculated theoretical
value, the measurement should be considered valid.
The
calculations behind this approach are as follows:
Moles of
sulfur (nS) = 
Moles of
carbon (nC) = 
Moles of
hydrogen (nH) = 
Moles of
oxygen (nO) = 
Moles of
nitrogen (nN) = 
Moles of
flue gas (nfg) = 
SO2
(ppmvd) = 
SO2
(lb/106 Btu) = 