Improving Incinerator Operation With Advanced Flue Gas Analysis.0 pages

OIL AND GAS

Improving Incinerator Operation
With Advanced Flue Gas Analysis.
BACKGROUND
Sulfur plant tail gas incinerators are used to oxidize
sulfur compounds that cannot be released directly into
the atmosphere. These sulfur compounds include H2S,
COS and CS2. Incinerators are operated at temperatures
that are sufficient for oxidation of the sulfur compounds
to SO2 as well as providing the required mechanism for
proper plume dispersion.
Sulfur plant incinerator control is typically based on
a closed loop control on the fuel gas flow providing
the incinerator temperature required. Natural draft
dampers that are manually opened or closed traditionally supply combustion air. Modern incinerator design
incorporates forced draft air for combustion air. This
allows closed loop temperature control where combustion air is provided based on the required ratio to fuel
gas. Closed loop control based on excess oxygen can be
used to optimize fuel gas control.

OPTIMIZING SULFUR INCINERATOR OPERATION
WITH AN IN SITU OXYGEN ANALYZER SULFUR

The recommended operating range for excess oxygen
is 2 to 5 percent. Operating below 2 percent may result
in insufficient oxidation of the sulfur compounds to SO2.
This may result in a violation of the allowable concentrations of H2S, COS and CS2 allowed in the incinerator
effluent. Operating above 5 percent will result in an
excessive use of incinerator fuel gas. Figure 1 illustrates
the relationship between relative fuel demand, stack
temperature and excess oxygen concentration.

•
Relative Fuel Demand (Percent)

Ideal operation of these incinerators is to provide an
excess of oxygen in the flue gas stream that ensures
complete oxidation of all sulfur compounds to SO2.
Sulfur plant incinerators are typically operated with
excess oxygen levels of 6 to 10 percent.

•

200

•

•

•

•

•

•

•

•

•

•
50 •
•

•
•

•
•

1000

1100

150

100

0

800

900

1200

Stack Temperature (F)

Relative Fuel Demand for Sulfur Plant Stack Operated at Various
Temperatures and O2 Concentrations

For more information
www.EmersonProcess.com/CustomerSuccess
www.RosemountAnalytical.com

CMB_ADS_106-100_O2_Analyzer_Chemical_Incinerator