EXPERT FOCUS
MEASURING CO AND CH 4 FOR
COMBUSTION SAFETY
The primary reasons for controlling
combustion in fired heaters are to
increase efficiency – lowering fuel
consumption and related costs – and to
ensure safety. Combustion is optimized
by balancing levels of oxygen (O 2 ) and
combustibles, usually in the form of
carbon monoxide (CO).
Zirconia sensors provide accurate,
continuous O 2 measurements, and can be
paired with a combustibles sensor for a
complete analysis solution.
However, Tunable Diode Laser (TDL)
technology delivers significant
advantages over combustible sensors,
with a faster response and an average
measurement across the process furnace,
enabling a more accurate indication of
CO and methane (CH 4 ) breakthrough.
The realization that a fuel-rich
environment (traditionally high CO, but
more recently the acceptance that CH 4
can be present) is a potential source of
explosions has moved CH 4 analysis from
a largely ignored measurement to a key
safety monitoring requirement.
Servomex’s SERVOTOUGH Laser 3
Plus Combustion TDL analyzer can be
optimized to measure CH 4 and CO at the
same time across the full temperature
range of the furnace from start-up to
operation, and customers are realizing
the importance of such a measurement.
TDL measurements are being built into
flame-out protection, specifically the
measurement of CH 4 . The TDL analyzer
is installed so that a burner flame-out
can be detected quickly, therefore
enabling greater safety and delivering
key information to aid control and shut
down processes.
Laser 3 Plus analyzers have Safety Integrity
Level (SIL) 2 certification, and so can be
easily incorporated into control loops and
used in safety shutdown systems.
They also incorporate “Line Lock”
technology to prevent the analyzer
measuring an adjacent line if the
measurement gas is absent. This ensures
that readings are correct and measure
the intended gas at all times – a clear
advantage for safety systems.
When safety is a primary concern, the
faster speed of response and the specificity
of the TDL wins out over a Zirconia
analyzer with an integrated combustibles
sensor, especially when coupled with SIL
safety assessments.
COAL TO OLEFINS
A COMPLEX CONVERSION PROCESS THAT REQUIRES GAS MONITORING TO ENSURE
EFFICIENCY AND SAFETY
With global demand for coal remaining
strong, the conversion of coal to a wide
range of chemicals is one of the fastest-
growing sectors in coal consumption.
One of the most important of these
processes is the conversion of coal to
olefins (also known as alkenes), particularly
ethylene and propylene which are key
components of the chemical industry.
The process follows two stages. Firstly,
coal is converted to methanol. Then,
using a recently developed technique,
the methanol is converted to olefins.
These applications are both complex
procedures that require a high degree
of gas analysis to maximize process
efficiency, as well as ensuring the safety
of flammable product streams.
Servomex supplies a comprehensive
suite of gas analyzers to provide the
versatile measurements required for
these processes. Led predominantly by
the SERVOTOUGH range, they deliver
highly accurate, reliable and safe
measurements, utilizing a wide variety of
non-depleting sensing technologies.
Combined into a complete system and
supported by a global Service Network,
Servomex’s expert gas analysis solutions
yield highly measurable efficiencies that
improve output and ensure safety, while
reducing maintenance requirements.
SERVOMEX ANALYZER SOLUTIONS FOR COAL TO OLEFIN PROCESSES
SERVOTOUGH
Oxy 1900 SERVOTOUGH
SpectraScan 2400 SERVOTOUGH
SpectraExact 2500
An award-winning, safety-enhanced
oxygen analyzer designed to deliver
accurate Paramagnetic measurements in
hazardous or challenging applications. A Tunable Filter Infrared absorption
on-line gas analysis platform ideal for
continuous flow-through monitoring of
light hydrocarbons. A robust Photometric multi-gas
analyzer designed to provide reliable
analysis in corrosive, toxic and flammable
gas streams.
SERVOTOUGH
LaserSP 2930 SERVOTOUGH
Laser 3 Plus Combustion SERVOPRO
MonoExact TCD
A high-sensitivity cross-stack Tunable
Diode Laser (TDL) analyzer optimized for
fast and accurate gas measurements in
hazardous locations. A full-featured compact TDL monitor
providing fast and accurate gas
measurements, optimized for O 2 , CO and
CO+CH 4 . A digital single-gas Thermal Conductivity
Detection analyzer optimized to meet
process control and product qualification
application needs.
SERVOTOUGH Laser 3 Plus Combustion
Measurement Specific to CO and/or CH 4
Lower Detection Limit* CO – 1ppm; CH 4 – 0.05%
Response time (T90)** <10s
SIL assessment SIL 2
* 95% confidence interval for 1m optical path length at 25 o C, 1Bara
** Faster response times available on request, at reduced specification
Find out more product data at: servomex.com/laser3pluscombustion
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See our analyzers across the process OVERLEAF
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