Panametrics XMO2 - A.2 Reactor feed gases in formaldehyde production

A.2 Reactor feed gases in formaldehyde production
The XMO2 transmitter and its associated sample system is often used to measure the concentration of oxygen (O
2
) in an air/
methanol (CH3OH) vapor mixture that is commonly used as a reactor feed gas in the production of formaldehyde.
A.2.1 The problem
In order to maximize the yield of the reaction, while maintaining the O
2
concentration at a safe level, the air/CH
3
OH vapor
mixture must be continuously monitored and accurately controlled.
A.2.2 Equipment used
A typical instrumentation package for this application includes an XMO2 transmitter configured for a range of 0-21% O
2
in N
2
or CO
2
and operating conditions of a controlled temperature and atmospheric pressure. The XMO2 is mounted in a sample
system similar to the one shown in Figure 60 below (ref. dwg. #731-185).
Figure 60: Formaldehyde feed gas sample system
The sample system in Figure 60 on page 42 consists of:
• Inlet, outlet, and calibration needle valves
• A filter/coalescer assembly
• Pressure gauges
• Flowmeters
All components are mounted on a painted steel plate in an enclosure that is heated to 75 ±10°F
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