Once harmful acid gases are removed from extracted natural gas, they are transferred to a sulfur recovery unit. This unit converts the hydrogen sulfide in the acid gas into elemental sulfur. This recovered sulfur, as well as sulfuric acid, is used in a variety of other industries, from fertilizer production to petroleum refining.
Of the processes available for sulfur conversions, the Claus process is by far the most well-known for recovering elemental sulfur, whereas the conventional Contact Process and the WSA Process are the most used technologies for recovering sulfuric acid. The residual gas from the Claus process is commonly called tail gas. Tail gas is subsequently processed in a gas treating unit.
This blog post, part of the Magnetrol® series on level measurement in natural gas processing applications, demonstrates how accurate instrumentation can ensure a safe and efficient sulfur recovery process.
Level Measurement Challenges and Considerations
The sulfur condenser vessel is equipped with a disengagement section on the outlet end. This allows for efficient separation of the liquid sulfur from the process gas. A collection vessel equipped with continuous level control is used to store and remove the sulfur product from the process. Monitoring both of these vessels is essential to keep the sulfur and gas from leaking or causing accidents.
In addition, natural gas processing plants are required to recover most, if not all, of the sulfur that is present in the sulfur recovery unit for environmental reasons. Reliable level measurement instrumentation that can monitor even low quantities of sulfur can help ensure that these stringent emissions regulations are met.
Level Measurement Solutions
MAGNETROL has produced level measurement solutions for sulfur recovery units:
- For point level:
Echotel® Model 961 ultrasonic switch or Thermatel® TD1/TD2 thermal dispersion switch
- For continuous level:
Eclipse® Model 706 guided wave radar transmitter
- For visual indication:
Atlas or Aurora® magnetic level indicators
For more information on level measurement solutions for sulfur recovery units and other natural gas processing applications, download the natural gas processing brochure.