Sulfur separation issues in Claus sulfur recovery
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This post was last edited by liaifeng on 2018-8-5 at 10:42. Our plant uses a two-stage Claus sulfur recovery process; the concentration of acidic gases is around 30%, and the total content of H2S and SO2 in the exhaust gas at the outlet is approximately 0.5%. However, the sulfur recovery rate can only reach 80%, and many liquid sulfur particles are present in the exhaust gas and cannot be separated. Currently, we are using a separation process that involves a first-stage and a second-stage sulfur condenser along with a sulfur separator. What is the effectiveness of sulfur recovery and separation in your plants? Are there any ideas for technical improvements? Thank you
Three-stage condensation with two-stage separation can be employed
Use complexed iron to carry out the transformation. After the second Claus unit, sulfur dioxide is removed through ammonia scrubbing; then the gas passes through the complexed iron system to have hydrogen sulfide converted directly into sulfur, with the resulting exhaust gases being discharged outside. It ensures that emissions meet the standards and that all sulfur is removed.
Are there any manufacturer recommendations and successful cases?
Normally, a three-stage sulfur cooler setup is used; you have one stage less, and I guess that’s where the problem lies. Don’t underestimate this last sulfur cooler – an increase of 1% in its efficiency can make things much easier later on!
Firstly, the separation temperature needs to be strictly controlled; secondly, an efficient sulfur separator is required, and the flow-guiding type separator we use works very well. With such a low recovery rate, renovation is definitely necessary; it needs to be above 98 at the very least, as emission requirements are high these days. Feel free to contact me if needed
Sulfur mist has formed; there is a problem with the condenser.