Q & A > Question Details
I wish to know whether it is possible to install a H2S analyzer in the FCC gascon section stripper column bottom liquid stream. The composition is C3-C10 hydrocarbons (propylene to naphtha range) and a little H2S and ethane. Also, a bit of RSH and COS are present too.
The requirement is to have an H2S analyser in this stream so that any slippage of H2S from stripper can be detected immediately and appropriate corrective action taken with minimum effect on downstream process. Is there any other indication of H2S slippage which can be used for monitoring purpose.
28/08/2016 A: Eric Hennings, Technip Stone & Webster, EHennings@technip.com
H2S analyzers are provided on LPG stream at inlet to RSH extraction unit. This provides a meaningful H2S reading as it is more concentrated. Note the analyzer can be combined with GC for hydrocarbon species to monitor separation in Stabilizer tower. The added "lag time" between Stripper bottoms and LPG is not significant.
04/07/2016 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
Those sulfur species do not “slip” into stripper bottoms. They will be present and should be removed from stripper bottoms by a treating unit. The objective in stripper bottoms should be only to reject C2’s.