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Is it possible to Hydrotreat Merox treated Naphtha in NHT?
 
Answers
01/06/2013 A: Sridhar Balakrishnan, Bharat Oman Refineries Limited , laksrid@yahoo.com
Yes, it is possible to Hydrotreat Mexor treated Naphtha in NHT. In Merox treated Naphtha the mercaptans are converted into disulphide, whereas in hydrotreating of naphtha the sulphur content of the naphtha is reduced to less than five ppm. However we can directly hydrotreat the product instead of merox treating and hydrotreating to save energy and time.



21/05/2013 A: Morgan Rodwell, Fluor Canada Limited, morgan.rodwell@fluor.com
As Mr. Ragsdale says - why not just bypass the Merox treater. Many plants take the DSO from a Merox unit and route that to NHT or DHT units for destruction.
If your separators are working well enough to remove the caustic from the naphtha down to the levels needed for blending or feeding to other catalytic units (reformer, steam cracker) then you should be fine routing to an NHT.
20/05/2013 A: Alan Goelzer, Jacobs Consultancy, alan.goelzer@jacobs.com
I concur with Ralph Ragsdale that bypassing the Merox [Catalyzed Caustic Treater] would be best.
If straight-run naphtha or especially if cracked naphtha has been through a Catalyzed Caustic Treater ahead of the NHTU, then I would strongly recommend splicing a recirculating water wash module between the Catalyzed Caustic Treater and the Feed Surge Drum of the Naphtha Hydrotreater Unit. This is so that minimal amounts of caustic and NaSH and other sodium derivatives and soluble catalyst metals are sent into the NHTU.
UOP and Merichem both offer water wash modules, although differing in concepts and hardware.
20/05/2013 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
Yes, but why not bypass the Merox treater?