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What steam stripping is preferred method for Diesel streams and re-boiler type of stripping is preferred for Naphtha?
 
Answers
16/09/2016 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
For both products, "live steam", as it is sometimes called, is most commonly used with success. A reboiler is used for jet fuel to meet the moisture spec.
15/09/2016 A: Sudhakara Babu Marpudi, Dangote Oil Refinery Company, m_sudhakarababu@yahoo.com
For streams such as Jet fuel, that has low tolerance to water / water contamination in final product is not at all allowed indirect stripping is done thru reboilers. Products like Diesel that do not demand water removal to very fine levels, steam stripping is acceptable. Similarly, Feed streams to catalytic reformers / processes that use catalysts where moisture content is not allowed direct steam stripping is not preferred (indirect stripping thru recoiling is preferred)
14/09/2016 A: Eric Vetters, ProCorr Consulting Services, ewvetters@yahoo.com
Having dry naphtha to feed a catalytic reformer is more critical than producing dry diesel, plus the lower boiling temperature of naphtha relative to diesel makes it relatively easy to use a waste heat driven reboiler. The higher boiling range of diesel will normally either require furnace or operating at vacuum to use a traditional reboiler. Rather than go to this extra cost to strip the diesel, a simple salt drier is more often used to lower the water content of the steam stripped diesel sufficiently to meet diesel quality specs.
14/09/2016 A: Ganesh Maturu, Self, maturu.ganesh@gmail.com
I am not sure if you are asking whether to go for steam stripping or reboiled stripping for diesel and naphtha. If u r asking preferred method, typically we go with steam stripping for diesel streams. It requires fired heater if we go for reboiled stripping which is not economical with respect to capex as well as opex. Hence refiners go with steam stripping and provide salt drier or vac drier to remove moisture from diesel. Another constraint is when we go above 700 deg f, there might be a chance of diesel cracking and coking issues...and hence avoid fired heater reboiler. If you have heating medium such as hot oil, u may go for reboiled stripping for diesel up to 700deg f. For naphtha services, it is preferred to go for reboiled stripping.