Stripping acidified spent caustic

Stripping is designed to serve two purposes. The first is to remove only HjS in supersaturation at acidification temperature. The second is to remove almost all the H2S liberated in order to yield an effluent with a residual S value compatible with discharge or with further treatment of the effluent. Depending on the goals, this residual value can 

Stripping is located upstream or downstream from the sprung acid separator according to 

Steam could also be contemplated, but entails a specific combustion unit for condensed vapors. 

Stripping is carried out either in compact, packingiess flash strippers or in conventional stripping columns. The conventional columns operate with a number of transfer units calculated on the basis of the required efficiency (from 3 to 5 transfer units). When ori ginat S concentrations are high ( 15 gd ), these two processes are combined. 

The flash drum (1) is simply supplied with a bumper gas flow for the H S in super-saturation. 

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