High efficiency in extraction operations, such as extracting mercaptans from hydrocarbons with caustic, is obtained over a wide range of flow rates through a single extraction column by the provision of an intermediate product drawoff means located between a downstream section of extraction trays having greatest efficiency at low throughputs and an upstream section of trays having peak efficiency at high throughputs. A second product stream is removed after passing through the low flow rate trays and is blended with the stream from the intermediate drawoff means.
A multiple stage extractor column for the countercurrent contact of an upwardly moving hydrocarbon phase and a downwardly moving solvent phase is disclosed. The column is particularly useful for the solvent extraction of aromatics from a hydrocarbon feedstock containing C.sub.9 aromatics. The contactor column embodies an upper extraction section comprising a first plurality of perforated extraction trays and a backwash section comprising a second plurality of perforated extraction trays, the upcomer means of said second plurality being of larger cross-sectional area whereby the solvent/hydrocarbon interface at the bottom of the column is more readily controlled.
A multiple stage extractor column for the countercurrent contact of an upwardly moving hydrocarbon phase and a downwardly moving solvent phase is disclosed. The column is particularly useful for the solvent extraction of aromatics from a hydrocarbon feedstock containing C.sub.9 aromatics. The contactor column embodies an upper extraction section comprising a first plurality of perforated extraction trays and a backwash section comprising a second plurality of perforated extraction trays, said second plurality of trays being vertically spaced apart a greater distance than the trays of said first plurality whereby the solvent/hydrocarbon interface at the bottom of the column is more readily controlled.
A multiple stage contactor column for the countercurrent contact of an upwardly moving hydrocarbon phase and a downwardly moving solvent phase is disclosed. The column is particularly useful for the solvent extraction of aromatics from a hydrocarbon feedstock containing C.sub.9 aromatics. The contactor column embodies an upper extraction section comprising a first plurality of perforated extraction trays and a backwash section comprising a second plurality of perforated extraction trays, the perforations of said second plurality being of larger cross-sectional area whereby the solvent/hydrocarbon interface at the bottom of the column is more readily controlled.
The present invention provides a solvent exchange column for continuously exchanging styrene monomer with the solvent used to produce polybutadiene and a method of use therefor. The solvent exchange column includes an exchange plate support structure coupled to and supporting spaced apart exchange plates, wherein each of the exchange plates has holes located therein to allow a passage of fluid therethrough. The solvent exchange column further includes a vapor ventilation system for allowing the volatized solvent to exit the solvent exchange column.
An improved process is described for removing mercaptan sulfur from sour hydrocarbon distillate streams comprising of treating a sour hydrocarbon distillate stream in two oxidation zones within a reaction vessel. The first treatment occurs in the presence of a fiber bundle and the subsequent treatment over a bed of supported oxidation catalyst. The improvement comprises continuously keeping the bed in contact with an aqueous alkali metal hydroxide to maintain the catalyst in a caustic-wetted state, without interrupting the operation of the process.
