Abstract: Sulfur compounds are separated from aqueous mixtures containing same by employing a stripper having at least two stripping sections with at least a portion of the stripper kettle product being recycled to the lower stripping section. The process is particularly effective in recovering mercaptans from steam condensate. In the production of mercaptans by reacting hydrogen sulfide with olefins, steam condensate contaminated with mercaptans is obtained from the steam ejector employed in the product fractionation column.

Abstract: A stream containing at least one noncondensible, under ordinary pressure and temperature, component and at least two components which are condensible under ordinary pressure and temperature are separated by subjecting said stream to successive fractional distillation conditions to successively remove highest boiling components. An overhead produced in one fractional distillation zone is introduced as a feed into the next fractional distillation zone. The penultimate overhead comprising only the noncondensible and a lowest boiling condensible component is partially condensed. The liquid phase is introduced onto the top tray of a last fractionation zone and the vapor phase is introduced below the top tray. A vapor stream containing a single condensible component and at least one noncondensible can be separated in the same manner as the penultimate overhead of a multi-component mixture.

Abstract: An apparatus is provided for recovering the particles entrained in a vaporous vent by passing the vent into a scrubber which uses as scrubbing liquid a liquid in which the particles are buoyant, maintaining a liquid level of scrubbing liquid in the base of the scrubber with overflow of floating polymer particles and scrubbing liquid from the surface of the liquid level. The particles can be passed back to the tank from which the particles were originally vented. A scrubbed, particle-free, vent gas is removed from the top of the scrubber and the scrubbing liquid can be recycled from the base of the scrubber for recontact with the vaporous vent containing particulate matter.

Abstract: In the fractional distillation of multicomponent mixtures where freezing of a component is encountered in the overhead condensing section and/or product decomposition is encountered at reboiling temperatures, these problems are obviated by carrying out the distillation in the presence of an added inert liquid which is somewhat more volatile than the component having a tendency to freeze. In one embodiment, the reaction effluent obtained in the production of thiophenol is subjected to fractional distillation wherein the distillation is carried out in the presence of a light hydrocarbon having a lower boiling point than an aromatic such as benzene so as to prevent freezing of benzene in the overhead condenser and at the same time lower the reboiler temperature to minimize thiophenol product decomposition.

Abstract: A method for the removal of substantially all of the reaction diluent from a reaction mixture containing poly(arylene sulfide) polymer, organic polar diluent, by-product alkali metal halide, and other impurities is provided by the atmospheric adiabatic expansion of the polymer slurry from about 200 pounds pressure in a transfer line to atmospheric pressure in a flash tank, the polymer being mixed at the point of pressure letdown with 200 psig steam which is reduced in pressure at the same point in the transfer line, to remove 75 to 98 percent of the reaction diluent from the flash tank as vapor. The polymer-salt-residual diluent mixture is then passed through heated blending and drying equipment into which superheated steam is flashed to remove the residual diluent. The residual polar diluent passes back through the equipment with the steam to be removed from the flash tank.

Abstract: A method for control of the steam flashing of poly(arylene sulfide) reaction product to remove substantially all of the reaction diluent from a reaction mixture containing poly(arylene sulfide) polymer, organic polar diluent, byproduct alkali metal halide, and reaction mixture impurities is provided by measuring the vapor effluent from the flashing operation, producing a signal representative of this flow, controlling the rate of flow of the effluent from the reactor in response to this signal, and controlling the rate of flow of steam admixed with the reactor effluent in ratio to the effluent flow.