An extraction method and a countercurrent liquid-liquid extraction column extracts a hydrogen peroxide containing oxidized working solution of an anthraquinone process. The extraction column includes a plurality of sieve trays, wherein at least one of said sieve trays is a valve sieve tray including a downcomer and at least one floating valve that includes a liftable opening member covering a valve hole in the valve sieve tray and can be lifted by the light phase below the sieve tray. A more stable operation of sieve tray extraction columns is possible by using a floating valve so that the flow rate of the oxidized working solution of an AO process and the daily production of hydrogen peroxide can be increased.

Contacting arrangements adapted to be installed within a liquid-liquid extraction column, and including pairs of disk and doughnut plates.

The present invention provides a process for the production of an aromatic dicarboxylic acid comprising the catalytic oxidation of a hydrocarbon precursor in an organic solvent, comprising the steps of: i) separating a vent gas from an oxidation stage into an organic solvent-rich liquid stream and a water-rich vapor stream in a distillation stage; and ii) separating an aqueous purification mother liquor comprising organic compounds from purified aromatic dicarboxylic acid crystals in a separation stage, characterized in that the process further comprises the steps of: iii) transferring the aqueous purification mother liquor from the separation stage to an extraction stage; iv) extracting said organic compounds from the aqueous purification mother liquor by contacting the aqueous purification mother liquor at a temperature of at least 90? C. with an organic liquid in the extraction stage to form an aqueous phase and an organic phase, wherein the concentration of said organic compounds in the aqueous phase is lower than the concentration of said organic compounds in the aqueous purification mother liquor; and v) transferring the aqueous phase to said distillation stage. The present invention further provides an apparatus for carrying out the process.

A method for removing dissolved hydrocarbons from water may comprise: cracking a mixed hydrocarbon stream in a cracking furnace to produce a cracked gas effluent; quenching the cracked gas effluent in a quench water tower with quench water to produce a quenched gas stream and a spent quench water stream comprising water, tars, heavy aromatic hydrocarbons, gasoline, dissolved oil, and dispersed oil; feeding the spent quench water stream to a liquid-liquid extraction unit wherein the liquid-liquid extraction unit removes at least a portion of the dissolved oil and produce an extracted effluent stream.

A method for removing dissolved hydrocarbons from water may comprise: cracking a mixed hydrocarbon stream in a cracking furnace to produce a cracked gas effluent; quenching the cracked gas effluent in a quench water tower with quench water to produce a quenched gas stream and a spent quench water stream comprising water, tars, heavy aromatic hydrocarbons, gasoline, dissolved oil, and dispersed oil; feeding the spent quench water stream to a liquid-liquid extraction unit wherein the liquid-liquid extraction unit removes at least a portion of the dissolved oil and produce an extracted effluent stream.

A method for separating an alkyl aromatic hydrocarbon, the method having a step of adding a first diluent and an extractant having a superacid to a mixture comprising the alkyl aromatic hydrocarbon and one or more isomers thereof to carry out an acid-base extraction to thereby form a complex of the alkyl aromatic hydrocarbon with the superacid, and thereafter separating the complex from the mixture, and a step of adding an eliminating agent having a relative basicity in a range of 0.06 to 10 with respect to the alkyl aromatic hydrocarbon and a second diluent to the complex, and carrying out complex exchange of the alkyl aromatic hydrocarbon for the eliminating agent to thereby separate the alkyl aromatic hydrocarbon from the complex.

A liquid-liquid extraction system (1) adapted for the flow of two or more liquids therein is disclosed. The system comprises a mixer settler sub-system (100) and a counter-current liquid-liquid extraction column (200). The sub-system (100) comprises one or more mixer settlers (110) connected in series, and the column (200) comprises either a mixing section (260) comprising an agitation means (261) and/or a static section (280) comprising an internal (281). The first outlet (131) of the mixer settler sub-system (100) is in fluid communication with the first inlet (221) of the column (200) and the second inlet (112) of the mixer settler sub-system (100) is in fluid communication with the second inlet (222) of the counter-current liquid-liquid extraction column (200). The invention further relates to a counter-current liquid-liquid extraction process for using said system 1. The present invention further relates also to the use of the system (5) or process in removing aromatic compounds from organic streams, in treating an oil stream of a refinery, or in a liquid-liquid extraction process having at least two feed streams of different viscosity, similar density, or low interfacial tension.

The present subject matter relates generally to methods for treating an organic feed. More specifically, the present subject matter relates to methods for reducing the water content of an organic feed before the organic feed enters a hydrogenation zone, thereby by improving the activity, conversion, and life of the hydrogenation catalyst. The hydrogenation zone product stream is then sent to a phenol recovery zone.

A method for separating an alkyl aromatic hydrocarbon, the method having a step of adding a first diluent and an extractant having a superacid to a mixture comprising the alkyl aromatic hydrocarbon and one or more isomers thereof to carry out an acid-base extraction to thereby form a complex of the alkyl aromatic hydrocarbon with the superacid, and thereafter separating the complex from the mixture, and a step of adding an eliminating agent having a relative basicity in a range of 0.06 to 10 with respect to the alkyl aromatic hydrocarbon and a second diluent to the complex, and carrying out complex exchange of the alkyl aromatic hydrocarbon for the eliminating agent to thereby separate the alkyl aromatic hydrocarbon from the complex.

Deep desulfurization of hydrocarbon feeds containing undesired organosulfur compounds to produce a hydrocarbon product having low levels of sulfur, i.e., 15 ppmw or less of sulfur, is achieved by hydrotreating the feed under mild conditions, and separating the hydrotreated effluent into an aromatic-rich fraction which contains a substantial amount of the aromatic refractory and sterically hindered sulfur-containing compounds, and an aromatic-lean fraction. The aromatic-rich fraction is contacted with isomerization catalyst, and the isomerized aromatic-rich fraction is recycled to the mild hydrotreating process.