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 vapour stream in a distillation stage; and ii) separating an aqueous purific ation mother liquor comprising organic compounds from purified aromatic dicarboxylic acid crystals in a separation stage, characterised 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 concentra tion 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.

The invention relates to packed contact devices used in heat/mass exchange column apparatuses in which the processes of rectification, distillation, absorption, and extraction are run, and can be applied in the oil refining, petrochemical, chemical, gas-processing, and food-manufacturing industries. A contact device for carrying out heat/mass exchange and separation of phases in sectional cross-flow packed columns in gas/liquid and liquid/liquid systems comprises a plurality of identical contact elements assembled one upon another in one or more rows in blocks held together by spokes and vertical posts, with formation of walls in the column body that are restricted on horizontal end faces by horizontal segmental baffles conjugated in an arc with the column body; thereat, arranged between the walls are liquid distributors having a perforated part, an additional baffle, deflector plates, and vertical support plates. The space between the lower and upper walls is sealed by means of battens.

A counter-current liquid-liquid extraction column (1) adapted for the flow of two or more liquids (2) therein is disclosed. The column comprises within one common vessel (3): a first inlet (41) for a first liquid feed stream (51), a second inlet (42) for a second liquid feed stream (52), a first outlet (61) for a product stream (71), a second outlet (62) for a byproduct stream (72), a mixing section (8) comprising an agitation means (9), a static section (10) comprising a packing (11), optionally a collector (12) and/or distributor (13), characterized in that within the common vessel (3) are only one mixing section (8) and only either one or two static sections (10). The invention further relates to a process for using said column. The present invention further relates also to the use of the column or process in removing aromatic compounds from organic streams, in treating an oil stream of a refinery, or in a liquid-liquid extraction process.

The invention concerns a method for purifying a hydroalcoholic feedstock, comprising: a) a step of counter-current liquid-liquid extraction, comprising an extraction section supplied at the top with said hydroalcoholic feedstock and at least one intermediate raffinate fraction from step b) and at the bottom with an extraction solvent, and producing at the top an extraction stream and at the bottom a raffinate, wherein the extraction section is operated at a mean temperature in the extractor of between 10 and 40° C.; b) a counter-current liquid-liquid back-extraction comprising a back-extraction section supplied at the top with an acidic aqueous solution, having a pH between 0.5 and 5.0, and at the bottom with the extraction stream from step a), and producing at the top an extract and at the bottom the intermediate raffinate, wherein the back-extraction section is operated at a mean temperature between 40 and 80° C.

A process for removing heavy polycyclic aromatic contaminants from a hydrocarbon stream using a quinolinium ionic liquid is described. The process includes contacting the hydrocarbon stream comprising the contaminant with a hydrocarbon-immiscible quinolinium ionic liquid to produce a mixture comprising the hydrocarbon and a hydrocarbon-immiscible quinolinium ionic liquid comprising at least a portion of the removed contaminant; and separating the mixture to produce a hydrocarbon effluent having a reduced level of the contaminant and a hydrocarbon-immiscible quinolinium ionic liquid effluent comprising the hydrocarbon-immiscible quinolinium ionic liquid comprising at least the portion of the removed contaminant.

A sample purification system includes a container assembly bounding a sample purification compartment and having an upper end and an opposing lower end, the sample purification compartment comprising mixing zones and settling zones. A plurality of shielding elements are positioned within the sample purification compartment so as to at least partially separate adjacent mixing zones and settling zones or separate adjacent mixing zones, the mixing zones being in fluid communication with the settling zones. A mixing element is disposed within each mixing zone. An acoustic wave settler is aligned with a portion of the container assembly, the acoustic wave settler being configured to emit an acoustic wave through the portion of the container assembly and a mixture disposed therein, the acoustic wave coalescing fluid phase droplets disposed in the mixture to increase the buoyancy or density of the fluid phase droplets.

A process for removing heavy polycyclic aromatic contaminants from a hydrocarbon stream using a quinolinium ionic liquid is described. The process includes contacting the hydrocarbon stream comprising the contaminant with a hydrocarbon-immiscible quinolinium ionic liquid to produce a mixture comprising the hydrocarbon and a hydrocarbon-immiscible quinolinium ionic liquid comprising at least a portion of the removed contaminant; and separating the mixture to produce a hydrocarbon effluent having a reduced level of the contaminant and a hydrocarbon-immiscible quinolinium ionic liquid effluent comprising the hydrocarbon-immiscible quinolinium ionic liquid comprising at least the portion of the removed contaminant.

An apparatus and method for extraction of oils from botanical material using high-pressure hydrocarbons such as propane, or butane, or mixtures thereof are described. A high-pressure propane or butane saturated liquid/vapor mixture formed by pressure reduction through a valve placed before an extraction column, thereby serving as an expansion port was employed. The apparatus is capable of both continuous liquid extraction or batch-style liquid operation through the use of a manifold valve, which directs the solvent liquid/vapor in the system to either a supply tank or an extraction column.

The present disclosure relates to an improved sieve tray assembly for a liquid-liquid treating column. The tray is a modular design with inlet and outlet downcomer assemblies that are mounted flush to or raised above the sieve deck upper surface. The raised downcomer assemblies provide increased surface area for light liquid upflow perforations and enhanced liquid-liquid contacting capacity and efficiency.

A reaction column comprises a plurality of cells each of which has a lower cell portion and an upper cell portion. The cells are arranged sequentially, from an uppermost cell to a lowermost cell. The fuel inlet is configured to direct fluid through the reaction column from a lower cell portion of the lowermost cell to an upper cell portion of the uppermost cell, and out of the fuel outlet. The reagent inlet is configured to direct reagent through the reaction column from the upper cell portion of the uppermost cell to the lower cell portion of the lowermost cell. The plurality of cells may be vertically or horizontally positioned, as well as inclined and the like. Systems and methods are likewise disclosed.