Abstract: The invention relates to a rectifying column for extractive distillation, comprising a column main section (204) and a raffinate section (205) above said main section, an evaporator (208) situated on the lower end of the column, an inlet (214) disposed between the main section of the column and the raffinate section and a solvent inlet (215) arranged on the top side of the raffinate section (205) for feeding an extracting agent. According to the invention, the main section (204) has two chambers (216, 217) connected in parallel. A stripping section (222) is disposed between the bottom of the column (221) and the main section (204), in which concentration of the extracting agent occurs from the top down. The bottom (221) is connected to the solvent inflow (215) by a device (223) for recycling the extracting agent.

Abstract: A process is disclosed for generating pure aromatic compounds from a reformed gasoline which contains aromatic compounds, olefins, diolefin, and triolefins, which comprises the steps of:(a) selectively hydrogenating the olefins, diolefins and triolefins in the reformed gasoline to obtain a mixture of hydrogenated, non-aromatic compounds and aromatic compounds; and(b) separating the aromatic compounds from the hydrogenated, non-aromatic compounds in the mixture formed during step (a) by either extractive distillation, liquid--liquid extraction or both to obtain the pure aromatic compounds.

Abstract: A process is provided for separating benzene from non-aromatics in a highly aromatic stream containing olefins in a concentration range of from about 0.05 to about 5.0, which process comprises predistilling said highly aromatic stream to produce a distilled fraction having a concentration of C.sub.8 and heavier compounds of less than about 0.1 wt percent; and extracting said distilled fraction with a solvent comprising substituted morpholines in an extractive distillation zone to produce a highly-pure benzene stream.

Abstract: In a method of optimizing the operation of a distillation column with a side heating device for reconditioning of extract which is received during the extraction of hydrocarbon-containing initial products with N-substituted morpholines whose substituents have not more than seven C-atoms as selective solvents a liquid is withdrawn to a side heating device through a chimney plate arranged above a feed plate, so that between 5 and 30 volume percent of the liquid supplied to the chimney plate is not withdrawn to the side heating device but instead supplied directly to a plate located underneath the chimney plate. A vapor-liquid mixture which has escaped through a top from the side heating device is returned back to the distillation column. The returned vapor-liquid mixture is fed either to the feed plate or to the plate located underneath the chimney plate. An arrangement for performing the inventive method is also provided.

Abstract: A hydrocarbon material of the starting product is separated in an extractive distillation column in which an N-substituted morpholine whose substituents do not have more than seven carbon atoms is used as a selective solvent. The overhead product comes down as a top product of the extractive distillation and is fed through a coalescer in which the sump product comes down with a solvent content of 20 to 75% by weight at a temperature of 20.degree. to 70.degree. C. and subsequent to that is fed into a separating vessel. There it is separated into a heavier and lighter phase. After that the heavier phase is conducted into an extractive distillation column and the lighter phase into the overhead product distillation column.

Abstract: In the method for the production of an aromate concentrate suitable for use as blending component for gasifier fuel, feed hydrocarbon mixtures having boiling ranges substantially between 40.degree. and 170.degree. C., are subjected, without any previous separation into individual fractions, to an extractive distillation employing N-substituted morpholine, substituents of which display no more than seven C-atoms, as selective solvent. Herewith, the lower boiling non-aromates with a boiling range up to about 105.degree. C., practically completely, and most of the higher boiling non-aromates with a boiling range between about 105.degree. and 160.degree. C., are recovered as raffinate, whereas the aromates, which are to be employed in whole or in part as blending component, come down in the extract of the extractive distillation.

Abstract: The process for production of an aromate concentrate for use as a blending component for gasification fuel includes subjecting another feed hydrocarbon mixture to an extractive distillation using N-substituted morpholines as selective solvent in a extractive distillation column. Low-boiling non-aromates with a boiling range up to about 105.degree. C. practically completely and higher-boiling non-aromates with a boiling range between about 105.degree. and 160.degree. C. to a substantial extent are discharged as a raffinate from the top of the extractive distillation column. The extract bottoms from the extractive distillation are fed to a solvent stripping column where the solvent is at least partially recovered from other hydrocarbons. To eliminate condensation and polymerization products due to components with a boiling point over 170.degree. C.

Abstract: A process is disclosed for the separation of aromates from hydrocarbon mixtures of optional aromate content through extractive distillation using N-substituted morpholine displaying substituents having no more than 7 C-atoms as selective solvent. Part of the solvent is delivered to the uppermost plate of the extractive distillation column and the remainder of the solvent, preferably amounting to between 10 and 40% by weight, is introduced into the extractive distillation column in at least two partial streams onto plates above the inlet for the hydrocarbon mixture. The temperature of the respective solvent partial streams is adjusted to neither exceed the temperature of the corresponding delivery plates nor fall below this temperature by more than 10.degree. C.

Abstract: Disclosed is a method for recovering pure aromatic substances from a mixture of hydrocarbons containing both aromatic and non-aromatic fractions. The input mixture is fed through an extractive stage provided with a preliminary distillation column. In the preliminary stage the aromatics-containing product is treated at a pressure up to 20 bar and a temperature up to 300.degree. C. The pressure is adjusted to a value at which the operational temperature of the preliminary stage is higher than the pressure and temperature in the extractive stage and the heat of the vapors discharged from the preliminary stage is used for heating the extractive stage.