Abstract: Methods for recovering organic heteroatom compounds from a hydrocarbon feedstock include feeding into a contactor a hydrocarbon feedstock and an aqueous solvent to form an extraction mixture of the aqueous solvent with the hydrocarbon feedstock. The hydrocarbon feedstock includes a hydrocarbon and an organic heteroatom compound. The aqueous solvent includes an ionic liquid formed from pressurized carbon dioxide and water. A pressure and temperature of the extraction mixture may be established that together tune the aqueous solvent to selectively form a solvent complex with the at least one organic heteroatom compound. Then, the solvent complex is extracted to a recovery vessel from the extraction mixture in the contactor. By adjustment of a recovery temperature of the recovery vessel, a recovery pressure of the recovery vessel, or both, the solvent complex decomposes into carbon dioxide and the organic heteroatom compound. The organic heteroatom compound is then recovered from the recovery vessel.

Abstract: Solvent regeneration to recover a polar hydrocarbon (HC) selective solvent substantially free of hydrocarbons (HCs) and other impurities from a solvent-rich stream containing selective solvent, heavy HCs, and polymeric materials (PMs) generated from reactions among thermally decomposed or oxidized solvent, heavy HCs, and additives is provided. A combination of displacement agent and associated co-displacement agent squeezes out the heavy HCs and PMs from the extractive solvent within a solvent clean-up zone. Simultaneously, a filter equipped with a magnetic field is positioned in a lean solvent circulation line to remove paramagnetic contaminants. The presence of the co-displacement agent significantly enhances the capability of the displacement agent in removing the heavy HCs and PMs from the extractive solvent.

Abstract: An improved solvent regeneration system for extractive distillation and liquid-liquid extraction processes capable of effectively removing heavy hydrocarbons and polymeric materials that otherwise develop in a closed solvent loop. The improved process employs a light hydrocarbon displacement agent, which is at least partially soluble in the solvent to squeeze the heavy hydrocarbons and polymeric materials out of the solvent, with virtually no additional energy requirement. It has been demonstrated that the light non-aromatic hydrocarbons in the raffinate stream generated from the extractive distillation or the liquid-liquid extractive process for aromatic hydrocarbons recovery can displace not only the heavy non-aromatic hydrocarbons but also the heavy aromatic hydrocarbons from the extractive solvent, especially when the aromatic hydrocarbons in the solvent are in the C10+ molecular weight range.

Abstract: Extractive distillation processes whereby water-soluble extractive distillation (ED) solvents are regenerated and recovered employ improved operations of the extractive distillation column (EDC) so that polar hydrocarbons are recovered and purified from mixtures containing polar and less polar hydrocarbons and measurable amounts of hydrocarbons that are heavier than intended feedstock and/or polymers that are generated in the ED process. The improved process can effectively remove and recover the heavy hydrocarbons and/or remove polymer contaminants from the solvent in a closed solvent circulating loop through mild operating conditions with no additional process energy being expended. With the improved process, the overhead reflux of the EDC may be eliminated to further reduce energy consumption and to enhance the loading and performance within the upper portion of the EDC, especially when two liquid phases exists therein.

Abstract: A process for recovering polar hydrocarbons from non-polar hydrocarbons, such as aromatics from non-aromatics, naphthenes from paraffins and isoparaffins, or olefins from paraffins and isoparaffins, in feed mixtures containing at least a measurable amount of heavier hydrocarbons. This improved extractive distillation (ED) process recovers aromatic hydrocarbons including benzene, toluene, and xylenes from the C6-C8 petroleum streams containing a measurable amount of C9+ hydrocarbons. The ED process also recovers benzene and toluene from the C6-C7 petroleum streams containing a measurable amount of C8+ hydrocarbons. The ED solvent utilized to recover and purify the aromatic hydrocarbons from the petroleum stream with a heavier than intended feedstock of hydrocarbons is also regenerated and recovered.

Abstract: A process for upgrading hydrocarbonaceous oil containing heteroatom-containing compounds where the hydrocarbonaceous oil is contacted with a solvent system that is a mixture of a major portion of a polar solvent having a dipole moment greater than about 1 debye and a minor portion of water to selectively separate the constituents of the carbonaceous oil into a heteroatom-depleted raffinate fraction and heteroatom-enriched extract fraction. The polar solvent and the water-in-solvent system are formulated at a ratio where the water is an antisolvent in an amount to inhibit solubility of heteroatom-containing compounds and the polar solvent in the raffinate, and to inhibit solubility of non-heteroatom-containing compounds in the extract. The ratio of the hydrocarbonaceous oil to the solvent system is such that a coefficient of separation is at least 50%.

Abstract: A method is provided for the recovery of aromatic hydrocarbons from the extract phase of aromatic-selective solvent extraction process which involves withdrawing a vapor side-cut fraction containing aromatic hydrocarbons and solvent from a stripping zone and passing the side-cut fraction to a rectification zone which can be refluxed with an aqueous condensate. The benefits of the invention are that the introduction of the rectification zone bottoms to the bottom of the stripping section provides an aromatic product comprising less than 100 wt. ppm. solvent, provides improved stripping over prior schemes, and reduces the flowrate of stripping medium throughout the stripping zone which results in energy saving.

Abstract: A method of separation of aromates from hydrocarbon mixtures by extractive distillation with a selective solvent, includes introducing a hydrocarbon mixture into the extractive distillation column, distillating out non-aromate components of the introduced hydrocarbon mixture from a head of the extractive distillation column, withdrawing aromates together with a used solvent from a sump of the extractive distillation column and supplying to a driving-out column, separating the aromates from the solvent in the driving-out column, withdrawing the aromates as a head product and the solvent as a sump product from the driving-out column, reintroducing the withdrawn solvent into the extractive distillation column, the withdrawing of the solvent from the driving-out column including withdrawing only part of the solvent with a high temperature required for the complete aromate driving-out from the sump of the driving-out column, while a rest of the solvent with a certain aromate content and a lower temperature is with

Abstract: In a combined solvent extraction/steam distillation process for the separation of aromatic hydrocarbons from a mixture of aromatic and non-aromatic hydrocarbons, there are three major thermal and material cycles: the solvent cycle, the hydrocarbon cycle, and the water cycle. The process is improved by redistributing the energy use between the three cycles to minimize the internal recycle within the process and to reduce the overall energy requirements. One means of the redistribution includes cooling of a lean solvent stream with liquid in a recovery or stripping column. Cooling of the lean solvent reduces flashing within an extract column and the resulting reflux of hydrocarbons to the extract column.

Abstract: Methods are provided for the recovery of aromatic hydrocarbons from the extract phase of aromatic-selective solvent extraction processes which involve withdrawing a vapor side-cut fraction containing aromatic hydrocarbons and solvents from a stripping zone and passing the side-cut fraction to a rectification zone which can be refluxed with aromatic hydrocarbons or aqueous condensate.

Abstract: An improved process for the extraction of aromatics from a mixed feed provides additional flexibility of operation which is especially useful when the feed contains relatively large amounts of nonaromatics and therefore produces a large raffinate stream. Water for washing the non-aromatic raffinate is obtained in part by condensing a portion of the steam generated for stripping aromatics from the extract.

Abstract: A process for the simultaneous separation of aromatics and non-aromatics from a heavy hydrocarbon stream and a light hydrocarbon stream in which process:(a) aromatics are extracted in a first extractor from the heavy hydrocarbon stream with the aid of a selective solvent which has a higher boiling point than that of said light hydrocarbon stream,(b) selective solvent is removed from the raffinate obtained from said first extractor, to yield heavy non-aromatics(c) aromatics are extracted from the light hydrocarbon stream in a second extractor with the aid of the extract phase obtained from the first extractor,(d) selective solvent is removed from the raffinate obtained from said second extractor to yield heavy aromatics and light non-aromatics(e) the extract phase from the second extractor is subjected to extractive distillation,(f) the bottom fraction of the extractive distillation is separated by distillation into light aromatics and selective solvent, and(g) the selective solvent obtained in step (f) is at

Abstract: A process for the recovery of aromatic hydrocarbons and a non-aromatic raffinate stream from a hydrocarbon charge stock is disclosed. The hydrocarbon charge stock is treated with an aromatics-selective solvent to provide an aromatics-rich solvent stream and a non-aromatic raffinate stream. The aromatics-rich solvent stream is treated in a stripper column at conditions to separate substantially all of the non-aromatic hydrocarbons therefrom. The rich solvent stream is subjected to steam stripping to provide a high purity aromatics stream and an aqueous stream comprising the steam condensate and residual aromatics. This aqueous stream is treated with a minor portion of the non-aromatic raffinate to remove the residual aromatics, and the resulting aqueous stream is utilized to wash the remainder of the raffinate free of solvent. The raffinate stream is recovered substantially free of aromatics.

Abstract: A solvent system composed essentially of sulfolane and a ketone, e.g., sulfolane and methyl ethyl ketone is employed in a liquid-liquid extraction operation to separate a low boiling olefin, e.g., pentene-2, hexene-1, octene-1, etc., from a corresponding close boiling paraffin, e.g., n-pentane, n-hexane, and n-octane, respectively, and wherein solvent is recovered by employing a portion thereof in a drying or stripping column.

Abstract: A process for contacting two immiscible fluids is disclosed. A liquid stream enters the top of an apparatus and travels downward within an annular bed of packing. A vapor stream or a less dense liquid stream enters the bottom of the apparatus and travels upward making many radial flow passes through succeedingly higher parts of the annular bed. The sigmoid flow of the rising stream is channeled by horizontal disks within the open central volume of the annular bed and by horizontal open-centered rings which surround the annular bed at staggered elevations.

Abstract: A process for the solvent extraction of aromatic hydrocarbons from a mixture thereof with non-aromatic hydrocarbons, and for the recovery of a non-aromatic fraction substantially free of aromatic hydrocarbons, is disclosed. Said mixture is treated with an aromatic-selective solvent in a first extraction zone to provide an aromatic-rich solvent stream and a non-aromatic raffinate stream. The rich solvent stream is treated in a first solvent recovery zone to provide a high purity aromatic stream and a lean solvent stream. One portion of the lean solvent stream is recycled to the first extraction zone, and residual aromatic hydrocarbons are stripped from the remaining portion. This aromatics-free solvent is then utilized to extract residual aromatics from a fraction of the non-aromatic raffinate to provide a high purity paraffin stream.

Abstract: It has been discovered that extraction processes which employ solvents to separate components from a feed stream and which solvents are themselves recovered by stripping from the thus produced extract or raffinate or both are improved in that the solvent is stripped from the extract, raffinate or both by the use of steam which has been previously distilled from a major portion of the process stream in one of the initial stages of the solvent recovery process, which steam rather than being vented or condensed for disposal is employed as a replacement for specifically generated fresh steam. This recycle steam is employed to strip any residual solvent from the extract, the raffinate or both. The steam and any residual solvent thus stripped is recycled from the extract stripper, raffinate stripper or both to the input feed of the solvent recovery train.

Abstract: This invention provides a unique means of effective corrosion inhibition and corrosion inhibitor utilization in a process for the extraction of aromatics from a hydrocarbon mixture using sulfolane. The corrosion inhibitor used is an organic amine. The invention involves introduction of the inhibitor into the overhead receiver of the benzene fractionation column and the recycle of water collected in that receiver to the stripper column overhead receiver. The inhibitor is thus effectively distributed throughout the process.

Abstract: High efficiency in liquid-liquid 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.

Abstract: Sulfolane is recovered from the extract and raffinate product streams of an extraction process employing sulfolane as the solvent by contacting the extract and raffinate product streams with a solid adsorbent and regenerating the adsorbent by displacing the adsorbed solvent with extraction process feed.