Abstract: A vapor distributor for use in atmospheric or vacuum columns includes a new design of vapor inlet device, or vapor horn, to provide superior mixing and distribution of a tangential first feed and a vertical second feed. New vapor inlet device has an inlet dividing the first feed into two portions, each flowing in respective housings in opposed circulation directions, and a plurality of vanes for redirection of vapor. Mixing and distribution of feeds by the vapor distributor is further enhanced by inclusion in vapor distributor of a mixer and vapor directing plates.

Abstract: The invention disclosed relates to an apparatus and method for recovering acetic acid from an aqueous feed stream containing acetic acid, in particular a stream generated during terephthalic acid production. The apparatus includes: a liquid-liquid extraction column to which water-rich feed streams are fed, having a guard bed situated near the top and within the extraction column for conversion by reaction with acetic acid of alcohol within the mixture to the corresponding ester; and an azeotropic distillation column to remove residual water from acetic acid, to which water-poor feed streams are fed directly at a height of the azeotropic distillation column at which the mixture therein has a similar water concentration. The liquid-liquid extraction column produces an extract comprising an extraction solvent and acetic acid which is sent to the azeotropic distillation column to separate residual water and acetic acid.

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: An energy-efficient extractive distillation process for producing anhydrous ethanol from aqueous/ethanol feeds containing any range of ethanol employs an extractive distillation column (EDC) that operates under no or greatly reduced liquid reflux conditions. The EDC can be incorporated into an integrated process for producing anhydrous ethanol used for gasoline blending from fermentation broth. By using a high-boiling extractive distillation solvent, no solvent, is entrained by the vapor phase to the EDC overhead stream, even under no liquid reflux conditions. The energy requirement and severity of the EDC can be further improved by limiting ethanol recovery in the EDC. In this partial ethanol recovery design, ethanol which remains in the aqueous stream from the EDC is recovered in a post-distillation column or the aqueous stream is recycled to a front-end pre-distillation column where the ethanol is readily recovered since the VLE curve for ethanol/water is extremely favorable for distillation.

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: A tray assembly is provided for improved gas/liquid contact when used in a large chemical process tower. Each tray has a downcomer wall of which the lower portion is a distributor. The distributor has discharge ports sized to control the rate of liquid flow at different positions across the distributor and flanges aligned individually to direct liquid flow from different discharge ports across different areas of the tray deck immediately below the downcomer. In combination, discharge ports and liquid flow directing flanges effect even liquid flow across the surface of the tray immediately below. Benefits of this invention are trays with better mass transfer efficiency and enhanced capacity compared with prior art trays.

Abstract: An energy-efficient extractive distillation process for producing anhydrous ethanol from aqueous/ethanol feeds containing any range of ethanol employs an extractive distillation column (EDC) that operates under no or greatly reduced liquid reflux conditions. The EDC can be incorporated into an integrated process for producing anhydrous ethanol used for gasoline blending from fermentation broth. By using a high-boiling extractive distillation solvent, no solvent is entrained by the vapor phase to the EDC overhead stream, even under no liquid reflux conditions. The energy requirement and severity of the EDC can be further improved by limiting ethanol recovery in the EDC. In this partial ethanol recovery design, ethanol which remains in the aqueous stream from the EDC is recovered in a post-distillation column or the aqueous stream is recycled to a front-end pre-distillation column where the ethanol is readily recovered since the VLE curve for ethanol/water is extremely favorable for distillation.

Abstract: The invention disclosed relates to catalytic distillation column internals providing improved liquid reaction mixture and catalyst contacting for simultaneous catalytic reaction and separation of the reaction mixture. The invention is an improved catalytic distillation apparatus providing optimum balance of catalytic reaction and mass transfer steps, wherein distribution, mixing and feeding of liquid reaction mixture to the reaction zone and distillation section are better controlled and more uniformly applied. At least one catalyst bed is situated in at least one receiving pan of a distillation tray so that the tray performs the functions of both of the reaction section and the distillation section of the catalytic distillation column simultaneously within a stage.

Abstract: An energy efficient, high throughput process for aromatics recovery can be readily implemented by revamping existing sulfolane solvent extraction facilities, or constructing new ones, so as to incorporate unique process operations involving liquid-liquid extraction and extractive distillation. Current industrial sulfolane solvent based liquid-liquid extraction processes employ a liquid-liquid extraction column, an extractive stripping column, a solvent recovery column, a raffinate wash column, and a solvent regenerator. The improved process for aromatic hydrocarbon recovery from a mixture of aromatic and non-aromatic hydrocarbons requires transformation of the extractive stripping column into a modified extractive distillation column. The revamping incorporates the unique advantages of liquid-liquid extraction and extractive distillation into one process to significantly reduce energy consumption and increase process throughput.

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 vapor distributor for use in atmospheric or vacuum columns includes a new design of vapor inlet device, or vapor horn, to provide superior mixing and distribution of a tangential first feed and a vertical second feed. New vapor inlet device has an inlet dividing the first feed into two portions, each flowing in respective housings in opposed circulation directions, and a plurality of vanes for redirection of vapor. Mixing and distribution of feeds by the vapor distributor is further enhanced by inclusion in vapor distributor of a mixer and vapor directing plates.

Abstract: An integrated, continuous process for transforming feedstock, e.g., reformate, which contains high levels of benzene into a low-benzene content feedstock that is suitable for gasoline blending initially removes benzene from the reformate by extractive distillation, then partially hydrogenating the high purity benzene into cyclohexane under mild conditions in a one-stage hydrogenation reactor, and thereafter recovering a cyclohexane product with high purity from the hydrogenation reactor effluent in a back-end purification step using extractive distillation. The initial or front-end separation step yields a low-benzene content reformate.

Abstract: A highly effective liquid-liquid extraction process to remove nitrogen compounds and especially basic nitrogen compounds from aromatic light petroleum oils with excellent recovery employs de-ionized water, which can be acidified, as the extractive solvent. The product is an aromatic hydrocarbon with ultra-low amounts of nitrogen poisons that can deactivate acidic catalysts. The extracted oils are suitable feedstock for the subsequent catalytic processes that are promoted with the high performance solid catalysts, which are extremely sensitive to nitrogen poison.

Abstract: A tray assembly is provided for improved gas/liquid contact when used in a large chemical process tower, resulting in better performance. Each tray assembly has two levels of tray decks and associated downcomers. Tray decks provide gas/liquid contact for mass transfer and the downcomers are required to clarify the liquid before entering the tray below. A novel downcomer configuration is provided for use in multipass trays. The shape of downcomer bottom chord is designed to allow for liquid to travel across any part of each tray deck at a similar distance between the inlet and the outlet weir. As a result, liquid on the tray deck travels in plug flow pattern. Benefits include a higher Murphree tray efficiency due to minimum liquid back-mixing, as well as minimum local entrainment due to uniform froth height.

Abstract: A highly effective liquid-liquid extraction process to remove nitrogen compounds and especially basic nitrogen compounds from aromatic light petroleum oils with excellent recovery employs de-ionized water, which can be acidified, as the extractive solvent. The product is an aromatic hydrocarbon with ultra-low amounts of nitrogen poisons that can deactivate acidic catalysts. The extracted oils are suitable feedstock for the subsequent catalytic processes that are promoted with the high performance solid catalysts, which are extremely sensitive to nitrogen poison.

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: An apparatus and process are described for recovery of a carboxylic acid by hydrolysis of an ester in a mixture comprising the ester, an alcohol and water. The apparatus comprises a catalytic distillation column containing an acidic catalyst and a distillation column. Simultaneously and interdependently the alcohol is catalytically dehydrated to the corresponding ether and water, and said water reacts with the ester to generate a carboxylic acid rich stream from the catalytic distillation column. The acid is recovered by distillation in the distillation column. The process requires no added water. A second embodiment of the apparatus and process has means to co-feed one or both of added methanol and/or water with the feed to maintain substantially optimum operation independent of feed composition.

Abstract: An apparatus is provided for improved gas/liquid contact in a chemical process tower, resulting in better performance. The apparatus includes a tower having a series of tray decks and downcomers. Tray decks provide gas/liquid contact for mass transfer and the downcomers are required to clarify the liquid before entering the tray below. In this invention, the trays have at least one downcomer and one adjacent active sump. The sump has at least one row of apertures for bubbling vapor through liquid flowing therein, and is separated from the downcomer by a baffle. The clarified liquid at the bottom of the sump is sent to the downcomer. The liquid entering the next tray can be assured to divide evenly for multiple-downcomer applications. Gas/liquid contact is thereby enhanced through the installation of these apertures, and clarification of the liquid from bubbles is thereby improved through the addition of the active sump. Benefits to the tower operation include higher tray capacity and efficiency.

Abstract: A tray assembly is provided for improved gas/liquid contact when used in a large chemical process tower. Each tray has a downcomer wall of which the lower portion is a distributor. The distributor has discharge ports sized to control the rate of liquid flow at different positions across the distributor and flanges aligned individually to direct liquid flow from different discharge ports across different areas of the tray deck immediately below the downcomer. In combination, discharge ports and liquid flow directing flanges effect even liquid flow across the surface of the tray immediately below. Benefits of this invention are trays with better mass transfer efficiency and enhanced capacity compared with prior art trays.

Abstract: The contact between, for example, ascending liquid droplets of lighter liquid, as the dispersed phase, and heavier liquid, as the continuous phase, flowing across perforated trays in a flooded liquid/liquid contacting column, is enhanced by providing upstanding baffles on lower trays, interspersed with depending baffles from the trays above. The baffles cause the heavy liquid to flow along an undulating path. Flow distributing partitions extend along the undulating flow path, between the baffles, to distribute liquid flow across the trays. The roles of the lighter liquid and the heavier liquid may be reversed as phases.