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.

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: The present invention relates to 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. According to the invention, an improved extractive distillation (ED) process is disclosed for recovering aromatic hydrocarbons including benzene, toluene, and xylenes (BTX aromatics) from the C6-C8 petroleum streams containing at least a measurable amount of C9+ hydrocarbons. The invention also relates to an improved ED process for recovering mainly benzene and toluene from the C6-C7 petroleum streams containing at least a measurable amount of C8+ hydrocarbons.

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: A gas-liquid contactor baffle includes a body having a first portion, a second portion and a middle portion, the middle portion being positioned between the first portion and the second portion. The middle portion is a corrugated sheet having a first face and a second face. The corrugated sheet has alternating ridges and open ended channels extending across each of the first face and the second face between the first portion and the second portion. The first portion has a first collection channel adapted to collect liquids from the open ended channels of the middle portion when flow is along the first face in a first direction. The second portion having a second collection channel adapted to collect liquids from the open ended channels of the middle portion when flow is along the second face in a second direction.

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 comprises 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. In this invention, 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 of this invention are higher Murphree tray efficiency due to minimum liquid back-mixing, as well as minimum local entrainment due to uniform froth height.

Abstract: An apparatus is provided for improved gas/liquid contact in a chemical process tower, resulting in better performance. The apparatus comprises 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 novel method for connecting multiple existing columns which are retrofitted into vapor-liquid contacting devices with trays or packings suitable for the operation of a three-phase (vapor-liquid-liquid) extractive distillation column for aromatics recovery. The retrofitted columns are connected by a vapor transfer line to transfer the vapor phase from the top of the lower column to the bottom of the upper column, and by a liquid transfer line to transfer the liquid phase from the bottom of the upper column to the top of the lower column of the three-phase extractive distillation column.

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 gas-liquid contactor baffle includes a body having a first portion, a second portion and a middle portion, the middle portion being positioned between the first portion and the second portion. The middle portion is a corrugated sheet having a first face and a second face. The corrugated sheet has alternating ridges and open ended channels extending across each of the first face and the second face between the first portion and the second portion. The first portion has a first collection channel adapted to collect liquids from the open ended channels of the middle portion when flow is along the first face in a first direction. The second portion having a second collection channel adapted to collect liquids from the open ended channels of the middle portion when flow is along second face in a second direction.

Abstract: The invention disclosed relates to catalytic distillation column internals providing improved liquid and catalyst contacting for simultaneous catalytic reaction and separation of the reaction mixture. The invention provides an improved catalytic distillation system providing optimum balance of catalytic reaction and mass transfer steps, wherein distribution, mixing and application of liquid to the reaction zone and separation zones is 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 said tray performs the functions of both of the reaction section and the separation section of the catalytic distillation column simultaneously within a stage.

Abstract: Disclosed is a distillation system and method for recovering acetic acid from a feed stream containing acetic acid and water stream generated during terephthalic acid production. The invention includes a liquid-liquid extraction column and a dehydration distillation column utilizing azeotropic distillation or conventional to recover the acetic acid. The liquid-liquid extraction column is installed upstream from the dehydration distillation column. The liquid-liquid extraction column produces an extract of an extraction solvent and acetic acid which is sent to the dehydration distillation column to separate the extraction solvent and acetic acid. The dehydration distillation column may be used with or without a condenser system to recover the energy. The condenser system is a steam generator that condenses the vapor into a concentrated acetic acid stream while generating a low pressure steam. Any remaining acetic acid in water is sent to a waste water recycling facility.

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: 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.

Abstract: An improved liquid flow distributor assembly for a process column of the type wherein the distributor is positioned above a packing section for the distribution of liquid downwardly therethrough. The improvement comprises a plurality of distributor troughs constructed with a series of internal distributor channels having stilling plates depending therefrom. Each channel is constructed of a generally U-shaped cross section, aligned with and affixed to the distributor trough for providing primary liquid flow to intermediate regions thereof. In this manner, liquid gradients between opposite ends of the troughs are eliminated and a uniform quiescent liquid level is maintained.