Abstract: A process for separating the isomers of dichlorotoluene from a feed mixture of the same. Separation of the isomers is effected by selective adsorption and desorption and is susceptible to various flow schemes for performing continuous adsorptive separations. The process uses an L-type adsorbent having alkali metal cations, or mixtures thereof as cations and a desorbent containing 1,2-dichlorobenzene or chlorobenzene alone or either admixed with saturated aliphatic hydrocarbons having less than 9 carbon atoms.

Abstract: A process for the liquid phase adsorptive separation of phenylalanine from a fermentation broth feed containing phenylalanine and salts. The feed is contacted with a Y zeolite adsorbent, exchanged with sodium, potassium or calcium ions, to selectively adsorb the phenylalanine onto said adsorbent to the substantial exclusion of the other feed components and recovering phenylalanine by desorbing with water. Phosphate salts can be recovered in the raffinate in the adsorption process by washing the adsorbent with acetic acid prior to use.

Abstract: A process for the separation of one or more hydroxy paraffinic dicarboxylic acids from a feed mixture comprising said acid(s), and one or more olefinic dicarboxylic acids which process employs an adsorbent comprising a non-zeolitic, hydrophobic, crystalline silica molecular sieve material, to selectively reject the hydroxy paraffinic dicarboxylic acid(s) to a raffinate stream for the ultimate recovery of a purified quantity of such acid(s). The olefinic dicarboxylic acid(s) are thereafter removed from the adsorbent by contacting the adsorbent with a desorbent material and said acid(s) is (are) recovered to an extract stream. In a preferred embodiment the process uses a silicalite adsorbent, aqueous acetone desorbent and a simulated moving-bed countercurrent flow system utilizing therein a pre-pulse technique.

Abstract: The separation of the para-isomer of a dialkyl benzene from a mixture of the isomers thereof, especially p-xylene, by contacting the mixture at adsorption conditions with a type X or type Y zeolite adsorbent, ion exchanged with barium and potassium, and recovering the para-alkylbenzene from the adsorbent by contacting the adsorbent with fluorobenzene or a difluorobenzene at desorption conditions.

Abstract: A chromatographic process able to separate para-xylene from C.sub.8 isomers and C.sub.9 aromatics. In the process, the para-xylene-containing feed mixture is contacted with an X or Y zeolite adsorbent having Group IA or IIA cations, e.g., barium and/or potassium, at exchangeable cationic sites. The para-xylene components are selectively adsorbed onto the adsorbent. The non-adsorbed feed is then removed from the adsorbent and the para-xylene recovered by desorption with tetralin. The C.sub.9 's and the other xylene isomers in the raffinate, can be separated from this heavy desorbent by fractionation of the raffinate and the desorbent recycled to the process.

Abstract: An adsorptive separation process for separating sterols from a tall oil feed mixture, which process comprises contacting the feed mixture with an adsorbent comprising an activated-type carbon sieve having a pore diameter of 15-20 .ANG. and a surface area of 300-1500 m.sup.2 /g, selectively adsorbing substantially all of the sterols to be separated on the adsorbent and thereafter recovering high purity sterols. A desorption step is used to desorb the adsorbed sterols with an aromatic liquid, e.g., chlorobenzene.

Abstract: Arabinose is separated from mixtures of monosaccharides containing arabinose and other aldopentoses and aldohexoses by adsorption on sulfonated polystyrene divinylbenzene crosslinked ion exchange resins exchanged with calcium-ammonium cationic and desorbing the adsorbate with water. The other saccharides are removed from the adsorption process in the raffinate.

Abstract: A process for the liquid phase adsorptive separation of psicose from an aqueous feed mixture of monosaccharides containing psicose along with other aldoses and ketoses. The feed is contacted with a calcium-Y type zeolite in two stages. Psicose and fructose are selectively adsorbed to the substantial exclusion of other aldoses and ketoses. In a first embodiment, the extract from the first stage is psicose and fructose is eluted with the raffinate components. In a second embodiment, psicose is again recovered in high purity from the first place as a first extract material while a second extract material, comprising highly purified fructose, is also recovered. The process can be carried out on a commercial scale by means of a simulated moving bed flow scheme.

Abstract: A process for the liquid phase adsorptive separation of 4,4'-dichlorodiphenylsulfone (4,4'-DCDPS) from crystallization residue feed mixture also containing other DCDPS isomers. The feed is contacted with an X or Y type zeolite, substituted with a cation of a Group IA or IIA metal or ammonium. The other isomers are selectively adsorbed to the substantial exclusion of 4,4'-DCDPS. The 4,4'-DCDPS is recovered in high purity by fractionating the raffinate to recover the desorbent, aliphatic alcohols having 4-8 carbon atoms either used alone or diluted with an aromatic compound.

Abstract: The polyurethanes and polyureas resulting from ambient-temperature-curing isocyanate-terminated urethane prepolymers with N-alkyl-substituted aromatic polyamines and, optionally, with an added polyol, but primary amine-free, in the presence of a combination catalyst comprising an aliphatic carboxylic acid, e.g., adipic, stearic, oleic acids, and an organometallic catalyst containing, e.g., tin, mercury, bismuth, etc. are broadly useful as coatings on the surface of objects made of metal, wood, glass, plastic or masonry materials such as concrete, bricks, etc. or as castings cured in situ. One-shot and quasi-prepolymer systems are also disclosed. The diamine N,N'-di-(sec-butyl)-4,4'-methylenedianiline is a particularly useful diamine.

Abstract: A chromatographic process able to separate para-xylene from C.sub.8 isomers and C.sub.9 aromatics. In the process, the para-xylene-containing feed mixture is contacted with an X or Y zeolite adsorbent having Group IA or IIA cations, e.g., barium and/or potassium at exchangeable cationic sites. The para-xylene is selectively adsorbed onto the adsorbent. The feed is then removed from the adsorbent and the para-xylene recovered by desorption with diethyltoluene. The C.sub.9 's and the other xylene isomers in the raffinate, can be separated from this heavy desorbent by fractionation of the raffinate and the desorbent recycled to the process.

Abstract: A process for the liquid phase adsorptive separation of arabinose from an aqueous feed mixture of monosaccharides containing arabinose along with other aldoses and ketoses. The feed is contacted with an ammonium X-type zeolite. Arabinose is selectively absorbed to the substantial exclusion of other aldoses and ketoses and thereafter is recovered in high purity by desorption with water. The process can be carried out on a commercial scale by means of a simulated moving bed flow scheme.

Abstract: Citric acid is separated from a fermentation broth by using an adsorbent comprising a water-insoluble macroreticular or gel weakly basic anionic exchange resin possessing tertiary amine functional groups or pyridine functional groups, said anionic exchange resin comprising a cross-linked acrylic or styrene resin matrix. Citric acid is desorbed by water or dilute sulfuric acid. The pH of the feed is maintained below the first ionization constant (pKa.sub.1) of citric acid to maintain selectivity.

Abstract: Citric acid is separated from a fermentation broth by using an adsorbent comprising a strongly water-insoluble, macroreticular or gel, basis anionic exchange resin possessing quaternary amine functional groups, said a anionic exchange resin having a cross-linked acrylic or styrene resin matrix and a desorbent comprising water or dilute sulfuric acid. The pH of the feed is maintained below the first ionization constant (pKa.sub.1) of citric acid to maintain selectivity.

Abstract: An adsorptive separation process for separating sterols from a tall oil feed mixture, which process comprises contacting the feed mixture with an adsorbent comprising a carbon sieve having average pore diameters greater than about 20 .ANG., especially 30-90 .ANG., and a surface area greater than about 300 m.sup.2 /g, especially 700-1100 m.sup.2 /g, and, preferably, a carbonaceous pyropolymer or carbonized resin, selectively adsorbing substantially all of the sterols to be separated to the substantial exclusion of the other components and thereafter recovering high purity sterols. A desorption step is used to desorb the adsorbed sterols with an aromatic liquid hydrocarbons, e.g., toluene or chlorobenzene.

Abstract: Mannose is separated from mixtures with glucose and other saccharides by adsorption of sulfonated polystyrene divinylbenzene crosslinked ion exchange resins, and desorbing the adsorbate with water. Glucose is removed from the adsorption process in the raffinate.

Abstract: This invention comprises a process for separating isomers of dihydroxybenzene (DHB) from a feed mixture comprising at least two of said isomers, which process comprises contacting the mixture at adsorption conditions with an adsorbent comprising a Y type zeolite cation exchanged with a cation in the group Ca, Ba or Li, thereby selectively adsorbing o-DHB (catechol), or K, thereby selectively adsorbing p-DHB (hydroquinone). In the case where all three isomers are present in the feed, a cation from the first group is used, the remainder of the feed mixture is removed from the adsorbent and o-DHB is recovered by desorption at desorption conditions with methanol. P-DHB is recovered from the remainder by adsorption with the same or other adsorbent listed above and desorption at desorption conditions with ethanol.

Abstract: The chromatographic adsorption separation of indene from petrochemical or synthetic feed mixtures with an Na- or K-exchanged X- or Y-zeolite and toluene, benzene, fluorobenzene or other halogen- or alkyl-substituted monocyclic aromatic desorbents. Selectivity of the separation is dependent on water content, from 1-8% (wt.), of the adsorbent.

Abstract: The separation of monoglycerides from diglycerides and triglycerides is performed by an adsorptive chromatographic process in liquid phase using sodium, magnesium, lithium or potassium-exchanged X zeolites or potassium or sodium-exchanged Y zeolite, or potassium-exchanged L zeolite as the adsorbent. A ketone or ketone/n-aliphatic hydrocarbon can be selected as the desorbent.

Abstract: A process for separating the para and ortho isomers of a halogen substituted toluene from a feed mixture of the same. Separation of the isomers is effected by selective adsorption and desorption and is susceptible to various flow schemes for performing continuous adsorptive separations. The process uses an X type zeolite adsorbent having calcium, barium, potassium, or combinations thereof as cations and a mixed desorbent containing chlorobenzene and/or bromobenzene and alicyclic hydrocarbons.