Abstract: A chromatographic process for separating normal olefins from mixtures with branched-chain olefins with a high silica zeolitic molecular sieve, e.g., silicalites, ZSM-5, etc., having low acid catalytic reactivity, which selectively adsorbs the normal olefins, and uses alkyl-substituted cycloparaffins, e.g., methylcyclohexane, as desorbents.

Abstract: The present invention relates in general to highly siliceous zeolitic molecular sieve adsorbent compositions having reduced catalytic activity and to the process for preparing such compositions. The number of acid sites in the so-called silica molecular sieves is very low, but exhibit a disproportionately high acid activity. In a variety of adsorptive separation applications in which the hydrophobic character of these molecular sieves is important, undesirable catalytic conversion of one or more of the adsorbates is frequently encountered. This acid activity is effectively eliminated by incorporating a stoichiometric excess with respect to the aluminum content of the molecular sieve of an alkali metal compound into the molecular sieve followed by calcining the loaded silicalite at temperatures of at least 750.degree.C. The adsorbent is particularly useful in separations of materials which are subject to catalytically initiated reactions, e.g., olefins and alcohols.

Abstract: A two-stage separation process for separating highly unsaturated triglycerides from an interesterification reaction product by sequential chromatographic separations wherein triglycerides are separated from saturated fatty acids in the first stage and unsaturated fatty acids are recovered in the second stage for recycle to the interesterification reaction zone. In a preferred embodiment using silica gel and silicalite in the two stages, respectively, and heptanone as desorbent in both stages, triglyceride product is removed as the first stage raffinate and the unsaturated fatty acid recycle product stream is removed as the raffinate in the second stage. In another embodiment, using silicalite adsorbent in both stages and 2-heptanone and acetone in the first and second stages, respectively, saturated fatty acids are removed as the extract in the first stage and triglycerides and unsaturated fatty acids are separated as raffinate product and extract product for recycle, respectively.

Abstract: The separation of durene in high purity from coal tar or petroleum fractions by an adsorptive chromatographic process and liquid phase with lithium-exchanged X zeolite as the adsorbent and liquid aromatic desorbents.

Abstract: Rigid urea-modified polyisocyanurate foams with improved dimensional stability and flame retardancy have densities of 1-12 p.c.f., a limiting oxygen index greater than 22 and dimensional changes at 100% R.H. and 70.degree. C. of less than 2% in any linear dimension and a method of making same. The method comprises reacting an organic polyisocyanate, a blowing agent and an N,N'-dialkyl aromatic diamine in the presence of a trimerization catalyst and, if water is used as the blowing agent, a blowing catalyst, wherein the N,N'-dialkyl aromatic diamine and an amine produced by water, if used, constitute the sole sources of active hydrogen.

Abstract: A chromatographic process for separating linear olefins from mixtures with branched-chain olefins with a high silica zeolitic molecular sieve, e.g., silicalites, ZSM-5, etc., having low acid catalytic reactivity, which selectively adsorbs the normal olefins, and uses ketones as desorbents.

Abstract: The separation of free fatty acids from triglycerides is performed by an adsorptive chromatographic process in liquid phase with silica gel as the adsorbent. A ketone, having from 3 to 8 carbon atoms, such as 2-heptanone, an ester or an ether can be selected as the desorbent.

Abstract: The separation of naphthalene in high purity from coal tar or petroleum fractions by an adsorptive chromatographic process and liquid phase with lithium-exchanged X zeolite as the adsorbent and aromatic desorbents.

Abstract: An adsorption process for separating the high octane components, including multi-branched paraffins and isopentane of a C.sub.5 -C.sub.6 isomerate from lower octane monobranched and normal paraffin components by contacting the isomerate with an X zeolite exchanged with a mixture of at least two cations from Group II-A. The adsorbed low octane components are preferably desorbed with a desorbent selected from the group consisting essentially of isooctane, 2,2,3-trimethyl pentane, 2,2,4-trimethyl pentane, 2,3,4-trimethyl pentane, 1,2-dimethyl cyclohexane, 2,2-dimethyl hexane, 2,2-dimethyl octane, 3-ethyl hexane, 2,2,4-trimethyl hexane and mixtures thereof.

Abstract: In the process flow scheme for chromatographically separating para-xylene from C.sub.8 isomers containing substantial amounts of C.sub.9 aromatic hydrocarbon impurities with BaX or KY zeolite adsorbent and heavy desorbents, e.g., tetralin and diethyltoluene, a bottoms stream from the extract fractionation column containing desorbent is recycled to the separation unit and a sidecut stream, containing C.sub.9 aromatic hydrocarbon impurities and a minor amount of the desorbent from the raffinate stream, is directed to the raffinate fractionation column, thereby removing C.sub.9 aromatic hydrocarbons from the desorbent before recycling the desorbent to the separation unit, and preventing C.sub.9 aromatics from building up in the desorbent input. A fractionator for the extract column bottoms stream is eliminated, lowering capital costs, and energy requirements for the raffinate column are reduced.

Abstract: The separation of monounsaturated triglycerides from polyunsaturated triglycerides is achieved by an adsorptive chromatographic process in liquid phase with silica gel as the adsorbent at temperatures higher than about 100.degree. C. Desorbents in the separation process include ketones, having from 3 to 8 carbon atoms in concentrations of up to about 25% (vol.) in normal or branched alkanes, e.g., n-hexane or iso-octane, or p-cymene in concentrations of 20% (vol.) to 100%.

Abstract: In the process flow scheme for chromatographically separating paraxylene from C.sub.8 isomers containing substantial amounts of C.sub.9 aromatic hydrocarbon impurities with an X or Y zeolite adsorbent and heavy desorbents, e.g., tetralin and derivatives thereof and diethyltoluene, a drag stream is split from the extract fractionation column bottoms stream, containing desorbent and C.sub.9 aromatic hydrocarbon impurities for recycling to the separation unit, and is directed to the raffinate fractionation column, where C.sub.9 aromatic hydrocarbons are removed to prevent C.sub.9 aromatic hydrocarbons from building up in the desorbent input to the separation unit. A fractionator for the extract column stream is eliminated, lowering capital costs.

Abstract: The separation of unsaturated triglycerides on the basis of degree of unsaturation is achieved by an adsorptive chromatographic process in liquid phase with silane- or alcohol-treated silica gel as the adsorbent. Desorbents in the separation process include ketones, having from 3 to 8 carbon atoms, low molecular weight esters, having from 3 to 8 carbon atoms or p-cymene, or mixtures thereof, alone or mixed with a hydrocarbon diluent. The preferred temperature in the separation column is from 120.degree.-150.degree. C.

Abstract: N,N'-di-sec-alkenyl-or-di-sec-alkyl-substituted methylene diphenyl diamines are effective curing agents for making polyurethane foams from MDI-based polyisocyanates. The diamines are especially advantageous since foams of lower density having lower hardness can be obtained without utilizing chlorofluorocarbous (CFC's) and without sacrificing tensile strength, tear strength, SAG or compression set values.

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 zeolite adsorbent having barium or barium and potassium ions, 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 indan or an alkyl derivative of indan. Any C.sub.9 aromatic hydrocarbons and the other xylene isomers in the raffinate can be separated from these heavy desorbents by fractionation of the raffinate and the desorbent can be recycled to the process.

Abstract: A process for the coextraction of para-cresol and meta-cresol from a feed mixture comprising p-cresol, o-cresol and m-cresol and one other alkyl phenol with an adsorbent comprising an X zeolite exchanged with barium ions or a mixture of barium and potassium ions at exchangeable sites to preferentially adsorb both para- and meta-cresol. The adsorbent must contain at least about 5 wt. % water (LOI method). The coextracted cresol isomers are thereafter removed from the adsorbent by contacting it with a desorbent material and recovering said coextracted cresols as a product stream. Para-cresol and meta-cresol can thereafter be recovered as purified individual isomers by a second state adsorptive separation using a second adsorbent selective for para-cresol, e.g., said first adsorbent dried to an LOI of less than about 4 wt. %, preferably about 2 wt. % water. In a preferred embodiment, the process uses a simulated moving-bed countercurrent flow system in both adsorption separation steps.

Abstract: A process for separating the ortho-isomer of chlorotoluene from a feed mixture containing ortho- and para-chlorotoluene by selective adsorption and desorption with an L zeolite adsorbent having potassium or potassium and sodium cations at cation exchange sites and a desorbent containing chlorobenzene or mixtures thereof with a saturated aliphatic hydrocarbon and especially 10-50% chlorobenzene and 50-90% saturated aliphatic hydrocarbon. The ortho-chlorotoluene is relatively non-absorbed on the adsorbent and is recovered prior to more strongly adsorbed species in a rejective separation process.

Abstract: The invention relates to the production of high octane fuels including a process for separating the high octane components for the gasoline pool from lower octane components, which are recycled to an isomerization reaction by adsorptively separating dimethyl paraffins from an isomerate with an aluminophosphate zeolite and SSZ-24, an all-silica zeolite adsorbent isostructural with AIPO.sub.4 -5, and a C.sub.6-10 normal paraffin desorbent. The lower octane components of the isomerate, normal paraffins and mono-branched paraffins, are recycled to the isomerization reaction zone for further conversion to multi-branched paraffins. The useful aluminophosphates are SAPO-5, AIPO.sub.4 -5 MgAPO-5 and MAPSO-5.

Abstract: A chromatographic process able to separate paraxylene 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 while maintaining the water content of the adsorbent at about 4.2-6% (LOI). 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 or alkyl derivatives of 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: The separation of free fatty acids from triglycerides and/or diglycerides is performed by an adsorptive chromatographic process in liquid phase with a crystalline aluminophosphate, e.g., AIPO.sub.4 -5, AIPO.sub.4 -11 or AIPO.sub.4 -54, as the adsorbent. A ketone, having from 3 to 8 carbon atoms, such as 2-heptanone, or a mixture thereof, alone or admixed with a normal alkane can be selected as the desorbent.