Abstract:
A method for the stabilization of aqueous solutions of nitroform, which process comprises adding a stabilizing amount of urea or a water-soluble carbamic acid alkyl ester, or a mixture thereof to an aqueous solution of nitroform so as to form the respective reaction product thereof with nitroform. The invention also encompasses stabilized such solutions.
Abstract:
AN IMPROVED APPARATUS IS PROVIDED FOR PROCESSING THE EXPLOSIVE KNOWN AS HEXANITROSTILBENE (HNS) FROM A FORM KNOWN AS HNS-I INTO A FORM KNOWN AS HNS-II, TO PROVIDE A REFINED PRODUCT WITH A UNIQUE CRYSTAL FORM SO AS TO FACILITATE HANDLING OF THE MATERIAL. THE APPARATUS OF THE INVENTION USES AN IMPROVED EXTRACTION TECHNIQUE INVOLVING THE USE OF A SOLUTION OF ACETONITRILE IN WHICH HNS-I IS SOLUBLE AND XYLENE IN WHICH HNS IS INSOLUBEL FOR REFINING THE HNS-I INTO AN IMPROVED TYPE OF HNS-II.
Abstract:
1,219,738. Separation of nitroethane from other nitroalkanes. COMMERCIAL SOLVENTS CORP. 9 July, 1969 [26 Aug., 1968], No. 34621/69. Heading C2C. Nitroethane is separated from a mixture with one or more other nitroalkanes, including nitromethane and 2-nitropropane by (a) mixing the nitroalkane mixture with a saturated aliphatic hydrocarbon having 7 or 8 carbon atoms; (b) distilling the mixture to form a distillate consisting of an upper layer and a lower layer comprising nitroethane, nitromethane and the hydrocarbon; (c) returning the upper layer to the distillation step; and (d) redistilling the lower layer until separation of the nitromethane and the hydrocarbon has been effected, thereby producing, as a distillation residue, purified nitroethane. The aliphatic hydrocarbon is preferably n-heptane, 2,2,4-trimethylpentane or 2,3,4-trimethylpentane.
Abstract:
The invention comprises a Werner complex of the general formula Ni(SCN)2Xn which is insoluble or sparingly soluble, in water at room temperature, wherein X is an alpha-arylalkylamine of the formula in which R1 is either hydrogen or a primary alkyl group and R2 is a phenyl radical carrying at least two further alkyl substituents in any of the 3-, 4- and 5-positions, and n is either 2 or 4. Preferably R1 contains 1 to 6 carbon atoms and the alkyl substituents of the phenyl radical have not more than two carbon atoms. The complexes may be made, for example, by adding a solution of the arylalkylamine in heptane, or heptane-chloroform mixture, at room temperature to an aqueous solution obtained by dissolving NiCl2.6H2O and KSCN in water, and separating the resulting precipitate by filtration. The complexes may be used to form clathrates with aromatic compounds and the complex may be formed in the presence of the compound to be clathrated. The clathrate may be formed by heating a complex Ni(SCN)2X4 with one or more clathratable compounds to a temperature sufficient to bring about complete dissociation of the complex into Ni(SCN)2X2 and free amine, and then cooling to effect recombination of the dissociated components to form a clathrate consisting of Ni(SCN)2X4 and the clathratable compound. The complexes of the formula Ni(SCN)2X4 may be used to resolve a mixture of aromatic organic compounds containing at least one clathratable compound by forming a clathrate, separating the clathrate from the mixture and dissociating the clathrate to recover the organic compounds. The clathrate may be dissociated by heating, by treatment with an acid which does not react with the clathrated compound, by steam stripping or treatment with an inert solvent. Clathratable compounds which may be extracted or resolved are, for instance, a ,a ,a -tri -fluorotoluene, nitrobenzene, nitrotoluenes, di-, chlorobenzenes, trichlorobenzenes, cresols, and benzonitrile. Novel amines which are suitable for complex formation are a -(3,4-dimethyl phenyl) ethylamine and corresponding butylamine and heptylamine; a - (3,4,5 - trimethylphenyl) - ethylamine and - propylamine; a -(3,5 - dimethylphenyl) ethylamine and a -(3,4,5 - triethylphenyl) ethylamine. They may be made by reductive amination of the corresponding ketone, for example by heating the ketone with ammonium formate. Specifications 931,775, 935,099 and 945,012 are referred to.
Abstract:
In a method of concentrating or separating a component of a homogenous liquid mixture of at least two substantially non-ionogenic compounds, at least one of which is organic, the mixture is contacted with a resin absorbent having a large surface area per unit weight, the resin absorbent being (a) a crosslinked addition polymer other than an ionexchange resin, (b) insoluble in the liquid mixture and (c) having a preferential absorptive capacity for the component to be concentrated. Absorption may be tested for by agitating the resin with a mixture for a given time and analysing the mixture before and after absorption. The separatory capacity of a resin is defined as where m is the weight of the resin in grams, V is the volume of liquid mixture added in ml., and c0 and c are the volume fractions of the preferentially absorbed component in the liquid phase before and after absorption respectively. Separatory capacities of various specified resins are given for each of the following in admixture with iso-octane: 4-vinylcyclohexene, cyclohexanol, toluene, ethyl acetate, methyl ethyl ketone, styrene, chlorobenzene, ethylene dichloride, chloroform, dioxane, pyridine, naphthalene, nitrobenzene and pyrrole; for each of ethylene dichloride, styrene, and chlorobenzene in admixture with toluene; and for the first named component of each of the following mixtures: ethylene dichloride-ethyl acetate, styrene-4-vinylcyclohexene, chlorobenzene-allyl alcohol, benzene-acrylonitrile, allyl alcohol-water, chloroform-acetone. The treatment of hydrocarbon mixtures such as paraffin/naphthene, olefin/paraffin and solvent mixtures containing alcohols, ketones, hydrocarbons and esters; and also mixtures of capryl alcohol with methyl hexyl ketone and n-butanol with water is referred to. The absorption process can be carried out batchwise or continuously. In the former the liquid mixture is passed through a column packed with resin particles, or the resin particles may pass countercurrent to the liquid. When a two-component mixture A and B, of which A is preferentially absorbed, is passed over the resin, B issues first from the resin until the limit of the absorption capacity for A is reached, after which the original mixture A and B will issue. Enriched A is separated from the resin e.g. by heat, steam distillation, extraction or desorption with another solvent. In the continuous treatment the use of a desorbent C allows complete separation of A and B, and the resin supported in a column is fed alternately with liquid mixture and with desorbent. The desorbent consists of one or more liquids, is completely miscible with A and B, and has a swelling power for the resin of the same order as that of one of the components of the liquid mixture to be separated. Examples describe batch methods for partially separating tolueneiso-octane, dimethyl sebacate-iso-octane, methyl caprate-iso-octane, ethylene dichloride-cyclohexane mixtures using copolymers of divinyl benzene with 2-ethylhexyl acrylate, n-butyl acrylate, n-butyl methacrylate, ethoxyethyl acrylate, and methyl acrylate as absorbents. Examples also describe continuous methods for completely separating toluene from isooctane using n-pentane as desorbent; dimethyl sebacate from methyl stearate and/or methyl caprate using iso-octane as desorbent; ethylene dichloride from cyclohexane and chloroform from acetone using toluene as desorbent in each case; also chlorobenzene from allyl alcohol, benzene from acrylonitrile, and nitrobenzene from iso-octane using as desorbents methanol, methylene dichloride and benzene respectively. Resins used in the examples of continuous methods are n-butyl and methyl acrylates copolymerized with divinylbenzene. Specifications 786,755, 846,890 and 858,865 are referred to.ALSO:In a method of concentrating or separating a component of a homogeneous liquid mixture of at least two substantially non-ionogenic compounds, at least one of which is organic, the mixture is contacted with a resin absorbent having a large surface area per unit weight, the resin absorbent being (a) a cross-linked addition polymer other than an ion-exchange resin, (b) insoluble in the liquid mixture and (c) having a preferential absorptive capacity for the component to be concentrated. Absorption may be tested for by agitating the resin with a mixture for a given time and analysing the mixture before and after absorption. The separatory capacity of a resin is defined as where m is the weight of the resin in grams, V is the volume of liquid mixture added in ml., and Co and C are the Volume fractions of the preferentially absorbed component in the liquid phase before and after absorption respectively. Separatory capacities of various specified resins are given for each of the following in admixture with iso-octane: 4-vinylcyclohexene, cyclohexanol, toluene, ethyl acetate, methylethylketone, styrene, chlorobenzene, ethylene dichloride, chloroform dioxane, pyridine, naphthalene, nitrobenzene, and pyrrole; for each of ethylene dichloride, styrene, and chlorobenzene in admixture with toluene; and for the first named component of each of the following mixtures: ethylene dichloride-ethyl acetate, styrene, 4-vinylcyclohexene, chlorobenzene-allyl alcohol, benzene-acrylonitrile, allyl alcohol-water, chloroform-acetone. The treatment of hydrocarbon mixtures such as paraffin/naphthene, olefin/paraffin and solvent mixtures containing alcohols. Ketones, hydrocarbons and esters; and also mixtures of capryl alcohol with methylhexyl ketone and n-butanol with water is referred to. The absorption process can be carried out batchwise or continuously. In the former the liquid mixture is passed through a column packed with resin particles, or the resin particles may pass countercurrent to the liquid. When a two-component mixture A and B, of which A is preferentially absorbed, is passed over the resin, B issues first from the resin until the limit of the absorption capacity for A is reached, after which the original mixture A and B will issue. Enriched A is separated from the resin e.g. by heat, steam distallition, extraction or desorption with another solvent. In the continuous treatment the use of a desorbent C allows complete separation of A and B and the resin supported in a column is fed alternately with liquid mixture and with desorbent. The desorbent consists of one or more liquids, is completely miscible with A and B, and has a swelling power for the resin of the same order as that of one of the components of the liquid mixture to be separated. Examples describe batch methods for partially separating toluene-iso - octane, dimethyl sebacate-iso-octane, p methyl caprate-iso-octane, ethylene dichloride-cyclohexane mixtures using copolymers of divinyl benzene with 2-ethylhexyl acrylate, n-butyl acrylate, n-butyl methacrylate, ethoxy-ethyl acrylate, and methyl acrylate as absorbents. Examples also describe continuous methods for completely separating toluene from iso-octane using n-pentane as desorbent: dimethyl sebacate from methyl stearate and/or methyl caprate using iso-octane as desorbent; ethylene dichloride from cyclohexane and chloroform from acetone using toluene as desorbent in each case; also chlorobenzene from allyl alcohol, benzene from acrylonitrile, and nitrobenzene from iso-octane using as desorbents methanol, methylene dichloride and benzene respectively. Resins used in the examples of continuous methods are n-butyl and methyl acrylates copolymerized with divinyl-benzene. Specifications 786,755, 846,890 and 858,865 are referred to.
Abstract:
A process for the purification of cystals such as for the separation and purification of at least one of the components of a mixture having at least one but not all of its components in crystalline form, comprises heating the crystals, introducing the heated crystals into an upstream portion (with respect to crystal movement) of an elongated purification zone, moving the crystals as a compact mass toward one end of the zone, melting at least a portion of the compact mass in the downstream end portion of the zone, displacing a portion of the resulting melt countercurrently through at least a portion of the length of the crystal mass to displace occluded impurities therefrom, removing displaced liquid from an upstream end portion (with respect to crystal movement) of the zone, and removing a purified product from the downstream end portion of the zone. A mixture of materials is fed by a conduit 11 (Fig. 1) to a heat exchanger such as a chiller 12 to obtain crystals of at least a portion of at least one constituent of the mixture. The slurry so obtained is fed to a filter 14 where uncrystallized material is removed. Crystals are then passed by a conduit 16 to a heating chamber 17 to melt a portion of the crystals to obtain a slurry, preferably containing 35 to 45 per cent by weight of solids, which is passed by a conduit 22 to a column 23. A piston 25 compacts the crystal mass and moves it downstream towards a heating element 28. A filter 29 removes liquid from the crystal mass, or the piston 25 may have a perforate lower face through which liquid may be removed. A portion of the material melted by heater 28 is displaced upstream through the compact crystal mass, thereby displacing occluded impurities from the crystals, the liquid being removed by filter 29, or through piston 25 when it is perforate. Purified material, which may be molten or partially solid, is removed through a conduit 32. In modifications conduits 16 and 22 may be heated and conduit 22 may be inclined. In a further modification material from heater 17 is passed through a chiller to cause further crystalliation before entering column 23. In examples para-xylene is separated from a mixture also containing ortho- and meta-xylenes, ethyl benzene and toluene. Lists are given of compounds which may be separated by the process.