Patent GB-823969-A (GB)
Title: Improvements in adsorbents and the separation of mixtures
IPC: B01J20/12
Filed: 1956-07-24
Abstract: Montmorillonite having some or all of the interlamellar ions replaced by substituted ammonium ions the substituents of which consist of methyl and/or ethyl radicals is prepared by mixing montmorillonite with a solution containing said ions and subsequently separating the treated montmorillonite.  Specified replacement ions are mono, di-, tri- and tetramethyl and tetraethyl ammonium ions, the substance used in solution being e.g. a chloride or bromide.  In an example, an aqueous montmorillonite dispersion and tetramethylammonium bromide were stirred and heated at 50 DEG  C. for thirty minutes and the modified montmorillonite washed, dried and heated at 50 DEG  C. in a vacuum to remove water.  The modified montmorillonite may be used as an adsorbent in the separation of fluid mixtures of organic substances.  Thus in the liquid phase, benzene may be separated from n-heptane and cyclohexane, and cyclohexane from toluene.  In the gas phase, cyclohexane, n-heptane, methyl alcohol, carbon tetrachloride or toluene may be separated from benzene, the latter being adsorbed, whilst thiophene and benzene may also be separated, the former being adsorbed; cyclohexane may be separated from n-heptane and cyclohexanol.  When separating vaporous mixtures a carrier gas, e.g. nitrogen, may be used.  A table is given in which there is disclosed the adsorption in the gas phase of the further substances methane, n- and iso-butane, n-, iso- and neo-pentanes, iso-octane, cyclopentane and o-, m- and p-xylenes. The modified montmorillonite may also be used to separate straight chain from branched chain hydrocarbons; t-butyl alcohol may also be adsorbed.  The modified montmorillonite may be used as an adsorbent for inorganic gases also; e.g. by contacting with oxygen and nitrogen and/or argon or with nitrogen and argon at 78-90 DEG  K., the first-named component is separated.ALSO:Montmorillonite having some or all of the interlamellar ions replaced by substituted ammonium ions the substituents of which consists of methyl and/or ethyl radicals is prepared by mixing montmorillonite with a solution containing said ions and subsequently separating the treated montmorillonite. Specified replacement ions are mono-, di-, tri- and tetra-methyl and tetraethyl ammonium ions, the substance used in solution being e.g. a chloride or bromide.  In an example, an aqueous montmorillonite dispersion and tetramethylammonium bromide were stirred and heated at 50 DEG  C. for thirty minutes and the modified montmorillonite washed, dried and heated at 50 DEG  C. in a vacuum to remove water. The modified montmorillonite may be used as an adsorbent in the separation of fluid mixtures of organic substances.  Thus in the liquid phase, benzene may be separated from n-heptane and cyclohexane and cyclohexane from toluene.  In the gas phase, cyclohexane, n-heptane, methyl alcohol, carbon tetrachloride or toluene may be separated from benzene, the latter being adsorbed, whilst thiophene and benzene may also be separated, the former being adsorbed; cyclohexane may be separated from n-heptane and cyclohexanol.  When separating vaporous mixtures a carrier gas, e.g. nitrogen, may be used.  A table is given in which there is disclosed the adsorption in the gas phase of the further substances methane, n- and iso-butane, n-, iso- and neo-pentanes, iso-octane, cyclopentane and o-, m- and p-xylenes. The modified montmorillonite may also be used to separate straight p  chain from branched chain hydrocarbons; t-butyl alcohol may also be adsorbed.