Abstract: Predominantly hydrogen gaseous flowstreams containing contaminating amounts of at least carbon monoxide and/or nitrogen impurities are purified by PSA adsorption of such impurities therefrom, via transport over a faujasite zeolite adsorbent, the Si/Al ratio of which ranges from 1 to 3, preferably from 1 to 1.5, and at least 85% of the aluminum tetrahedra comprising the crystal lattices being combined with lithium and calcium cations, the lithium/lithium+calcium ratio therein being at least 70%.

Abstract: The present invention relates to agglomerated zeolite adsorbents based on faujasite with an Si/Al ratio such that 1≦Si/Al≦1.15, at least 70% exchanged with barium and optionally with potassium, and on a binder, preferably a zeolitizable binder. They are obtained by agglomerating zeolite powder with a binder, followed by exchange of the zeolite ions for barium ions and activation of the adsorbents thus exchanged. These adsorbents are particularly suitable for the adsorption of the para-xylene contained in aromatic C8 hydrocarbon fractions in the liquid phase, in processes of simulated fluid-bed type.

Abstract: The present invention relates to a process for the preparation of zeolites X and LSX agglomerated with a binder and for which approximately 50 to approximately 99% of the exchangeable sites are occupied by lithium ions, which consists in carrying out the exchange with lithium of a portion of the exchangeable cations of the starting zeolite by bringing the said zeolite, distributed in a carrousel of at least 2 receptacles in the stationary bed form which are arranged in series in an interchangeable manner, into contact with a solution of lithium compounds (1) conveyed through the-said carrousel whose sequence of receptacles is modified cyclically at given time intervals; when the desired degree of exchange with regard to lithium is achieved for the zeolite of the 1st receptacle, the latter is taken out of the carrousel and the zeolite which is present therein is freed from the solution of lithium compounds by washing, then discharged (4) and optionally replaced by a fresh charge of zeolite to be exchanged, and

Abstract: The present invention relates to zeolites X, most of the exchangeable sites of which are occupied by lithium and di- and/or trivalent cations, having an improved thermal stability and an improved crystallinity with respect to zeolites of the prior art with the same degree of exchange of lithium and of di- and/or trivalent cations.

Abstract: A process for the production of faujasite X agglomerates containing at least 95% of faujasite LSX, that is to say with an Si/Al ratio equal to 1, constituting the active adsorbent. The agglomerate is formed from zeolite LSX and from a binder which can be converted to zeolite, the conversion of which to active zeolite is obtained by conversion to zeolite in a sodium hydroxide/potassium hydroxide or sodium hydroxide liquor.

Abstract: The performances of the industrial manufacture of LSX faujasite are improved by proceeding to the aging and the crystallization of the gel by stirring with a Archimedean screw stirrer. In particular, the duration of the aging is shortened considerably without affecting the crystallinity of the final product.

Abstract: Paraffin cuts contaminated with aromatic compounds are brought in contact at ambient temperature with faujasites, in which the Si/Al ratio is less than 1.2, in particular, sodium faujasites which were partially exchanged with lithium. Thus, one can obtain purified cuts which are practically totally free from aromatic contaminants.

Abstract: This invention relates to compositions resulting from the reaction, in aqueous phase, of aluminum hydroxide, of alkali metal cation hydroxide and of calcium or strontium hydroxide. The addition of such a composition to PVC resins or to olefinic resins from Ziegler catalysis prevents the degradation of these resins under the effect of light or of heat, in particular during extrusion.

Abstract: It is now possible to desulfurize gases containing appreciable carbon dioxide proportions by limiting the production of carbon oxysulfide to a very low level, by treating these gases with adsorbents composed of very small, partially calcic zeolite A crystals agglomerated by clays containing low levels of iron and having reduced acidity and basicity. These clays may be obtained by phosphatization of montmorillonite, bentonite, attapulgite, or kaolin.

Abstract: The invention describes a process for thermal activation of zeolites that are sensitive to hydrothermal degradation by percolating a hot gas through a homogeneous bed of granulates of the said zeolites. It applies to type A an X zeolites, and more particularly to their forms exchanged by potassium or calcium and one preferably uses air, the temperature of which ranges between about 300.degree. C. and 700.degree. C., preferably between 550.degree. C. and 600.degree. C., and preferably with dehydrated and decarbonated air, forced through the bed of granulates at linear velocities ranging between 0.01 and 1 m/second NTP. The process makes it possible to obtain novel zeolites with high nitrogen adsorption capacity.

Abstract: An industrial shaped adsorbent for the non-cryogenic separation of gases from air, comprising from 70 to 95% by weight zeolites, and, correspondingly, from 30 to 5% by weight of a clay binder,(a) said zeolites consisting essentially of mixtures of X and A zeolites having an X crystallinity greater than or equal to 95% and an A crystallinity less than or equal to 5%, a toleune standard adsorption of 23.+-.1% and an X-ray spectrum characteristic of a practically pure faujasite, and with the Si/Al ratio of the crystalline component being 1.+-.0.03, and(b) with the adsorbent having a 2Ca/Al ratio between about 80 and 99%, a nitrogen adsorption between 16 and 23.5 L/kg and a ratio of the nitrogen to the oxygen adsorption capacities under 1 bar between 3.5 and 4.5 and the process of making such adsorbents.

Abstract: A process for obtaining zeolite agglomerates for molecular sieves by forming a paste from a zeolite powder, a siliceous earth, and a sodium aluminate solution, shaping the paste into agglomerates, aging the agglomerates under ambient conditions, heat-treating, and then calcining the agglomerates and the resultant agglomerates.