Abstract: The present invention is directed to an at least binary exchanged X-zeolite having lithium and zinc cations in a ratio of preferably 5% to 40% zinc and 50% to 95% lithium, wherein the sum of the lithium and zinc ion exchange is at least 65% of the exchangeable ion content. Theses adsorbents are useful in a process for separating nitrogen from gas mixtures containing nitrogen and less strongly adsorbed components such as oxygen, hydrogen, argon or helium.

Abstract: The present invention is directed to an at least binary exchanged X-zeolite having lithium and a divalent cation selected from the group consisting of cobalt, copper, chromium, iron, manganese, nickel and mixtures thereof in a ratio of preferably 5% to 50% of the divalent cation and 50% to 95% lithium. Theses adsorbents are useful in a process for separating nitrogen from gas mixtures containing nitrogen and less strongly adsorbed components such as oxygen, hydrogen, argon or helium.

Abstract: Low silica X (LSX) zeolites having a framework Si/Al ratio equal to 1.0 with lithium exchange levels greater than a threshold level of 70% exhibit unexpectedly higher capacity for nitrogen adsorption compared to LSX-zeolite with lower lithium exchange levels. These materials provide high performance adsorbents for PSA air separation processes at a lower cost for the adsorbent because of the lower threshold lithium exchange levels compared to highly exchanged lithium X-zeolite known in the prior art.

Abstract: The invention is a process for selectively adsorbing nitrogen from a gas mixture which comprises contacting the gas mixture with an adsorbent that has a moderate nitrogen capacity and a high selectivity for nitrogen over the other components in the mixture. With respect to air separation, improved adsorbents have low O.sub.2 capacity with N.sub.2 capacity at roughly the same level as current adsorbents such as CaA. O.sub.2 VSA computer process simulations have shown the unexpected result that for materials with the same binary isothermal working selectivity, those with lower isothermal nitrogen working capacity are superior O.sub.2 VSA adsorbents, provided that they have a nitrogen working capacity of at least about 0.3 mmol/g.

Abstract: The present invention is directed to adsorptive separation of nitrogen with active adsorbent phases with high N.sub.2 capacity and high heats of adsorption when diluted with inert material at levels ranging from 5% to 80%. The presence of diluent reduces the temperature swings in the adsorbent bed, which increases the utilizable effective N.sub.2 working capacity and decreases the relative amount of O.sub.2 left unrecovered on the active adsorbent phase. The net result is equal or better process performance allowing utilization of a lower amount of active adsorbent phase. Use of a diluent having a higher heat capacity than that of the active adsorbent phase increases these benefits, but dilution effects are beneficial even for diluents with heat capacities equal to or lower than that of the active adsorbent phase.

Abstract: The present invention is directed to a process for separating nitrogen from gas mixtures containing nitrogen and less strongly adsorbed components such as oxygen, hydrogen, argon or helium by use of an at least binary exchanged X-zeolite having lithium and a divalent cation selected from the group consisting of barium, cobalt, copper, chromium, iron, magnesium, manganese, nickel, zinc and mixtures thereof in a ratio of preferably 5% to 50% of the divalent cation and 50% to 95% lithium.

Abstract: The present invention is directed to a process for separating nitrogen from gas mixtures containing nitrogen and less strongly adsorbed components such as oxygen, hydrogen, argon or helium by use of an at least binary exchanged X-zeolite having lithium and calcium and/or strontium ions in ratio of preferably 5% to 50% calcium and/or strontium and 50% to 95% lithium.

Abstract: The surface properties of iron or ferrous alloy are improved by borosiliconizing the surface by contact with a stream of reducing gas containing hydrogen, optionally with an inert gas, to which a gaseous halide or hydride of boron and silicon have been added, either together or sequentially. The temperature of treatment is elevated, e.g. above 350.degree. C., but below 1200.degree. C. Diffusion coatings of both boron and silicon are formed in the ferrous surface. Typical surces of boron and silicon inlude boron trichloride, diborane and silane.

Abstract: Silicon carbide protective films are produced on the surface of metallic or metal-impregnated substrates. A silicide or silicon diffusion coating is initially formed on the surface of the substrate, and subsequently said surface is treated with a gas stream which is reducing to the coating and substrate and contains a gaseous carbon source at a temperature greater than 500.degree. C.

Abstract: A silicon diffusion coating is formed in the surface of a metal article by exposing the metal article to a reducing atmosphere followed by treatment in an atmosphere of 1 ppm to 100% by volume silane, balance hydrogen or hydrogen inert gas mixture. Hydrogen with a controlled dew point is utilized as a surface preparation agent and diluent for the silane.

Abstract: A process for bright annealing of chromium containing alloys such as stainless steels in an atmosphere of nitrogen and hydrogen containing controlled additions of an inhibitor as described in U.S. Pat. No. 4,334,938 wherein at least one element provided at the surface of the article being annealed in an amount such that it is oxidized in preference to the chromium in said article, whereby nitrogen uptake is inhibited and dulling of the metal surface by formation of a film containing chromium oxide is avoided.

Abstract: A silicon diffusion coating is formed in the surface of a metal article by exposing the metal article to a reducing atmosphere followed by treatment in an atmosphere of 1 ppm to 100% by volume silane, balance hydrogen or hydrogen inert gas mixture. Hydrogen with a controlled dew point is utilized as a surface preparation agent and diluent for the silane.

Abstract: A method for reheating of a catalytic reactor by successive oxidations and reductions of a multiple oxidation state catalyst.Heat is added to the catalyst bed by a series of successive oxidation and reduction reactions occurring on the catalyst. Both catalyst oxidation and catalyst reduction are exothermic reactions, and both reactions generate heat to increase the temperature of the catalyst bed.

Abstract: The process for preparing a regionalized platinum/rhodium catalyst using a single impregnating step. The process is particularly effective in preparing such a catalyst for use as an automotive emissions control catalyst. A substantially alumina support is impregnated in a platinum/rhodium controlled acidic solution of a strong acid and an ammonium salt or equivalent thereof.