Bayer Aktiengesellschaft

Uop Lcc

Gerhard Reiss

Lothar Puppe

Bruno Hees

Raimund Wambach

Sigurd Hartung

Manfred Mengel

Gerhard Heinze

The present invention relates to binder-free molecular sieve zeolite granules of lithium zeolite A and lithium zeolite X, a process for preparing these molecular sieve zeolite granules and their use for preparing nitrogen or oxygen from air by pressure swing adsorption.

Binder-free molecular sieve zeolite granules which contain zeolites of

In an adsorptive alternating pressure process for the enrichment of air with oxygen using a molecular sieve zeolite in an adsorber, wherein adsorbed components are desorbed under a pressure below the pressure at which air separation and N.sub.2 adsorption is effected and, after desorption, the molecular sieve adsorber is at least partly returned to the air separation pressure with oxygen gas produced in countercurrent to the air separation gas flow, the improvement which comprises cooling product gas and covering the molecular sieve adsorber with the cooled product gas.

Oxygen enrichment process

In the pressure swing adsorption of nitrogen from gas mixtures with less polar gas components at temperatures of between 20.degree. and 50.degree. C., wherein the gas mixture is passed through an adsorber which is filled with packings of zeolite pellets and has an inlet zone and an outlet zone, the improvement which comprises providing at least two packings in the adsorber, a packing of Li-zeolite X in the inlet zone of the adsorber and a packing of at least one of Ca-zeolite A and Ca-zeolite X in the outlet zone of the adsorber.

Process for the adsorption of nitrogen from gas mixtures by means of

An improved process for the oxygen enrichment of air by vacuum swing adsorption, pressure swing adsorption or a combination thereof, wherein the improvement comprises providing at least one packing at each of the air inlet to and air outlet from the adsorber, the packing at the air inlet side of the adsorber comprising Na-Ca zeolite X with an SiO.sub.2 /Al.sub.2 O.sub.3 ratio of 2.0 to 2.5 and with a CaO/Al.sub.2 O.sub.3 ratio of 0.4 to 0.75, the ratio being dependent upon the air inlet temperature, at an air inlet temperature of 20.degree. to 30.degree. C., the CaO/Al.sub.2 O.sub.3 ratio of the Na-Ca zeolite X at the inlet zone being 0.4 to 0.6, at an air inlet temperature of 30.degree. to 40.degree. C., the CaO/Al.sub.2 O.sub.3 ratio of the Ca zeolite X at the inlet zone being 0.55 to 0.65 and at an air inlet temperature of 40.degree. to 50.degree. C., the CaO/Al.sub.2 O.sub.3 ratio of the Na-Ca zeolite X at the inlet zone being 0.6 to 0.75, the packing at the air outlet side of the adsorber comprising Na-Ca zeolite A with a CaO/Al.sub.2 O.sub.3 ratio of 0.5 to 1.0 or Na-Ca zeolite X with CaO/Al.sub.2 O.sub.3 ratio of 0.4 to 1.0, above the CaO/Al.sub.2 O.sub.3 ratio of the Na-Ca zeolite X at the inlet side.

Adsorptive oxygen enrichment of air with mixtures of molecular sieve

A process for oxygen-enrichment of air by means of vacuum swing adsorption (VSA) using Ca zeolite A molecular sieves, the improvement wherein the adsorbers of the VSA units are filled with Ca zeolite A molecular sieves which have different adsorption characteristics.

Process for the adsorptive oxygen-enrichment of air with mixtures of Ca

2-adsorber systems of the VSA process have been found which, surprisingly, require only a slightly higher energy consumption in comparison with the 3-adsorber systems, but are considerably more favorable in terms of investment in the plant because of the small number of valves and adsorbers, and in particular adsorptive separation of a gas mixture (crude gas) in containers (adsorbers) filled with adsorbent, with the phase which is adsorbed less strongly, if at all, being obtained and the adsorbed gas content (adsorbate) being desorbed under reduced pressure, e.g. by means of a vacuum pump has been found. The process is characterized in that two adsorbers (A and B) are operated alternately so that the crude gas feed and also the desorption of the adsorbate, i.e. connection of the vacuum pump, is not stopped at any time during the separation process, separation of the crude gas partly taking place under reduced pressure when the maximum adsorption pressure has been reached.

Separation of gas mixtures by vacuum swing adsorption (VSA) in a

A SiO.sub.2 -bound, substantially carbonate-free, calcium-containing zeolite A granulate in which the calcium content is 0.4 to 1 mole CaO/mole Al.sub.2 O.sub.3 and a process for the production such SiO.sub.2 -bound calcium exchanged zeolite A granulate in a CO.sub.2 -free atmosphere at temperatures of 350.degree. C. to 700.degree. C. The SiO.sub.2 -bound zeolite granulate A being useful as an adsorbent in the recovery of oxygen by the pressure change adsorption process.

Silica-bound calcium-containing zeolite a granulate

An improved continuously operating adsorption process for the purification and separation of gaseous mixtures by pressure swing adsorption is disclosed. The improvement is achieved by heating the gaseous mixture to be separated by heat exchange with the vacuum pump which consists of at least two in series operating pumps. The present process is especially suited for efficiently producing oxygen-enriched air.

Pressure swing process for the adsorptive separation of gaseous mixtures

In the increase of the hydrogen content of a gas rich in hydrogen by contacting the gas with a zeolite which selectively adsorbs the gases other than hydrogen to leave the non-adsorbed gas enriched in hydrogen, and then desorbing the adsorbed gases from the zeolite, the improvement which comprises employing as said zeolite Ca-zeolite X granulate in which at least about 50% of the Na initially present in the zeolite has been replaced by calcium.

Molecular sieve zeolite for producing hydrogen by pressure variation

A process for the separation of isomeric dichlorotoluenes is described wherein an isomeric mixture of dichlorotoluenes is passed over a zeolite of the X or Y type, non-adsorbed dichlorotoluene is separated off and the adsorbed dichlorotoluene is eluted from the zeolite by contacting the same with an eluant.

Separation process

A type A zeolite corresponding to the formula

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Leverkusen, Germany

Gerhard Reiss