Abstract: A process is disclosed for preparing a carbon molecular sieve used for the separation of oxygen from nitrogen, which comprises the steps of:(a) milling hard coal to a grain size of 95%<20.mu.m;(b) oxidizing the finely milled hard coal with air in a fluidized bed;(c) adding water and coal tar pitch as a binder and molding the finely milled hard coal into shape;(d) carbonizing the finely milled hard coal molded into shape in a rotary kiln at a temperature of 500 .degree.to 850.degree. C., with a dwelling time of 55 to 65 minutes, in order to obtain a carbonization product with a bulk density of 530 to 560 g/l;(e) activating the carbonization product with steam at to 900.degree. C. for 165 to 195 minutes to obtain a sintered carbonaceous product having a bulk density of 590 to 650 g/l; and(f) treating the sintered carbonaceous product at 750 to 850.degree. C. with carbon-splitting hydrocarbons to obtain said carbon molecular sieve.

Abstract: A method of making conference call connections in computer-controlled telephone exchanges includes combining voice signals of conference participants on a digital basis, forming a signal of a total of speaking levels of a given number of the most active participants, distributing the signal in an undamped manner, and suppressing voice signals of the inactive participants. A bit stream of the conference participants reaching a conference assembly through an incoming line is distributed to m adding processors having n channels each, and the PCM words are linearized with a code table and stored in level memories for each particular participant. A total of the linear values is formed, is added to individual participant evaluation totals and is stored in evaluation memories for each particular participant. The participant evaluation totals are transmitted to an evaluation processor which determines active channels by using a delayed mean value of the participant levels and transmits it to the adding processors.

Abstract: With the extraction method, a material exchange column with an ordered packing 2a or 2b on the basis of a plurality of layers 3 stacked parallel to the column axis and making point contact with one another is used. The packing 2a, 2b is perfused by a continuous and a dispersed phase in a counter current. The packing has a very large specific surface area of at least 300 m.sup.2 /m.sup.3 of packing volume. At the periphery of the packing 2a, 2b, the two phase streams are re-circulated into the packing at regular intervals through a rim seal composed of an elastic material not wettable by the dispersed phase. The rim seal is placed round the packing in the form of an elastic tube or pipe and seals the intermediate space between the internal column wall and the packing. A further improvement in the separating capacity can be achieved if pulsating operation is adopted.

Abstract: An adsorption-desorption process for the recovery of hydrogen from a feed gas containing trace pollutants adapted to be strongly adsorbed, in concentrations generally below 1% by volume and containing components adapted for only light adsorption, in concentrations above 1% by volume is operated through a preliminary first adsorption stage for the strongly adsorbable trace pollutants and a second main adsorption stage for the light adsorbable components and for the discharge of hydrogen. Contrary to the prior art where the adsorption-desorption was effected by alternating high pressure and low pressure cycles in the main adsorption stage only, the pressure cycles in the present case are carried out both in the preliminary first adsorption stage and in the second main adsorption stage, preferably by arranging the two adsorption states in series. The process substantially extends the service time of the adsorber used in the first adsorption stage.

Abstract: A process for the purification of a solution of .epsilon.-caprolactam in benzene, toluene or xylene by washing with a liquid, wherein the washing liquid is a solution of .epsilon.-caprolactam in water in a weight ratio of from 15 : 1 to 1 : 3, which is used in a quantity of from 5 to 20% by weight, based on the solution of caprolactam in benzene, toluene or xylene, and wherein there are several washing stages so that the equilibrium between the two solutions can be readjusted.

Abstract: A carbonaceous adsorbent in the form of a shaped body which has been heated to about 400 to 1400.degree. C in an inert atmosphere is composed essentially of a mixture of finely divided carbonaceous material of a grain size below 50 and up to below 100 microns with a binder composed of about 1 to 20% by weight of a natural or synthetic elastomer and about 1 to 15% by weight of a thermoplastic material. The adsorbent is made by subjecting the mixture to a shaping step followed by heating to a temperature of about 400.degree. to 1400.degree. C in an inert atmosphere which step may be followed by an activation of the carbonaceous material.

Abstract: Process for the separation or purification of heat-sensitive compounds by carrier-vapor distillation, wherein the superheated solvent vapor which is loaded with the compound to be distilled is cooled by treatment with condensed solvent in counter-current and the amount of condensed solvent is measured in such a manner that a saturated solution of the compound which is almost at boiling point is formed from the superheated, loaded vapor. The process being especially apted for separating or purifying 4-hydroxybenzaldehydes optionally substituted by one or more C.sub.1 -C.sub.4 -alkoxy groups.

Abstract: A method for treating waste gases containing radioactive contamination, particularly krypton and xenon nuclides. The waste gas stream to be decontaminated is initially conducted through an enrichment system wherein the waste gas stream is divided into at least two partial streams one of which is substantially free from the radioactive impurities and constitutes the poor gas fraction and another of which constitutes the rich gas fraction. The poor gas fraction is discharged, at least in part into the atmosphere while the rich gas fraction is fed into an activated carbon delay path whose output is discharged, either directly or indirectly into the atmosphere. Apparatus for carrying out the method is also disclosed.