Abstract: Reactor heads for the feed and withdrawal of a fuel gas/air mixture and of an educt gas mixture into the heating ducts and reaction ducts respectively of a monolithic countercurrent reactor. The reactor heads are provided with guide pipes, which feed the gas mixtures into the ducts assigned to them and withdraw them from these ducts.

Abstract: A coating dispersion is shown for the production of catalysis-promoting coatings on an inert, structure-reinforcing element. The solids of the dispersion are present in various particle fractions and lead to a relatively rough coating surface with improved exchange between the exhaust gas and the catalyst surface. This results in improved heat-up behavior of the catalyst.

Abstract: Silica with the following physico-chemical properties:______________________________________ Specific surface m.sup.2 /g 80-400 Primary particle size nm 7-40 Tapped density g/l 50-300 pH value 3-10 Carbon content % 0.1-15 DBP number % <200 ______________________________________is produced by spraying a silica under intensive mixing, optionally with water or dilute acid at first and then with a surface-modifying reagent or a mixture of several surface-modifying reagents, then mixing, tempering, and subsequently destructuring/compressing and grinding.

Abstract: The use of modified silicon dioxide as a catalyst support in catalytic reactions under hydrothermal conditions is described. The pore structure of the supports may be stabilized against hydrothermal reaction conditions by impregnating the catalyst supports with elements of Group IVB of the Periodic Tube of Elements.

Abstract: An emptying device for bulk bags having an inner and outer sack in which disturbances during emptying and contact with the bulk material are avoided. The device includes a holding device for the bulk bag, a double tube device arranged centrally beneath the holding device and having an inner tube, an outer tube arranged around the inner tube with an outlet fitted to its lower edge, and a closing ring which can be raised and lowered for closing the upper end of the annular gap formed by the two tubes. The device can additionally include at least one gripping device for securing the sack outlet of the inner sack, which gripping device can be moved up and down within the inner tube and can be pulled downwards by means of a pulling device operable from outside the double tube device.

Abstract: A catalyst for purifying the exhaust gases from diesel engines. The catalyst contains a zeolite mixture of several zeolites with different moduli and platinum group metals as well as further metal oxides from the group aluminum silicate, aluminum oxide and titanium oxide, wherein the aluminum silicate has a ratio by weight of silicon dioxide to aluminum oxide of 0.005 to 1 and the platinum group metals are deposited on only the further metal oxides.

Abstract: Acrolein-releasing emulsion homopolymers release acrolein in aqueous systems. They are produced by adding acrolein, at least 95% by weight pure, to a solution of an alkali hydroxide, with the temperature not exceeding 25.degree. C. during the addition, and then adjusting the pH to 5 to 7 by adding a mineral acid.