Bayer Aktiengesellschaft

Krupp Vdm Gmbh

Kurt-Wilhelm Eichenhofer

Reinhard Schliebs

Ulrich Heubner

Klaus Geisler

Karl Brandle

Martin Schweitzer

Michael Kohler

Hans Toepsch

Martin Kürten

Michael Renner

Klaus-Peter Grabowski

Klaus-P Grabowski

Gunter Putz

Armand deMontigny

Günter Dräger

Hermann Brandl

Heinrich Kohnen

The invention relates to a process for the continuous preparation of oleum of a concentration of 10 to 45% by weight of SOand/or sulphuric acid of a concentration of 94 to 100% by weight of HSOby combustion of sulphur with atmospheric oxygen according to the principle of superstoichiometric combustion, cooling the resultant sulphur-dioxide-containing gases to 350&#xb0; C. to 500&#xb0; C., catalytic conversion of these cooled gases to give sulphur-trioxide-containing gases in the presence of a vanadium-containing catalyst using single or double contact catalysis, absorption of the sulphur-trioxide-containing gases after cooling, if appropriate removal of liquids from the gases after absorption and energy recovery, with liquid sulphur being injected into the hot combustion gas stream perpendicular to the main direction of flow in the form of a fan using one or more bimodal fan-type nozzles.

Process for the combustion of sulphur for the preparation of oleum and sulphuric acid with reduced (NO)x content

The present invention relates to high chromium, corrosion resistant, austenitic alloys and to the use thereof.

Austenitic alloys and use thereof

In the continuous production of oleum having a concentration of 10 to 45% by weight SO.sub.3 and/or sulfuric acid having a concentration of 94 to 100% by weight H.sub.2 SO.sub.4 by burning sulfur with atomospheric oxygen on the principle of overstoichiometric or understoichiometric burning, cooling the resulting SO.sub.2 -containing gas to 390.degree.-480.degree. C., catalytically reacting the cooled gas to SO.sub.3 -containing gas on a vanadium-containing catalyst on the principle of single- or double-contact catalysis, absorbing the SO.sub.3 -containing gas after cooling and, optionally, separating liquid from the gas after absorption, followed by recovering energy, the improvement which comprises effecting the burning of the sulfur with atomospheric oxygen in the presence of a dry SO.sub.2 -containing gas which contains up to 5,000 ppm (NO).sub.x expressed as NO.

Process for the production of oleum and sulfuric acid

A process for the purification of waste water produced in hydrazine production by the oxidation of ammonia or an amine with an oxidizing agent in the presence of an aldehyde or ketone, comprising intensively mixing the waste water with chlorine or a hypochlorite at a temperature of about 10.degree. C to 110.degree. C and a pH of about 5 to 10 until the treated waste water reaches a redox potential to platinum, relative to Ag/AgCl, of about -400 mV to +800 mV. Advantageously a small amount of waste water is distilled off both before and after the chlorine or hypochlorite treatment.

Purification of waste water from hydrazine production

A composition for coating paper, films and fiber materials, comprising

Non-stick polyorganosiloxane coating compositions

In the production of hydrazine wherein aqueous ammonia is oxidized in the presence of a ketone to form an aqueous solution containing at least one of a hydrazone and a ketazine along with ammonia, the hydrazone and ketazine are concentrated and the hydrazone and ketazine are subsequently hydrolyzed to hydrazine and ketone, the improvement which comprises effecting the concentration of the hydrazone and ketazine by extracting the aqueous solution with a substantially water-immiscible organic solvent whereby the hydrazone and ketazine preferentially enter the water-immiscible solvent, and separating the water-immiscible solvent extract from the aqueous solution. The organic solvent is preferably a higher alcohol, a chlorinated hydrocarbon, benzene or a substitution product thereof. The organic solvent extract, in one or more stages, and optionally with addition of ketone, can be re-extracted with water, hydrolyzed with aqueous acid or subjected to distillation to separate the hydrazine values from the organic solvent.

Working up synthesis solutions obtained in production of hydrazine

A process for the production of a ketazine of the general formula ##EQU1## in which R.sub.1, R.sub.2, R.sub.3 and R.sub.4 each independently is an alkyl, cycloalkyl or aralkyl radical with up to 12 carbon atoms; or an optionally substituted aryl radical with up to 10 carbon atoms, at most two of the radicals R.sub.1, R.sub.2, R.sub.3 and R.sub.4 being aryl radicals, or

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Leverkusen, Germany

Kurt-Wilhelm Eichenhofer