Abstract: A catalyst for the synthesis of methyl mercaptan from hydrogen sulfide and methanol, as well as a process for preparing the catalyst. The catalyst contains active aluminum oxide on which 15% to 40% by weight cesium tungstate is deposited as the activator. The activator, cesium tungstate, gives an unexpected increase in activity and selectivity as compared with potassium tungstate, which is used exclusively at the present state of the art.
Type:
Grant
Filed:
June 30, 1997
Date of Patent:
December 22, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Joerg Sauer, Wolfgang Boeck, Lukas von Hippel, Werner Burkhardt, Stephan Rautenberg, Dietrich Arntz, Willi Hofen
Abstract: In order to produce precious metal powders of uniform particle size and low BET specific surface, appropriate aerosols are introduced into a flame reactor, whereby the aerosols are first freed of solvent as completely as possible by a thermal treatment.
Type:
Grant
Filed:
September 30, 1996
Date of Patent:
December 22, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Hauke Jacobsen, Werner Hartmann, Stipan Katusic, Karl-Anton Starz
Abstract: Precipitated silica with the following physical-chemical characteristics:______________________________________ BET surface: DIN 66131 100-130 m.sup.2 /g DBP absorption DIN 53601 .gtoreq.275 g/100 g (anhydrous) ASTM D 2414 Loss on drying DIN ISO 787/II (2 h/105.degree. C.) ASTM D 280 3.5-5.5 wt. % JIS K 5101/21 Oversize with ALPINE air-jet sieve: >63 .mu.m .ltoreq.10.0 wt. % >150 .mu.m .ltoreq.0.1 wt. % >250 .mu.m .ltoreq.0.01 wt. % Chloride content: .ltoreq.100 ppm ______________________________________is prepared by introducing water into a precipitation vessel, adding water glass until an alkali value of 5-15 is reached, then adding further water glass and sulfuric acid simultaneously, interrupting the precipitated silica suspension with sulfuric acid to a pH-value of 8.5, with stirring, then continuing acidification with concentrated sulfuric acid to a pH-value of 4, then separating and washing the precipitated silica which has a solids content in the suspension of approx.
Type:
Grant
Filed:
July 1, 1996
Date of Patent:
December 22, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Gunter Turk, Gerold Schmidt, Mustafa Siray, Karl Meier
Abstract: A catalyst for the dehydrogenation of C6.sub.6 -C.sub.15 paraffins is disclosed. The catalyst contains, on a support, at least one platinum group component, at least one promoter component from the group tin, germanium and lead, and at least one additional modifier. The additional modifier contains at least one alkaline earth metal. The stability of the catalyst is essentially higher than that achieved by conventional use of an alkali metal.
Type:
Grant
Filed:
November 17, 1995
Date of Patent:
December 15, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Hans Lansink Rotgerink, Thomas Tacke, Reinhold Brand, Peter Panster
Abstract: Alkylalkoxysilyl-1,3-oxazolines, their production by reacting 2?-alkenyl!-1,3-oxazolines with alkylalkoxysilanes or cyano alkylene silane compounds with amino alcohols and the use of the compounds for modifying materials with siliceous surfaces.
Type:
Grant
Filed:
February 20, 1997
Date of Patent:
December 8, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Jorg Munzenberg, Rolf Mulhaupt, Philipp Muller
Abstract: The present invention relates to a simplified method of producing .+-.2-azabicyclo?2.2.1!hept-5-en-3-one from cyclopentadiene and sulfocyanides by reacting cyclopentadiene with sulfonylcyanides without the use of organic solvents.
Type:
Grant
Filed:
June 25, 1997
Date of Patent:
December 8, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Frank Romanowski, Kurt Vroman, Rudolf Vanheertum
Abstract: A precipitated silica with the following physicochemical properties:______________________________________ BET surface area 35 to 350 m.sup.2 /g BET/CTAB surface area ratio 0.8 to 1.1 Pore volume, PV 1.6 to 3.4 ml/g Silanol group density (V2 = 6 to 20 ml NaOH consumption) Average aggregate size 250 to 1500 nm CTAB surface area 30 to 350 m.sup.2 /g DBP value 150 to 300 ml/100 g V.sub.2 /V.sub.1 by Hg porosimetry 0.19 to 0.46 DBP/CTAB 1.2 to 2.4. ______________________________________is produced by reacting alkali silicate with mineral acids at temperatures of 60.degree. to 95.degree. C. while maintaining a pH of 7.5 to 10.5 and continuously stirring, continuing the reaction to a solids concentration in the precipitation suspension of 90 to 120 g/l, adjusting the pH value to a value of less than or equal to 5, filtering out, washing, drying and optionally grinding or granulating the precipitated silica. The precipitated silica is used as a filler in vulcanizable rubber compounds and vulcanizates.
Type:
Grant
Filed:
July 10, 1997
Date of Patent:
December 8, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Heinz Esch, Udo Gorl, Robert Kuhlmann, Ralf Rausch
Abstract: Known processes for producing 2-hydroxy-4-methylthiobutyric acid (MHA) use a liquid-liquid extraction or a combined liquid/liquid and solid/liquid phase separation to isolate MHA from a reaction mixture produced by hydrolysing MMP-cyanhydrine. These processes are either costly or produce waste that is difficult to dispose of. These disadvantages are eliminated by isolating MHA by solid/liquid separation. The reaction mixture is evaporated until a MHA-containing salt residue with little or no residual water is obtained the MHA-containing, salt residue is treated with an organic solvent to produce a suspension, solid components are separated from the thus obtained suspension until a MHA-containing solution is obtained, the organic solvent is removed from the MHA-containing solution until a MHA residue is obtained and if required the MHA residue is then conditioned by water admixture. Besides high quality MHA, this process produces marketable crystalline ammonium sulphate and/or hydrogenated ammonium sulphate.
Abstract: A method of producing L-amino acids by fermentation. Microorganisms of the genus Corynebacterium which exhibit an auxotrophy relative to an amino acid are used as biocatalysts. The method is characterized in that the carbon source on the one hand and the limiting amino acid on the other hand are fed in two or more different infeed currents to the process. The infeed profiles have, for example, a concave (saccharose) and an exponential (amino acid) form or a convex (saccharose) and likewise a convex (amino acid) form, with specific differing degrees of increase of the currents relative to each other over time.
Type:
Grant
Filed:
December 19, 1996
Date of Patent:
November 24, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Holger Werning, Harald Voss, Walter Pfefferle, Wolfgang Leuchtenberger
Abstract: A process for the preparation of an animal feed supplement based on fermentation broth is disclosed, wherein the supplement contains wholly or predominantly a fermentation product and the other constituents of the fermentation broth, which is characterised in that the fermentation broth is granulated, compacted and dried in a fluidised bed in one step whilst a sufficient amount of energy to obtain a desired particle diameter and a desired bulk density is introduced into the fluidised bed by mechanical device in addition to the energy required to produce the fluidised bed. As a result of this, it is possible, inter alia, to prepare continuously, in a single process step, granules conforming to specification of additives such as lysine, threonine or tryptophan using, in particular, raw fermentation broths as starting substance.
Abstract: Silver-iron materials for electrical switching contacts with properties which come very close to those of silver-nickel materials formed of 0.5 to 4.5% by weight iron and 0.05 to 2% by weight of one or more of the oxides magnesium oxide, calcium oxide, yttrium oxide, lanthanum oxide, titanium oxide, zirconium oxide, hafnium oxide, cerium oxide, niobium oxide, tantalum oxide, chromium oxide, manganese oxide, iron oxide, zinc oxide, aluminum oxide, indium oxide, silicon oxide, and tin oxide, the balance being silver.
Type:
Grant
Filed:
November 19, 1996
Date of Patent:
November 24, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Wolfgang Weise, Willi Malikowski, Roger Wolmer, Peter Braumann, Andreas Koffler
Abstract: A process for the electrolytic removal of contaminants from gases, wherein a gas and a liquid electrolyte are passed co- or counter-currently through a fixed bed electrode of an electrolysis cell which has a counterelectrode separated from the fixed bed electrode by a separator and the contaminant is electrochemically converted at an effective cell voltage. Such cells have hitherto been operated in a flooded state. The degree of purification may be substantially increased if the fixed bed electrode is operated as a trickle bed reactor.
Type:
Grant
Filed:
August 30, 1996
Date of Patent:
November 24, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Thomas Lehmann, Dieter Engel, Rainer Sanzenbacher
Abstract: Precision attachments containing a titanium-containing gold alloy which is covered with a gold film, capable of being cast on, which have a golden yellow color, are extremely corrosion-resistant and, despite base metal constituents, form no oxides at the place of casting-on.
Type:
Grant
Filed:
February 23, 1996
Date of Patent:
November 10, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Bernd Kempf, Hans Martin Ringelstein, Alexander Voelcker, Ulrich Birkholz
Abstract: 3-hydroxy propionic acid is obtained in high yield through the catalytic oxidation of 3-hydroxy propionaldehyde with O.sub.2 or an O.sub.2 -containing gas in the aqueous phase in the presence of a platinum-group catalyst, in particular a Pd or Pt supported catalyst. The catalyst is used in a quantity corresponding to at least 10 percent by weight of the platinum-group metal relative to 3-hydroxy propionaldehyde.
Type:
Grant
Filed:
July 21, 1997
Date of Patent:
November 3, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Thomas Haas, Martin Meier, Christoph Brossmer, Dietrich Arntz, Andreas Freund
Abstract: The invention relates to novel microorganisms, their use and method of producing L-.alpha.-amino acids. In particular, microorganisms DSM 7329 and 7330 are suitable for the production of L-.alpha.-amino acids from corresponding hydantoins or carbamoyl-.alpha.-amino acids. These novel microorganisms are simple to cultivate and make possible high L-.alpha.-amino acid yields from different substrates.
Type:
Grant
Filed:
February 1, 1996
Date of Patent:
October 27, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Fritz Wagner, Dirk Volkel, Andreas Bommarius, Karlheinz Drauz
Abstract: A phosphoric acid catalyst on a shaped, inorganic support and its use for the hydration of olefins. At least 90 wt. % of the catalyst support consists of titanium dioxide and/or zirconium dioxide and has outstanding ageing stability under the hydrothermal conditions existing during hydration processes.
Type:
Grant
Filed:
March 27, 1997
Date of Patent:
October 20, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Hermanus Lansink-Rotgerink, Harald Hoecker, Stefan Wieland, Steffen Seebald, Heike Riedemann
Abstract: Malonic acid or a salt of the same is obtained at high yield according to the invention through the catalytic oxidation with oxygen or an O.sub.2 -containing gas of 3-hydroxy propionaldehyde or 3-hydroxy propionic acid in the aqueous phase. The conversion takes place in the presence of at least 10 percent by weight, relative to the C.sub.3 building block used, of a precious metal from the platinum group. Pd and Pt supported catalysts are preferred.
Type:
Grant
Filed:
July 21, 1997
Date of Patent:
October 6, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Thomas Haas, Martin Meier, Christoph Brossmer, Dietrich Arntz, Andreas Freund
Abstract: Silver-iron materials for electrical switching contacts with properties which come very close to those of silver-nickel materials formed of 4.6 to 15% by weight iron and 0.05 to 5% by weight of one or more of the oxides magnesium oxide, calcium oxide, yttrium oxide, lanthanum oxide, cerium oxide, chromium oxide, iron oxide, aluminum oxide, indium oxide, silicon oxide, and tin oxide, the balance being silver.
Type:
Grant
Filed:
November 19, 1996
Date of Patent:
September 15, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Wolfgang Weise, Willi Malikowski, Roger Wolmer, Peter Braumann, Andreas Koffler
Abstract: A continuous method of producing .gamma.-aminopropyltrialkoxysilanes as well as mixtures of primary and secondary aminosilanes by reacting .gamma.-chloropropyltrialkoxysilane with ammonia is disclosed. The steps are:a) .gamma.-chloropropyltrialkoxysilane and ammonia are first mixed in the desired amount ratio,b) this mixture is heated to the reaction temperature,c) allowed to run through a pressure reactor with a dwell time sufficient for the complete reaction, during which the mixture can run through several temperature zones,d) the reaction mixture is subsequently cooled off,e) the product (.gamma.-aminopropyltrialkoxysilanes or the mixtures) is separated out of a two-phase mixture andf) the ammoniacal phase returned into the reactor.
Type:
Grant
Filed:
December 15, 1997
Date of Patent:
September 15, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Torsten Balduf, Stefan Wieland, Wolfgang Lortz, Joachim Pohlisch, Thomas Gobel, Horst Grethe
Abstract: A catalyst and method of its production for use in making vinyl acetate monomer. The carrier is impregnated with a basic solution and a solution containing gold salts and palladium salts and finally impregnated with alkali acetate. The activity and selectivity of the catalyst, its mechanical strength, the noble-metal adhesion and the dispersion of noble metal on the carrier can be improved if the carrier is impregnated in a pretreatment with salts containing as cation elements of groups IA, IIA, IIIA and IVB of the periodic table and as anions elements of group VIIA or complex anions such as nitrate, sulfate or anions of organic acids such as acetate and lactate and is subsequently dried and calcined at temperatures of at least 160.degree. C.
Type:
Grant
Filed:
January 23, 1996
Date of Patent:
September 15, 1998
Assignee:
Degussa Aktiengesellschaft
Inventors:
Thomas Tacke, Herbert Mueller, Uwe Ohlrogge, Francis P. Daly, Hans Lansink Rotgerink, Helmfried Krause