Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V.

Fraunhofer-ges. Zur Förderung Der Angewandten Forschung E.v.

Rainer Schweppe

Thomas Hirth

Gerd Unkelbach

Jochen Forstner

Klemens Flick

Jürgen Graf

Rainer Busch

Matthias Pursch

Kai H&ouml;hn

The invention relates to a process for the continuous production of one or more olefins from an aqueous solution of corresponding alcohol(s) including: Providing a solid-free aqueous solution of the alcohol(s); putting the solution through a reactor, which is filled with a fixed-bed catalyst such that the solution comes into contact with the catalyst when flowing through the reactor at a temperature of at least 300&#xb0; C. and a pressure of at least 220 bar in such a temperature/pressure combination that the alcohol(s) are reacted under supercritical conditions; and transferring a resulting two-stage mixture to a separator, in which the mixture is separated in a raw olefin gas phase and an aqueous liquid phase; wherein the catalyst is selected from among metal oxides having the properties of a Bronstedt acid, insoluble metallic or semi-metallic phosphates as well as porous materials selected from among pumice and carbon, the surface area of which is coated with inorganic acid groups.

Process for preparing ethylene and other olefins from aqueous solutions of the corresponding alcohols

Method for the manufacture of furan compounds by using a heterogeneous catalyst in aqueous solution.

Method for the manufacture of furan compounds for renewable primary products

Disclosed is a method for producing polyalcohols in the form of sugar alcohols from the group comprising sorbitol and mannitol and other optional Cto Cpolyols. According to said method, a monosaccharide, disaccharide, oligosaccharide, or polysaccharide containing at least one glucose unit and/or at least one fructose unit is continuously reacted with hydrogen at an elevated temperature and at a great pressure in an aqueous phase in the presence of a hydrogenating catalyst based on ruthenium or ruthenium oxide so as to obtain the inventive polyalcohols. The minimum temperature is set at 100&#xb0; C. while the minimum pressure is set at 150 bar and the maximum dwell time of the reactants during catalytic hydrogenation is set at 600 s. The inventive method is particularly suitable for producing the sugar alcohols sorbitol and/or mannitol or Cto Cpolyols from glucose, fructose, or disaccharides, oligosaccharides, or polysaccharides containing glucose units or fructose units, especially saccharose, practically all the used saccharides being reacted without turning into caramel. Furthermore, the yield of said sugar alcohols or Cto Cpolyols is exceptionally high while the selectivity for the desired products can be varied in a simple manner within broad boundaries.

Process for the production of sugar alcohols

Process for utilizing liquid manure material

Growing community of inventors

Karlsruhe, Germany

Rainer Schweppe