Ticona Gmbh

Siemens Axiva Gmbh & Co. Kg

Elke Schweers

Thomas Kaiser

Michael Rosenberg

Christine Meister

Michael Haubs

Rolf Schulz

Uwe Dingerdissen

Werner Sievers

Ulrich Bauer

Albert Reichl

Harald Werner

Heinz Alexander

Gerhard Geiss

Helmut Gursky

Dirk Scheid

Stefan Heffels

Helmut Tr&auml;nkler

Olaf Mientkewitz

Elfriede Hufsky

Frank Olschewski

Ioannis Nicolaou

Hubert M&uuml;ller

Hagen Kniep

Raimo Dr&ouml;gemeier

A process for preparing trioxane by converting methanol to formaldehyde by dehydrogenation at a temperature of 300 to 1000&deg; C., in the presence of a catalyst, wherein the catalyst is generated physically separately from the reactor and at a temperature above the dehydrogenation temperature, and trimerizing the formaldehyde prepared in this way to give trioxane. Also described is a process for preparing polyoxymethylene and polyoxymethylene copolymers from the formaldehyde.

Process for preparing trioxane, polyoxymethylene and polyoxymethylene copolymers

The invention relates to a process for the comminution of bulk materials comprising synthetic polymers which do not have an elastomeric behavior by mechanical, thermal or electromagnetic loading of the bulk materials, which comprises treating the bulk materials, before and/or during the loading, with oxidants which have a redox potential of greater than 1.5 V or subjecting them to corona, UV or plasma treatment without complete oxidation of the synthetic polymer taking place.

Process for increasing the effectiveness of the comminution of bulk materials by oxidation

An apparatus for preparing formaldehyde from methanol by dehydrogenation in a reactor in the presence of a catalyst at a temperature in the range from 300 to 1000&deg; C., a carrier gas stream which has a temperature above the dehydrogenation temperature is fed to the reactor.

Apparatus for the preparation of formaldehyde from methanol

The invention relates to a method for producing formaldehyde from methanol by non-oxidative dehydrogenation, in a reactor, in the presence of a catalyst at a temperature between 300 and 1000&deg; C. Said method is characterized in that the generation of the catalyst takes place spatially separate from the reactor and at a temperature greater than the dehydrogenation.

Process for the non-oxidative preparation of formaldehyde from methanol

Process for the removal of trioxane from a liquid mixture comprising trioxane, formaldehyde, alcohol, hemiformals formed from the form-aldehyde and the alcohol, usual secondary components arising in the preparation of trioxane, and, in addition or as an alternative to the alcohol and the hemiformals, water, in which the trioxane is transferred into the gas phase by vaporization or evaporation and subsequently converted into a liquid state by condensation and obtained as condensate or converted into a solid state by desublimation and obtained as desublimate. Through the process, an increase in the concentration of the trioxane by 2.5 times or more is achieved.

Separation of trioxane from liquid mixtures

A process for the post-purification in particular of pyrolysis gases for preparing pure formaldehyde, hemiformal being pyrolyzed in an evaporator, the resulting formaldehyde vapor being passed through a condensed liquid component collected in the bottom area of the evaporator, the condensed liquid component being passed out as a falling film situated on the inner wall through a cooled outlet tube disposed in the bottom area of the evaporator and the formaldehyde vapor being passed through the cooled outlet tube in cocurrent and the liquid component and the formaldehyde being taken off separately at the outlet tube end remote from the evaporator.

Process and device for preparing pure formaldehyde

Processes for making trioxane, polyoxymethylene and polyoxymethylene copolymers from formaldehyde, made by the dehydrogenation of methanol in the presence of a catalytic active species set free from a sodium compound, at a temperature in the range of 300&deg; C. to 1000&deg; C., wherein a carrier gas stream which has a temperature above the dehydrogenation temperature is fed to the reactor.

Process for the preparation of trioxane and polyoxymethylene copolymers

In a process for preparing formaldehyde from methanol by dehydrogenation in a reactor in the presence of a catalyst at a temperature in the range from 300 to 1000&deg; C., a circulating gas stream comprising by-products of the dehydrogenation is passed through the reactor.

Method for producing formaldehyde from methanol

In a process for preparing formaldehyde from methanol by dehydrogenation in a reactor in the presence of a catalyst at a temperature in the range from 300 to 1000&deg; C., a carrier gas stream which has a temperature above the dehydrogenation temperature is fed to the reactor.

A process for the gas-phase trimerization of formaldehyde to give trioxane using solid phosphoric acid catalysts. Particularly suitable catalysts for this process are SPA catalysts (solid phosphorous acid), for example &ldquo;silicon phosphates&rdquo;. The main advantage of this catalyst system is its simple and inexpensive production and ready availability and also, in particular, its improved long-term stability compared to the few previously described catalysts which are mostly based on supported heteropolyacids.

Trimerization of formaldehyde in the gas phase

Process for the nonoxidative preparation of formaldehyde from methanol The invention relates to a process for preparing formaldehyde from methanol by dehydrogenation in a reactor at temperatures in the range from 300 to 1000&deg; C. in the presence of a catalyst which is introduced into the reactor with the aid of a carrier gas to give a product gas mixture, wherein the formaldehyde is separated from the product gas mixture and at least part of the remaining product gas mixture is recirculated to the reactor in a circulating gas stream and the carrier gas used is a carbon-free gas or gas mixture.

Method for non-oxidative production of formaldehyde from methanol

Abstract A process for purifying formaldehyde in which the formaldehyde is scrubbed with alcohol in an absorption unit and in the course of this reacted virtually completely to form the hemiformal and is simultaneously separated off from gaseous impurities in a first purification step. In a desorption unit, the residual impurities are then converted into a gaseous state and separated off from the liquid hemiformal, whereupon the purified hemiformal is thermally cleaved into alcohol and formaldehyde in a pyrolysis unit. The formaldehyde thus prepared is suitable, for example, for preparing oligomers, polymers, dyestuffs and fertilizers, as well as for the treatment of seeds. Process for purifying formaldehyde, its use and plastics prepared using it

Method for purification of formaldehyde, use thereof and plastics produced therewith

The invention relates to a method for separating a gaseous mixture comprising formaldehyde and trioxane, wherein at least some of the formaldehyde and the trioxane are dissolved from the mixture in a alcohol-containing liquid and the trioxane is crystallized from the solution thus obtained and is separated.

Growing community of inventors

Bad Soden, Germany

Elke Schweers