Lurgi Gmbh

Lurgi Ag

Mg Technologies Ag

Jürgen Eberhardt

Henning Buchold

Hans-Jörg Wölk

Ulrich Wagner

Martin Müller-Hasky

Arne Schadt

Walter Boll

Holger Dropsch

The invention concerns a method for producing melamine by dissolving urea, in which solid, liquid or gaseous media other than the gas mixture consisting of the components formed during the reaction is used to desublime the melamine from the gas phase.

Method for producing melamine

The invention relates to a method for producing melamine by decomposing urea inside a fluidised bed reactor, during which the hot reaction gas is cooled inside a gas cooler, and the obtained heat is directly used for pre-heating the fluidizing gas required for creating the fluidized bed.

Method for producing melamine with heat recovery

The invention relates to a method for the production of monomer organic carbonates from a mixture of organic carbonates and carbamates which are obtained by reacting urea, substituted urea, a salt or ester of carbamide acid or one of the N-substituted derivatives thereof with a polyalkylene glycol, polyester-polyol or a polyether-polyol of general formula (I), wherein R represents a linear or branched alkylene group having 2-12 carbon atoms and n represents a number between 2 and 20, or with a completely or partially hydrolysed polyvinyl alcohol of general formula (II), wherein R' represents an alkyl group, an aryl group or an acyl group having 1-12 carbon atoms, p and q represent a number between 120, or with mixtures of said compounds in the presence of a catalyst facilitating the separation of ammonia and the ammonia becomes free or the amine is removed from the reaction mixture by means of a strip gas, whereby said mixture is reacted with an alcohol or a phenol whereby monomer carbonates are formed and polymer polyalcohols of formulae (I) or (II) are reformed. 

Method for the production of organic carbonates

The invention relates to a method for the production of monomer organic carbonates, wherein urea, substituted urea, a salt or an ester of carbamide acid or one of the N-substituted derivatives thereof is reacted in a first step in a polyalkylene glycol, a polyester-polyol or a polyether-polyol of general formula (I), wherein R represents a linear or branched alkylene group having 2-12 carbon atoms and n is a number between (2) and (20), or in a completely or partially hydrolysed polyvinyl alcohol of general formula (II) wherein R' represents an alkyl group, an aryl group or an acyl group having 1-12 carbon atoms, p and q are numbers between 1 and 20, or in mixtures of said compounds in the presence of a catalyst facilitating the separation of ammonia in order to form a mixture containing carbonates and carbamates, the ammonia becomes free or the amine is removed form the reaction mixture by means of a strip gas. In a second reaction step (transesterification), the mixture containing the carbonates and carbamates is reacted with a monomer alcohol or a phenol whereby monomer carbonates are formed and polymer polyalcohols of formulae (I) or (II) are reformed.HO&#x2014;ROH&#x2003;&#x2003;(I)

In the presence of a catalyst, at least one isoparaffin having 4 to 6 C atoms per molecule is reacted with at least one olefin having 2 to 6 C atoms per molecule in a liquid phase to obtain a product containing alkylate, a suspension containing isoparaffin and a granular zeolite catalyst being supplied to the upper region of a reaction column. Below the point where the catalyst-containing suspension is supplied, an isoparaffin-olefin mixture is introduced into the reaction column, the temperatures in the reaction column being maintained in the range from 50 to 120&#xb0; C. From the bottom region of the reaction column a product mixture containing alkylate is withdrawn, and in a separation by distillation alkylate product is recovered therefrom. Preferably, isoparaffin and catalyst are recovered from the separation by distillation and at least partly recirculated to the upper region of the reaction column.

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Rodgau, Germany

Jürgen Eberhardt