Abstract: 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.

Abstract: 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 fluidising gas required for creating the fluidised bed.

Abstract: The invention relates to an intermediate product based on the organic carbonates and carbamates mixture and method for the production thereof. The inventive method consists in reacting a carbamide, a substituted carbamide, a carbamic acid salt or ester or one of the N-substituted derivatives thereof in a glycol polyalkylene, polyol polyester or a polyol polyether of general formula (I), wherein R is a linear or branched alkylene group having from 2 to 12 carbon atoms and n is a number ranging from 1 to 20, or in a totally or partly hydrolysed polyvinyl alcohol of general formula (II), wherein R? is an alkyl, aryl or acyl group having from 1 to 12 carbon atoms p and q are numbers ranging from 1 to 20, or dissolving in the mixture of said compounds with an alkaline catalyst promoting the ammonia separation. The thus free ammonia or an amine produced by the reaction mixture is removed by a stripping gas.

Abstract: 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 m with an alcohol or a phenol whereby monomer carbonates are formed and

Abstract: 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.

Abstract: 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° 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.