Abstract:
The invention relates to a process for a polyamide based on dicarboxylic acids and diamines, comprising the following stages: A) providing an aqueous monomer mixture composed of dicarboxylic acids and diamines; B) transferring the aqueous mixture from stage A) into a continuous evaporator reactor in which diamines and dicarboxylic acids are converted at a temperature in the range from 100 to 370°C and a pressure in the range from 2 to 51 bar (abs), the evaporator reactor being a vertical tube bundle reactor through which the flow is from the top downward; C) transferring the mixture from stage B) into a separator which is operated at a temperature in the range from 100 to 370°C and a pressure in the range from 1 to 50 bar with removal of gaseous components; wherein the tubes of the evaporator reactor have internals which direct the flow of the liquid phase of the mixture close to the wall towards the middle of the tubes and have free flow paths for the gas phase produced in the evaporator reactor over their axial length along the inner wall of the tubes.
Abstract:
Verfahren zur Herstellung von Blausäure durch Thermolyse von gasförmigem Formamid in einem Reaktor in Gegenwart eines Katalysators, wobei a)der Katalysator (i)ein Aluminiumoxid-Katalysator ist, enthaltend -90 bis 100 Gew.-%, bevorzugt 99 bis 100 Gew.-% Aluminiumoxid als Komponente A, -0 bis 10Gew.-%, bevorzugt 0 bis 1 Gew.-% Siliziumdioxid als Komponente B, und -0 bis maximal 0,1Gew.-% Eisen oder Eisen enthaltende Verbindungen als Komponente C, wobei die Gesamtsumme der Komponenten A, B und C 100 Gew.-% beträgt, und (ii)eine BET-Oberfläche, gemessen gemäß DINISO 9277 : 2003-05 von 2 /g aufweist, und (iii)bei Temperaturen von >1400 °C für 1 bis 30 h, bevorzugt ≥1500 °C für 1 bis 30 h, besonders bevorzugt bei 1500 °C bis 1800 °C für 2 bis 10 h getempert wird, und b)der Reaktor eine innere Oberfläche aufweist, die bezüglich der Thermolyse von Formamid inert ist; sowie Verwendung des Katalysators in einem Verfahren zur Herstellung von Blausäure durch Thermolyse von gasförmigem Formamidin einem Reaktor, der eine innere Oberfläche aufweist, die bezüglich der Thermolyse von Formamid inert ist.
Abstract:
The invention relates to a method for producing hydrocyanic acid by the thermolysis of gaseous formamide in a reactor in the presence of a catalyst, wherein a) the catalyst (i) is an aluminum oxide catalyst, containing - 90 to 100 wt%, preferably 99 to 100 wt%, of aluminum oxide as component A, - 0 to 10 wt%, preferably 0 to 1 wt%, of silicon dioxide as component B, and - 0 to at most 0.1 wt% of iron or compounds containing iron as component C, wherein the total sum of components A, B, and C is 100 wt%, and (ii) has a BET surface area, measured as per DIN ISO 9277 : 2003-05, of 2 /g, and (iii) is tempered at temperatures of > 1400 °C for 1 to 30 h, preferably ≥ 1500 °C for 1 to 30 h, especially preferably at 1500 °C to 1800 °C for 2 to 10 h, and b) the reactor has an inner surface that is inert with respect to the thermolysis of formamide; and use of the catalyst in a method for producing hydrocyanic acid by the thermolysis of gaseous formamide in a reactor that has an inner surface that is inert with respect to the thermolysis of formamide.