Abstract: The present invention relates to a process for the purification of hydrogen cyanide, comprising the steps of a) splitting a liquid feed stream (1) comprising hydrogen cyanide into at least a first liquid stream (2) and a second liquid stream (3), b) introducing the first liquid stream (2) into a distillation column (4) at a point between the top and the bottom of the distillation column, c) introducing the second liquid stream (3) into the distillation column (4) at the top of the distillation column, d) withdrawing an overhead vapor stream (5) enriched in hydrogen cyanide from the distillation column (4), and e), withdrawing a bottom stream (6) depleted in hydrogen cyanide, wherein the temperature of the second liquid stream (3) in step c) is lower than the temperature of the first liquid stream (2) in step b).

Abstract: The invention refers to the use of a particulate catalyst containing 60.0 to 99.5 wt. % ZrO2 stabilised with an oxide of the element Hf and at least one oxide of the element M, wherein M=Ce, Si, Ti, or Y, for the hydrolysis reaction of methionine amide to methionine, wherein the median particle size x50 of the particulate catalyst is in the range of from 0.8 to 9.0 mm, preferably of from 1.0 to 7.0 mm. The invention also refers to a process for preparing methionine comprising a step of contacting a solution or suspension comprising methionine amide and water with said particulate catalyst to provide a reaction mixture comprising methionine and/or its ammonium salt from which methionine can be isolated.

Abstract: The present invention relates to a process for the purification of hydrogen cyanide, comprising the steps of a) splitting a liquid feed stream (1) comprising hydrogen cyanide into at least a first liquid stream (2) and a second liquid stream (3), b) introducing the first liquid stream (2) into a distillation column (4) at a point between the top and the bottom of the distillation column, c) introducing the second liquid stream (3) into the distillation column (4) at the top of the distillation column, d) withdrawing an overhead vapor stream (5) enriched in hydrogen cyanide from the distillation column (4), and e), withdrawing a bottom stream (6) depleted in hydrogen cyanide, wherein the temperature of the second liquid stream (3) in step c) is lower than the temperature of the first liquid stream (2) in step b).

Abstract: A process for preparing methionine includes the alkaline hydrolysis of 5-(2-methylmercaptoethyl)-hydantoin (methionine hydantoin) in an aqueous process solution containing alkali metal hydroxide and/or alkali metal carbonate and/or alkali metal hydrogencarbonate. The alkali metal cations in the process solution are potassium and sodium having a K/Na molar ratio range from 99/1 to 20/80.

Abstract: A process for preparing methionine includes the alkaline hydrolysis of 5-(2-methylmercaptoethyl)-hydantoin (methionine hydantoin) in an aqueous process solution containing alkali metal hydroxide and/or alkali metal carbonate and/or alkali metal hydrogencarbonate. The alkali metal cations in the process solution are potassium and sodium having a K/Na molar ratio range from 99/1 to 20/80.

Abstract: The reaction tube for preparing hydrogen cyanide comprises a cylindrical tube composed of ceramic, a catalyst comprising platinum applied to the inner wall of the tube and also at least one insert composed of ceramic, having three or four fins pointing from the tube axis to the inner wall of the tube, which is inserted into the cylindrical tube, wherein the fins divide the tube interior space into substantially straight channels with substantially identical circle segment cross sections and wherein the mean gap between the ends of the fins and the inner wall of the tube is in the range of 0.1 to 3 mm. In the method for preparing hydrogen cyanide, ammonia and at least one aliphatic hydrocarbon having 1 to 4 carbon atoms are reacted in the reaction tube at 1000 to 1400° C.

Abstract: The invention relates to a method for thermally after-burning the waste gas flows developing during the production of acrolein in a gas phase process and for thermally after-burning the waste gas flows developing during the production of hydrocyanic acid in a gas phase process, characterized in that the waste gas flows from the production of acrolein and the waste gas flows from the production of hydrocyanic acid are supplied to a joint thermal after-burning process.

Abstract: The reaction tube for preparing hydrogen cyanide comprises a cylindrical tube composed of ceramic, a catalyst comprising platinum applied to the inner wall of the tube and also at least one insert composed of ceramic, having three or four fins pointing from the tube axis to the inner wall of the tube, which is inserted into the cylindrical tube, wherein the fins divide the tube interior space into substantially straight channels with substantially identical circle segment cross sections and wherein the mean gap between the ends of the fins and the inner wall of the tube is in the range of 0.1 to 3 mm. In the method for preparing hydrogen cyanide, ammonia and at least one aliphatic hydrocarbon having 1 to 4 carbon atoms are reacted in the reaction tube at 1000 to 1400° C.

Abstract: The invention relates to a method for crystallizing D,L-methionine from aqueous solutions and/or suspensions containing D,L-methionine and D,L-methionine ammonium salts, having a Met content of 70-180 g/kg, an NH4+ content of 1-5 g/kg, in the presence of a crystallization additive, which comprises a nonionic or anionic surfactant or a mixture of various nonionic or anionic surfactants, in which the temperature of the solution and/or suspension is lowered directly or stepwise from T1=85-110° C. to T2=30-50° C., so that D,L-methionine precipitates as a solid.

Abstract: The application relates to a process for the production of granules optimized for feed use containing amino acids and optionally constituents of the fermentation broth for use as feed additives, the granulation being carried out in a stationary or circulating fluidized bed, an aqueous suspension or an aqueous solution of the amino acid being sprayed in a granulation chamber containing a fluidized bed, the drying gas flow on flowing into the granulation chamber having a temperature of 120 to 450° C. and a water vapour content of more than 16 g of water/kg of drying gas.

Abstract: The reaction tube comprises a cylindrical ceramic tube and a catalyst comprising platinum applied to the inner surface of the tube, wherein the reaction tube has fins on the inner surface which run in the longitudinal direction of the tube, extend into the interior space of the reaction tube and are coated with catalyst. The reaction tube is suitable for preparing hydrogen cyanide by reacting ammonia and at least one aliphatic hydrocarbon having 1 to 4 carbon atoms at a temperature of 1000 to 1400° C.

Abstract: The present invention relates to a reactor and to a process for synthesis of hydrogen sulphide from elemental sulphur and hydrogen at elevated pressure and elevated temperature. The invention further relates to the use of the reactor for preparation of hydrogen sulphide in high yield and with a low H2Sx content.

Abstract: The present invention relates to a reactor and to a process for synthesis of hydrogen sulphide from elemental sulphur and hydrogen at elevated pressure and elevated temperature. The invention further relates to the use of the reactor for preparation of hydrogen sulphide in high yield and with a low H2Sx content.

Abstract: The invention relates to a method for thermally after-burning the waste gas flows developing during the production of acrolein in a gas phase process and for thermally after-burning the waste gas flows developing during the production of hydrocyanic acid in a gas phase process, characterized in that the waste gas flows from the production of acrolein and the waste gas flows from the production of hydrocyanic acid are supplied to a joint thermal after-burning process.

Abstract: A process for purifying CO2 offgas streams to free them of chemical compounds, and to the recycling of the purified gas streams into the production process.

Abstract: The present invention is directed to an improved process for producing methionine in which the by-product methionyl-methionine is quickly converted to the product methionine by a hydrolysis reaction. The process is performed at high temperatures (200° C. to 280° C.) and short residence times (20 s to 200 s) and results in an improved yield of end product methionine.

Abstract: A process for purifying CO2 offgas streams to free them of chemical compounds, and to the recycling of the purified gas streams into the production process.

Abstract: The present invention is directed to an improved process for producing methionine in which the by-product methionyl-methionine is quickly converted to the product methionine by a hydrolysis reaction. The process is performed at high temperatures (200° C. to 280° C.) and short residence times (20 s to 200 s) and results in an improved yield of end product methionine.

Abstract: Active compound formulations for animal nutrition of amino acids, vitamins, enzymes and pigments, which are suitable for providing the active compounds in protected form for the nutrition of stock animals, in particular ruminants, and a process for the preparation of these protected active compound formulations.

Abstract: A process for the preparation of &agr;-amino acids by hydrolysis of hydantoins in the presence of water and at least one metallic oxide under conditions such that all the starting materials are completely dissolved in the water as a result of high pressure and high temperature and only one further phase is present in the reactor in addition to the metallic oxide phase.