Abstract: An improved process can be used for the acid hydrolysis of polylaurolactam with sulfuric acid. An especially suitable starting material is polylaurolactam which is intended for recycling and which is characterized by a low laurolactam content.

Abstract: A pipe, the inner surface of which is lined with a thermoplastic layer, is produced by a process comprising the following steps: a) a metal pipe is provided, b) a tubular inliner composed of a thermoplastic material is provided, c) a tape is cohesively helically bonded to the inliner, wherein the region of the contact surface of the tape consists of a moulding composition or an adhesive which adhere firmly to the surface of the inliner, and wherein the region of the opposing surface of the tape consists of a moulding composition or an adhesive which adhere firmly to the metal of the pipe, wherein the tape contains unidirectional reinforcing fibers; d) the cross section of the inliner is optionally reduced by exposure to an external force, e) the inliner is inserted into the metal pipe, f) by means of contact pressure and optionally heat, the inliner and metal pipe are firmly bonded to each other.

Abstract: A pipe, the inner surface of which is lined with a thermoplastic layer, is produced by a process comprising the following steps: a) a metal pipe is provided, b) a tubular inliner composed of a thermoplastic material is provided, c) a tape is cohesively helically bonded to the inliner, wherein the region of the contact surface of the tape consists of a moulding composition or an adhesive which adhere firmly to the surface of the inliner, and wherein the region of the opposing surface of the tape consists of a moulding composition or an adhesive which adhere firmly to the metal of the pipe, wherein the tape contains unidirectional reinforcing fibers; d) the cross section of the inliner is optionally reduced by exposure to an external force, e) the inliner is inserted into the metal pipe, f) by means of contact pressure and optionally heat, the inliner and metal pipe are firmly bonded to each other.

Abstract: The present application relates to a process for removing an organic compound having one or more positive charges from an aqueous solution, comprising the steps a) provision of the aqueous solution comprising the organic compound and of a hydrophobic organic solution which comprises a liquid cation exchanger, where the liquid cation exchanger is hydrophobic, and where the liquid cation exchanger has one or more negative charges and an overall negative charge, b) contacting the aqueous solution and the organic solution, and c) separating off the organic solution from the aqueous solution.

Abstract: A process for removing a cyclododecanone-rich target fraction (A) from a dehydrogenation mixture (O) comprising low boilers (LB), cyclododecanone (CDON), medium boilers (MB), cyclododecanol (CDOL) and high boilers (HB) is provided. According to the process, substantially pure CDON is obtained via a distillative sequence of two side draw columns connected in series, wherein the sidestream of the primary side draw column is fed into the secondary side draw column. From the top of each of the two side draw columns, a CDON-rich fraction is drawn off, and these are combined to form a target fraction, which is essentially pure CDON.

Abstract: The invention relates to a method for removing an organic compound having one or more positive charges from an aqueous solution. Said method consists of the following steps a) the aqueous solution containing the organic compound, and a hydrophobic organic solution which contains a hydrophobic liquid cation exchanger having one or more negative charges and a negative total charge, are provided, b) the aqueous solution and the organic solution are brought into contact with each other and c) the organic solution is separated from the aqueous solution.

Abstract: A process for removing a cyclododecanone-rich fraction from a dehydrogenation mixture containing low boilers, cyclododecanone, medium boilers, cyclododecanol and high boilers is provided. According to the process, the cyclododecanone is separated from the cyclododecanol in a dividing wall column. The apparatus which is the dividing wall column is also provided within this invention.

Abstract: A process for removing a cyclododecanone-rich fraction from a dehydrogenation mixture comprising low boilers, cyclododecanone, medium boilers, cyclododecanol and high boilers is provided. According to the process, the cyclododecanone is separated from the cyclododecanol in a dividing wall column. The apparatus which is the dividing wall column is also provided within this invention.

Abstract: A process for removing a cyclododecanone-rich target fraction (A) from a dehydrogenation mixture (O) comprising low boilers (LB), cyclododecanone (CDON), medium boilers (MB), cyclododecanol (CDOL) and high boilers (HB) is provided. According to the process, substantially pure CDON is obtained via a distillative sequence of two side draw columns connected in series, wherein the sidestream of the primary side draw column is fed into the secondary side draw column. From the top of each of the two side draw columns, a CDON-rich fraction is drawn off, and these are combined to form a target fraction, which is essentially pure CDON.

Abstract: The present application relates to a process for removing an organic compound having one or more positive charges from an aqueous solution, comprising the steps a) provision of the aqueous solution comprising the organic compound and of a hydrophobic organic solution which comprises a liquid cation exchanger, where the liquid cation exchanger is hydrophobic, and where the liquid cation exchanger has one or more negative charges and an overall negative charge, b) contacting the aqueous solution and the organic solution, and c) separating off the organic solution from the aqueous solution.

Abstract: The invention relates to a method for removing an organic compound having one or more positive charges from an aqueous solution. Said method consists of the following steps a) the aqueous solution containing the organic compound, and a hydrophobic organic solution which contains a hydrophobic liquid cation exchanger having one or more negative charges and a negative total charge, are provided, b) the aqueous solution and the organic solution are brought into contact with each other and c) the organic solution is separated from the aqueous solution.

Abstract: A process for purifying laurolactam by means of integrated connection of distillation and crystallization is provided. The crystallization is performed as a solution or melt crystallization. The process reduces thermal stress applied to the laurolactam stream and improved yields are obtained. Raw materials are recovered and recycled in the production sequence.

Abstract: A process for purifying laurolactam by means of integrated connection of distillation and crystallization is provided. The crystallization is performed as a solution or melt crystallization. The process reduces thermal stress applied to the laurolactam stream and improved yields are obtained. Raw materials are recovered and recycled in the production sequence.