摘要:
A process for working up at least partially deactivated polymerization catalysts for the polymerization or copolymerization of THF which are contaminated with the products of the polymerization or copolymerization of THF comprises (a) in a first step, cleaning the polymerization catalyst by treatment with steam at from 80 to 250° C. and a pressure of from 0.5 to 40 bar and, preferably, (b) in a second step, regenerating the clean polymerization catalyst.
摘要:
In a process for preparing polytetrahydrofuran, tetrahydrofuran copolymers, diesters or monoesters of these polymers having a low color number, the polymers obtained by cationic polymerization of tetrahydrofuran are hydrogenated in the presence of a macroporous, supported heterogeneous catalyst comprising at least one metal of groups 7 to 10 of the Periodic Table of the Elements as active metal.
摘要:
The invention provides a process for preparing polytetrahydrofuran, tetrahydrofuran copolymers, their monoesters or diesters and the monoesters or diesters of polytetrahydrofuran having a low color number in the presence of a catalyst, which comprises converting crude tetrahydrofuran which has been prepared in a manner per se into pure tetrahydrofuran by distillation, subsequently subjecting the latter to essentially complete hydrogenation and using the high-purity tetrahydrofuran obtained in this way for the polymerization directly after its preparation.
摘要:
The invention provides a process for preparing polytetrahydrofuran, tetrahydrofuran copolymers, their monoesters or diesters and the monoesters or diesters of polytetrahydrofuran having a low color number in the presence of a catalyst, which comprises converting crude tetrahydrofuran which has been prepared in a manner per se into pure tetrahydrofuran by distillation, subsequently subjecting the latter to essentially complete hydrogenation and using the high-purity tetrahydrofuran obtained in this way for the polymerization directly after its preparation.
摘要:
A process for preparing a diamine from a corresponding aminoalkyl nitrile, which is prepared by reaction of a corresponding monoamine with a corresponding alkenyl nitrile in a continuous mode of operation, comprising the steps: a) introduction of the corresponding monoamine into a continuously conveyed reaction stream; b) introduction of the corresponding alkenyl nitrile into the reaction stream, with this already comprising the aminoalkyl nitrile on addition; c) reaction of the reaction stream in a first reaction region; d) at least partial transfer of the reaction stream into at least one second reaction region for further reaction; e) discharge of the reaction stream from the second reaction region after the reaction; f) introduction of the reaction stream discharged in step (a) into a reduction region; and g) reduction of the aminoalkyl nitrile present in the reaction stream to the corresponding diamine.
摘要:
The present invention relates to a process for preparing an aminoalkyl nitrile by reaction of a corresponding monoamine with a corresponding alkenyl nitrile in a continuous mode of operation, which comprises the steps (a) introduction of the corresponding monoamine into a continuously conveyed reaction stream; (b) introduction of the corresponding alkenyl nitrite into the reaction stream, with this already comprising the aminoalkyl nitrile on addition; (c) reaction of the reaction stream in a first reaction region; and (d) at least partial transfer of the reaction stream into at least one second reaction region for further reaction. The invention further relates to a process for preparing a diamine from the aminoalkyl nitrile, suitable apparatuses for carrying out the processes and their corresponding use.
摘要:
The present invention relates to a process for preparing an aminoalkyl nitrile by reaction of a corresponding monoamine with a corresponding alkenyl nitrile in a continuous mode of operation, which comprises the steps (a) introduction of the corresponding monoamine into a continuously conveyed reaction stream; (b) introduction of the corresponding alkenyl nitrite into the reaction stream, with this already comprising the aminoalkyl nitrile on addition; (c) reaction of the reaction stream in a first reaction region; and (d) at least partial transfer of the reaction stream into at least one second reaction region for further reaction. The invention further relates to a process for preparing a diamine from the aminoalkyl nitrile, suitable apparatuses for carrying out the processes and their corresponding use.
摘要:
A process for preparing a diamine from a corresponding aminoalkyl nitrile, which is prepared by reaction of a corresponding monoamine with a corresponding alkenyl nitrile in a continuous mode of operation, comprising the steps: a) introduction of the corresponding monoamine into a continuously conveyed reaction stream; b) introduction of the corresponding alkenyl nitrile into the reaction stream, with this already comprising the aminoalkyl nitrile on addition; c) reaction of the reaction stream in a first reaction region; d) at least partial transfer of the reaction stream into at least one second reaction region for further reaction; e) discharge of the reaction stream from the second reaction region after the reaction; f) introduction of the reaction stream discharged in step (a) into a reduction region; and g) reduction of the aminoalkyl nitrile present in the reaction stream to the corresponding diamine.
摘要:
A process for obtaining oligomers of polytetrahydrofuran or of tetrahydrofuran copolymers from a methanolic crude product which contains polytetrahydrofuran or tetrahydrofuran copolymers and is obtained in the transesterification of the mono- and/or diesters of polytetrahydrofuran or tetrahydrofuran copolymers with methanol, which includes a) removing the majority of the methanol from the crude product in a first distillation stage, b) separating the resulting bottom product by distillation into a top fraction containing the oligomers of polytetrahydrofuran or of tetrahydrofuran copolymers, and polytetrahydrofuran or tetrahydrofuran copolymer, and c) condensing the oligomers of polytetrahydrofuran or of tetrahydrofuran copolymers out of the top fraction from stage b).
摘要:
A process is disclosed for the selective hydrogenation of butynediol to 2-butene-1,4-diol using a palladium catalyst to which either copper and zinc, or silver and zinc, or copper, silver and zinc are added as doping agents. In the preferred embodiment, it has been possible, by optimizing the composition of the catalyst, to improve the activity and selectivity of the catalysts in question while also eliminating the need to handle toxic substances during the catalyst manufacturing process.