摘要:
The invention relates to a process for continuously, distillatively removing piperazine from an ethylenediamine-piperazine mixture under pressure at elevated temperature, by discharging the ethylenediamine at the top and the piperazine at the bottom of a distillation column. For the purpose of improving the quality of the piperazine, especially its color and color stability, the piperazine is subjected directly to circulation conveying it through an evaporator unit operated at a temperature of from about 160° C. to about 170° C. and returning it into the distillation column. After a residence time of from about 30 min to about 60 min in the circulation system, the piperazine is discharged in vapor form from a side draw in the lower section of the distillation column.
摘要:
The present invention describes a process for the preparation of triethylenediamine by reacting piperazine over a zeolite catalyst which, in addition to SiO2, contains an oxide of at least one further divalent, trivalent or tetravalent metal M, wherein the zeolite has a molar Si/M ratio of >100. In particular, a zeolite of the ZSM-5 type is used. The use of the zeolites permits suppression of the undesired formation of the byproduct 2-ethylpiperazine and hence considerable simplification of the working-up, in combination with high piperazine conversions and a small excess of water.
摘要:
The invention relates to the preparation of pure triethylenediamine (TEDA) by evaporating TEDA from the mixture comprising a solvent or diluent, where the solvent or diluent has a boiling point at atmospheric pressure in the range from 175 to 250° C., passing the vapor-form TEDA into a liquid solvent, and subsequently crystallizing the TEDA out of the resultant solution.
摘要:
Processes comprising: providing a starting material comprising diethylene glycol; and reacting the starting material with ammonia in the presence of a heterogeneous transition metal catalyst to form a reaction product comprising aminodiglycol and morpholine; wherein the catalyst comprises a catalytically active composition, which prior to treatment with hydrogen, comprises a mixture of oxygen-containing compounds of copper, nickel, cobalt and at least one of aluminum and zirconium; and wherein the catalyst is present as one or more shaped catalyst particles selected from spheres, extrudates, pellets and other geometries, wherein the sphere or extradate has a diameter of
摘要:
The invention relates to a process for continuously, distillatively removing piperazine from an ethylenediamine-piperazine mixture under pressure at elevated temperature, by discharging the ethylenediamine at the top and the piperazine at the bottom of a distillation column. For the purpose of improving the quality of the piperazine, especially its color and color stability, the piperazine is subjected directly to circulation conveying it through an evaporator unit operated at a temperature of from about 160° C. to about 170° C. and returning it into the distillation column. After a residence time of from about 30 min to about 60 min in the circulation system, the piperazine is discharged in vapor form from a side draw in the lower section of the distillation column.