摘要:
Highly pure triethylenediamine is obtained by a process in which triethylenediamine is freed from high boilers and then the triethylenediamine is vaporized from the mixture thus obtained and is passed into a liquid solvent. The process makes it possible in particular to obtain highly pure solutions of triethylenediamine. Crystallization is generally unnecessary.
摘要:
In a process for the purification of triethylenediamine (TEDA) in which TEDA is vaporized and the gaseous TEDA is passed into a liquid solvent and is subsequently crystallized from this, the mother liquor obtained after the TEDA has been crystallized is extracted with an extractant which is immiscible or only slightly miscible with the solvent of the mother liquor and in which TEDA is readily soluble, and the TEDA-depleted mother liquor obtained after extraction and/or the TEDA-enriched extractant which has been used for the extraction are/is returned to the process.
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:
Process for recovering cyclododecatriene (CDT) from a solution comprising CDT and high boilers such as deactivated catalyst and polymers, which comprises feeding the solution into a preheater and heating it, subsequently depressurizing it through a downstream pressure maintenance device and feeding the resulting two-phase mixture into a helical tube evaporator and there reducing the CDT content of the liquid phase by partial evaporation and discharging a gaseous product stream having an increased concentration of CDT.
摘要:
Process for recovering cyclododecatriene (CDT) from a solution containing CDT and high boilers such as deactivated catalyst and polymers, which includes feeding the solution into a preheater and heating it, subsequently depressurizing it through a downstream pressure maintenance device and feeding the resulting two-phase mixture into a helical tube evaporator and there reducing the CDT content of the liquid phase by partial evaporation and discharging a gaseous product stream having an increased concentration of CDT.
摘要:
A process for preparing a high-concentration formaldehyde solution by removing water from a lower-concentration formaldehyde solution having a formaldehyde content of from 5 to 50% by weight, in which the lower-concentration formaldehyde solution is fed to a preheater and heated in the preheater, depressurized via a pressure maintenance device and concentrated in a helical tube evaporator to give a vapor stream and the high-concentration formaldehyde solution as bottom stream, wherein the heated lower-concentration formaldehyde hyde solution is depressurized in the pressure maintenance device to give a two-phase mixture which is fed into the helical tube evaporator, is proposed.
摘要:
A process for preparing a high-concentration formaldehyde solution by removing water from a lower-concentration formaldehyde solution having a formaldehyde content of from 5 to 50% by weight, in which the lower-concentration formaldehyde solution is fed to a preheater and heated in the preheater, depressurized via a pressure maintenance device and concentrated in a helical tube evaporator to give a vapor stream and the high-concentration formaldehyde solution as bottom stream, wherein the heated lower-concentration formaldehyde hyde solution is depressurized in the pressure maintenance device to give a two-phase mixture which is fed into the helical tube evaporator, is proposed.
摘要:
A process for purifying an aqueous glyoxal solution comprising at least one acid by extractive acid removal, comprising i) mixing and dispersion of the aqueous glyoxal solution with an ion exchanger solution comprising a tertiary amine and an organic solvent, ii) phase separation and removal of the ion exchanger solution laden with the acid from the aqueous glyoxal solution, and iii) regeneration of the ion exchanger solution by contacting with a basic compound for neutralization of the acid and removal of the basic compound, iv) mixing and dispersion of the ion exchanger solution with water to obtain a dispersion of water and ion exchanger solution, v) Phase separation and removal of the aqueous phase from the ion exchanger solution in such a way that the content of the aqueous phase of the regenerated ion exchanger solution is
摘要:
A device (1) for supplying electric current to the fuel pump (2) of a motor vehicle internal combustion engine (3) comprises a DC/DC converter (13) which increases voltage to a predetermined value in the event of a voltage drop of a direct current source (7). This ensures an adequate voltage supply of the fuel pump (2) even at low voltages of the direct voltage source. When the voltage (15) of the direct voltage source (7) is sufficient, the DC/DC converter (13) is bridged, so that the fuel pump (2) is directly supplied with fuel from the direct voltage source (7). The DC/DC converter is also bridged when the device is faulty.