Recovery of N-ethylpiperazine by distillation
AssigneeBASF SE
InventorsKlaus-Dieter Malsch, Douglas Hutton, Ernst Lang
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Abstract
In a process for the recovery of N-ethylpiperazine by distillation from mixtures with N,N'-diethylpiperazine, piperazine, ethanol, water and accompanying substances, water is added in a manner such that, at the location of the addition of the water, the piperazine concentration is greater than the N-ethylpiperazine concentration. The water may be added to the reflux to the top of the column.
Claims4
A process for the recovery of N-ethylpiperazine by distillation from mixtures with N,N'-diethylpiperazine, piperazine, ethanol, water and accompanying substances in a distillation column having a still, trays or packings and at its top a condenser for producing reflux, wherein, a stepwise distillation of the mixture proceeds as follows:
- a) in the first distillation step at about 98.degree. C., a forerun comprising water, piperazine and small amounts of N-ethypiperazine is obtained;
- b) in the subsequent second distillation step at about 150.degree. C., water is added to the reflux and a fraction of piperazine, water and small amounts of N-ethylpiperazine is obtained;
- c) in the third distillation step at 155.degree. C. pure N-ethylpiperazine is removed;
- leaving a bottom fraction which contains N,N'-diethylpiperazine and other high-boiling components.
Dependencies are inferred from the claim text.