Production of hydroxyethylpiperazine

Abstract

Embodiments relate to a continuous process for the production of hydroxyethylpiperazine that includes feeding neat piperazine, recycled piperazine, and ethylene oxide to a reactor to form crude hydroxyethylpiperazine, in which the reactor is a continuous stirred tank reactor or a plug flow reactor. The process further includes continuously feeding the crude hydroxyethylpiperazine from the reactor to a distillation system that includes at least one distillation column, the distillation system produces at least a recycled piperazine stream and a hydroxyethylpiperazine stream, the recycled piperazine stream includes the recycled piperazine that is fed to the reactor to form the crude hydroxyethylpiperazine, and the hydroxyethylpiperazine stream includes at least 60 wt% of hydroxyethylpiperazine based on a total weight of the hydroxyethylpiperazine stream.

Description

technical field [0001] The examples relate to processes for the preparation of hydroxyethylpiperazine and hydroxyethylpiperazine products prepared according to the process. Background technique [0002] Piperazine ("PIP") is an organic compound comprising a six-membered ring containing two nitrogen atoms. Piperazine may be formed as a by-product in the chlorination of 1,2-dichloroethane or ethanolamine. Hydroxyethylpiperazine ("HEP") is a piperazine further comprising a hydroxyethyl group, which may be referred to as 1-(2-hydroxyethyl)piperazine. For example, hydroxyethylpiperazine can have the following structure: [0003] [0004] Hydroxyethylpiperazine can be formed by ethoxylation of piperazine (eg, by reaction of preformed piperazine with ethylene oxide). The process used to make hydroxyethylpiperazine can produce hydroxyethylpiperazine and dihydroxyethylpiperazine ("DiHEP"). The resulting product can be used as a mixture or additional processing steps can be uti...

AI Technical Summary

Problems solved by technology

For example, a high molar ratio of ethylene oxide to piperazine can dominate the production of dihydroxyethylpiperazine and reduce the yield of hydroxyethylpiperazine, which is desirable when seeking to produce high-purity hydroxyethylpiperazine is unfavorable

Further, the low molar ratio of ethylene oxide to piperazine may result in a large amount of unreacted piperazine, and since piperazine solidifies at room temperature, it is difficult to isolate unreacted piperazine on a commercial scale.

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