US 11,987,562 B2
Production of hydroxyethylpiperazine
Amanda M. Goodman, Missouri City, TX (US); Jianping Zeng, Manvel, TX (US); Barry Archer, Lake Jackson, TX (US); and Christophe R. Laroche, Lake Jackson, TX (US)
Assigned to Dow Global Technologies LLC, Midland, MI (US)
Appl. No. 17/287,628
Filed by Dow Global Technologies LLC, Midland, MI (US)
PCT Filed Oct. 23, 2019, PCT No. PCT/US2019/057612
§ 371(c)(1), (2) Date Apr. 22, 2021,
PCT Pub. No. WO2020/092082, PCT Pub. Date May 7, 2020.
Claims priority of provisional application 62/752,437, filed on Oct. 30, 2018.
Prior Publication US 2021/0395211 A1, Dec. 23, 2021
Int. Cl. C07D 295/088 (2006.01); B01D 3/00 (2006.01); B01D 3/14 (2006.01)
CPC C07D 295/088 (2013.01) [B01D 3/009 (2013.01); B01D 3/143 (2013.01)] 8 Claims
 
1. A continuous process for the production of hydroxyethylpiperazine, the process comprising:
feeding neat piperazine, recycled piperazine, and ethylene oxide to a reactor to form crude hydroxyethylpiperazine, the reactor being a continuous stirred tank reactor or a plug flow reactor, wherein a molar ratio of ethylene oxide to neat piperazine added to the reactor is greater than 1.01; and
continuously feeding the crude hydroxyethylpiperazine from the reactor to a distillation system that includes at least one distillation column, the distillation system producing at least a recycled piperazine stream and a hydroxyethylpiperazine stream, the recycled piperazine stream including the recycled piperazine that is fed to the reactor to form the crude hydroxyethylpiperazine and the hydroxyethylpiperazine stream including at least 60 wt % of hydroxyethylpiperazine based on a total weight of the hydroxyethylpiperazine stream.