Process for continuous hydrogenation or hydrogenating amination

  • US 8,557,985 B2
  • Filed: 03/19/2012
  • Issued: 10/15/2013
  • Est. Priority Date: 10/17/2005
  • Status: Expired due to Fees
First Claim
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1. A process for continuously hydrogenating unsaturated compounds, in whicha) particles of a first hydrogenation catalyst are suspended in a liquid phase in which an unsaturated compound is dissolved,b) the liquid phase, in the presence of a hydrogenous gas at a first partial hydrogen pressure and at a first temperature, is conducted through a packed bubble column reactor in cocurrent counter to the direction of gravity,c) the effluent from the bubble column reactor is sent to a gas-liquid separation,d) the liquid phase from step c) is sent to a crossfiltration to obtain a retentate and a filtrate,e) the retentate is recycled into step b),f) the filtrate, in the presence of a hydrogenous gas at a second partial hydrogen pressure and at a second temperature, is passed over a bed of a second hydrogenation catalyst,wherein the unsaturated compound is an enamine which is prepared in situ from a carbonyl compound and a primary or secondary amine,wherein the carbonyl compound is selected from 2-methyl-3-(p-tert-butylphenyl)-propanal, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-pentanal, n-hexanal, 2-ethylhexanal, 2-methylpentanal, 3-methylpentanal, 4-methylpentanal, glyoxal, benzaldehyde, p-methoxybenzaldehyde, p-methylbenzaldehyde, phenylacetaldehyde, (p-methoxyphenyl)acetaldehyde, (3,4-dimethoxyphenyl)acetaldehyde, furfural, 4-formyltetrahydropyran, 3-formyltetrahydrofuran, 5-formylvaleronitrile, hydroformylated polyisobutene, hydroformylated oligomers obtained by metathesis of 1-pentene and cyclopentene, acetone, 2-butanone, 3-methylbutan-2-one, 4-methylpentan-2-one, diethylketone, tetralone, acetophenone, p-methylacetophenone, p-methoxyacetophenone, m-methoxyacetophenone, 1-acetylnaphtalene, 2-acetylnaphtalene 1-phenyl-3-butanone, benzophenone cyclobutanone, cyclopentanone, cyclopentenone, cyclohexanone, cyclohexenone and 2,6-dimethylcyclohexanone, andwherein the amine is selected from methylamine, dimethylamine, ethylamine, diethylamine, n-propylamine, di-n-propylamine, iso-propylamine, diisopropylamine, isopropylethylamine, n-butylamine, di-n-butylamine, s-butylamine, di-s-butylamine, isobutylamine, n-pentylamine, s-pentylamine, iso-pentylamine, n-hexylamine, s-hexylamine, isohexylamine, cyclohexylamine, aniline, toluidene, piperidine, morpholine, cis-2-6-dimethylmorpholine and pyrrolidine.

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