Process for the conversion of aromatic nitro compound into amines

Patent metadata

Field	Value
Publication number	US-9533939-B2
Application number	US-201013583941-A
Country	US
Kind code	B2
Filing date	Mar 18, 2010
Priority date	Mar 18, 2010
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

A process for hydrogenating an aromatic nitro compound according to the invention comprises
providing a hydrogen gas stream and a liquid aromatic nitro compound stream; providing a fixed bed catalytic reactor having an inflow side and an outflow side; feeding to the inflow side, the hydrogen gas stream and the liquid aromatic nitro compound stream; converting the hydrogen gas and the aromatic nitro compound into an aromatic amine, thereby providing a reactor effluent comprising the aromatic amine and water; evacuating the reactor effluent from the reactor at the outflow side of the reactor;

wherein an inert solvent or water is fed to the inflow side of the reactor at a molar ratio of moles inert solvent or water to moles hydrogen is more than 1.

First claim

The invention claimed is:

1. A process for hydrogenating an aromatic nitro compound, the process comprising:
providing a hydrogen gas stream and a liquid aromatic nitro compound stream;
providing a fixed bed catalytic reactor having an inflow side and an outflow side;
feeding to said inflow side, said hydrogen gas stream and said liquid aromatic nitro compound stream;
converting said hydrogen gas and said aromatic nitro compound into an aromatic amine, thereby providing a reactor effluent comprising said aromatic amine and water; and
evacuating said reactor effluent from the reactor at the outflow side of said reactor;
wherein an inert solvent or water is fed to the inflow side of the reactor at a molar ratio of moles inert solvent or water to moles hydrogen is in a range of about 1.5 to 7.5 and wherein the pressure at the inflow side, the outflow side and throughout the reactor is kept within a range of 30 to 40 barg and the pressure drop between the inflow side and outflow side of the reactor is 0.2 to 4 barg and the aromatic nitro compound is nitrobenzene and the aromatic amine is aniline.

2. The process for hydrogenating an aromatic nitro compound according to claim 1 , wherein a part of the reactor effluent is recycled to the inflow side of the reactor.

3. The process for hydrogenating an aromatic nitro compound according to claim 1 , wherein at least part of the water from the reactor effluent is recycled to the inflow side of the reactor.

4. A process for hydrogenating an aromatic nitro compound, comprising:
feeding a hydrogen gas stream, a liquid aromatic nitro compound stream and an inert solvent or water to an inflow side of a fixed bed catalytic reactor, wherein the inert solvent or water is fed to the inflow side of the reactor at a molar ratio of moles inert solvent or water to moles hydrogen in a range of about 1.5 to 7.5 and wherein the pressure at the inflow side, the outflow side and throughout the reactor is kept within a range of 30 to 40 barg and the pressure drop between the inflow side and outflow side of the reactor is 0.2 to 4 barg; and
converting the hydrogen gas and the aromatic nitro compound into an aromatic amine wherein the aromatic nitro compound is nitrobenzene and the aromatic amine is aniline.

5. The process of claim 4 , further comprising forming an effluent in the fixed bed catalytic reactor and evacuating the effluent out of the fixed bed catalytic reactor at an outflow side of the fixed bed catalytic reactor, wherein the effluent includes the aromatic amine and water, and wherein a part of the effluent is recycled to the inflow side of the fixed bed catalytic reactor.

6. The process of claim 5 , wherein at least part of the water from the effluent is recycled to the inflow side of the fixed bed catalytic reactor.

7. The process of claim 5 , wherein a hydrogen partial pressure at the inflow side is maintained to be higher than a hydrogen partial pressure at the outflow side.

8. A process for hydrogenating an aromatic nitro compound, comprising:
feeding a hydrogen gas stream, a liquid aromatic nitro compound stream and an inert solvent or water to an inflow side of a fixed bed catalytic reactor wherein a molar ratio of the inert solvent or water to the hydrogen gas is in a range of about 1.8 to 7 and wherein the pressure at the inflow side, the outflow side and throughout the reactor is kept within a range of 30 to 40 barg and the pressure drop between the inflow side and outflow side of the reactor is 0.2 to 4 barg;
converting the hydrogen gas and the aromatic nitro compound into an aromatic amine;
forming an effluent in the fixed bed catalytic reactor, wherein the effluent includes the aromatic amine and water; and
evacuating the effluent out of the fixed bed catalytic reactor at an outflow side of the fixed bed catalytic reactor, wherein the effluent contains less than 7500 ppm of over-hydrogenated impurities wherein the aromatic nitro compound is nitrobenzene and the aromatic amine is aniline.

9. The process of claim 8 , wherein a part of the effluent is recycled to the inflow side of the fixed bed catalytic reactor.

10. The process of claim 9 , wherein at least part of the water from the effluent is recycled to the inflow side of the fixed bed catalytic reactor.

Assignees

• Mitchell Christopher John
• Stewart Douglas Hyndman
• Huntsman Int Llc

Inventors

• Mitchell Christopher John
• Stewart Douglas Hyndman

Classifications

• C07C209/36 Primary

  by reduction of nitro groups bound to carbon atoms of six-membered aromatic rings {in presence of hydrogen-containing gases and a catalyst} · CPC title

• C07C211/50

  with at least two amino groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton · CPC title

• C07C211/46

  Aniline · CPC title

• B01J31/0239

  Quaternary ammonium compounds · CPC title

• C07B41/02

  of hydroxy or O-metal groups · CPC title