Process for the recovery of furfural

Patent metadata

Field	Value
Publication number	US-10899725-B2
Application number	US-201716346264-A
Country	US
Kind code	B2
Filing date	Oct 30, 2017
Priority date	Nov 1, 2016
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

Disclosed is a process for the extraction of furfural. The process includes subjecting a composition comprising furfural, water, at least one acid and an aromatic solvent, with a boiling point higher than that of furfural, to a first separation step in a first liquid-liquid separator providing a first organic phase and a first aqueous phase; conveying the first organic phase along a first line to a distillation column and subjecting the first organic phase to a distillation step providing a top stream comprising furfural and a bottom stream comprising the aromatic solvent; subjecting the first aqueous phase and a portion of the bottom stream to a second separation step providing a second organic phase; conveying the second organic phase along a second line which either feeds its contents into the first line or into the distillation column and subjecting the resultant mixture to said distillation step.

First claim

That which is claimed is:

1. A process for the extraction of furfural from a composition ( 1 ) comprising an aromatic solvent and a dehydration reaction mixture comprising furfural, water, and at least one acid, wherein the aromatic solvent has a boiling point higher than that of furfural, said process comprising:
(a) subjecting the composition ( 1 ) to a first liquid-liquid separation step in a first liquid-liquid separator ( 6 ) to provide:
a first organic phase ( 7 ) comprising the aromatic solvent and a portion of the furfural, and
a first aqueous phase ( 8 ) comprising the remainder of the furfural and the at least one acid;

(b) conveying the first organic phase ( 7 ) from step (a) along a first line ( 12 ) to a distillation column ( 9 ) and subjecting the first organic phase ( 7 ) to a distillation step to provide:
a top stream ( 2 ) comprising furfural, and
a bottom stream ( 3 ) comprising the aromatic solvent;

(c) conveying the first aqueous phase ( 8 ) from step (a) and a portion of the bottom stream ( 4 ) from step (b) to a second liquid-liquid separator ( 10 ), and subjecting the first aqueous phase ( 8 ) from step (a) and the portion of the bottom stream ( 4 ) from step (b) to an extraction step to provide:
a second organic phase ( 11 ) comprising the aromatic solvent and a portion of the furfural, and an aqueous waste stream ( 5 ) comprising water and the at least one
acid;

(d) conveying the second organic phase ( 11 ) from step (c) along a second line ( 14 ) which either feeds its contents into the first line ( 12 ) or into the distillation column ( 9 ) and subjecting the resultant mixture to the distillation step of step (b),
wherein the dehydration reaction mixture to aromatic solvent ratio is from at least 1 to 0.05% vol to at most 1 to 2.5% vol.

2. The process according to claim 1 , wherein the composition ( 1 ) is derived from a product stream of a pentose dehydration step wherein a pentose feed stream is dehydrated.

3. The process according to claim 2 , wherein the pentose feed stream is derived from a hydrolysis step wherein a lignocellulosic biomass is hydrolysed.

4. The process according to claim 2 , wherein a portion of the bottom stream ( 3 ) of step (b) comprising the aromatic solvent is recycled as a feed to the pentose dehydration step.

5. The process according to claim 2 , wherein the aqueous waste stream ( 5 ) of step (c) comprising water and the at least one acid is recycled as a feed to the hydrolysis step.

6. The process according to claim 1 , wherein the aromatic solvent has a ratio of aromatic carbons to aliphatic carbons of greater than 1.

7. The process according to claim 1 , wherein the aromatic solvent is selected from the group consisting of 1-ethyl-2,3-dimethylbenzene, 1-ethyl-2,5-dimethylbenzene, 1-ethyl-2,4-dimethylbenzene, 1-ethyl-3,4-dimethylbenzene, 1,2,3,5-tetramethylbenzene, 1,2,3,4-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, n- and sec-propyl-methyl benzenes, n- and sec-butyl benzene and n- and sec-pentyl benzene, or any combination thereof.

8. The process according to claim 1 , wherein the distillation step is an atmospheric distillation step, or is a vacuum distillation step.

9. The process according to claim 1 , wherein the first liquid-liquid separation step is operated at a temperature range of from ambient temperature to 200° C.

10. The process according to claim 1 , wherein the second liquid-liquid separation step is operated at a temperature range of from ambient temperature to 120° C.

Assignees

• Shell Oil Co

Inventors

• Chheda Juben Nemchand
• Lange Jean Paul Andre Marie Joseph Ghislain

Classifications

• C07D307/48 Primary

  Furfural · CPC title

• C07D307/50 Primary

  Preparation from natural products · CPC title

• B01D11/0288

  Applications, solvents · CPC title

• B01D3/10

  Vacuum distillation (B01D3/12 takes precedence) · CPC title

• B01D11/028

  Flow sheets · CPC title