Process for the preparation of 5-hydroxymethylfurfural (HMF)

Patent metadata

Field	Value
Publication number	US-9260402-B2
Application number	US-201414302046-A
Country	US
Kind code	B2
Filing date	Jun 11, 2014
Priority date	Jun 12, 2013
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

A process is described for the preparation of 5-hydroxymethylfurfural (HMF), which comprises the following steps:
provision or preparation of a starting mixture, comprising one, two or more starting compounds selected from the group consisting of hexoses, oligosaccharides comprising hexose units, and polysaccharides comprising hexose units, one, two or more organic salts with a melting point <180° C. and a boiling point >200° C. at 1013.25 hPa, optionally additionally one or more catalysts for the conversion of the one starting compound or at least one of the two or more starting compounds to 5-hydroxymethylfurfural (HMF), optionally water, optionally further substances, adjustment of reaction conditions such that an amount of the starting compound or starting compounds converts to HMF.

First claim

The invention claimed is:

1. A process for the preparation of 5-hydroxymethylfurfural (HMF), having the following steps:
(a) providing or preparing a starting mixture, comprising
(i) one, two or more starting compounds selected from the group consisting of hexoses, oligosaccharides comprising hexose units, and polysaccharides comprising hexose units,
(ii) one, two or more organic salts having a melting point <180° C. and a boiling point >200° C. at 1013.25 hPa,
(iii) optionally one or more catalysts capable of converting the one starting compound or at least one of the two or more starting compounds to 5-hydroxymethylfurfural (HMF),
(iv) optionally water, and
(v) optionally further substances,
(b) subjecting the starting mixture of (a) to first reaction conditions, such that a first amount of the one starting compound or at least one of the two or more starting compounds is converted to HMF and form an intermediate product mixture, where a temperature under the first reaction conditions is in the range from 100 to 160° C., then
(c) subjecting the intermediate product mixture of (b) or a fraction of the intermediate product mixture of (b) to second reaction conditions, such that an amount of the intermediate product mixture converts to HMF and forms a product mixture, where a temperature under the second reaction conditions is in the range from 165 to 250° C., with HMF being separated off from the product mixture during this conversion by distillation.

2. The process according to claim 1 , where
the temperature under the second reaction conditions is in the range from 180 to 250° C., and/or where
the temperature under the first reaction conditions is in the range from 100 to 140° C.

3. The process according to claim 1 , where, under the second reaction conditions, HMF is separated off from the product mixture by means of carrier vapor distillation.

4. The process according to claim 1 , where, for the separation by means of distillation, the product mixture is brought into contact with a gas co-currently or countercurrently under the second reaction conditions,
where the gas comprises one or more compounds having a boiling point which is lower than 200° C. at 1013.25 hPa.

5. The process according to claim 4 , where the gas comprises one or more compounds selected from the group consisting of water, alcohols, monoethers, diethers, polyethers, ketones, esters, and aromatics.

6. The process according to claim 1 , where the pressure under the second reaction conditions is below 1000 mbar.

7. The process according to claim 1 , where
the starting mixture is prepared or provided in a first reactor and the first reaction conditions in the first reactor are established such that the intermediate product mixture is formed,

and
the intermediate product mixture is transferred, completely or in part, to a second reactor, where the second reaction conditions in the second reactor are established, and where the second reactor is a reactive distillation device.

8. The process according to claim 7 , where
the intermediate product mixture or parts thereof to be transferred to the second reactor is subjected, before or upon entry into the second reactor, to the conditions of a distillation, with HMF being separated off
and/or
the reactive distillation device has an overflow valve for generating a flash vacuum effect.

9. The process according to claim 1 , where
the provision or preparation of the starting mixture and the conversion to the intermediate product mixture takes place in a continuous process.

10. The process according to claim 1 , where the conversion of the mixture which comprises the intermediate product mixture or a fraction of the intermediate product mixture to the product mixture takes place in a continuous, semicontinuous or discontinuous process.

11. The process according to claim 1 , where a residue, present after separating off HMF, of the conversion of the intermediate product mixture to the product mixture is completely or partly recycled for use in producing the starting mixture, after separating off byproducts.

12. The process according to claim 1 , where the first reaction conditions are such that
in the intermediate product mixture before establishing the second reaction conditions at most an amount of HMF is present which corresponds to a molar yield of 55 to 80%, based on the total amount of hexoses or hexose units used in the starting mixture.

13. The process according to claim 1 , where the second reaction conditions are such that
the molar total yield of HMF exceeds a value of 60%, based on the total amount of hexoses or hexose units used in the starting mixture

and/or
the amount of hexoses or hexose units converted in total exceeds a value of 98 mol %, based on the amount of hexoses or hexose units used in the starting mixture.

14. The process according to claim 1 , where the starting mixture comprises one or more catalyst capable of converting the starting compound or at least one of the two or more starting compounds to HMF, where the one or more catalyst is selected from the group consisting of
acids having a boiling point >200° C. at 1013.25 hPa dispersed or dissolved in the starting mixture,
metal salts,
metal oxides,
ion exchange resins, and
zeolites.

15. The process according to claim 1 , where said organic salt or one, two or all of said one, two or more organic salts has a melting point <180° C. and a boiling point >200° C. at 1013.25 hPa
is or are selected from the group of the salts with a boiling point >250° C. at 1013.25 hPa and/or
is or are selected from the group of the salts with a melting point <150° C. at 1013.25 hPa.

16. The process according to claim 1 , having the following steps:
(a) providing or preparing a starting mixture in a first reactor, the starting mixture comprising
(i) one, two or more starting compounds selected from the group consisting of hexoses, oligosaccharides comprising hexose units, and polysaccharides comprising hexose units,
(ii) one, two or more organic salts with a melting point <180° C. and a boiling point >200° C. at 1013.25 hPa,
(iii) optionally one or more catalysts capable of converting the one starting compound or at least one of the two or more starting compounds to 5-hydroxymethylfurfural (HMF),
(iv) optionally water, and
(v) optionally further substances,
(b) subjecting the starting mixture of (a) in the first reactor to first reaction conditions such that the first amount of the one starting compound or at least one of the two or more starting compounds is converted to HMF and form an intermediate product mixture, where the temperature under the first reaction conditions is in the range from 100 to 160° C.,
(c) transferring the intermediate product mixture of (b) completely or in part to a second reactor, to provide a mixture comprising the intermediate product mixture or a fraction of the intermediate product mixture,
(d) subjecting the intermediate product mixture of (c) to second reaction conditions in the second reactor to convert a further amount of the intermediate product mixture to HMF and form a product mixture, where the temperature under the second reaction conditions is in the range from 165 to 250° C.,
where
during the conversion under the second reaction conditions, HMF is separated off from the product mixture by means of carrier vapor distillation, where, for the separation by means of carrier vapor distillation, the product is brought into contact under the second reaction conditions with a gas which comprises one or more compounds, where the

Assignees

• Basf Se

Inventors

• Blank Benoit
• Kindler Alois
• Bassler Peter
• Piepenbrink Markus
• Lang Ortmund
• Feldner Carmen

Classifications

• C07D307/48

  Furfural · CPC title

• C07D307/46 Primary

  Doubly bound oxygen atoms, or two oxygen atoms singly bound to the same carbon atom · CPC title

• B01D3/009

  in combination with chemical reactions · CPC title

• Y02P20/10

  Process efficiency · CPC title