Process for removing formaldehyde from a composition comprising glycolaldehyde

Abstract

A process for reducing the percentage by weight of formaldehyde present in a composition comprising glycolaldehyde, wherein formaldehyde is transformed into one or more formaldehyde acetal(s) and removed from the reactive distillation reaction solution by reactive distillation in the presence of at least one alcohol and a catalyst.

Claims

1. A process for reducing the percentage by weight of formaldehyde present in a composition, comprising: a) mixing an aqueous feed composition comprising glycoaldehyde at a first concentration and formaldehyde with an alcohol in a volume ratio of 1:9 to 9:1 to obtain a reactive distillation reaction solution; b) contacting the reactive distillation reaction solution with an acid catalyst while distilling formaldehyde acetal produced in the reactive distillation to obtain a reactive distillation product solution; and c) contacting the reactive distillation product solution with an acid catalyst while distilling excess alcohol from the reactive distillation product solution to obtain a final product solution comprising aqueous glycolaldehyde having a concentration greater than said first concentration.

2. A process according to claim 1, wherein the alcohol is selected from one or more of the group consisting of methanol, ethanol, ethylene glycol and propylene glycol.

3. A process according to claim 1, wherein the acid catalyst is selected from one or more of the group consisting of a solid catalyst, mineral acid catalyst and organic acid.

4. A process according to claim 1, wherein the acid catalyst is selected from one or more of the group consisting of an acidic resin, molecular sieves and a mineral acid.

5. A process according to claim 1, wherein the acid catalyst is selected from one or more of the group consisting of Brønsted acidic resins and concentrated sulphuric acid.

6. A process according to claim 1, wherein the distillation is carried out at a temperature less than 120° C.

7. A process according to claim 1, wherein the distillation is carried out under reduced pressure.

8. A process according to claim 1, further comprising adding water to the reaction solution after reactive distillation, heating and reducing the volume of the solution.

9. A process according to claim 1, wherein the feed composition comprising glycolaldehyde is obtained by pyrolysis of organic matter selected from the group consisting of biomass, wood and sugars.

10. A process according to claim 1, wherein the feed composition comprising glycolaldehyde is obtained by pyrolysis of one or more sugars selected from the group consisting of glucose, sucrose, xylose, fructose and galactose.

11. A process according to claim 1, wherein the feed composition comprising glycolaldehyde is obtained by hydroformylation.

12. A process for the preparation of ethylene glycol, comprising subjecting the final product solution prepared according to claim 1 to hydrogenation.

13. A process for the preparation of amines wherein the product solution composition comprising glycolaldehyde according to claim 1 is reductively aminated.

14. A process for preparing straight and branched chain oxygenated C4-alkyl and C4-alkenyl compounds, comprising: providing the final product solution according to claim 1, and converting the glycolaldehyde to straight and branched chain oxygenated C4-alkyl and C4-alkenyl compounds.

15. A process for reducing the formaldehyde content of a glycolaldehyde composition, comprising: a) mixing an aqueous feed composition comprising at least 8.5 wt. % glycolaldehyde with an alcohol in a volume ratio of 1:9 to 9:1 to obtain a reactive distillation reaction solution; b) contacting the reactive distillation reaction solution with an acid catalyst while distilling formaldehyde acetal produced in the reactive distillation to obtain a reactive distillation product solution; and c) contacting the reactive distillation product solution with an acid catalyst while distilling excess alcohol from the reactive distillation product solution to obtain a final product solution comprising glycolaldehyde having a concentration greater than that of said aqueous feed.

Description

EXAMPLE 1

(1) A composition comprising one or more low molecular weight carbonyl compounds was obtained by pyrolysis of a 10 wt. % aqueous glucose (D-glucose monohydrate; Sigma Aldrich) solution as described in U.S. Pat. No. 7,094,932. The typical composition of the pyrolysis product composition is given in Table 1.

(2) TABLE-US-00001 TABLE 1 GLA GLO PYR FOR ACE (g/l) (g/l) (g/l) (g/l) (g/l) Example 1 67.0 3.5 8.2 6.8 1.3 GLA = Glycolaldehyde GLO = Glyoxal PYR = Pyruvaldehyde FOR = Formaldehyde ACE = Acetol
Removing Formaldehyde from a composition comprising One or more low molecular weight carbonyl compounds:

EXAMPLE 2

(3) 300 ml methanol along with 10 g of the Brønsted acidic resin Amberlyst-131 (Sigma Aldrich) was added to 300 ml of an aqueous solution of the pyrolysis product composition comprising one or more low molecular weight carbonyl compounds obtained in Example 1. The solution was transferred to a reactive distillation setup. An inert atmosphere was established by passing 20 ml/min of N.sub.2 through the reaction solution while stirring before heating the solution until boiling at approximately between 78 to 79° C. Small amounts of distillate product were continuously condensed from the top of the distillation column and collected. A constant volumetric ratio of methanol and aqueous solution (and constant temperature of the boiling solution) was achieved by continuously adding a volume of methanol equivalent to the volume recovered as distillate product. The distillate product was analyzed by gas chromatography and shown to contain mainly methanol and formaldehyde dimethyl acetal formed by acetalization of formaldehyde in the solution. Small amounts of methyl formate, methyl acetate, acetaldehyde and acetaldehyde dimethyl acetal were also detected.

(4) After 5-7 hours of reaction time the remaining reactive distillation reaction solution was analyzed by HPLC and less than 0.01% by weight of formaldehyde was detected. The HPLC analysis was performed on an Aminex HPX-87H column with a 0.005 M H.sub.2SO.sub.4 eluent which converted all acetals into the aldehydes before detection.

EXAMPLE 3

(5) A reactive distillation reaction as described in Example 2 was performed with the exception that 150 ml methanol was added to 450 ml of an aqueous solution of the composition comprising one or more low molecular weight carbonyl compounds obtained in Example 1. The boiling point of the reactive distillation reaction solution was approximately between 85 and 86° C.

EXAMPLE 4

(6) A reactive distillation as described in Example 2 was performed with the exception that 450 ml methanol was added to 150 ml of an aqueous solution of the composition comprising one or more low molecular weight carbonyl compounds obtained in Example 1. The boiling point of the reaction solution was approximately 72° C.

EXAMPLE 5

(7) A reactive distillation reaction as described in Example 2 was performed with the exception that 2 g of concentrated sulfuric acid was used as the acetalization catalyst instead of the 10 g Amberlyst-131 used in Example 1.

EXAMPLE 6

(8) A reactive distillation reaction as described in Example 2 was performed with the exception that 300 ml ethanol instead of 300 ml methanol was used and the reaction time was increased to approximately 10 hours. The distillate contained mainly ethanol and formaldehyde diethyl acetal.

EXAMPLE 7

(9) A reactive distillation reaction as described in Example 2 was performed with the exception that 300 ml ethyleneglycol instead of 300 ml methanol was used. The boiling point of the reactive distillation reaction solution was approximately between 107-108° C. The distillate product contained mainly water and 1,3-dioxolane.

(10) Table 2 shows the content of the major components in the reactive distillation reaction solution before and after the reactive distillation reaction of the present invention.

(11) TABLE-US-00002 TABLE 2 Formal- Glycolaldehyde Glyoxal Pyruvaldehyde dehyde Acetol (g) (g) (g) (g) (g) 2 B 19.9 1.1 2.5 2.1 0.5 A 19.1 1.0 2.1 0.0 0.4 3 B 30.2 1.6 3.7 3.1 0.6 A 25.5 1.9 2.6 0.0 0.6 4 B 8.7 0.6 1.4 1.3 0.3 A 8.5 0.5 1.2 0.0 0.3 5 B 16.6 1.1 2.5 2.4 0.6 A 16.4 0.9 2.2 0.0 0.6 6 B 17.0 1.1 2.6 2.6 0.6 A 13.7 1.3 1.8 0.0 0.8 B means the composition before the composition comprising one or more low molecular weight carbonyl compounds is subjected to the conditions of the present invention, i.e. reactive distillation. A means the composition after the composition comprising one or more low molecular weight carbonyl compounds is subjected to the conditions of the present invention, i.e. reactive distillation.

(12) Table 3 shows the percentage by weight of formaldehyde removal and the percentage weight recovery of glycolaldehyde and pyruvaldehyde compared to the composition of Example 1, Table 1 (the pyrolysis product composition), i.e. the composition comprising one or more low molecular weight carbonyl compounds before it is subjected to the conditions of the present invention.

(13) TABLE-US-00003 TABLE 3 Removal of Recovery of Recovery of Example formaldehyde glycolaldehyde pyruvaldehyde 2 >99% 96% 84% 3 >99% 84% 70% 4 >99% 98% 86% 5 >99% 99% 88% 6 >99% 81% 69%
Recovery of the free aldehyde of the low molecular weight carbonyl compounds.

EXAMPLE 7

(14) GC and HPLC analysis of the reactive distillation product solution from Example 2, from here on named solution A, revealed that 53% of the glycolaldehyde in the solution was present as glycolaldehyde dimethyl acetal.

(15) 0.5 g Amberlyst-131 was added to 100 ml of solution A and placed in a rotary evaporator. After 4 hours at reduced pressure (about 100 mbar) and 50° C., all methanol and approximately half the water had been evaporated. Amberlyst-131 was removed from the solution by filtration and GC and HPLC analysis of the concentrated solution revealed that it contained no glycolaldehyde dimethyl acetal.

(16) Table 4 shows the amount of remaining methanol, the content of glycolaldehyde dimethyl acetal in the concentrated solution and the amount of recovered glycolaldehyde and pyruvaldehyde compared to solution A.

(17) TABLE-US-00004 TABLE 4 Glycoladehyde present as Removal glycolaldehyde of Recovery of Recovery of dimethyl Example methanol glycolaldehyde pyruvaldehyde acetal 7 >99% >95% 87% <0.5%
Hydrogenation of low molecular weight carbonyl compounds.

EXAMPLE 8

(18) 0.50 g crystalline glycolaldehyde dimer (Sigma Aldrich) was dissolved in 15 ml of water and loaded in an autoclave (50 ccm) along with 0.10 g of the hydrogenation catalyst 5% Ru supported on carbon. The autoclave was purged 3 times with hydrogen and subsequently pressurized to 30 bars with H.sub.2. The solution was heated to 60° C. from room temperature in the course of 15 min and kept at this temperature for 3 hours while stirred. After reaction the autoclave was cooled to room temperature and the decrease in H.sub.2 pressure was noted.

(19) The product mixture was isolated from the catalyst by filtration and analyzed by HPLC and GC.

(20) The yield of ethylene glycol was >98%.

(21) TABLE-US-00005 TABLE 5 Yields of ethylene glycol from example 8-17. Yield of ethyleneglycol (carbon %) Example 8  >98% Example 9 42.8% Example 10 40.0% Example 11 66.8% Example 12 95.4% Example 13 97.3%

EXAMPLE 9

(22) 0.50 g crystalline glycolaldehyde dimer (Sigma Aldrich) was dissolved in 15 ml of water and hydrogenated as described in Example 8 with the exception that 0.056 g of formaldehyde was added to the glycolaldehyde solution before the catalyst was added.

(23) The yield of ethylene glycol was 42.8%.

EXAMPLE 10

(24) 7.5 g of the composition comprising one or more carbonyl compounds obtained in Example 1 and as described in Table 1 (containing 0.50 g glycolaldehyde) was added to 8.0 g water and loaded in an autoclave along with 0.10 g of the hydrogenation catalyst 5% Ru on Carbon. The autoclave was purged 3 times with hydrogen and subsequently pressurized to 30 bars with H.sub.2. The mixture was heated to 60° C. from room temperature in the course of 15 min and kept at this temperature for 3 hours while stirred. After reaction the autoclave was cooled to room temperature and the decrease in H.sub.2 pressure was noted.

(25) The hydrogenated product mixture was isolated from the catalyst by filtration and analyzed by HPLC.

(26) The maximum theoretical yield of ethylene glycol was based on hydrogenation of both glyoxal and glycolaldehyde into ethylene glycol.

(27) The yield of ethylene glycol was 40.0%.

EXAMPLE 11

(28) 1.9 g of water was added to 13.7 g of solution A prepared in Example 2 giving a solution which contained 0.5 g of glycolaldehyde and the solution was hydrogenated as described in Example 8.

(29) The maximum theoretical yield of ethylene glycol was based on hydrogenation of both glyoxal and glycolaldehyde into ethylene glycol.

(30) The yield of ethylene glycol was 66.8%.

EXAMPLE 12

(31) 1.9 g water was added to 13.7 g of solution A prepared in Example 2 containing 0.50 g of glycolaldehyde and the solution was hydrogenated as described in Example 8 with exception that the addition that 0.2 g of Amberlyst-131 was added to the solution along with the hydrogenation catalyst.

(32) The maximum theoretical yield of ethylene glycol was based on hydrogenation of both glyoxal and glycolaldehyde into ethylene glycol.

(33) The yield of ethylene glycol was 95.4%.

EXAMPLE 13

(34) 12.3 g of water was added to 3.2 g of the concentrated product obtained in Example 7 containing 0.50 g of glycolaldehyde. The solution was hydrogenated as described in Example 8.

(35) The maximum theoretical yield of ethylene glycol was based on hydrogenation of both glyoxal and glycolaldehyde into ethylene glycol.

(36) The yield of ethylene glycol was 97.3%.