Methods for the valorization of carbohydrates

Abstract

There are provided methods for the valorization of carbohydrates. The methods comprise reacting a fluid comprising at least one carbohydrate with at least one metal catalyst or at least one metal catalytic system in a fluidized bed reactor so as to obtain at least one organic acid or a derivative thereof.

Claims

1. A method for the valorization of carbohydrates, said method comprising: reacting a composition comprising at least one hexose and water with at least one oxidation metal catalyst or at least one oxidation metal catalytic system in a fluidized bed reactor so as to obtain at least one organic acid or an anhydride thereof, said at least one organic acid having 6 carbon atoms or less, said reacting comprising injecting atomized droplets of said composition into said fluidized bed reactor, said at least one oxidation metal catalyst or said at least one oxidation metal catalytic system comprising at least one metal chosen from V, Pt, Al, Mo, Pd, Si, Cu, Zr, Ti, Mn, Zn, W, Ni and Fe.

2. The method of claim 1, wherein said atomized droplets are vaporized in situ when inserted into said fluidized bed reactor.

3. The method of claim 1, wherein said at least one hexose is at a concentration of about 1 wt % to about 20 wt %, based on the total weight of the composition.

4. The method of claim 1, wherein said at least one hexose is at a concentration of about 5 wt % to about 15 wt %, based on the total weight of the composition.

5. The method of claim 1, wherein said composition is injected at a rate of about 0.5 mL/minute to about 10 mL/minute per about 0.2 L of capacity of said fluidized bed reactor.

6. The method of claim 1, wherein said at least one oxidation metal catalyst is chosen from vanadium pyrophosphate, iron phosphate, V.sub.2O.sub.5, and a mixture thereof.

7. The method of claim 1, wherein said at least one oxidation metal catalyst or said at least one oxidation metal catalytic system includes any or a combination of Pt, Pd, Cu, Ni or Fe supported over TiO.sub.2, alumina, silica or zeolites as well as Mo, Fe, Pd, Cu or Pt supported over HZSM-5.

8. The method of claim 1, wherein said at least one oxidation metal catalyst or said at least one oxidation metal catalytic system is chosen from Cu/SiO.sub.2, Cu/Al.sub.2O.sub.3, Cu/CeO.sub.2, CuMnO.sub.2, Cu/CuO, Cu/CuO/Al.sub.2O.sub.3, Cu/ZnO/Al.sub.2O.sub.3, Cu/ZnO/Cr.sub.2O.sub.3, CuZnZrAlO, MgAl.sub.2O.sub.4, Ag/TiO.sub.2, V.sub.2O.sub.5/TiO.sub.2, Pt/TiO.sub.2, Pt/Al.sub.2O.sub.3, Pt/CeZr oxides, Pt/Cu/MnO.sub.2, Pd/SiO.sub.2, Pd/WO.sub.3/ZrO.sub.2, ZrO.sub.2, ZnO.sub.2/FeO/Al.sub.2O.sub.3, and mixtures thereof.

9. The method of claim 1, wherein said at least one metal catalytic system is HSA alumina, Raney Cu on Pyrex, Cu flakes/chips, Cu over HSA silica or Cu over colloidal silica.

10. The method of claim 1, wherein said at least one oxidation metal catalyst comprises a VPO catalyst.

11. The method of claim 1, wherein said at least one oxidation metal catalyst comprises VOPO.sub.4, VOHPO.sub.4, (VO).sub.2P.sub.2O.sub.7, VO(PO.sub.3).sub.2, VO(H.sub.2 PO.sub.4).sub.2 or mixtures thereof.

12. The method of claim 1, wherein said method comprises obtaining at least one organic acid.

13. The method of claim 1, wherein said method comprises obtaining at least one organic acid anhydride.

14. The method of claim 1, wherein said method comprises obtaining maleic acid anhydride.

15. A method for the valorization of carbohydrates, said method comprising: reacting a composition comprising at least one hexose and water with at least one oxidation metal catalyst or at least one oxidation metal catalytic system in a fluidized bed reactor so as to obtain at least one organic acid or an anhydride thereof, said at least one organic acid having 6 carbon atoms or less, said reacting comprising iniecting atomized droplets of said composition into said fluidized bed reactor, said at least one oxidation metal catalyst or said at least one oxidation metal catalytic system comprising: any or a combination of Pt, Pd, Cu, Ni or Fe supported over alumina, silica or zeolites as well as Mo, Fe, Pd, Cu or Pt supported over HZSM-5; at least one oxidation metal catalytic system chosen from Cu/SiO.sub.2, Cu/Al.sub.2O.sub.3, Cu/CeO.sub.2, CuMnO.sub.2, Cu/CuO, Cu/CuO/Al.sub.2O.sub.3, Cu/ZnO/Al.sub.2O.sub.3, Cu/ZnO/Cr.sub.2O.sub.3, CuZnZrAlO, MgAl.sub.2O.sub.4, Ag/TiO.sub.2, V.sub.2O.sub.5/TiO.sub.2, Pt/TiO.sub.2, Pt/Al.sub.2O.sub.3, Pt/CeZr oxides, Pt/Cu/MnO.sub.2, Pd/SiO.sub.2, Pd/WO.sub.3/ZrO.sub.2, ZrO.sub.2, ZnO.sub.2/FeO/Al.sub.2O.sub.3, and mixtures thereof; at least one oxidation metal catalytic system that is HSA alumina, Raney Cu on Pyrex, Cu flakes/chips, Cu over HSA silica or Cu over colloidal silica; at least one oxidation metal catalyst comprises a VPO catalyst; or at least one oxidation metal catalyst comprises VOPO.sub.4, VOHPO.sub.4, (VO).sub.2P.sub.2O.sub.7, VO(PO.sub.3).sub.2, VO(H.sub.2PO.sub.4).sub.2 or mixtures thereof.

16. The method of claim 15, wherein said method comprises obtaining at least one organic acid anhydride.

17. The method of claim 15, wherein said method comprises obtaining maleic acid anhydride.

18. The method of claim 1, wherein said at least one organic acid is chosen from acrylic acid, methacrylic acid, maleic acid, fumaric acid and acetic acid.

19. The method of claim 1, wherein said at least one hexose is glucose.

20. The method of claim 17, wherein said at least one organic acid is chosen from acrylic acid, methacrylic acid, maleic acid, fumaric acid and acetic acid.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further features and advantages of the disclosure will become more readily apparent from the following description of various embodiments as illustrated by way of examples in the appended figures wherein:

(2) FIG. 1 is a schematic representation of an example of a reactor that can be used for carrying out the methods described in the present disclosure; and

(3) FIG. 2 represents High Pressure Liquid Chromatography (HPLC) results obtained from a sample prepared in accordance with an example of a method as described in the present disclosure.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

(4) Further features and advantages will become more readily apparent from the following description of various embodiments as illustrated by way of examples only and in a non-limitative manner.

(5) The expression organic acid or a derivative thereof as used herein refers to an organic acid or a derivative thereof. For example, the derivative of the organic acid can be an anhydride, a salt, an amide, an ester, an acid halide etc.

(6) The term suitable as used herein means that the selection of the particular compound and/or conditions would depend on the specific manipulation to be performed, but the selection would be well within the skill of a person trained in the art. All process/method described herein are to be conducted under conditions sufficient to provide the desired product (for example at least one organic acid or a derivative thereof). A person skilled in the art would understand that all reaction conditions, including, for example, reaction time, reaction temperature, reaction pressure, reactants concentration and/or ratio, injection rates (carbohydrate or a composition thereof and/or fluidization gas) and whether or not the reaction should be performed under inert atmosphere, can be varied to optimize the yield of the desired product and it is within their skill to do so.

(7) Terms of degree such as about and approximately as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms of degree should be construed as including a deviation of at least 5% or at least 10% of the modified term if this deviation would not negate the meaning of the word it modifies.

(8) For example, the method can comprise injecting atomized droplets of a carbohydrate-containing composition that comprises the at least one carbohydrate and water into the fluidized bed reactor.

(9) For example, the atomized droplets can be vaporized in situ when inserted into the fluidized bed reactor.

(10) For example, the fluid can be a gas, a liquid or a mixture thereof. According to one embodiment, the fluid can be synthetic air. According to another embodiment, the fluid can be air having a concentration of O.sub.2 of about 0 to about 21%.

(11) The carbohydrate can be at a concentration of about 1 wt % to about 20 wt %, about 2 wt % to about 18 wt %, about 5 wt % to about 15 wt %, about 10 wt % to about 15 wt %, about 8 wt % to about 12 wt %, or about 10 wt %, based on the total weight of the carbohydrate-containing composition.

(12) For example, the composition can be injected at a rate of about 0.5 mL/minute to about 10 mL/minute, about 1 mL/minute to about 8 mL/minute, about 2 mL/minute to about 6 mL/minute or about 3 mL/minute to about 5 mL/minute per about 0.2 L of capacity of the fluidized bed reactor.

(13) For example, the fluidization gas can be injected at a flow rate of about 100 mL to about 20000 mL/minute, 400 mL/minute to about 2000 mL/minute, about 500 mL/minute to about 1500 mL/minute, about 600 mL/minute to about 1200 mL/minute, or about 800 mL/minute to about 1000 mL/minute per 0.2 L of capacity of the fluidized bed reactor.

(14) For example, the at least one metal catalyst or the at least one metal catalytic system can be an oxidation catalyst.

(15) Examples of oxidation catalysts can comprise vanadium pyrophosphate, iron phosphate, VPO catalyst, V.sub.2O.sub.5 or mixtures thereof.

(16) Examples of oxidation catalysts can comprise VOPO.sub.4 (for example -VOPO.sub.4 or -VOPO.sub.4) VOHPO.sub.4, (VO).sub.2P.sub.2O.sub.7, VO(PO.sub.3).sub.2, VO(H.sub.2 PO.sub.4).sub.2 or mixtures thereof.

(17) Examples of oxidation catalysts can be chosen from vanadium phosphorus oxide catalysts.

(18) Other examples of metal catalysts or metal catalytic systems can include any or a combination of Au, Pt, Rh, Ru, Pd, Cu, Ni or Fe or generally the transition metals supported over alumina, silica or zeolites as well as Mo, Re, Fe, Pd, Cu or Pt supported over HZSM-5 or Rh supported over NaY zeolites. Specific examples include supported or bulk Sn based catalysts such as SnCl.sub.2 or Cu/SiO.sub.2, Cu/Al.sub.2O.sub.3, Cu/CeO.sub.2, CuMnO.sub.2, Cu/CuO, Cu/CuO/Al.sub.2O.sub.3, Cu/ZnO/Al.sub.2O.sub.3, Cu/ZnO/Cr.sub.2O.sub.3, CuZnZrAlO systems as well as MgAl.sub.2O.sub.4, Ag/TiO.sub.2, V.sub.2O.sub.5/TiO.sub.2, Pt/TiO.sub.2, Pt/Al.sub.2O.sub.3, Pt/CeZr oxides, Pt/Cu/MnO.sub.2, Pd/SiO.sub.2, Pd/WO.sub.3/ZrO.sub.2, ZrO.sub.2, ZnO.sub.2/FeO/Al.sub.2O.sub.3. Other examples include HSA alumina, Raney Cu on Pyrex, Cu flakes/chips, Cu over HSA silica and Cu over colloidal silica. Raney Ni can be used for hydrogenation pathways while Rh and Pt are also capable of facilitating the hydrolysis reactions. Further examples include supported or non-supported catalytic systems of the type ABCD-O, ABCD-PO or ABCD, where A, B, C and D may represent any or a combination of Mo, V, Te, Ta, Si, Sb or Nb.

(19) For example, the at least one carbohydrate can be a hexose, a pentose, or a mixture thereof.

(20) For example, the at least one carbohydrate can be chosen from xylose, arabinose, lyxose, ribose, ribulose, xylulose, allose, altrose, glucose, mannose, gulose, idose, galactose, talose, and mixtures thereof.

(21) For example, the at least one carbohydrate can be chosen from the family of aldopentoses, ketopentoses, aldohexoses, and/or ketohexoses, including their hemiacetals and hemiketals ring structures.

(22) The at least one carbohydrate can be reacted with the metal catalyst at a temperature of about 240 C. to about 360 C., about 260 C. to about 320 C., about 275 C. to about 325 C., about 290 C. to about 310 C., or about 280 C. to about 300 C.

(23) For example, the at least one organic acid can be chosen from acrylic acid, methacrylic acid, maleic acid, fumaric acid, acetic acid, and mixtures thereof.

(24) For example, the methods can be carried out under conditions suitable for at least substantially preventing caramelization of the at least one carbohydrate. For example, the conditions suitable for at least substantially preventing caramelization of the at least one carbohydrate can comprise conditions at which caramelization of the at least one carbohydrate is slower than the reaction between the at least one carbohydrate and the at least one metal catalyst that produces the at least one organic acid or a derivative thereof. For example, the conditions suitable for at least substantially preventing caramelization of the at least one carbohydrate can comprise carrying out the reaction out at a temperature below a temperature at which caramelization of the at least one carbohydrate is faster than the reaction between the at least one carbohydrate and the at least one metal catalyst that produces the at least one organic acid or a derivative thereof.

(25) Experiments of catalytic sugar oxidation process in a fluidized bed at high temperature have been carried out for the valorization of carbohydrates. Such experiments have been carried out using a fluidized bed as shown in FIG. 1. A aqueous solution of 10 wt % of xylose was injected to the fluidized catalyst bed at a rate of 0.5 mL/min via a metering pump. The fluidization gas was synthetic air (21% oxygen in argon) and the gas flow rate was 800-1000 ml/min and was controlled by a flow meter. About 200 g of a calcined VPO catalyst were used and the reaction temperature was about 300 C. and maintained by the heating elements (connected to thermocouple). The reactor temperature was stable throughout the reaction and no crystallization or deposition of sugar inside the bed was observed. In the conditions described above, about 24 g of solution were collected after 1 hour of reaction. It was analyzed by HPLC and GC (Gas Chromatography). The gas portion was analyzed by MS (Mass Spectrometry). FIG. 2, demonstrates a graphical view of the HPLC analysis results performed on the liquid produced from the reaction at 300 C. The HPLC analysis showed a range of organic acids and some other acid products. The major produced acids were maleic acid and acrylic acid. Moreover, methacrylic acid and fumaric acid were also observed.

(26) The person skilled in the art would understand that, when applicable, all the various embodiments presented in the present disclosure can be used in combination with all the methods described in the SUMMARY OF THE DISCLOSURE section. Moreover, the person skilled in the art would understand that, when applicable, all the various embodiments presented in the present disclosure can be used in combination with any other embodiments presented in the present disclosure and/or in the SUMMARY OF THE DISCLOSURE section.

(27) While a description was made with particular reference to the specific embodiments, it will be understood that numerous modifications thereto will appear to those skilled in the art. Accordingly, the above description and accompanying drawings should be taken as specific examples and not in a limiting sense.