METHOD FOR PRODUCING LEVULINIC ACID IN MOLTEN SALT HYDRATE FROM CELLULOSE HYDROLYSIS

Abstract

The disclosure relates to a method for producing levulinic acid in a molten salt hydrate from cellulose hydrolysis. An inorganic molten salt hydrate was prepared by mixing an inorganic salt with water, cellulose is added and stirred to dissolve, a solid catalyst is added and heated up for reaction to obtain a reactant, the reactant is cooled and subjected to a separation to obtain the levulinic acid, and the inorganic molten salt hydrate and the solid catalyst obtained after the separation are recycled, wherein the inorganic salt is one or more selected from the group consisting of LiCl, LiBr, CaBr.sub.2, Ca(NO.sub.3).sub.2, LiNO.sub.3 and KNO.sub.3.

Claims

1. A method for producing levulinic acid in a molten salt hydrate from cellulose hydrolysis, comprising preparing an inorganic molten salt hydrate by mixing water with an inorganic salt, adding cellulose and stirring to dissolve, adding a solid catalyst and heating up for reaction to obtain a reactant, cooling, and subjecting the cooled reactant to a separation to obtain the levulinic acid, and recycling the inorganic molten salt hydrate and the solid catalyst obtained after the separation, wherein the inorganic salt is one or more selected from the group consisting of LiCl, LiBr, CaBr.sub.2, Ca(NO.sub.3).sub.2, LiNO.sub.3 and KNO.sub.3.

2. The method for producing levulinic acid in a molten salt hydrate from cellulose hydrolysis according to claim 1, wherein a molar ratio of the water to the inorganic salt is (1-6):1.

3. The method for preparing levulinic acid in a molten salt hydrate from cellulose hydrolysis according to claim 1, wherein 10-50 g of the cellulose is added to every 1 L of the inorganic molten salt hydrate.

4. The method for producing levulinic acid in a molten salt hydrate from cellulose hydrolysis according to claim 1, wherein the solid catalyst is one or two selected from the group consisting of Nb—Ce/SBA-15 and Nb—CeP/SBA-15.

5. The method for producing levulinic acid in a molten salt hydrate from cellulose hydrolysis according to claim 1, wherein a mass ratio of the solid catalyst to the cellulose is 1:(1-5).

6. The method for producing levulinic acid in a molten salt hydrate from cellulose hydrolysis according to claim 1, wherein heating up for reaction is conducted after adding the solid catalyst and an extractant.

7. The method for producing levulinic acid in a molten salt hydrate from cellulose hydrolysis according to claim 6, wherein the extractant is one or more selected from the group consisting of methyl isobutyl ketone (MIBK), n-butanol, ethyl acetate and octanol.

8. The method for producing levulinic acid in a molten salt hydrate from cellulose hydrolysis according to claim 7, wherein a volume ratio of the extractant to the inorganic molten salt hydrate is (0-3):1.

9. The method for producing levulinic acid in a molten salt hydrate from cellulose hydrolysis according to claim 1, wherein the reaction is conducted at 150-200° C.

10. The method for producing levulinic acid in a molten salt hydrate from cellulose hydrolysis according to claim 1, wherein the reaction is conducted for 30-120 min.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] Hereinafter, the present disclosure will be further described in conjunction with examples.

Example 1

[0035] (1) First a certain amount of LiBr was weighed, and then water was added thereto based on the 3:1 molar ratio of water:LiBr while stirring until LiBr was dissolved, obtaining LiBr.3H.sub.2O.

[0036] (2) 0.1 g of cellulose was added to 5 mL of LiBr.3H.sub.2O, stirred to dissolve, and 0.1 g of Nb—Ce/SBA-15 and 5 mL of MIBK were added.

[0037] (3) The resulting mixture was heated up to 150° C., and subjected to a reaction at this temperature for 120 min.

[0038] (4) After reaction, the resulting reactant was cooled, and centrifuged, and then detected. Separated LiBr.3H.sub.2O and Nb—Ce/SBA-15 were recycled.

[0039] After detection, the yield of levulinic acid is 91.3%.

Example 2

[0040] (1) First a certain amount of LiCl was weighed, and then water was added thereto based on the 2:1 molar ratio of water:LiCl while stirring until LiCi was dissolved, obtaining LiCl.2H.sub.2O.

[0041] (2) 0.2 g of cellulose was added to 5 mL of LiCl.2H.sub.2O, stirred to dissolve, and 0.1 g of Nb—Ce/SBA-15 and 10 mL of MIBK were added.

[0042] (3) The resulting mixture was heated up to 175° C., and subjected to a reaction at this temperature for 90 min.

[0043] (4) After reaction, the resulting reactant was cooled, and centrifuged, and then detected. Separated LiCl.2H.sub.2O and Nb—Ce/SBA-15 were recycled.

[0044] After detection, the yield of levulinic acid is 92.7%.

Example 3

[0045] (1) First a certain amount of LiCl was weighted, and then water was added thereto based on the 3:1 molar ratio of water:salt while stirring until LiCl was dissolved, obtaining LiCl.3H.sub.2O.

[0046] (2) 0.1 g of cellulose was added to 5 mL of LiCl.3H.sub.2O, stirred to dissolve, and 0.1 g Nb—Ce/SBA-15 and 5 mL of MIBK were added.

[0047] (3) The resulting mixture was heated up to 160° C., and subjected to a reaction at this temperature for 120 min.

[0048] (4) After reaction, the resulting reactant was cooled, and centrifuged, and then detected. Separated LiCl.3H.sub.2O and Nb—Ce/SBA-15 were recycled.

[0049] After detection, the yield of levulinic acid is 91.2%.

Example 4

[0050] (1) First a certain amount of LiBr was weighed, and then water was added thereto based on the 4:1 molar ratio of water:LiBr while stirring until LiBr was dissolved, obtaining LiBr.4H.sub.2O.

[0051] (2) 0.1 g of cellulose was added to 5 mL of LiBr.4H.sub.2O, stirred to dissolve, and 0.1 g of Nb—CeP/SBA-15 and 5 mL of octanol were added.

[0052] (3) The resulting mixture was heated up to 175° C., and subjected to a reaction at this temperature for 60 min.

[0053] (4) After reaction, the resulting reactant was cooled, and centrifuged, and then detected. Separated LiBr.4H.sub.2O and Nb—CeP/SBA-15 was recycled.

[0054] After detection, the yield of levulinic acid is 93.1%.

Example 5

[0055] (1) First a certain amount of LiBr was weighed, and then water was added thereto based on the 2:1 molar ratio of water:LiBr while stirring until LiBr was dissolved, obtaining LiBr.2H.sub.2O. A certain amount of Ca(NO.sub.3).sub.2 was weighed, and water was added thereto based on the 2:1 molar ratio of water:Ca(NO.sub.3).sub.2 while stirring until Ca(NO.sub.3).sub.2 was dissolved, obtaining Ca(NO.sub.3).sub.2.2H.sub.2O.

[0056] (2) 0.1 g of cellulose was added to 5 mL of LiBr.2H.sub.2O+Ca(NO.sub.3).sub.2.2H.sub.2O (with a volume ratio of LiBr.2H.sub.2O to Ca(NO.sub.3).sub.2.2H.sub.2O of 1:1), stirred to dissolve, and 0.1 g of Nb—CeP/SBA-15 and 5 mL of MIBK were added.

[0057] (3) The resulting mixture was heated up to 160° C., and subjected to a reaction at this temperature for 50 min.

[0058] (4) After reaction, the resulting reactant was cooled, and centrifuged, and then detected. Separated LiBr.2H.sub.2O+Ca(NO.sub.3).sub.2.2H.sub.2O and Nb—CeP/SBA-15 were recycled.

[0059] After detection, the yield of levulinic acid is 92.2%.

Example 6

[0060] (1) First a certain amount of LiCl was weighed, and then water was added thereto based on the 2:1 molar ratio of water:LiCl while stirring until LiCl was dissolved, obtaining LiCl.2H.sub.2O. A certain amount of LiNO.sub.3 was weighed, and then water was added thereto based on the 2:1 molar ratio of water:LiNO.sub.3 while stirring until LiNO.sub.3 was dissolved, obtaining LiNO.sub.3.2H.sub.2O.

[0061] (2) 0.2 g of cellulose was added to 5 mL of LiCl.2H.sub.2O+LiNO.sub.3.2H.sub.2O (with a volume ratio of LiCl.2H.sub.2O to LiNO.sub.3.2H.sub.2O of 1:1), stirred to dissolve, and 0.1 g of Nb—CeP/SBA-15 was added.

[0062] (3) The resulting mixture was heated up to 175° C., and subjected to a reaction at this temperature for 30 min.

[0063] (4) After reaction, the resulting reactant was cooled, and centrifuged, and then detected. Separated LiCl.2H.sub.2O+LiNO.sub.3.2H.sub.2O and Nb—CeP/SBA-15 were recycled.

[0064] After detection, the yield of levulinic acid is 91.3%.

Example 7

[0065] (1) First a certain amount of LiCl was weighed, and then water was added thereto based on the 2:1 molar ratio of water:LiCl while stirring until LiCl was dissolved, obtaining LiCl.2H.sub.2O. A certain amount of KNO.sub.3 was weighed, and then water was added thereto based on the 1:1 molar ratio of water:KNO.sub.3 while stirring until KNO.sub.3 was dissolved, obtaining KNO.sub.3.H.sub.2O.

[0066] (2) 0.2 g of cellulose was added to 5 mL of LiCl.2H.sub.2O+KNO.sub.3.H.sub.2O (with a volume ratio of LiCl.2H.sub.2O to KNO.sub.3.H.sub.2O of 1:1), stirred to dissolve, and 0.1 g of Nb—CeP/SBA-15 and 10 mL of MIBK were added.

[0067] (3) The resulting mixture was heated up to 175° C., and subjected to a reaction at this temperature for 30 min.

[0068] (4) After reaction, the resulting reactant was cooled, and centrifuged, and then detected. Separated LiCl.2H.sub.2O+KNO.sub.3.H.sub.2O and Nb—CeP/SBA-15 were recycled.

[0069] After detection, the yield of levulinic acid is 93.6%.

Example 8

[0070] (1) First a certain amount of CaBr.sub.2 was weighed, and then water was added thereto based on the 2:1 molar ratio of water:CaBr.sub.2 while stirring until CaBr.sub.2 was dissolved, obtaining CaBr.sub.22H.sub.2O.

[0071] (2) 0.2 g of cellulose was added to 5 mL of CaBr.sub.2 2H.sub.2O, stirred to dissolve, and 0.1 g of Nb—CeP/SBA-15 was added.

[0072] (3) The resulting mixture was heated up to 175° C., and subjected to a reaction at this temperature for 30 min.

[0073] (4) After reaction, the resulting reactant was cooled, and centrifuged, and then detected. Separated CaBr.sub.2 2H.sub.2O and Nb—CeP/SBA-15 were recycled.

[0074] After detection, the yield of levulinic acid is 90.4%.

Comparative Example 1

[0075] (1) 0.1 g of cellulose was added to 5 mL of H.sub.2O, stirred to dissolve, and 0.1 g Nb—CeP/SBA-15 was added.

[0076] (2) The resulting mixture was heated up to 175° C., and subjected to a reaction at this temperature for 30 min.

[0077] (3) After reaction, the resulting reactant was cooled, and centrifuged, and then detected.

[0078] After detection, the yield of levulinic acid is 33.8%.

Comparative Example 2

[0079] (1) 0.1 g of cellulose was added to 5 mL of H.sub.2O, stirred to dissolve, and 0.1 g of Nb—Ce/SBA-15 and 10 mL of MIBK were added.

[0080] (2) The resulting mixture was heated up to 175° C., and subjected to a reaction at this temperature for 30 min.

[0081] (3) After reaction, the resulting reactant was cooled, and centrifuged, and then detected.

[0082] After detection, the yield of levulinic acid is 30.2%.

[0083] Detection results of Examples 1-8 and Comparative Examples 1-2 are shown in Table 1.

TABLE-US-00001 TABLE 1 Results of Examples 1-8 and Comparative Examples 1-2 Reaction Levulinic Inorganic molten salt temperature Retention acid hydrate composition Catalyst Extractant (° C.) time (min) yield, % Example 1 LiBr•3H.sub.2O Nb-Ce/SBA-15 MIBK 150 120 91.3 Example 2 LiCl•2H.sub.2O Nb-Ce/SBA-15 MIBK 175 90 92.7 Example 3 LiCl•3H.sub.2O Nb-Ce/SBA-15 MIBK 160 120 91.2 Example 4 LiBr•2H.sub.2O Nb-CeP/SBA-15 Octanol 175 60 93.1 Example 5 LiBr•2H.sub.2O + Ca(NO.sub.3).sub.2•2H.sub.2O Nb-CeP/SBA-15 MIBK 160 50 92.2 Example 6 LiCl•2H.sub.2O + LiNO.sub.3•2H.sub.2O Nb-CeP/SBA-15 None 175 30 91.3 Example 7 LiCl•2H.sub.2O + KNO.sub.3•H.sub.2O Nb-CeP/SBA-15 MIBK 175 30 93.6 Example 8 CaBr.sub.2•2H.sub.2O Nb-CeP/SBA-15 None 175 30 90.4 Comparative H.sub.2O Nb-CeP/SBA-15 None 175 30 33.8 Example 1 Comparative H.sub.2O Nb-Ce/SBA-15 MIBK 175 30 30.2 Example 2

[0084] It can be seen from Table 1 that in the present disclosure, under a combined action of the inorganic molten salt hydrate, the extractant and the solid catalyst, yields of levulinic acid are all not less than 90%.