Catalyst and method for synthesis of lactic acid and its derivatives
A catalyst for synthesis of lactic acid and it derivatives is provided. The catalyst includes SnY2.mH 2 O and at least one of NH 4 X or quaternary ammonium salts, wherein X and Y are selected from F—, Cl—, Br—, I—, CH 3 SO 3 —, C 6 H 5 SO 3 —, CH 3 C 6 H 4 SO 3 — or CN—, m represents an integer of 1 to 15. A method for synthesis of lactic acid and it derivatives with the above catalyst is also provided. By using the above catalyst and method, it is capable of converting carbohydrate-containing raw material to lactic acid and its derivatives directly in a more efficient and economical way.
1. A catalyst for synthesis of lactic acid and its derivatives, comprising:
SnY 2 .mH 2 O and at least one of NH 4 X or quaternary ammonium salts, wherein X and Y are selected from F − , Cl − , Br − , I − , CH 3 SO 3 − , C 6 H 5 SO 3 − , CH 3 C 6 H 4 SO 3 − or CN − , m represents an integer of 1 to 15, and the mass ratio of the at least one of NH 4 X or quaternary ammonium salts to the SnY 2 .mH 2 O is in a range from 1:2 to 5:2.
2. The catalyst for synthesis of lactic acid and its derivatives of claim 1 , wherein the cation of the quaternary ammonium salts has a general formula of (NR 1 R 2 R 3 R 4 ) + , in which, the R 1 , R 2 , R 3 , and R 4 are alkyl groups with formula of C n H 2n+1 , wherein n represents an integer of 1 to 30.
3. A method for synthesis of lactic acid and its derivatives, comprising:
providing a mixture, comprising: at least one carbohydrate-containing raw material, at least one alcohol, at least one catalyst, and at least one solvent, wherein the catalyst comprising SnY 2 .mH 2 O and at least one of NH 4 X or quaternary ammonium salts, wherein X and Y are selected from F − , Cl − , Br − , I − , CH 3 SO 3 − , C 6 H 5 SO 3 − CH 3 C 6 H 4 SO 3 − or CN − , m represents an integer of 1 to 15,and the mass ratio of the at least one of NH 4 X or quaternary ammonium salts to the SnY 2 .mH 2 O is in a range from 1:2 to 5:2; and
heating the mixture to obtain lactic acid and its derivatives.
4. The method for synthesis of lactic acid and its derivatives of claim 3 , wherein the alcohol is selected from the group consisting of monohydroxyl alcohols, dihydroxyl alcohols, and trihydroxyl alcohols.
5. The method for synthesis of lactic acid and its derivatives of claim 4 , wherein the alcohol is a monohydroxyl alcohol, and the monohydroxyl alcohol is selected from a group consisting of methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and tert-butanol.
6. The method for synthesis of lactic acid and its derivatives of claim 4 , wherein the alcohol is a dihydroxyl alcohol, and the dihydroxyl alcohol is selected from the group consisting of ethylene glycol, 1, 2-propandiol, and 1, 3-propandiol.
7. The method for synthesis of lactic acid and its derivatives of claim 4 , wherein the alcohol is trihydroxyl alcohol, and the trihydroxyl alcohol is glycerol.
8. The method for synthesis of lactic acid and its derivatives of claim 3 , wherein the mass ratio of the at least one alcohol to the at least one carbohydrate-containing raw material is greater than 1.
9. The method for synthesis of lactic acid and its derivatives of claim 8 , wherein the mass ratio of the at least one alcohol to the at least one carbohydrate-containing raw material is greater than 3:2.
10. The method for synthesis of lactic acid and its derivatives of claim 3 , wherein the at least one solvent is a polar solvent.
11. The method for synthesis of lactic acid and its derivatives of claim 10 , wherein the polar solvent is selected from a group consisting of water, alcohols, the methyl esters of C8 to C22 fatty acids, or mixtures thereof.
12. The method for synthesis of lactic acid and its derivatives of claim 3 , wherein a reaction temperature of the heating step is between 25 and 200° C.
13. The method for synthesis of lactic acid and its derivatives of claim 12 , wherein the reaction temperature of the heating step is between 25 and 180° C.
14. The method for synthesis of lactic acid and its derivatives of claim 3 , wherein the at least one carbohydrate-containing raw material comprises cellulose and the reaction temperature of the heating step is between 80 and 180° C.
15. The method for synthesis of lactic acid and its derivatives of claim 14 , wherein the reaction temperature of the heating step is between 100 and 180° C.
16. The method for synthesis of lactic acid and its derivatives of claim 3 , wherein the at least one carbohydrate-containing raw material comprises starch and the reaction temperature of the heating step is between 80 and 180° C.
17. The method for synthesis of lactic acid and its derivatives of claim 14 , wherein the reaction temperature of the heating step is between 80 and 160° C.
18. The method for synthesis of lactic acid and its derivatives of claim 3 , wherein the at least one carbohydrate-containing raw material comprises sucrose or glucose and the reaction temperature of the heating step is between 25 and 180° C.
19. The method for synthesis of lactic acid and its derivatives of claim 18 , wherein the reaction temperature of the heating step is between 25 and 140° C.