A process is provided for the preparation of anhydrosugar alcohols. The process involves heating a sugar alcohol or a monoanhydrosugar alcohol starting material in the presence of an acid catalyst and under pressure. Optionally the resulting product is purified. Very high purities are achieved, without necessitating the use of organic solvents in the process.
Description
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a flow chart showing a continuous reactor process as taught herein. The reactor vessel may be, for example, but is not limited to a pipe, tube, or wire.
Claims
1. A process for the production of an anhydrosugar alcohol, comprising:
(a) mixing a pentitol or hexitol sugar alcohol or monoanhydrosugar alcohol starting material with a solvent to form a starting material solution, and, optionally, stirring said starting material solution;(b) heating said starting material solution;(c) pressurizing said starting material solution; and(d) forming an anhydrosugar alcohol.
2. The process of claim 1, further comprising collecting said anhydrosugar alcohol.
3. The process of claim 1, including wherein said pentitol or hexitol sugar alcohol or monoanhydrosugar starting material is selected from the group consisting of arabinitol, ribitol, glucitol, mannitol, galactitol, iditol, erythritol, threitol, and mixtures thereof.
4. The process of claim 1, including wherein said hexitol sugar alcohol starting material is glucitol.
5. The process of claim 1, including wherein said solvent is water.
6. The process of claim 1, including wherein said anhydrosugar alcohol is formed in the presence of a catalyst.
7. The process of claim 6, including wherein said catalyst is selected from the group consisting of at least one solid acid catalyst and at least one soluble acid catalyst.
8. The process of claim 6, including wherein said catalyst is selected from the group consisting of sulfuric acid, phosphoric acid, p-toluenesulfonic acid, and p-methanesulfonic acid.
9. The process of claim 6, including wherein said catalyst is an inorganic acid exchange material.
10. The process of claim 9, including wherein said inorganic acid exchange material is a zeolite.
11. The process of claim 10, including wherein said zeolite is a calcined zeolite.
12. The process of claim 10, including wherein said zeolite is selected from the group consisting of CBV 3024, CBV 5534G, T-2665, T-4480, and CS 331-3.
13. The process of claim 9, including wherein said inorganic acid exchange material is an acidic ion exchange resin.
14. The process of claim 13, including wherein said acidic ion exchange resin is selected from the group consisting of AG50W-X12, Amberlyst 15, Amberlyst 35, Amberlyst 36, Amberlyst 131, Lewatit S2328, Amberlyst 35, Amberlyst 36, Amberlyst 15, Amberlyst 131, Lewatit S2328, Lewatit K2431, Lewatit S2568, Lewatit K2629, Dianion SK104, Dianion PK228, Dianion RCP160, and Relite RAD/F, RCP21H, and Dowex 50Wx5.
15. The process of claim 13, including wherein said acidic ion exchange resin is a sulfonated divinylbenzene/styrene copolymer acidic ion exchange resin.
16. The process of claim 6, including wherein said catalyst is present in an amount between about 0.10 equivalents to about 1.00 equivalents by weight of starting material.
17. The process of claim 1, including wherein said starting material solution is reacted at a pressure between about 300 psi to about 2000 psi.
18. The process of claim 1, including wherein said starting material solution is heated to a temperature selected from the group consisting of a temperature between about 150° C. to about 350° C., a temperature between about 200° C. to about 300° C., a temperature between about 210° C. to about 290° C., a temperature between about 215° C. to about 280° C., a temperature between about 230° C. to about 270° C., and a temperature between about 240° C. to about 260° C.
19. The process of claim 1, including wherein said heating and pressurizing steps under microwave irradiation.
20. The process of claim 1, including wherein said heating and pressurizing occur in at least one tube during a constant throughput of starting material.
Patent Application
20070213544
