Method for recovering solvents
View Patent ↗A method for recovering a solvent from its mixture containing oligomers extracted from grafted polyolefins is disclosed. The method includes distilling the solvent from the mixture in the presence of a naphthalene compound. The method of the invention significantly increases the solvent recovering yield without causing the vessel fouling.
1. A method for recovering a solvent, said method comprising distilling the solvent, in the presence of a naphthalene compound in an amount from about 5 wt % to about 50 wt % of the solvent, from a mixture comprising the solvent and oligomers extracted from a grafted polyolefin.
2. The method of claim 1 wherein the naphthalene compound is an alkylnaphthalene.
3. The method of claim 2 wherein the alkylnaphthalene is selected from the group consisting of 1-methylnaphthalene, 2-methylnaphthalene, 1-ethylnaphthalene, 2-ethylnaphthalene, and mixtures thereof.
4. The method of claim 1 wherein the naphthalene compound is a mixture of naphthalene and methylnaphthalenes.
5. The method of claim 1 wherein the grafted polyolefin is a maleic anhydride-grafted polyolefin.
6. The method of claim 1 wherein the grafted polyolefin is a maleic anhydride-grafted propylene homopolymer.
7. The method of claim 1 wherein the grafted polyolefin is a maleic anhydride-grafted impact polypropylene.
8. The method of claim 1 wherein the solvent is selected from the group consisting of C 5 -C 8 hydrocarbons, C 1 -C 10 oxygen-containing compounds, and mixtures thereof.
9. The method of claim 8 wherein the C 1 -C 10 oxygen-containing compound is selected from the group consisting of alcohols, aliphatic ketones, aliphatic esters, and mixtures thereof.
10. The method of claim 8 wherein the C 5 -C 8 hydrocarbon is selected from the group consisting of hexane, cyclohexane, octane, toluene, xylenes, and mixtures thereof.
11. The method of claim 8 wherein the solvent is an azeotropic mixture of a C 5 -C 8 hydrocarbon and a C 1 -C 10 oxygen-containing compound.
12. The method of claim 11 wherein the solvent is an azeotropic mixture of hexane and ethyl acetate.
13. The method of claim 1 wherein the naphthalene compound is present in an amount from about 5 wt % to about 20 wt % of the solvent.
14. The method of claim 1 which recovers at least 80% of the solvent without causing vessel fouling.
15. The method of claim 1 which recovers at least 90% of the solvent without causing vessel fouling.