Claims
- 1. A method for selectively producing a substantially fiberized, substantially delignified, high yield cellulosic pulp, which comprises
- (a) forming an aqueous pulping system comprising lignocellulose, a pulping liquor including water and a pulping agent, said pulping agent comprising a water-miscible organic reagent selected from the group consisting of aliphatic alcohols, aliphatic ketones, and mixtures thereof, and a sulfide or bisulfide compound selected from the group consisting of ammonium sulfide and ammonium bisulfide, and mixtures thereof; and
- (b) pulping said lignocellulose at an elevated temperature for a time sufficient to selectively produce said substantially fiberized, substantially delignified cellulosic pulp.
- 2. The method of claim 1, wherein said water-miscible reagent is an aliphatic ketone having from 1 to 6 carbon atoms.
- 3. The method of claim 1, wherein said water-miscible reagent is an aliphatic alcohol having from 1 to 6 carbon atoms.
- 4. The method of claim 3, wherein the aliphatic alcohol is ethanol.
- 5. The method of claim 3, wherein the aliphatic alcohol is methanol.
- 6. The method of claim 1, wherein the initial pH of the system is from a pH of greater than about 7.0, up to a pH of about 12.5.
- 7. The method of claim 1, wherein said initial pH is from about 8.0, up to about 12.0.
- 8. The method of claim 1, wherein the elevated temperature is from about 150.degree. C., up to about 190.degree. C.
- 9. The method of claim 1, wherein the time period for conducting the defiberization-delignification is from about 0.5 hour, to about 6 hours.
- 10. An aqueous pulping system capable of selectively producing a substantially fiberized, substantially delignified, high yield, cellulosic pulp, which comprises
- (a) lignocellulose;
- (b) water;
- (c) a water-miscible organic reagent selected from the group consisting of aliphatic alcohols, aliphatic ketones, and mixtures thereof; and
- (d) a sulfide or bisulfide compound selected from the group consisting of ammonium sulfide and ammonium bisulfide, and mixtures thereof.
- 11. The system of claim 10, wherein said water-miscible reagent is an aliphatic alcohol having from 1 to 6 carbon atoms.
- 12. The system of claim 10, wherein the aliphatic alcohol is methanol.
- 13. The system of claim 10, wherein the water-miscible reagent is an aliphatic ketone having from 1 to 6 carbon atoms.
- 14. The aqueous pulping system of claim 10, wherein the reagent is methanol.
- 15. The aqueous pulping system of claim 10, wherein the initial pH of the system is from about greater than a pH of about 7.0, up to a pH of about 12.5.
- 16. The aqueous pulping system of claim 10, wherein said initial pH is from about 8.0, up to about 12.0.
- 17. The system of claim 10, wherein the reagent is ethanol.
BACKGROUND OF THE INVENTION
The invention described herein was made during the course of, or under, a grant from the National Science Foundation. The Government has rights in this invention pursuant to Contract Number AER-77-08979 awarded by the National Science Foundation.
US Referenced Citations (5)