Method for treatment of sulfite spent liquor
Abstract
Abstract THE PH OF SULFITE SPENT LIQUOR TO BE TREATED IS FIRST ADJUSTED TO NEUTRALITY OR WEAK ACIDITY. TO THE RESULTING LIQUOR IS ADDED A WATER-MISCIBLE ORGANIC SOLVENT HAVING A SOLUBILITY PARAMETER VALUE OF 9.0 TO 12.5 IN AN AMOUNT SUCH THAT THE WEIGHT RATIO OF THE SOLVENT TO WATER PRESENT IN THE SPENT LIQUOR WILL FALL IN THE RANGE OF FROM 6:4 TO 4:6 THUS CAUSING HEMICELLULOSES TO BE PRECIPITATED FIRST. THE HEMICELLULOSES ARE REMOVED FROM THE LIQUOR. THEN, THE ORGANIC SOLVENT IS ADDED AGAIN TO THE RESIDUAL LIQUOR AFTER THE REMOVAL OF HEMICELLULOSES SO AS TO CAUSE FORMATION OF A HEAVY LIQUID PHASE CONTAINING LIGNOSULFONATES AND A LIGHT LIQUID PHASE CNTAINING MONOSACCHARIDES. THE TWO PHASES THUS FORMED ARE SEPARATED AND REFINED TO PRODUCE LIGNOSULFONATES AND MONOSACCHARIDES. THE ORGANIC SOLVENT USED IN THE PRESENT TRETMENT IS RECOVERED FROM THE LIGHT LIQUID PHASE.
Inventors
- 👤 Y Ikari
- 👤 S Yokoyama
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |