US2976273A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of kraft black liquor and product
Assignee: West Virginia Pulp and Paper Co
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Filing: 1958-09-10
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Granted: 1961-03-21
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Expires: 1978-09-10
Abstract
No abstract record available.
Inventors
- 👤 Frank J Ball
- 👤 Pueschel Richard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:02
CPC Classifications
C; C08; C08H; C08H6/00; D; D21; D21C; D21C11/00; D21C11/0007
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
130 words
THE METHOD OF TREATING RESIDUAL BLACK LIQUOR OF THE KRAFT PULPING PROCESS HAVING A SMALL INITIAL RATIO OF SULFIDIC SULFUR TO TOTAL SOLIDS INHERENTLY PRESENT AND A CONSIDERABLY LARGER INITIAL RATIO OF CHEMICALLY COMBINED, NONSULFIDIC SULFUR TO TOTAL SOLIDS INHERENTLY PRESENT, WHICH COMPRISES HEATING SUCH BLACK LIQUOR, CONCENTRATED TO A SOLIDS CONTENT OF 25 TO 60%, TO, AND MAINTAINING IT IN, THE RANGE OF 220* TO 350*C. UNDER A PRESSURE WHICH IS AT ALL TIMES AT LEAST AS GREAT AS THE VAPOR PRESSURE OF THE BLACK LIQUOR AT THE EXISTING TEMPERATURE OF THE BLACK LIQUOR, THEREBY PRODUCTING A QUANTITY OF DIMETHYL SULFIDE WHOSE SULFUR CONTENT IS DERIVED CHIEFLY FROM THE INITIALLY NON-SULFIDIC SULFUR OF THE BLACK LIQUOR, AND SEPARATING AND RECOVERING FROM THE BACK LIQUOR THE DIMETHYL SULFIDE SO PRODUCED.
Claim 2
Independent Claim
130 words
THE METHOD OF TREATING RESIDUAL BLACK LIQUOR OF THE KRAFT PULPING PROCESS HAVING A SMALL INITIAL RATIO OF SULFIDIC SULFUR TO TOTAL SOLIDS INHERENTLY PRESENT AND A CONSIDERABLY LARGER INITIAL RATIO OF CHEMICALLY COMBINED, NONSULFIDIC SULFUR TO TOTAL SOLIDS INHERENTLY PRESENT, WHICH COMPRISES HEATING SUCH BLACK LIQUOR, CONCENTRATED TO A SOLIDS CONTENT OF 25 TO 60%, TO, AND MAINTAINING IT IN, THE RANGE OF 220* TO 350*C. UNDER A PRESSURE WHICH IS AT ALL TIMES AT LEAST AS GREAT AS THE VAPOR PRESSURE OF THE BLACK LIQUOR AT THE EXISTING TEMPERATURE OF THE BLACK LIQUOR, THEREBY PRODUCTING A QUANTITY OF DIMETHYL SULFIDE WHOSE SULFUR CONTENT IS DERIVED CHIEFLY FROM THE INITIALLY NON-SULFIDIC SULFUR OF THE BLACK LIQUOR, AND SEPARATING AND RECOVERING FROM THE BACK LIQUOR THE DIMETHYL SULFIDE SO PRODUCED.
Claim 3
Dependent Claim
181 words
A MODIFIED LIGNIN PRODUCT, OBTAINED FROM BLACK LIQUOR FROM THE KRAFT PROCESS OF PULPING WOOD HAVING A SMALL INITAL RATIO OF SULFIDIC SULFUR TO TOTAL SOLIDS INHERENTLY PRESENT AND A CONSIDERABLY LARGER INITAL RATIO OF CHEMICALLY COMBINED NON-SULFIDIC SULFUR TO TOTAL SOLIDS INHERENTLY PRESENT, BY HEATING SUCH BLACK LIQUOR, CONCENTRATED TO A SOLIDS COSNTENT OF 25 TO 60%, TO, AND MAINTAINING IT IN, THE RANGE OF 220* TO 350*C. UNDER A PRESSURE WHICH IS AT ALL TIMES AT LEAST AS GREAT AS THE VAPOR PRESSURE OF THE BLACK LIQUOR AT THE EXISTING TEMPERATURE OF THE BLACK LIQUOR, AND SEPARATING THE MOFIFIED LIGNIN PRODUCT FROM THE BLACK LIQUOR BY ACIDIFYING THE LIQUOR TO PRECIPITATE THE MOFIFIED LIGNIN PRODUCT THEREFROM, SAID MODIFIED PRODUCT BEING CHARACTERIZED BY HAVING A SULFUR CONTENT BETWEEN 0.5 AND 2.0% BY WEIGHT AND HAVING, WHEN COMPARED TO THE KRAFT LIGNING FROM WHICH THE MODIFIED LIGNIN WAS PREPARED, A SUBSTANTIALLY REDUCED METHOXY CONTENT, GREATER ACIDIC GROUP CONTENT, GREATER ETHER EXTRACTABLE CONTENT, INCREASED REACTIVITY TOWARD OXYGEN AND FORMALDEHYDE, AND SUBSTANTIALLY INCREASED SOLUBILITY IN EACH OF ACETONE, HEZANOL, AND 1:1 MIXTURE METHANOLBENZENE.
Claim 4
Dependent Claim
181 words
A MODIFIED LIGNIN PRODUCT, OBTAINED FROM BLACK LIQUOR FROM THE KRAFT PROCESS OF PULPING WOOD HAVING A SMALL INITAL RATIO OF SULFIDIC SULFUR TO TOTAL SOLIDS INHERENTLY PRESENT AND A CONSIDERABLY LARGER INITAL RATIO OF CHEMICALLY COMBINED NON-SULFIDIC SULFUR TO TOTAL SOLIDS INHERENTLY PRESENT, BY HEATING SUCH BLACK LIQUOR, CONCENTRATED TO A SOLIDS COSNTENT OF 25 TO 60%, TO, AND MAINTAINING IT IN, THE RANGE OF 220* TO 350*C. UNDER A PRESSURE WHICH IS AT ALL TIMES AT LEAST AS GREAT AS THE VAPOR PRESSURE OF THE BLACK LIQUOR AT THE EXISTING TEMPERATURE OF THE BLACK LIQUOR, AND SEPARATING THE MOFIFIED LIGNIN PRODUCT FROM THE BLACK LIQUOR BY ACIDIFYING THE LIQUOR TO PRECIPITATE THE MOFIFIED LIGNIN PRODUCT THEREFROM, SAID MODIFIED PRODUCT BEING CHARACTERIZED BY HAVING A SULFUR CONTENT BETWEEN 0.5 AND 2.0% BY WEIGHT AND HAVING, WHEN COMPARED TO THE KRAFT LIGNING FROM WHICH THE MODIFIED LIGNIN WAS PREPARED, A SUBSTANTIALLY REDUCED METHOXY CONTENT, GREATER ACIDIC GROUP CONTENT, GREATER ETHER EXTRACTABLE CONTENT, INCREASED REACTIVITY TOWARD OXYGEN AND FORMALDEHYDE, AND SUBSTANTIALLY INCREASED SOLUBILITY IN EACH OF ACETONE, HEZANOL, AND 1:1 MIXTURE METHANOLBENZENE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-03-20 | 1964-09-19 | 1965-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-03-20 | 1968-09-19 | 1969-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-03-20 | 1972-09-19 | 1973-03-21 | $7700.00 | Window Closed / Lapsed |