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US4718979A
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Method for rapid determination of the contents of lignin, monosaccharides and organic acids in the process solutions of sulfite pulping
Assignee: Advanced Forest Automation Oy AB
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Filing: 1986-01-15
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Granted: 1988-01-12
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Expires: 2006-01-15
Abstract
Abstract A method for rapid determination of the contents of lignin, monosaccharides and organic acids in the process solutions of sulfite pulping. Accordingly, any non-ionized compounds that disturbs the measurement of these concentrations are separated from the lignin material by an ion-exclusion technique. The measurements of concentrations are carried out by means of the UV-method, refractive-index method, and/or by means of the polarimetric method. The method of the present invention is usable for the controlling of sulfite cooking or other pulping or by-product production processes as well as for the characterization of the spent liquor.
Inventors
- 👤 Panu Tikka
- 👤 Nils-Erik Virkola
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:46
CPC Classifications
D; D21; D21C; D21C3/00; D21C3/22; D21C3/228; G; G01; G01N; G01N33/00; G01N33/34; G01N33/343; Y; Y10; Y10T; Y10T436/00; Y10T436/25; Y10T436/25125
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
138 words
A method for controlling a sulfite cooking process by determining the lignin, monosaccaride and organic acid contents of sulfite cooking liquior comprising: (a) passing a quantity of sulfite cooking liquor containing lignin and monosacharides, lignin and organic acid, or lignin, monosaccharides and organic acids from a sulfite cooking process through a body of cation exchange material under ion-exclusion separation conditions effective to provide an effluent containing a substantially ionic portion and a substantially non-ironic portion; (b) determining the content of lignin by UV light analysis and refractive index analysis of said ionic portion, determining the context of monosaccharides by polarimetric analysis of said non-ionic portion, and determining the content of organic acids by refractive index analysis of said non-ionic portion; and (c) terminating the sulfide cooking process when the lignin, monosaccharide and organic acid contents reach desired values.
Claim 2
Independent Claim
138 words
A method for controlling a sulfite cooking process by determining the lignin, monosaccaride and organic acid contents of sulfite cooking liquior comprising: (a) passing a quantity of sulfite cooking liquor containing lignin and monosacharides, lignin and organic acid, or lignin, monosaccharides and organic acids from a sulfite cooking process through a body of cation exchange material under ion-exclusion separation conditions effective to provide an effluent containing a substantially ionic portion and a substantially non-ironic portion; (b) determining the content of lignin by UV light analysis and refractive index analysis of said ionic portion, determining the context of monosaccharides by polarimetric analysis of said non-ionic portion, and determining the content of organic acids by refractive index analysis of said non-ionic portion; and (c) terminating the sulfide cooking process when the lignin, monosaccharide and organic acid contents reach desired values.
Claim 3
Dependent Claim
21 words
A method according to claim 1, wherein said cation exchange material is styrene-divinylbenzene resin having a partical size of 100-200 mesh.
Claim 4
Dependent Claim
22 words
A method according to claim 1, wherein said cation exchange material is stryene-divinylbenzene resin having a particle size of about 200-400 mesh.
Claim 5
Dependent Claim
16 words
A method according to claim 1, wherein said cation exchange material contains 4 to 5% divinylbenzene.
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) | 1991-01-11 | 1991-07-13 | 1992-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-11 | 1995-07-13 | 1996-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-11 | 1999-07-13 | 2000-01-12 | $7700.00 | Window Closed / Lapsed |