Determination of sodium sulfide and sulfidity in green liquors a

Paper making and fiber liberation – Processes of chemical liberation – recovery or purification... – With testing – sampling or analyzing

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162238, 162263, 162DIG10, D21C 714

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056162146

ABSTRACT:
A rapid method is provided for the on-line determination of sodium sulfide concentration and/or percent sulfidity in green liquors or smelt solutions used for the production of either kraft or sulfite pulp. The method eliminates manual sampling, and the need for frequent equipment maintenance. The method includes the steps of withdrawing samples of a smelt solution or green liquor from the kraft or sulfite manufacturing process, subjecting the samples to near-infrared spectrophotometry over a predetermined range of wave numbers so as to produce absorbance measurements relative to a reference spectrum of either water or a caustic soda-sodium carbonate solution, determining the absorbance shown by different combinations of sodium sulfide, sodium hydroxide, sodium carbonate and sodium chloride concentrations, correlating by multivariate calibration the relationships between the absorbance measurements of unknown samples and the absorbance shown by different combinations of sodium sulfide, sodium hydroxide, sodium carbonate and sodium chloride so that the amount of sodium sulfide and/or the percent sulfidity can be accurately determined for any levels of TTA or chloride present in the liquor.

REFERENCES:
patent: 4717672 (1988-01-01), Fleming et al.
patent: 4743339 (1988-05-01), Faix et al.
patent: 5104485 (1992-04-01), Weyer
patent: 5282931 (1994-02-01), LeClerc et al.
patent: 5364502 (1994-11-01), Leclerc et al.
patent: 5378320 (1995-01-01), Leclerc et al.
Haaland D. M. et al., "Partial Least-Squares Methods for Spectral Analyses 1. Relation to Other Quantitative Calibration Methods and the Extraction of Qualitative Information" Analytical Chemistry, vol. 60 No. 11:1193-1202 Jun. 1, 1988.
Haaland D. M. et al., "Partial Least-Squares Methods for Spectral Analyses. 2. Application to Simulated and Glass Spectral Data" Analytical Chemistry, vol. 60, No. 11:1202-1208 Jun. 1, 1988.
Banfill et al. "Reduced Emissions Change Chemical Balances in Bleached Kraft Pulp Mills" Pulp & Paper Canada Mag. 1993 94(1) T21-t24.
D.C. Taflin "Estimating the Impact on Makeup & the Liquor Loop . . . " Proc. 1991 Tappi Pulp Conf. Orlando FL. pp. 821-827, Tappi Press, Atlanta, GA.
D. Peramunage et al. "Activity & Spectroscopic Analysis of Concentrated . . . " Anal. Chem. 1994, vol. 66, No. 3, 378-383.
Paulonis et al. "Kraft White & Green Liquor Composition Analysis. Part I: Discrete Sample Analyser. " J. Pulp Paper Sci. 1994, vol. 20 No. 9, J254-258.
Salomon D R "Applications of Capillary Ion Electrophoresis in the Pulp & Paper Industry" J. Chromatogr. 1992 602(1-2) 219-225
D.R. Salomon et al. "Rapid Ion Monitoring of Kraft Process Liquors by Capillary Electrophoresis" Process Control & Quality, 1992 3(1-4) 219-27.
P. Isaak et al. "Stickiness of Fireside Deposits in Kraft Recovery Units. Part II. The Effects of Potassiium and Surface Treatment. " J. Pulp Paper Sci. 1987, 13(5), J154.
A.J. Michell "Kappa Number Determination in Kraft Pulping by FTIR Spectroscopic Measurements on Spent Liquors" Tappi Journal 1990, 73(4), 235.
O. Faix et al. "Continuous Process Control of Pulping by FTIR Spectroscopy" Tappi Proceedings, 1989 Wood & Pulping Chemistry Symposium, Raleigh NC.
D.F. Leclerc et al. "Rapid Determination of Effective Alkali and Dead Load Concentrations in Kraft . . . " J. Pulp Paper Sci. 1995, 21(7), J231.
Watson et al. "On-line Analysis of Caustic Streams by Near Infrared Spectroscopy" Spectroscopy, 1990 2(1) 44.
T. Hirschfeld "Salinity Determination Using NIRA" Appl. Spectroscopy 1985 39(4), 740-1.
Grant et al. "Simultaneous Determination of Sodium Hydroxide, Sodium Carbonate & Sodium Chloride . . . " Analyst, 1989, 114(7), 819-22.
Haaland D M et al. "Partial Least Squares Methods for Spectral Analyses 1. Relation to Other . . . " Anal. Chem. 60(10):1193-1202, 1988.
J. Lin et al. "Near IR Spectroscopic Determination of NaCl in Aqueous Solution" Appl. Spectrosc. 1992 46(12), 1809-15.
J. Lin et al. "Near IR Spectroscopic Measurement of Seawater Salinity" Environ. Sci. Technol. 1993, 27(8), 1611-6.
J. Lin et al. "Near-IR Fiber Optic Probe for Electrolytes in Aqueous Solution" Anal. Chem. 1993, 65(3), 287-92.
J. Lin et al. "Near IR Fiber Optic Temperature Sensor" Appl. Spectrosc. 1993 47(1),62-8.
J. Lin et al. "Spectroscopic Measurement of NaCl and Seawater Salinity in the Near IR Region . . . " Appl. Spectrosc. 1993. (47(2), 239-41.
M.K. Phelan et al. "Measurement of Caustic Brine Solutions by Spectroscopic Detection of the Hydroxide . . . " Anal. Chem. 1989, 61(13), 1419-24.

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