Determination of the stability constant of the calcium binding ligand in black liquor (BL) by potentiometric titration
-
Kim Granholm
,
Tomasz Sokalski
Abstract
The calcium binding ligand in black liquor (BL) has been investigated by the new CSSP (circumvention of slope and standard potential) method, which converts the potential of an ion-selective electrode to concentration or activity. The advantage of this approach is that the knowledge about the electrode standard potential and the slope of the calibration curve is not needed. Instead, two activities of calcium ion on the titration curve have to be estimated, for instance the starting activity before the titration begins and the activity at the end of the titration in presence of a large excess of the titrant. A solid-contact Ca2+-selective electrode was used to determine the stability constant of the Ca binding ligand in BL. In addition, the concentration of free and bound calcium was determined. The total Ca concentration obtained by the CSSP approach agreed well to that obtained by the ICP-OES technique. Other metal ions did not influence the determination if the BL concentration is around 3%.
Acknowledgments
The authors would like to express their gratitude to Finnish Funding Agency for Technology and Innovation, TEKES for their financial support. We also want to thank Dr. Nikolai DeMartini for the valuable discussions. This work is part of the activities at the Johan Gadolin Process Chemistry Centre, a Centre of Excellence financed by Åbo Akademi University.
References
Bobacka, J., Vázquez, M., Sundfors, F., Mikhelson, A., Lewenstam, A., Ivaska, A. (2007) Determination of Ca(II) in wood pulpd using a calcium-selective electrode with poly(3,4-ethylenedioxytiophene) as ion-to-electron transducer. In: Electrochemical Sensor Analysis, Part 2 Procedures, Poteniometric sensors. Eds. Alegret, S., Merkoci, A. Elsevier, Amsterdam, The Netherlands. pp. e25–e28.10.1016/S0166-526X(06)49047-4Suche in Google Scholar
DeMartini, N.A., Verrill, C.L. (2005) Evaporator fouling mitigation – case studies. In: TAPPI Engineering, Pulping and Environmental Conference, Philadelphia, PA, United States.Suche in Google Scholar
Frederick, W.J., Grace, T.M. (1981) Scaling in alkaline spent pulping liquor evaporators. In: Fouling of Heat Transfer Equipment. Eds. Somerscales, E.F.C., Knudsen, J.G. Hemisphere Publishing Corporation, Washington.Suche in Google Scholar
Granholm, K., Ek, P., Sokalski, T., Harju, L., Bobacka, J., Ivaska, A. (2009) Determination of calcium with ion-selective electrode in black liquor from a kraft pulping process. Electroanalysis 21:2014–2021.10.1002/elan.200904633Suche in Google Scholar
Granholm, K., Sokalski, T., Lewenstam, A., Ivaska, A. (2015) Ion-selective electrodes in potentiometric titrations; a new method for processing and evaluating titration data. Anal. Chim. Acta. 888:36–43.10.1016/j.aca.2015.05.056Suche in Google Scholar
Holmlund, K., Parviainen, K. (2000) Evaporation of black liquor. In: Chemical Pulping. Eds. Gullichsen, J., Fogelholm, C.-J. Fapet Oy, Jyväskylä. Fapet Oy, Jyväskylä, Finland, Vol. 6B, pp. 37–93.Suche in Google Scholar
Muller-Steinhagen, H., Branch, C.A. (1997) Heat transfer and heat transfer fouling in kraft black liquor evaporators. Exp. Therm Fluid Sci. 14:425–437.10.1016/S0894-1777(96)00143-4Suche in Google Scholar
Ringbom, A. Complexation in Analytical Chemistry. Wiley, New York, 1963.Suche in Google Scholar
Ulmgren, P. (1997) Non-process elements in a bleached kraft pulp mill with a high degree of system closure – state of the art. Nord. Pulp Pap. Res. J. 12:32–31.10.3183/npprj-1997-12-01-p032-041Suche in Google Scholar
Westervelt, H.H. (1982) The determination and temperature-dependence of the stability constant of the calcium-catechol-4-sulfonate complex in alkaline aqueous-media. Anal. Chim. Acta. 138:237–243.10.1016/S0003-2670(01)85307-1Suche in Google Scholar
Westervelt, H.H., Frederick, W.J., Malcolm, E.W., Easty, D.B. (1982) New evidence concerning the role of black liquor organics in calcium-carbonate scale formation. Tappi. 65:179–180.Suche in Google Scholar
©2016 Walter de Gruyter GmbH, Berlin/Boston
Artikel in diesem Heft
- Frontmatter
- Original Articles
- UV-protection of wood surfaces by controlled morphology fine-tuning of ZnO nanostructures
- Solid-state 29Si NMR and FTIR analyses of lignin-silica coprecipitates
- Monitoring of free phenol content in lignosulfonates by ClO2 titration and UV difference spectroscopy
- Self-assembly of kraft lignin into nanospheres in dioxane-water mixtures
- Determination of the stability constant of the calcium binding ligand in black liquor (BL) by potentiometric titration
- Thermo-hydro treated (THT) birch veneers for producing plywood with improved properties
- Reactions between peracetic acid and lipophilic extractives – methodologies and implications in post bleaching of kraft pulps
- Geopolymers as potential new binder class for the wood based composite industry
- Assessing the role of adhesives in durability of laminated veneer lumber (LVL) by fracture mechanics
- Review
- Rolling shear modulus and strength of beech wood laminations
- Original Articles
- Influence of sugar and starch content of palm wood on fungal development and prevention of fungal colonization by acid treatment
- Dimensional stability, fungal resistance and mechanical properties of radiata pine after combined thermo-mechanical compression and oil heat-treatment
Artikel in diesem Heft
- Frontmatter
- Original Articles
- UV-protection of wood surfaces by controlled morphology fine-tuning of ZnO nanostructures
- Solid-state 29Si NMR and FTIR analyses of lignin-silica coprecipitates
- Monitoring of free phenol content in lignosulfonates by ClO2 titration and UV difference spectroscopy
- Self-assembly of kraft lignin into nanospheres in dioxane-water mixtures
- Determination of the stability constant of the calcium binding ligand in black liquor (BL) by potentiometric titration
- Thermo-hydro treated (THT) birch veneers for producing plywood with improved properties
- Reactions between peracetic acid and lipophilic extractives – methodologies and implications in post bleaching of kraft pulps
- Geopolymers as potential new binder class for the wood based composite industry
- Assessing the role of adhesives in durability of laminated veneer lumber (LVL) by fracture mechanics
- Review
- Rolling shear modulus and strength of beech wood laminations
- Original Articles
- Influence of sugar and starch content of palm wood on fungal development and prevention of fungal colonization by acid treatment
- Dimensional stability, fungal resistance and mechanical properties of radiata pine after combined thermo-mechanical compression and oil heat-treatment
