Measurement of black liquor surface tension: Technical report No. 3. [Black liquor]
Surface tension and density of two kraft black liquors were measured at a series of temperatures, from a minimum value when gas bubbles can be blown into the liquor to a maximum value near the elevated boiling point of a particular sample. Available methods for the measurement of surface tension were evaluated critically and, as a result, the maximum bubble pressure method was selected. Varying the flow rate of the gas changes the frequency of bubble formation and thereby the age of the surface. The parameter has been utilized by many researchers to monitor the diffusion of low surface energy components (e.g., surfactants) to the liquid/air interface. The effect of bubble frequency when tested with a few pure liquids, indicated that the dynamics of bubble formation had to be further examined to separate out inertial and viscous effects from purely surface tension related pressure. The pressure versus flow rate data were extrapolated to zero flow rate and surface tension and density were calculated using these extrapolated values. As expected, surface tension decreased with increasing temperature for all the samples. Surface tension decreases with increasing solids content (when compared with the value for water) to a certain level (about 20%) and it starts to increase again. The decrease in surface tension in the dilute black liquor, is probably due to the decrease in the concentration of water, which has a high surface tension value. The occurrence of the minimum is probably due to the effect of inorganic components dominating over the effect of surfactants and other components. Reduction in the solubilities of the inorganics, promotion of micelles of the surfactants and reduction in the diffusion of surfactants to the surface, also could contribute to this phenomenon. 54 refs., 54 figs., 12 tabs.
- Research Organization:
- Maine Univ., Orono (USA)
- DOE Contract Number:
- AC02-83CE40626
- OSTI ID:
- 6807560
- Report Number(s):
- DOE/CE/40626-T3; ON: DE88015384
- Resource Relation:
- Other Information: Thesis (Ph.D.). Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BLACK LIQUIDS
DENSITY
SURFACE TENSION
MEASURING METHODS
COMPARATIVE EVALUATIONS
PAPER INDUSTRY
TEMPERATURE DEPENDENCE
BUBBLES
CALCULATION METHODS
DIFFUSION
DROPLETS
EXTRAPOLATION
FLOW RATE
MOLECULAR WEIGHT
SURFACTANTS
FLUIDS
INDUSTRY
LIQUIDS
NUMERICAL SOLUTION
PARTICLES
PHYSICAL PROPERTIES
SURFACE PROPERTIES
WOOD PRODUCTS INDUSTRY
440300* - Miscellaneous Instruments- (-1989)