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Comment on “Evaluation of the Performance of Newly Developed Demulsifiers on Dilbit Dehydration, Demineralization, and Hydrocarbon Losses to Tailings” Indervir Shukla Karachi 75600, Pakistan
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the third paragraph of Section 3.2 of their paper1 that the composition of the solids was examined by using XRD analysis and was summarized in Figure 7. This statement clearly suggested that the complete XRD data are shown in Figure 7, which is not true. Moreover, readers reading this paper do not know how many components exist in the solids and what the effects of demulsifier application on their removal are. (3) The silicon contents of the bottom fraction solids extracted from the control, demulsifier X, and demulsifier Y treated bitumen froth shown in Figure 8(C) in their paper1 are 35%, 34%, and 33%, respectively. The silicon contents of these solids are very high. Since the authors deleted quartz from the solids composition in Figure 7, the results in Figure 8 cannot be justified by the results in Figure 7. (4) The particle size distribution in Figure 11 in their paper1 shows that there are more large particles remaining at the interface after froth treatment with demulsifier X or demulsifier Y, compared to no demulsifier application in the same settling time. For example, the interface after treatment with demulsifier X or demulsifier Y has 4 times of 16 μm and 7 times of 32 μm particles, as compared to the control (without demulsifier application). The results in Figure 11 clearly demonstrated that the demulsifier application hindered the settling of large particles from the interface. Therefore, these demulsifiers are not effective in demineralization. Moreover, the authors were unable to explain the sources of the large particles in Figure 11 because they deleted quartz (known as coarse particles) and other components from the solids composition in Figure 7. (5) Since the particle densities are similar, regardless of particle size, larger particles have greater mass, because they have larger volume, based on simple math. If the solids collected after demulsifier treatment have fewer smaller particles and much more large particles, as shown in Figure 11, then the mass of the solids after treatment by a demulsifier should be greater than that of the untreated solids from the control. Clearly, the results in Figure 11 contradict the results in Figure 6, which shows that the control has more solids at the interface. (6) In the Conclusion section of their paper,1 the authors claimed that demulsifier Y helps to resolve the interfacial materials by removing the minerals that have a tendency to form a rag layer. In fact, Figure 11 shows that the application of demulsifier Y led to an accumulation of large particles at the interface. Any mineral components remaining at the interface, regardless of particle size, will help form a rag layer with unresolved emulsion. An effective demulsifier can remove both
here are several issues related to the data and conclusions in the paper by Ishpinder Kailey and Jacqueline Behles, titled “Evaluation of the Performance of Newly Developed Demulsifiers on Dilbit Dehydration, Demineralization, and Hydrocarbon Losses to Tailings”.1 (1) Many publications have shown that quartz (SiO2) is the main component in the Athabasca oil sands in Alberta, Canada. X-ray diffraction (XRD) studies indicate that quartz is the main component in the solids contained in bitumen froth, which is generated from the bitumen extraction process. The authors used the bitumen froth from the Athabasca region in this work. However, their XRD data in Figure 7 of their paper1 showed no existence of quartz in the solids extracted from the dilbit, the dilbit/water interface, and the settled tailings. Since quartz is the primary component in the solids contained in the bitumen froth, it must be either in the dilbit, the dilbit/water interface, the tailings, or in all three fractions after froth treatment. Apparently, the authors deleted this important component from the XRD data. Since one of the core focuses of the paper is the performance of the demulsifiers on demineralization, the performance of the demulsifiers with regard to removing quartz, the main component from bitumen froth, should be seriously considered. On the other hand, the elemental analysis and particle size distribution studies used the same solids as the XRD analysis. Since there is no way to remove quartz and other components from the elemental analysis and particle size distribution results, removal of any components from the XRD data will make the results from the elemental analysis and particle size distribution studies inconsistent with the XRD data. It is also inappropriate to delete components from XRD data without any statement and justification in the paper. (2) It is also well-known that XRD measures the crystalline components in powder solids. The amount of each component in the solids is expressed as a percentage and the sum of the components is 100%. Any comparison between components is based on this foundationthat is, the total must be 100%. In Figure 7(A) of their paper, for the top fraction solids, the sums of all components in the solids from the control, demulsifier X, and demulsifier Y treated bitumen froth are ∼76%, ∼71%, and ∼69%, respectively. In Figure 7(B), for the interface fraction solids, the sums of all components in the solids from the control, demulsifier X, and demulsifier Y treated bitumen froth are ∼72%, ∼62%, and ∼51%, respectively. In Figure 7(C),1 for the bottom fraction solids, the sums of all components in the solids from the control, demulsifier X, and demulsifier Y treated bitumen froth are ∼30%, ∼34%, and ∼39%, respectively. Clearly, the sums are not 100% and are far below 100%. Hence, the authors made comparisons between the solids components based on incomplete XRD data. However, the authors stated in © XXXX American Chemical Society
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DOI: 10.1021/acs.iecr.7b04597 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Industrial & Engineering Chemistry Research
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small and large particles from the interface. The results in Figure 11 do not support the authors’ conclusion. (7) Also in the Conclusion section of their paper,1 the authors stated that 70.8% of the magnetite was removed with the application of a demulsifier. Magnetite was also mentioned in the Abstract. However, magnetite did not exist in the solids composition shown in Figure 7, and no magnetite data was shown anywhere in the paper. As a reader, I cannot understand how the authors made the conclusion that 70.8% of the magnetite was removed, because it does not exist in the paper. In summary, this paper has many issues, with regard to data collection, data analysis, and the conclusion.
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AUTHOR INFORMATION
Notes
The author declares no competing financial interest.
REFERENCES
(1) Kailey, I.; Behles, J. Evaluation of the Performance of Newly Developed Demulsifiers on Dilbit Dehydration, Demineralization, and Hydrocarbon Losses to Tailings. Ind. Eng. Chem. Res. 2015, 54 (17), 4839−4850.
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DOI: 10.1021/acs.iecr.7b04597 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
