Performance Evaluation of Fly Ash as a Potential Demulsifier for Water-in-Crude-Oil Emulsion Stabilized by Asphaltenes
- Ahmad A Adewunmi (King Fahd University of Petroleum and Minerals) | Muhammad Shahzad Kamal (King Fahd University of Petroleum and Minerals)
- Document ID
- Society of Petroleum Engineers
- SPE Production & Operations
- Publication Date
- November 2019
- Document Type
- Journal Paper
- 820 - 829
- 2019.Society of Petroleum Engineers
- chemical demulsifier, interfacial rheology, fly ash
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- 112 since 2007
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The quest for smart and cost-effective demulsification materials to separate water-in-crude-oil (W/O) emulsions is ongoing in the petroleum industry. We conducted an assessment study on the potency of coal fly ash (CFA) as a demulsifier for W/O emulsions. To our knowledge, this is the first study reporting CFA as a demulsifier for highly stable W/O emulsions. Samples of W/O emulsions were prepared without using any conventional emulsifier. Asphaltenes in the crude oil acted as an emulsifier, and stable emulsions were produced. Six W/O-emulsion samples of the same crude-oil/water volume ratio (4:6) were formulated. A reference sample was selected for comparison during demulsification. Demulsification tests were performed at room temperature (25°C). Demulsification results obtained using bottle tests showed that the reference sample (blank) without CFA remained stable without water separation after 48 hours, while the addition of various CFA quantities (1 to 7%) brought about the separation of water from the oil phase. Separation of water was observed to have increased with increasing CFA addition in the emulsion. Water separation continued for each sample until approximately 24 hours, when equilibrium was attained and water separation remained constant. The W/O emulsion containing 7% CFA displayed the highest performance with demulsification efficiency (DE) of 96.67%. Demulsification-comparison test results between CFA and a commercial demulsifier (poloxamer 407) using the same concentration and under room temperature showed that CFA was capable of separating water better than this commercial demulsifier. This observation indicates that CFA can compete favorably with many commercial demulsifiers available in the market. In addition, the outcome of DE of 7% CFA at elevated temperatures (i.e., 60 and 80°C) was approximately 98%. More importantly, the separated water at these elevated temperatures was clearer and contained fewer oil floccules than the separated water phase observed during demulsification tests conducted under room-temperature (25°C) conditions. Shear-rheology measurement reveals that adding CFA altered the viscoelastic characteristics at the crude-oil/water interface at an aging time of 10 hours and 55 minutes. The viscous modulus remained stagnant, whereas the elastic modulus dropped significantly. Interfacial-tension (IFT) results show that CFA particles often tend to diminish the interfacial films existing between crude oil and water. Optical morphology revealed the phase transformation in the as-prepared W/O emulsion before and after the addition of CFA particles. We propose a possible mechanism governing the demulsification of W/O emulsion driven by CFA particles. We believe that this work will be relevant to petroleum-exploration/refining operations.
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Acevedo, S., Escobar, G., Gutiérrez, L. B. et al. 1993. Interfacial Rheological Studies of Extra-Heavy Crude Oils and Asphaltenes: Role of the Dispersion Effect of Resins in the Adsorption of Asphaltenes at the Interface of Water-in-Crude Oil Emulsions. Colloids Surf A Physicochem Eng Asp 71 (1): 65–71. https://doi.org/10.1016/0927-7757(93)80028-D.
Ali, N., Zhang, B., Zhang, H. et al. 2015. Interfacially Active and Magnetically Responsive Composite Nanoparticles With Raspberry Like Structure; Synthesis and its Applications for Heavy Crude Oil/Water Separation. Colloids Surf A Physicochem Eng Asp 472 (5 May): 38–49. https://doi.org/10.1016/j.colsurfa.2015.01.087.
Alsabagh, A. M., Hassan, M. E., Desouky, S. E. M. et al. 2016. Demulsification of W/O Emulsion at Petroleum Field and Reservoir Conditions Using Some Demulsifiers Based on Polyethylene and Propylene Oxides. Egypt J Petrol 25 (4): 585–595. https://doi.org/10.1016/j.ejpe.2016.05.008.
Balsamo, M., Erto, A., and Lancia, A. 2017. Chemical Demulsification of Model Water-in-Oil Emulsions With Low Water Content by Means of Ionic Liquids. Braz. J. Chem. Eng. 34 (1): 273–282. https://doi.org/10.1590/0104-6632.20170341s20150583.
Binner, E. R., Robinson, J. P., Silvester, S. A. et al. 2014. Investigation Into the Mechanisms by Which Microwave Heating Enhances Separation of Water-in-Oil Emulsions. Fuel 116 (15 January): 516–521. https://doi.org/10.1016/j.fuel.2013.08.042.
Carneiro, G. F., Silva, R. C., Barbosa, L. L. et al. 2015. Characterisation and Selection of Demulsifiers for Water-in-Crude Oil Emulsions Using Low-Field 1H NMR and ESI-FT-ICR MS. Fuel 140 (15 January): 762–769. https://doi.org/10.1016/j.fuel.2014.10.020.
Chen, Y., Liu, N., Cao, Y. et al. 2016. Fabrication of Silica Nanospheres Coated Membranes: Towards the Effective Separation of Oil-in-Water Emulsion in Extremely Acidic and Concentrated Salty Environments. Sci Rep 6: 32540. https://doi.org/10.1038/srep32540.
Chen, Z., Zhang, L., Zhao, S. et al. 2015. Molecular Structure and Association Behavior of Petroleum Asphaltene. In Structure and Modeling of Complex Petroleum Mixtures, ed. C. Xu and Q. Shi, 1–38. Basel, Switzerland: Structure and Bonding Series, Springer Nature.
Dickinson, E. 2001. Milk Protein Interfacial Layers and the Relationship to Emulsion Stability and Rheology. Colloids Surf B Biointerfaces 20 (3): 197–210. https://doi.org/10.1016/S0927-7765(00)00204-6.
Dudásová, D., Simon, S., Hemmingsen, P. V. et al. 2008. Study of Asphaltenes Adsorption Onto Different Minerals and Clays: Part 1. Experimental Adsorption With UV Depletion Detection. Colloids Surf A Physicochem Eng Asp 317 (1–3): 1–9. https://doi.org/10.1016/j.colsurfa.2007.09.023.
El Gamal, M., Mohamed, A.-M. O., and Zekri, A. Y. 2005. Effect of Asphaltene, Carbonate, and Clay Mineral Contents on Water Cut Determination in Water-Oil Emulsions. J Pet Sci Eng 46 (3): 209–224. https://doi.org/10.1016/J.PETROL.2004.11.002.
Fang, S., Chen, T., Chen, B. et al. 2016a. Graphene Oxide at Oil-Water Interfaces: Adsorption, Assembly & Demulsification. Colloids Surf A Physico-chem Eng Asp 511 (20 December): 47–54. https://doi.org/10.1016/j.colsurfa.2016.09.058.
Fang, S., Chen, T., Wang, R. et al. 2016b. Assembly of Graphene Oxide at the Crude Oil/Water Interface: A New Approach to Efficient Demulsification. Energy Fuels 30 (4): 3355–3364. https://doi.org/10.1021/acs.energyfuels.6b00195.
Feng, X. and Behles, J. A. 2015. Understanding the Demulsification of Water-in-Diluted Bitumen Froth Emulsions. Energy Fuels 29 (7): 4616–4623. https://doi.org/10.1021/acs.energyfuels.5b00798.
Hajivand, P. and Vaziri, A. 2015. Optimization of Demulsifier Formulation for Separation of Water From Crude Oil Emulsions. Braz. J. Chem. Eng. 32 (1): 107–118. https://doi.org/10.1590/0104-6632.20150321s00002755.
Hippmann, S., Ahmed, S. S., Fröhlich, P. et al. 2018. Demulsification of Water/Crude Oil Emulsion Using Natural Rock Alginite. Colloids Surf A Physicochem Eng Asp 553 (20 September): 71–79. https://doi.org/10.1016/j.colsurfa.2018.05.031.
Huang, X., Xiong, Y., Yin, W. et al. 2016. Demulsification of a New Magnetically Responsive Bacterial Demulsifier for Water-in-Oil Emulsions. Energy Fuels 30 (6): 5190–5197. https://doi.org/10.1021/acs.energyfuels.6b00687.
Liang, J., Du, N., Song, S. et al. 2015. Magnetic Demulsification of Diluted Crude Oil-in-Water Nanoemulsions Using Oleic Acid-Coated Magnetite Nanoparticles. Colloids Surf A Physicochem Eng Asp 466 (5 February): 197–202. https://doi.org/10.1016/j.colsurfa.2014.11.050.
Liang, J., Li, H., Yan, J. et al. 2014. Demulsification of Oleic-Acid-Coated Magnetite Nanoparticles for Cyclohexane-in-Water Nanoemulsions. Energy Fuels 28 (9): 6172–6178. https://doi.org/10.1021/ef501169m.
Liu, J., Li, X., Jia, W. et al. 2015. Demulsification of Crude Oil-in-Water Emulsions Driven by Graphene Oxide Nanosheets. Energy Fuels 29 (7): 4644–4653. https://doi.org/10.1021/acs.energyfuels.5b00966.
Lü, T., Chen, Y., Qi, D. et al. 2017. Treatment of Emulsified Oil Wastewaters by Using Chitosan Grafted Magnetic Nanoparticles. J Alloys Compd 696 (5 March): 1205–1212. https://doi.org/10.1016/j.jallcom.2016.12.118.
Lü, T., Zhang, S., Qi, D. et al. 2016. Thermosensitive Poly (N-Isopropylacrylamide)-Grafted Magnetic Nanoparticles for Efficient Treatment of Emulsified Oily Wastewater. J Alloys Compd 688B (15 December): 513–520. https://doi.org/10.1016/j.jallcom.2016.07.262.
Martínez-Palou, R., Cerón-Camacho, R., Chávez, B. et al. 2013. Demulsification of Heavy Crude Oil-in-Water Emulsions: A Comparative Study Between Microwave and Thermal Heating. Fuel 113 (November): 407–414. https://doi.org/10.1016/j.fuel.2013.05.094.
McLean, J. D. and Kilpatrick, P. K. 1997. Effects of Asphaltene Solvency on Stability of Water-in-Crude-Oil Emulsions. J Colloid Interface Sci 189 (2): 242–253. https://doi.org/10.1006/jcis.1997.4807.
Nikkhah, M., Tohidian, T., Rahimpour, M. R. et al. 2015. Efficient Demulsification of Water-in-Oil Emulsion by a Novel Nano-Titania Modified Chemical Demulsifier. Chem. Eng. Res. Des. 94 (February): 164–172. https://doi.org/10.1016/j.cherd.2014.07.021.
Pensini, E., Harbottle, D., Yang, F. et al. 2014. Demulsification Mechanism of Asphaltene-Stabilized Water-in-Oil Emulsions by a Polymeric Ethylene Oxide-Propylene Oxide Demulsifier. Energy Fuels 28 (11): 6760–6771. https://doi.org/10.1021/ef501387k.
Razi, M., Rahimpour, M. R., Jahanmiri, A. et al. 2011. Effect of a Different Formulation of Demulsifiers on the Efficiency of Chemical Demulsification of Heavy Crude Oil. J. Chem. Eng. Data 56 (6): 2936–2945. https://doi.org/10.1021/je2001733.
Shehzad, F., Hussein, I. A., Kamal, M. S. et al. 2017. Polymeric Surfactants and Emerging Alternatives Used in the Demulsification of Produced Water: A Review. Polym Rev 58 (1): 63–101. https://doi.org/10.1080/15583724.2017.1340308.
Silva, E. B., Santos, D., Alves, D. R. M. et al. 2013. Demulsification of Heavy Crude Oil Emulsions Using Ionic Liquids. Energy Fuels 27 (10): 6311–6315. https://doi.org/10.1021/ef302008d.
Soorghali, F., Zolghadr, A., and Ayatollahi, S. 2014. Effect of Resins on Asphaltene Deposition and the Changes of Surface Properties at Different Pressures: A Microstructure Study. Energy Fuels 28 (4): 2415–2421. https://doi.org/10.1021/ef500020n.
Spiecker, P. M., Gawrys, K. L., Trail, C. B. et al. 2003. Effects of Petroleum Resins on Asphaltene Aggregation and Water-in-Oil Emulsion Formation. Colloids Surf A Physicochem Eng Asp 220 (1–3): 9–27. https://doi.org/10.1016/S0927-7757(03)00079-7.
Subramanian, S., Simon, S., Gao, B. et al. 2016. Asphaltene Fractionation Based on Adsorption Onto Calcium Carbonate: Part 1. Characterization of Sub-Fractions and QCM-D Measurements. Colloids Surf A Physicochem Eng Asp 495 (20 April): 136–148. https://doi.org/10.1016/J.COLSURFA.2016.02.011.
Tao, J., Shi, P., Fang, S. et al. 2015. Effect of Rheology Properties of Oil/Water Interface on Demulsification of Crude Oil Emulsions. Ind. Eng. Chem. Res. 54 (17): 4851–4860. https://doi.org/10.1021/acs.iecr.5b00639.
Yang, X., Tan, W., and Bu, Y. 2009. Demulsification of Asphaltenes and Resins Stabilized Emulsions via the Freeze/Thaw Method. Energy Fuels 23 (1): 481–486. https://doi.org/10.1021/ef800600v.
Zaki, N. N., Carbonell, R. G., and Kilpatrick, P. K. 2003. A Novel Process for Demulsification of Water-in-Crude Oil Emulsions by Dense Carbon Dioxide. Ind. Eng. Chem. Res. 42 (25): 6661–6672. https://doi.org/10.1021/ie0303597.
Zhang, S., Lü, T., Qi, D. et al. 2017. Synthesis of Quaternized Chitosan-Coated Magnetic Nanoparticles for Oil-Water Separation. Mater Lett 191 (15 March): 128–131. https://doi.org/10.1016/j.matlet.2016.12.092.
Zhou, J. E., Chang, Q., Wang, Y. et al. 2010. Separation of Stable Oil-Water Emulsion by the Hydrophilic Nano-Sized ZrO2 Modified Al2O3 Microfiltration Membrane. Sep Purif Technol 75 (3): 243–248. https://doi.org/10.1016/j.seppur.2010.08.008.