The Potential of Microwave Heating in Separating Water-in-Oil (w/o) Emulsions ScienceDirect Available online at www.sciencedirect.comAvailable online at www.sciencedirect.com ScienceDirect Energy Procedia 00 (2017) 000–000 www.elsevier.com/locate/procedia 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. The 15th International Symposium on District Heating and Cooling Assessing the feasibility of using the heat demand-outdoor temperature function for a long-term district heat demand forecast I. Andrića,b,c*, A. Pinaa, P. Ferrãoa, J. Fournierb., B. Lacarrièrec, O. Le Correc aIN+ Center for Innovation, Technology and Policy Research - Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal bVeolia Recherche & Innovation, 291 Avenue Dreyfous Daniel, 78520 Limay, France cDépartement Systèmes Énergétiques et Environnement - IMT Atlantique, 4 rue Alfred Kastler, 44300 Nantes, France Abstract District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the greenhouse gas emissions from the building sector. These systems require high investments which are returned through the heat sales. Due to the changed climate conditions and building renovation policies, heat demand in the future could decrease, prolonging the investment return period. The main scope of this paper is to assess the feasibility of using the heat demand – outdoor temperature function for heat demand forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 buildings that vary in both construction period and typology. Three weather scenarios (low, medium, high) and three district renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were compared with results from a dynamic heat demand model, previously developed and validated by the authors. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations. © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. Keywords: Heat demand; Forecast; Climate change Energy Procedia 138 (2017) 1023–1028 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the 2017 International Conference on Alternative Energy in Developing Countries and Emerging Economies. 10.1016/j.egypro.2017.10.123 10.1016/j.egypro.2017.10.123 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the 2017 International Conference on Alternative Energy in Developing Countries and Emerging Economies. Available online at www.sciencedirect.com ScienceDirect Energy Procedia 00 (2017) 000–000 www.elsevier.com/locate/procedia 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Organizing Committee of 2017 AEDCEE. 2017 International Conference on Alternative Energy in Developing Countries and Emerging Economies 2017 AEDCEE, 25‐26 May 2017, Bangkok, Thailand The Potential of Microwave Heating in Separating Water-in-Oil (w/o) Emulsions N.H. Abdurahmana ; R.M.Yunusa ; N.H. Azharib; N.Saida and Z. Hassana aFaculty of Chemical and Natural Resources Engineering, University Malaysia Pahang-UMP bFaculty of Pure and Applied Sciences International University of Africa, Khartoum, Sudan Abstract With the increasing energy crisis and the drive to reduce CO2 emissions, the mechanism of microwave heating is essentially that of dielectric heating. In this study, microwave demulsification method was investigated in a 50-50% and 20-80% water-in-oil emulsions with microwave exposure time varied from 20 seconds to 180 seconds. Transient temperature profiles of water-in-oil emulsions inside a cylindrical container were measured. The temperature rise at a given location was almost horizontal (linear). The rate of temperature increase of emulsions decreased at higher temperature due to decreasing dielectric loss of water. Results of this work shown that microwave radiation is a dielectric heating technique with the unique characteristic of penetration, fast, volumetric, and selective heating is appropriate and has the potential to be used as an alternative way in the demulsification process. Microwave demulsification of water-in-oil emulsions does not require chemical additions. © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Organizing Committee of 2017 AEDCEE. Keywords: Demulsification, temperature profile, w/o emulsion. Microwave heating, stability Corresponding email: nour2000_99@yahoo.com Available online at www.sciencedirect.com ScienceDirect Energy Procedia 00 (2017) 000–000 www.elsevier.com/locate/procedia 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Organizing Committee of 2017 AEDCEE. 2017 International Conference on Alternative Energy in Developing Countries and Emerging Economies 2017 AEDCEE, 25‐26 May 2017, Bangkok, Thailand The Potential of Microwave Heating in Separating Water-in-Oil (w/o) Emulsions N.H. Abdurahmana ; R.M.Yunusa ; N.H. Azharib; N.Saida and Z. Hassana aFaculty of Chemical and Natural Resources Engineering, University Malaysia Pahang-UMP bFaculty of Pure and Applied Sciences International University of Africa, Khartoum, Sudan Abstract With the increasing energy crisis and the drive to reduce CO2 emissions, the mechanism of microwave heating is essentially that of dielectric heating. In this study, microwave demulsification method was investigated in a 50-50% and 20-80% water-in-oil emulsions with microwave exposure time varied from 20 seconds to 180 seconds. Transient temperature profiles of water-in-oil emulsions inside a cylindrical container were measured. The temperature rise at a given location was almost horizontal (linear). The rate of temperature increase of emulsions decreased at higher temperature due to decreasing dielectric loss of water. Results of this work shown that microwave radiation is a dielectric heating technique with the unique characteristic of penetration, fast, volumetric, and selective heating is appropriate and has the potential to be used as an alternative way in the demulsification process. Microwave demulsification of water-in-oil emulsions does not require chemical additions. © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Organizing Committee of 2017 AEDCEE. Keywords: Demulsification, temperature profile, w/o emulsion. Microwave heating, stability Corresponding email: nour2000_99@yahoo.com http://crossmark.crossref.org/dialog/?doi=10.1016/j.egypro.2017.10.123&domain=pdf 1024 N.H. Abdurahman et al. / Energy Procedia 138 (2017) 1023–1028 2 Abdurahman.N.H et.al / Energy Procedia 00 (2017) 000–000 1. Introduction A problem in mature oil fields is the sizeable amount of water accompanying the produced crude oil. Water is also injected into the crude in course of steam treatment of producing wells or during de-salting operations. Petroleum emulsions readily form from water/oil mixtures in turbulent flows or due to pressure gradients in reservoir pores, in the chokes at the wellheads and in various valves in piping used for oil production. These emulsions can increase pumping and transportation costs, facilitate the corrosion of producing and processing equipment, and the poisoning of refinery catalysts [1-3]; [4]. [5], mentioned that the emulsifying agent separates the dispersed droplets from the continuous phase. Many industrial processes of demulsification have been employed in one application or the other including chemical and electromagnetic processes [6]; [7]; [8]; and [9]. The first application of microwave irradiation as an emulsion separation technique was by the pioneering works of [10] and [11]. Since then, there have been a significant number of research interests in this technique [12]; [13]; [14]; [15]; [16]; and [17]. The effects of inorganic salts and inorganic acids in microwave demulsification of water-oil emulsions were investigated by [18]. According to the authors, the separation efficiency as well as the demulsification rate are enhanced with increasing concentration of inorganic acids and also with the inorganic salt (NaCl, KCl, NaNO3, and Na2SO4) concentration in dilute range (<0.5 M). Using water-n-decane emulsion, [19] studied the role of asphaltenes and resins on the stability of emulsion during microwave demulsification process. [14] Depicted that the rate of temperature increase decreases the dielectric properties and volumetric heat generated. [16] Showed that emulsion stability was related to surfactant concentration, stirring time, temperature, the water-to-oil phase ratio and agitation speed. [17], performed comparative analyses of the demulsification of water-oil emulsion using microwave irradiation energy and conventional thermal heating by comparing the percentage of water separated, and droplets size distribution in each crude oil. The objective of the current research was to investigate the potential of microwave heating technology on the separation of 50-50% and 20-80% water-in-oil (w/o) emulsions. 2. Materials and Methods In this manuscript, Elba domestic microwave oven model: EMO 808SS, its rated power output is 900 watts and its operation frequency is 2450 MHz was modified and converted from batch process system into a continuous process and used as shown in Figure 1. Figure 1: Continuous microwave processes Microwave control panel Feed Tank Pump Data Loggers Thermocouples PC with PicoLog R508 software Glass coil tube Turntable Microwave Cavity Abdurahman.N.H et.al / Energy Procedia 00 (2017) 000–000 3 Three thermocouples type (K-IEC-584-3) were connected to Pico-TC-08 data loggers, and then the thermocouples connected to the settling tank. The data logger was connected to Pc; with Pico Log Rs.08.3 software. The thermocouples were inserted in the settling tank to different locations top, middle, and bottom of the emulsion sample to measure local temperatures. The rate of water separation in sedimentation depends on the settling velocity of water droplets in the emulsion. According to the force balance and Stoke’s law, the settling velocity of water droplets through the oil is given by: o ow w Dg v µ ρρ 18 *)( 2− = (1) Where: wv = settling velocity of water; =wρ Density of water; =oρ Density of oil; =oµ Viscosity of oil; g = gravity acceleration; D= diameter of droplets. From above equation (1), the viscosity of oil ( oµ ), is very sensitive to temperature. As temperature increases due to microwave radiation, viscosity decreases much faster than density difference )( ow ρρ − . Therefore, the heating, either by microwave or by conventional heat, increase the velocity of water, ( wv ), and makes the separation of water-in-oil emulsion faster. 2.1 Sample Preparation and Procedures A crude oil sample was collected from Malaka Refinery, Malaysia. At the laboratory, samples of 20-80% and 50-50 % water-in-oil emulsions were prepared using crude oil and tap water. Agent-in-oil method techniques followed for samples preparation. In this method, the emulsifying agent is dissolved in the oil phase. Then water has been added directly to the mixture and agitated vigorously with mixture for 10 minutes. The emulsifying agent used in this study is natural surfactant, NS-16-1 which is UMP product. The prepared samples were tested for w/o or o/w emulsions. All samples were w/o type. The glass container, containing 500 ml graduated beaker of emulsion sample was placed in the center of EMO 808SS microwave oven, and microwave radiation was applied at the highest power setting (900 watt). The radiation time varied from 1-10 minutes irradiation of microwave at 2450 MHz. After radiation, samples were taken out quickly from the oven and a calibrated glass thermometer was inserted in the sample in order to read the temperature at different locations. Table 1 shows experimental results of microwave heating. Table 1: Experimental Results of Microwave Heating Radiation Time t, sec Temperature Increase, dTCo Heating rate dT/dt, C/sec Volume rate of heat generation MWq cal/sec-cm3 Water: 60 12.5 0.208 0.248 90 35.5 0.395 0.394 120 51.5 0.429 0.443 150 69.5 0.463 0.475 180 73.5 0.408 0.481 210 73.5 0.350 0.388 240 73. 0.306 0.345 270 73.5 0.272 0.271 300 73.5 0.245 0.245 Crude Oil: 60 6.5 0.108 0.192 90 14.5 0.161 0.253 120 36.5 0.304 0.343 150 50.5 0.337 0.366 180 59.5 0.331 0.281 210 68.5 0.326 0.277 240 74.5 0.311 0.264 270 83.5 0.309 0.263 300 89.5 0.298 0.272 N.H. Abdurahman et al. / Energy Procedia 138 (2017) 1023–1028 1025 2 Abdurahman.N.H et.al / Energy Procedia 00 (2017) 000–000 1. Introduction A problem in mature oil fields is the sizeable amount of water accompanying the produced crude oil. Water is also injected into the crude in course of steam treatment of producing wells or during de-salting operations. Petroleum emulsions readily form from water/oil mixtures in turbulent flows or due to pressure gradients in reservoir pores, in the chokes at the wellheads and in various valves in piping used for oil production. These emulsions can increase pumping and transportation costs, facilitate the corrosion of producing and processing equipment, and the poisoning of refinery catalysts [1-3]; [4]. [5], mentioned that the emulsifying agent separates the dispersed droplets from the continuous phase. Many industrial processes of demulsification have been employed in one application or the other including chemical and electromagnetic processes [6]; [7]; [8]; and [9]. The first application of microwave irradiation as an emulsion separation technique was by the pioneering works of [10] and [11]. Since then, there have been a significant number of research interests in this technique [12]; [13]; [14]; [15]; [16]; and [17]. The effects of inorganic salts and inorganic acids in microwave demulsification of water-oil emulsions were investigated by [18]. According to the authors, the separation efficiency as well as the demulsification rate are enhanced with increasing concentration of inorganic acids and also with the inorganic salt (NaCl, KCl, NaNO3, and Na2SO4) concentration in dilute range (<0.5 M). Using water-n-decane emulsion, [19] studied the role of asphaltenes and resins on the stability of emulsion during microwave demulsification process. [14] Depicted that the rate of temperature increase decreases the dielectric properties and volumetric heat generated. [16] Showed that emulsion stability was related to surfactant concentration, stirring time, temperature, the water-to-oil phase ratio and agitation speed. [17], performed comparative analyses of the demulsification of water-oil emulsion using microwave irradiation energy and conventional thermal heating by comparing the percentage of water separated, and droplets size distribution in each crude oil. The objective of the current research was to investigate the potential of microwave heating technology on the separation of 50-50% and 20-80% water-in-oil (w/o) emulsions. 2. Materials and Methods In this manuscript, Elba domestic microwave oven model: EMO 808SS, its rated power output is 900 watts and its operation frequency is 2450 MHz was modified and converted from batch process system into a continuous process and used as shown in Figure 1. Figure 1: Continuous microwave processes Microwave control panel Feed Tank Pump Data Loggers Thermocouples PC with PicoLog R508 software Glass coil tube Turntable Microwave Cavity Abdurahman.N.H et.al / Energy Procedia 00 (2017) 000–000 3 Three thermocouples type (K-IEC-584-3) were connected to Pico-TC-08 data loggers, and then the thermocouples connected to the settling tank. The data logger was connected to Pc; with Pico Log Rs.08.3 software. The thermocouples were inserted in the settling tank to different locations top, middle, and bottom of the emulsion sample to measure local temperatures. The rate of water separation in sedimentation depends on the settling velocity of water droplets in the emulsion. According to the force balance and Stoke’s law, the settling velocity of water droplets through the oil is given by: o ow w Dg v µ ρρ 18 *)( 2− = (1) Where: wv = settling velocity of water; =wρ Density of water; =oρ Density of oil; =oµ Viscosity of oil; g = gravity acceleration; D= diameter of droplets. From above equation (1), the viscosity of oil ( oµ ), is very sensitive to temperature. As temperature increases due to microwave radiation, viscosity decreases much faster than density difference )( ow ρρ − . Therefore, the heating, either by microwave or by conventional heat, increase the velocity of water, ( wv ), and makes the separation of water-in-oil emulsion faster. 2.1 Sample Preparation and Procedures A crude oil sample was collected from Malaka Refinery, Malaysia. At the laboratory, samples of 20-80% and 50-50 % water-in-oil emulsions were prepared using crude oil and tap water. Agent-in-oil method techniques followed for samples preparation. In this method, the emulsifying agent is dissolved in the oil phase. Then water has been added directly to the mixture and agitated vigorously with mixture for 10 minutes. The emulsifying agent used in this study is natural surfactant, NS-16-1 which is UMP product. The prepared samples were tested for w/o or o/w emulsions. All samples were w/o type. The glass container, containing 500 ml graduated beaker of emulsion sample was placed in the center of EMO 808SS microwave oven, and microwave radiation was applied at the highest power setting (900 watt). The radiation time varied from 1-10 minutes irradiation of microwave at 2450 MHz. After radiation, samples were taken out quickly from the oven and a calibrated glass thermometer was inserted in the sample in order to read the temperature at different locations. Table 1 shows experimental results of microwave heating. Table 1: Experimental Results of Microwave Heating Radiation Time t, sec Temperature Increase, dTCo Heating rate dT/dt, C/sec Volume rate of heat generation MWq cal/sec-cm3 Water: 60 12.5 0.208 0.248 90 35.5 0.395 0.394 120 51.5 0.429 0.443 150 69.5 0.463 0.475 180 73.5 0.408 0.481 210 73.5 0.350 0.388 240 73. 0.306 0.345 270 73.5 0.272 0.271 300 73.5 0.245 0.245 Crude Oil: 60 6.5 0.108 0.192 90 14.5 0.161 0.253 120 36.5 0.304 0.343 150 50.5 0.337 0.366 180 59.5 0.331 0.281 210 68.5 0.326 0.277 240 74.5 0.311 0.264 270 83.5 0.309 0.263 300 89.5 0.298 0.272 1026 N.H. Abdurahman et al. / Energy Procedia 138 (2017) 1023–1028 4 Abdurahman.N.H et.al / Energy Procedia 00 (2017) 000–000 Table 2 depicts experimental results of microwave heating. Table 2: Experimental Results of Microwave Heating Radiation Time t, sec Temperature increased dT, Co Heating rate dT/dt, C/sec Volume of heat generation MWq cal/sec-cm3 50-50% w/o emulsion 60 24.5 0.408 0.246 90 50.5 0.561 0.338 120 69.5 0.579 0.349 150 81.5 0.543 0.327 180 85.5 0.475 0.286 210 97.5 0.464 0.280 240 105.5 0.440 0.265 270 109.5 0.406 0.245 300 114.5 0.382 0.230 20-80% w/o emulsion 60 29.5 0.492 0.301 90 54.5 0.606 0.373 120 77.5 0.646 0.402 150 89.5 0.597 0.387 180 94.5 0.525 0.392 210 108.5 0.517 0.386 240 114.5 0.477 0.381 270 122.5 0.454 0.374 300 127.5 0.425 0.364 3. Results and Discussion The average temperature increasing rates for emulsion ratios of 50-50%, and 20-80% of water-in-oil emulsions were 0.473, and 0.527 respectively. It is observed that the rates of heating decreases with temperature increases, this might attributed due to decreasing of dielectric loss of water [14; 16; 17], Figure 2 shows the phenomena, while Figure 3 depicted the volume rates of heat generation versus the radiation time, it is clearly that the volume rates of heat generation increases in early stages of the microwave radiation, then it states decreases at microwave exposure time increases [18]. 50 100 150 200 250 300 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Radiation time [t,sec] H ea tin g ra te [d T/ dt , C /s ec ] Water crude oil 50-50% w/o 20-80% w/o Figure 2: Heating rates vs. Radiation time Abdurahman.N.H et.al / Energy Procedia 00 (2017) 000–000 5 50 100 150 200 250 300 0.2 0.25 0.3 0.35 0.4 0.45 0.5 Radiation time, [t sec] V ol um e ra te , Q [c al /s ec .c m 3] 20-80% w/o Crude oil Water 50-50% w/o Figure 3: Volume rate of heat generation vs. Radiation time Figures 4 and 5 have shown the separation of water from 50-50 % and 20-80 % water-in-oil emulsions respectively. All experimental tests have shown that microwave radiation is very effective in separation of water-in-oil emulsions, [14; 17]. Results of Figures 4 and 5 illustrate that microwave radiation can raise the temperature of emulsion, reduce viscosity and make separation is faster, as suggested by equation (1). Figure 4: Separation of water from 50-50 % water-in-oil emulsion Figure 5: Separation of water from 20-80 % water-in-oil emulsion N.H. Abdurahman et al. / Energy Procedia 138 (2017) 1023–1028 1027 4 Abdurahman.N.H et.al / Energy Procedia 00 (2017) 000–000 Table 2 depicts experimental results of microwave heating. Table 2: Experimental Results of Microwave Heating Radiation Time t, sec Temperature increased dT, Co Heating rate dT/dt, C/sec Volume of heat generation MWq cal/sec-cm3 50-50% w/o emulsion 60 24.5 0.408 0.246 90 50.5 0.561 0.338 120 69.5 0.579 0.349 150 81.5 0.543 0.327 180 85.5 0.475 0.286 210 97.5 0.464 0.280 240 105.5 0.440 0.265 270 109.5 0.406 0.245 300 114.5 0.382 0.230 20-80% w/o emulsion 60 29.5 0.492 0.301 90 54.5 0.606 0.373 120 77.5 0.646 0.402 150 89.5 0.597 0.387 180 94.5 0.525 0.392 210 108.5 0.517 0.386 240 114.5 0.477 0.381 270 122.5 0.454 0.374 300 127.5 0.425 0.364 3. Results and Discussion The average temperature increasing rates for emulsion ratios of 50-50%, and 20-80% of water-in-oil emulsions were 0.473, and 0.527 respectively. It is observed that the rates of heating decreases with temperature increases, this might attributed due to decreasing of dielectric loss of water [14; 16; 17], Figure 2 shows the phenomena, while Figure 3 depicted the volume rates of heat generation versus the radiation time, it is clearly that the volume rates of heat generation increases in early stages of the microwave radiation, then it states decreases at microwave exposure time increases [18]. 50 100 150 200 250 300 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Radiation time [t,sec] H ea tin g ra te [d T/ dt , C /s ec ] Water crude oil 50-50% w/o 20-80% w/o Figure 2: Heating rates vs. Radiation time Abdurahman.N.H et.al / Energy Procedia 00 (2017) 000–000 5 50 100 150 200 250 300 0.2 0.25 0.3 0.35 0.4 0.45 0.5 Radiation time, [t sec] V ol um e ra te , Q [c al /s ec .c m 3] 20-80% w/o Crude oil Water 50-50% w/o Figure 3: Volume rate of heat generation vs. Radiation time Figures 4 and 5 have shown the separation of water from 50-50 % and 20-80 % water-in-oil emulsions respectively. All experimental tests have shown that microwave radiation is very effective in separation of water-in-oil emulsions, [14; 17]. Results of Figures 4 and 5 illustrate that microwave radiation can raise the temperature of emulsion, reduce viscosity and make separation is faster, as suggested by equation (1). Figure 4: Separation of water from 50-50 % water-in-oil emulsion Figure 5: Separation of water from 20-80 % water-in-oil emulsion 1028 N.H. Abdurahman et al. / Energy Procedia 138 (2017) 1023–1028 6 Abdurahman.N.H et.al / Energy Procedia 00 (2017) 000–000 Conclusions Based on results of this manuscript, it can be concluded that microwave heating technology has been successfully applied for demulsification of 50-50% and 20-80% water-in-oil emulsions. Microwave radiation is very effective in separation of water-in-oil emulsions, in this regards the average temperature increasing rates for emulsion ratios of 50-50%, and 20-80% of water-in-oil emulsions were 0.473, and 0.527 respectively. The results obtained in this study have exposed the capability of microwave heating technology in demulsification of water –in-crude oil emulsion. Further works are nevertheless required to provide deeper understanding of the mechanisms involved to facilitate the development of an optimum system applicable to the industry. References [1] Sjoblom, J., Ming Yuan, L., Hoiland, H and Johansen, J.E. Water-in-Crude Oil Emulsions from the Norwegian Continental Shelf, Part III. A Comparative Destabilization of Model Systems. Surfaces. 46, (1990) 127-139. [2] Sjoblom, J., Mingyuan, L., Christy, A.A and Gu, T. Water-in-Crude Oil Emulsions stability. Colloids and Interfaces. (1992), 66: 55-62. [3] Sjoblom, J., Mingyuan, L., Christy, A.A and Ronningsen, H.P. Water-in-Crude Oil Emulsions from the Norwegian Continental Shelf,10. Ageing of the Interfacially Active Compounds and the Influence of the stability. Colloid and Surf.A, (1995), 96: 261-272. [4] Schramm, L. L. Petroleum Emulsion. In.: Schramm, L.L. Emulsions Fundamentals and Applications in the Petroleum Industry, 1-45. American Chemical Society, Washington DC. 1992. [5] Kenneth J. Lissant, "Emulsification and De-emulsification, A Historical Overview", Colloids and surfaces, 29, (1998). [6] Chen, G., He, G. Separation of water and oil from water-in-oil emulsion by freeze/thaw method. Sep. Purif. Technol. 31, (2003) 83-89. [7] Rajakovic, V., Skala, D. Separation of water-in-oil emulsions by freeze/thaw method and microwave radiation. Sep. Purif. Technol. 49, (2006) 192-196. [8] Selvarajan R., Anantha subramaniam S., and Robert A. M. "Aqueous Dispersion of an Oil Soluble Demulsifier for Breaking Crude Oil Emulsions", (US Patent No. 6,294,093), (2001). [9] Eow, J. S., Ghadiri, M., Sharif, A. O., Williams, T. J. Electrostatic enhancement of coalescence of water droplets in oil: a review of the current understanding. Chemical Engineering Journal 84 (3), (2001) 173–192. [10] Klaila, W. J. Method and apparatus for controlling fluency of high viscosity hydrocarbon fluids. US Patent 4,067,683, January 10, 1978. [11] Wolf, N. O. Use of microwave radiation in separating emulsion and dispersion of hydrocarbons and water. US Patent 4,582,629, April 15, 1986. [12] Fang, C. S., Lai, P. M. C. Microwave heating and separation of water-in-oil emulsion. J. Microw. Power Electromagn. Energy, 30 (1), (1995) 46-57. [13] Fortuny, M., Oliveira, C. B. Z., Melo, R. L. F. V., Nele, M., Coutinho, R. C. C., Santo, A. F. Effect of salinity, temperature, water content, and pH on the microwave demulsification of crude oil emulsion. Energy & Fuels 21, (2007) 1358-1364. [14] Anisa, A.N.I., Nour, A.H. “Emulsion Separation Rate Enhancement via Microwave Heating Tech”., National Conference on Postgraduate Research (NCON-PGR), UMP Conference Hall, Malaysia. 2009. [15] Huda, S.N., Nour, A.H. Microwave Separation of Water-In-Crude Oil Emulsions, International Journal of Chemical and Environmental Engineering, 2,(1), (2011) Page 36-41. [16] Abdulbari, H.A., Abdurahman, N.H., Rosli1, Y.M., Mahmood, W.K., Azhari, H.N. Demulsification of petroleum emulsions using microwave separation method, International Journal of the Physical Sciences Vol. 6(23), (2011) 5376- 5382. [17] Nour, A.H., Anisa, A.N.I., Nour, A.H. Demulsification of water-in-oil (W/O) emulsion via microwave irradiation: An optimization, Scientific Research and Essays Vol. 7(2), (2012) 231-243. [18] Chan, C. C., Chen, Y. C. Demulsification of W/O emulsions by microwave radiation. Sep. Sci. Technol. 37 (15), (2002) 3407-3420. [19] Xia, L. X., Lu, S. W., Cao, G. Y., 2004. Salt-assisted microwave demulsification. Chem. Eng. Commun. 191, 1053-1063.