Upgrading and Viscosity Reduction of Heavy Oil by Catalytic Ionic

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Upgrading and viscosity reduction of heavy oil By Catalytic ionic liquid Seham Ali Shaban, Saad Desouky, Abd El Fattah M. Badawi, Ahmed El sabagh, Ahmed Abd R. Zahran, and Mahmoud A. Mousa Energy Fuels, Just Accepted Manuscript • DOI: 10.1021/ef500993d • Publication Date (Web): 04 Sep 2014 Downloaded from http://pubs.acs.org on September 5, 2014

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Upgrading and viscosity reduction of heavy oil By Catalytic ionic liquid Seham Shaban*, Saad Desouky, Abd El Fatah Badawi, Ahmed El sabagh, Ahmed Zahran Egyptian Petroleum Research Institute Nasr,1 Ahmed El Zomour St., Nasr city, P.O. Box 11727, Cairo, Egypt.

Mahmoud Mousa Chemistry Department, Faculty of Science, Banha University

* To whom correspondence should be addressed. Telephone (002) 0222736349, Fax: (002) 02- 22747433 E-mail address: [email protected] Seham Shaban ABSTRACT A new class of catalytic ionic liquids, containing Imidazolium chloride [BMIM][Cl] and its modified imidazolium tetracholoferrate [BMIM][FeCl4] based ionic liquid were systematically investigated. The modified ionic liquid

imidazolium tetrachloroferrate [BMIM][FeCl4] used to upgrade heavy crude oils. The effect of reaction temperature and the amount of water on upgrading heavy crude oils were studied. The reduction of viscosity by [BMIM][ FeCl4] is remarkable when the amount of water in heavy crude oils is less than 8%. It is found that [BMIM][FeCl4] based ionic liquids has the best effect on the heavy

crude oil upgrade at optimum temperature between 70–90oC. Results showed that the viscosity reduction rise from 26.8 to 78.6 % by treating the heavy crude oil with [BMIM][FeCl4] (at 90oC), also, the sulfur reduction rise to 20%. The ionic liquid and modified (imidazolium chloride and imidazolium

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tetrachloroferrate) were studied by physicochemical methods and catalytic activity measurements in upgrading of heavy oils. Keywords: upgrading heavy oil; ionic liquid; catalysis; viscosity reduction. 1. INTRODUCTION The world’s population aspires to a better quality of life, global energy consumption and the demand for transportation fuels can only be projected to increase for the foreseeable future. Crude oil is also very difficult to flow due to high viscosity and density, which make the production of heavy crude oil a difficult and energy-intensive task. In the coming few years' conventional oil production is decline irreversibly, for more essential needs future energy increasingly making unconventional oil. Presently, heavy oil reserves have a large portion of unconventional resources (coalbed methane, tight gas and hydrates). In the past decade has increased the production of heavy oil due to the need of the market demand. Therefore, many researchers are studying the reduc viscosity investigate and improve the transport properties of heavy crude oil more efficiently from upstream to downstream or from field to another, so they use several techniques in this process such as thermal recovery and thermal catalytic recovery1. Steam flooding is one means of introducing heat to the reservoir, heating are broken down asphaltene molecules to small molecules. Thermal methods of recovery reduce the viscosity of the crude oil by heat so that it flows more easily into the production well. Using Catalyst, the 2 ACS Paragon Plus Environment

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viscosity is reduced sharply2. This is the process target of the above researchers work to bridge this problem. Catalytic cracking is better than thermal cracking since catalytic cracking has many functions such as sulfur reduction, asphaltene cracking, resin cracking, high yield, high product selectivity, high yields of aromatics, low gas yields and more flexible in terms of product slate, hence we will proceed to use the catalytic cracking3. The common properties of heavy crude oils are high specific gravity (lesser than 20 degrees API), high viscosity (higher than 1000 centipoise), low hydrogen to carbon ratios, high carbon residues, and high asphaltene, heavy metal, sulfur and nitrogen content. Heavy and extra heavy crude oils are difficult to produce economically due to their low gravities and correspondingly high viscosities that hinder their ability to flow within a reservoir4. Therefore, the modern petroleum industry is facing several problems in petroleum production and refining. In recent years, ionic liquids have attracted attention as a result of their properties and versatility of potential application in the petroleum industry. Ionic liquids may be use to augment the flow ability of viscous and bituminous HCOs that could increase oil production, transportation and inhibit the aggregation of asphaltenes and paraffins. Because of the technological, environmental and economical impacts, this work is focused on increasing in petroleum production by the application of ionic liquids5. 3 ACS Paragon Plus Environment

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Have been tested ionic liquids (ILs) for the superiority of production, transportation and refining of crude oil in the laboratory scale. However, there is still need to prove their potential application in the field of production. Must solve many problems before the application of ionic liquids currently in the oil industry. Must be assessed, the technological feasibility and environmental economic production on a large scale and the use of ionic liquids (ILs) before accepting any petroleum company used daily. You confirmed the effect of the presence of ILs in crude oil in order to identify operational issues during production, transportation and refining. A lot of the necessary work of the pilot-scale field support and resolve operational problems and the dimensions of the available infrastructure and ionic liquids handling. Ionic liquids still need to prove safely used in oil operations, We believe that it has already opened a large area and the solutions more secure environment-friendly and specifically designed for the Real problems of the oil industry6. Recently, Ionic liquids (ILs) which are introduced as green solvents draw researchers’ attention because of their appealing properties such as low vapor pressure, high thermal stability, being liquid over a wide temperature range, nonflammability and being soluble in many organic and inorganic compounds7. Based on these characteristics the ILs are stable at the challenging reservoir conditions. Fan Hong-fu et al.6 and Nares et al.8 worked on upgrading heavy oil with ionic liquid and illustrated that they can improve 4 ACS Paragon Plus Environment

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heavy oil quality. Also, ionic liquids are used widely in the extraction and removal of sulfur9, due to catalytic and efficiency of solubility in a wide temperature10,11. The observed significant reduction of viscosity and asphaltene content when treating heavy crude oil with ionic liquids at lower temperature ionic liquids this attentions because of their potential application as an environmentally friendly and catalytically active solvent compared with other alternatives regarding the same process as aquathermolysis method. Aquathermolysis method Is the most efficient way to decrease the viscosity of heavy oil12. Aquathermolysis can increase the quantity of saturates and aromatic with decrease resins and asphaltenes in heavy oils. However aquathermolysis method operates at relativtely high temperatures, which results in the process hard to be practically handled and poor economical performance13, 14. In this article, we can use ionic liquids and ionic liquids modified to examine their ability to reduce the viscosity of heavy oils; and the results of heavy crude oils treatment with change of sulfur content are also discussed. EXPERIMENTAL 2.1. Feed stock The heavy crude oil used in this study was supplied by GPC company. The main characteristics of crude oil are present in Table (1).


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2.2. Materials All chemicals used in this study in reagent grade. 1-butyl 3-methyl imdazolium chloride [BMIM][Cl], Cyclohexane and Iron (III) chloride were purchased from Aldrich. 2.3. Dual-functionalised ionic liquids preparation The synthesis of the modified ionic liquid is the following. Under the protection of nitrogen, the dual-functionalized’ ionic liquid (modified ionic liquid) was prepared by simple addition of metal chloride to imidazolium cations (imidazolium chloride) with molar ratio (1:1). Imidazolium cations were placed in the three-neck glass flask with stirring ; then the metal chloride was added very slowly under stirring Eq. (1)15. The reaction of metal chloride and imidazolium cations was exothermic reaction and care must be taken not to exceed the temperature of this blend (not height above 60°C); otherwise, may occur decomposition thermally. The preparing mixture was used for testing the reactions16.

+

FeCl3 (1)

2.4. Measurements of viscosity Viscosity can be defined as the measurement of a liquid's resistance to flow. The viscosity normally express in terms of the time needed for standard amount of liquid at a specific temperature to flow through standardized slot, higher value, the more viscous liquid. The viscosity varies inversely with 6 ACS Paragon Plus Environment

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temperature, and its value has no meaning unless accompanied by a temperature that it is determined. With petroleum oil, is commonplace now mentioned in centistokes The viscosity (CST), and is measured in either 40°C or 100 ° C (ASTM D445 method - kinematic viscosity). 2.5. Oil sample Treatment with ionic liquids Upgrading of the heavy oils was conducted in a stainless steel reactor. The reactor was made of 316 stainless steel pipe and having the following dimensions; 5 mm internal diameter (i.d.), 8 mm external diameter (e.x.) and 25 cm length. The designated quantity of heavy crude (One hundred grams) and ionic liquids (0.25, 0.5, 1.0) were loaded into the reactor. Was maintaining the temperature and pressure of the reaction constant for a certain period, other this analyzed the oil samples were collected from the reactor. The operating conditions are summarized in Table (2). 2.6. Element content of sulfur The sulfur content was determined by the ED-XRF Analyser-Phoenix 11. The determination of sulfur in fuels is one of the most important analytical applications in the petroleum oil industry. As one of the worldwide leading manufacturers of analytical instruments for energy dispersive X-ray fluorescence analysis (EDXRF), SPECTRO has prepared a new application for the SPECTRO PHOENIX II EDXRF analyzer for this analytical task. This inexpensive compact instrument has been designed for utilization in refineries, pipelines, terminals, tank farms and distribution centers and is 7 ACS Paragon Plus Environment

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especially easy to operate. In production control and sorting control of sulfur petroleum oils, the instrument enables sulfur determination in accordance with ASTM D4294, IP 336, IP 496, ISO 8754 and ISO 20847. 2.7. Catalyst characterization 2.7.1. Fourier Transform Infrared (FTIR) spectroscopy To obtain information about the molecular structure of the supported catalysts, the IR transmission spectroscopic investigation was carried out at room temperature on Mattson 8100 Spectrometer using KBr disc method. Data were collected through infrared, on average 32 spectral scans with a resolution of 4 cm-1 wave number scale of 400-1200 cm-1. Fourier transform infrared spectroscopic (FTIR) analysis was carried out by using an ATI Mattson Genessis Ser FTIR Tm infrared spectrophotometer.

2.7.2. Differential thermal analysis (DTA) and Thermalgravimetric analysis (TGA) Differential thermal analysis (DTA) and Thermogravimetric analysis (TGA), were carried out follow changes structure due to the thermal processing. This method has been recorded at one time on an Device manufactured by TGA-50 shimadzu instrument, Within the scope of 40 to 600°C.The heating rate was 10 K/min under nitrogen atmosphere. 2.7.3. Gas Liquid Chromatography The compositions of paraffin’s and aromatics in liquid samples were determined using Clarus 500 Perken Elmer Gas Chromatograph using selective PIONA column capillary of 100 meter in length and 0.25 mm 8 ACS Paragon Plus Environment

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internal diameter. Suitable sample capacity was injected into split / split less injector through a micro syringe according to both response and linear range of FID detector. The system enables to detect the composition up to C36 +. 2.7.4. Spectroscopy measurements: UV–Vis absorption spectra were recorded on UV/Vis/NIR spectrophotometer (Jasco-V-570), after dilution of irradiated samples with water (the factor of dilution of about 40 and 600). 2.7.5. Raman spectra were obtained using a Raman Spectroscopy (senterra) Braker - Germany. It is worth noting that the strong fluorescence resulted by Using green 514.5 nm light, Therefore, all spectrum have been measured at room temperature in mini pipes made with laser light of 785 nm, all spectrum compiled from 100–4000 cm-1.

3. RESULTS & DISCUSSION 3.1. Fourier Transform Infrared (FTIR) spectroscopy Much broader band was observed for ionic liquid [BMIM][Cl] (sample a) which is assigned to N-H stretch at wave number at 3600-3180 cm-1, this peak disappeared in the modified ionic liquid [BMIM][FeCl4] (sample b), but observed

bands

in

the

3755-3410

cm-1

region,

show

the existence of Lewis and Brönshated acid sites, which is the main property to refer the catalytic activity of ionic liquid. Figure (1) shows several bands in the spectrum were identified from which correspond to alkenes asymmetric stretching bands of CH and C=C at wave numbers 3081 and 1629 cm-1 for sample (a), which were shifted to 9 ACS Paragon Plus Environment

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bands at wave numbers of 3103 and 1721 cm-1 (sample b) due to the interaction with the iron salt (FeCl3). The very sharp bands in samples (a & b) at wave number 1186 cm-1 can be due to the existence of the C-N stretch band related to imidazolium ring. The peak at 1570 cm-1 that corresponds to the imidazole ring stretching in pure [BMIM]Cl; the occurrence of complexation between [FeCl3] and the pure [BMIM]Cl can be further proved by the formation of a shoulder at 1571 cm-1 in [BMIM][FeCl4]. 3.2. Thermal Decomposition Temperatures Thermal gravimetric analysis (TGA) Thermal decomposition of ionic liquids appears in the DTA curves, Figure (2). Several endothermic peaks were noted at the DTA curve. The 1st peak is located at about 70.61oC, indicating the loss of water of crystallization (H2O) for [BMIM] FeCl4 (MIL). The increment of temperature was accompanied by the successive appearance of other endothermic peaks; their maxima are located at 380.26oC for [BMIM] FeCl4, based ionic liquid, respectively. These peaks are concerning to the successive decomposition of the produced type of imidazolium chloride based on ionic liquids, which decomposed gradually with two steps and slightly affected by the alkyl chain in the ionic liquid and the variation of anions, i.e. different combination of cation-anion leads to thermal stability. 10 ACS Paragon Plus Environment

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The result from TGA curves is shown in Figure (2) for [BMIM] FeCl4 based on ionic liquid. Figure (2) show that the sample was standed to decompose gradually at 270.15, 380.26oC with a total loss of 19.62 and 58.95 wt %, respectively. This showed that the stability of [BMIM] FeCl4 based on ionic liquid is attained up to 380oC. 3.3. Gas chromatography (GC) for the analysis of heavy oil According to slandered boiling point of hydrocarbon in heavy gas oil Figure (3) Table (3) , Figures (4,5) show the heavy oil composition with and without treated by imidazolium tetracholoferrate based ionic liquid. It is easy to see, the additional peaks appear as a result of increased hydrocarbon content of less than C7 from 3.73% to 51.54%, and higher hydrocarbon content of C25 goes down even from 50,6 % to 9.8%. This suggests that the catalytic cracking of heavy oil with modified ionic liquid was proceeding out due to the increment of the acidity after the modification with the imidazolium chloride with FeCl3, which increase the catalytic activity. This is agree with FTIR spectrum characteristic of modified ionic liquid, which appearance of bands indicates the existences of Lewis and Brönshted acid sites in the modified ionic liquid Figure (1). 3.4. UV-Vis spectra analysis of [BMIM][Cl] and [BMIM][FeCl4] Figure (6) shows the dose dependence of the UV-Vis absorption of [BMIM][Cl]. The irradiated [BMIM][Cl] showed obvious absorbance bands from 250 to 600 nm17, 18, a distinct absorption peak appeared at 290 nm19. 11 ACS Paragon Plus Environment

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The ionic liquid species, [BMIM] FeCl4, was formed by adding FeCl3 into [BMIM]Cl. The results showed that the presence of FeCl4− significantly improved the radiation resistance of [BMIM]Cl. Meanwhile, under irradiation, Fe (II) was generated from Fe (III), which was reduced by solvated electron, also the results showed that the presence of FeCl4− significantly improved the radiation resistance of [BMIM][Cl]. Meanwhile, under irradiation, Fe (II) was generated from Fe (III), which was reduced by solvated electron. Generally, [BMIM][FeCl4] exhibited absorbance bands at 296 and 342 nm which are refer to the FeCl4− anion and showed the presences of the tetrachloroferrate species (Fig. 7) 20. 3.5. Raman spectra of irradiated[BMIM][Cl] and [BMIM][FeCl4] Figures (8, 9) compares the Raman spectrum of [BMIM][ FeCl4] with that of [BMIM]Cl, to determine the vibration frequencies of Cl Fe Cl and Fe Cl in the tetrachloroferrate (III) ion, thus the spectrum was donated from 400 to 100 cm−1. Figure (9), shows a strong band at 330 cm-1, which is designated

to

symmetric Fe–Cl band of [FeCl4]- stretching vibration21. As

illustrate from Figure (9) the absorption bands from 50 to 500 cm-1 are related to [BMIM]Cl, which are Set for the [bmim]+ cation vibrations. Thus, the results suggest that the trait is synthesized ionic liquid [BMIM] [FeCl4] 22.


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3.6. Effects of ionic liquid and modified ionic liquids in the viscosity reduction of heavy crude oil After the treatment of the heavy oil with ionic liquids the viscosity was examined, and the findings shown in Figure (10) that the ionic liquids reduced the viscosity of the heavy oil. This shows that ionic liquids modified by metal ion have positive effects on the viscosity reduction of the heavy crude oil. The modified ionic liquid ([BMIM][FeCl4]) had the best performance for the viscosity reduction of the heavy crude oil from 57.8 to 40 cp, and the viscosity of the heavy crude oil is reduced to 70.20 % and 78.63 % for [BMIM][Cl] and [BMIM][FeCl4] respectively, where the viscosity of the untreated heavy crude oil is reduced by 26.83% as the effect of temperature without ionic liquid23, 24. On other hand, we can observe that there are no resin or asphaltene contents when processing heavy crude oil by ionic liquids, thus due to the ionic liquids capacity to dissolve asphaltenes. Murillo, et al., 200925 Suggested asphaltene decomposition occurs by ILS as a result of breaking the hydrogen bonds in the asphaltene aggregation. We have demonstrated that the combination of functionalized imidazolium cations and metal anion not just gives the IL with additional posts, but lowers the their viscosity and melting point. These groups all of the functionalized cations and anions enrichment the ionic liquid field by adding another dimension to their determination. Duel-function ionic liquid ([BMIM] [FeCl4]) reported this document consists of groups of potential donors of transition metals. This has been selected DF13 ACS Paragon Plus Environment

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IL ([BMIM] [FeCl4]) to study the Continuity of our work, which show the best performance reducing viscosity of the heavy oil. 3.7. The effects of temperature on the viscosity reduction of Heavy Oil The oil sample and desired amounts of [BMIM][Cl] or [BMIM][FeCl4] ionic liquid were placed in the autoclave. The interaction was conducted for 72 hr. at different temperatures (70–90oC). The impact of viscosity reduction by temperature are shown in Figure (11); then we can observe that the viscosity was reduced with the increment of the temperature due to perfect solubility and catalytic characteristics in a broad range of temperature. Temperature 70–90oC was the best range to deal the heavy crude oil with [BMIM] [FeCl4] ionic liquid26. 3.8. Effect of water on the Viscosity Reduction of Heavy Oil Most of the heavy oil reservoirs have a definite amount of water. The main point is to show the water has implications for upgrading and lowering the viscosity of heavy oils. Oil sample is mixed thoroughly with a certain amount of water and then add the ionic liquids Table (4). The interaction lasted for 72 hr. at a pressure 3.5 MPa and temperature of 90oC, and the results showed samples of the oil processor in the Figure 12. As is evident in Table 5, for a given amount of ionic liquids with increasing water content, we observe an increase in the contents of sulfur and asphaltene in oil samples treated with the decrease of viscosity reduction ratio. If the increased water content in the heavy oil to reach the higher of the 8%, it is extremely difficult to promote 14 ACS Paragon Plus Environment

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upgradjng and reduce the viscosity of heavy oil through better mass fraction of [BMIM] [FeCl4] ionic liquid27. To reduce the viscosity and to upgrade heavy oil using [BMIM] [FeCl4] ionic liquid, and less than 5% of the water content is the best, because the active sites of catalytic ionic liquid [BMIM][FeCl4] lies mainly on the protons of hydrogen in the imidazole ring. When the interaction of ionic liquid with water, the imidazole ring proton and water molecules can easily form hydrogen bonds, this bond is stronger than the usual hydrogen bonding interactions, and this leads to a reduction of ionic liquid activity. Heavy oil in reservoir certainly has a definite quantity of water, and therefore can be used ionic liquids when the water content is up to 5% Figure (12). On other hand, the main disadvantage for some of ionic liquids is sensitivity towards water, the presence of water in the autoclave appears to poison the catalytic ability of ionic liquids27, 28. 3.9. Influence the amount of Ionic Liquids on the sulfur Reduction of Heavy Oil Table (5) showing the contents of sulfur in the heavy oil sample. It can be observed that after treated with ionic liquids, the amount of sulfur in the heavy oil samples is decreased by increasing the quantity of ionic liquid. Thus, reduce the viscosity of heavy oil processor using ionic liquids may be caused by the breakup of C−S bonds. During the treatment process, the organic sulfur in the heavy oil react with transition metal modified by ionic 15 ACS Paragon Plus Environment

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liquids to form the complex, which can weaken the C−S bonds and cause the breakage of the heavy oil molecules. As a consequence the reaction, H2S is released and the content of sulfur in the heavy oil decreases18. According to the reaction of thiophenic sulfur with transition metal salts, the reaction mechanism of the viscosity reduction and the upgrading of the heavy oil by ionic liquids can be described in Figure (13). Also, the breakage of the heavy oil molecules lead to the increment of the contents of saturates and aromatics in the heavy oils treated by ionic liquids can also be in favor of reducing the viscosity of heavy oil Table (5) 29, 30. 3.9.1 Determination of the equilibrium time In the present study, treatment of heavy oil with [BMIM][FeCl4] to establish the time required to reach the absorption equilibrium. The single extractions were conducted for 12, 24, 48, 70 and 120 hr. at 90 oC. The results, in Figure (14) show that 72 hr. of contact between the heavy oil and the ionic liquid is more than sufficient to establish the equilibrium, where more than this time the reduction of sulfur increase slightly, then we can used this time (72 hr.) as more economy than (120 hr.) 27. The ionic liquids have strong affinity for the sulfur compounds The powerful affinity of the ionic liquid for the sulfur compounds is related to the high polarity of the ionic liquid. The mechanisms to extract compounds that contain sulfur with Lewis-acidic ionic liquid are because of


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the formation of liquid-clathrate compounds and π-π interactions between the imidazolium ring system and aromatic structures of the extraction target31-33. 3.9.2. Desulfurization kinetics of heavy oil with IL Most of heavy oil was desulfurized within the first 72 hr., Figure (14) shows the progress of sulfur reduction with reaction time. The loss of sulfur-containing compounds with the reaction time tracking the reaction kinetics of the first order, which can be described as follows34: The experimental rate of gas oil desulfurization with ionic liquids can be description as Eq. (2) ʋ = -dc / dt = k cn (2) The integral formula of Eq. (2) are Eq. (3).

ln ʋ = n lnc + ln k

(3)

where ʋ is the rate of reaction, C the concentrations, k rate constant the first-order (h-1), and n the order of the reaction. ʋ =-dc / dt = kc

(4)

The integration formula of Eq. (4) are.

Ln (C0/Ct) = kt

(5)

Where C0 and Ct are the amount of sulfur in heavy oil at zero and t(s) time, respectively. And half-lives (t1/2 (s)) are calculated using Eq. (6), t1/2 = ln2/k

(6)


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Figure (15) indicate the time-course divergence of ln (C0/Ct), the data was obtained from data which showed in Figure (14). The desulfurization process of heavy oil is fitted by different time. The results are displayed in Figure (15) Table (6), where the reaction order can be approximated by the reaction to 1 and the correlation coefficient is higher than 0.97. Results reveal that the kinetics of desulfurization of heavy oil can be agree kinetically with the first-order equation35, also the values of t1/2 of 38.5 hr. Table (6), faster rate occurred with desulfurization process of heavy oil by using ionic liquid.

4. CONCLUSIONS On the basis of the experimental results, the following conclusion can be drawn: 1. The oil samples treated by ionic liquid modified with transition metal [BMIM][FeCl4] leads to higher viscosity reduction ratio and lower resin content compared with samples handling with ionic liquid only. 2. The complex formed between the ionic liquids and the sulfur compound in heavy oil, which weakens the C-S bonds and causes the breakage of the C-S bonds. 3. The presences of water in the heavy oil has detrimental effect on the upgrading and reduced viscosity of heavy oils by [BMIM][FeCl4] ionic liquid. 18 ACS Paragon Plus Environment

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4. When heavy oils treated by [BMIM][FeCl4] ionic liquid in presences of water leads to negative effects on the viscosity reduction and upgrading of heavy oils 5. At the optimum temperature from 70 90oC, which lower the viscosity reduction and upgrading of heavy oils by ionic liquid.


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5. REFRENCES 1) Shokrlua, Y.H.; Mahamb, Y.; Tanb, X.; Babadaglia, T.; Gray, M., J. Fuel, 2013, 105, 397-407. 2) Chuan, W.U.; Guang-Lun, L.E.I.; Chuan-jin, Y.A.O.; Ke-ji, S.U.N.; Ping-yuan, G.; Yanbin, C.A.O., J. Fuel Chem. & Technol., 2010, 38 (6), 684-690. 3) Maity, S.K.; Ancheyta, J.; Marroquı´n, G., J. Energy & Fuels, 2010, 24, 2809–2816. 4) Aburto, J.; Mar-Juárez, E.; Juárez-Soto, C., Recent Patents on Chemical Engineering, 2009, 2 (2), 86-97. 5) Liu, Y.; Hu, Y.; Wang, H.; Xu, Ch.; Ji, D.; Sun, Y.; Guo, T., Chinese J. Chem. Eng., 2005, 13 (4), 564-567. 6) Hong-fu, F.A.N.; Zhong-bao, L.I.; Tao L.I.A.N.G., J. Fuel Chem. & Technol., 2007, 35 (1), 32-35. 7) Bui, T.L.T., The 7th Asian Petroleum Technology Symposium, 2007. 8) Fan, H.F.; Li, Z.; Liang, T., J. of Fuel Chemistry and Technology, 2007, 35(1), 32-35. 9) Huang, L.; Huang, W.; Fu, H.; Wu, G.; Guo, Z.; Wu, W.; Chen, S., J. Chin. Sci. Bull., 2013, 58 (10), 1150-1155. 10) Han, F., Pei, L., Wang, L.M., J. Filtration & Separation, 2009, 19(2), 19–22. 11) Wang, L.S.; You, Q.; Zhao, F.L., Chinese J. Appl. Chem., 2005, 5, 603–604. 12) Fan, H.F.; Liu, Y.J.; Zhao, F.A., Oilfield Chemistry, 2001, 18(1), 13−16. 13) Ze-xia, F.; Teng-fei, W.; Yu-hai, H., J. Fuel Chem. & Technol., 2009, 37(6), 690-693. 14) Betiha, M. I.; Ghanem, A.A.; Mousa, M. A.; Al Sabagh, A. M.; Desouky, S.E.M.; Badawi A.M., Egypt . J . of Appl. Sci ., 2013, 28 (2). 15) Zhao, D.; Fei, Z.; Andre´ Ohlin, C.; Laurenczy G.´bor; Dyson, P. J., J. Chem. Commun., 2004, 7(21), 2500-2501.


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16) Ze-xia, F.A.N.; Teng-fei, W.A.N.G.; Yu-hai, H.E., J. Fuel Chem. & Technol., 2009, 37(6), 690-693. 17) Chandrasekhar, N.; Schalk, O., J. Phys. Chem. B, 2008, 112, 15718–15724 18) Shkrob, I.A.; Wishart, J.F., J Phys. Chem. B, 2009, 113, 5582–5592 19) He, Y.; Yu, J.; Chen, L.B., CIESC J, 2010, 61, 963–968. 20) Kogelnig, D.; Stojanovic, A.; Kammer, F.v.d.; Terzieff, P.; Galanski, M.; Jirsa, F.; Krachler, R.; Hofmann, T.; Keppler, B.K., J. Inorg. Chem. Communic., 2010, 13, 1485– 1488. 21) Sitze, M.S.; Schreiter, E.R.; Patterson, E.V.; Freeman, R.G., J. Inorg. Chem., 2001, 40 (10), 2298-2304. 22) Wanga, H.; Yan, R.; Li, Z.; Zhang, X.; Zhang, S.; Wang, H.; Yan, R.; Li, Z.; Zhang, X.; Zhang, S., J. Catal. Communic., 2010, 11, 763–767 23) Hong-Fu, L. Zhong-Bao, L. Tao, J. Fuel Chemistry & Technology, 2007, 35(1), 32-35. 24) Sakal, S.A.; Lu, Y.-z.; Jiang, X.-c.; Shen, C.; Li, C.-x., J. Chemical & Engineering Data, 2014, 59(3), 533-539. 25) Murillo-Hernández, J.; García-Cruz, I.; López-Ramírez, S.; Durán-Valencia, C.; Domínguez, J.M.; Aburto, J., J. Energy & Fuels, 2009, 23, 4584-4592. 26) Shadi, H.W.; Mamdouh, G.T.; Nabil, E., J. Fuel, 2010, 89(5), 1095–1100. 27) Zahran, A.A., Msc. Thesis, Faculty of Science- Banha University, 2013. 28) Swatloski, R.P.; Holbrey J.D.; Rogers, R.D., J. Green Chemistry, 2003, 5, 361-366. 29) Fan, H.F.; Liu, Y.J.; Zhao, X.F., J. Fuel Chem. & Technol., 2001, 29 (3), 269-272. 30) Zou, C.J.; Liu, C.; Luo, P.Y., J. Chem. Ind. and Eng. (China), 2004, 55(12), 2095−2098. 31) Zhang, S.; Zhang, Q.; Zhang, Z., J. Ind. Eng. Chem. Res., 2004, 43(2), 614− 622. 32) Holbrey, J.D.; Reichert, W.M.; Nieuwenhuyzen, M.; Sheppard, O.; Hardacre, C.; Rogers, R.D., J. Chem. Commun., 2003, 4, 467−477.


Energy & Fuels

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33) Jian-long, W.; Di-shun, Z.; Er-peng, Z.; Zhi, D., J Fuel Chem. &Technol., 2007, 35(3), 293−296. 34) Ma, X.; Sakanishi, K.; Mochida, I., J. Ind. Eng. Chem. Res., 1996, 35, 2487-2494. 35) Yahaya, G.O.; Bahamdan, A.A.; Hamad, F.; Ramakrishna, T.V.V.; Hamad, E.Z., Saudi Aramco J. of Technology, 2012, 60-69.


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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Table 1: The main properties of crude oil. Property

Analysis

standard methods

Density at 15.6o C

0.9812

(ASTM D-1298)

Total Sulfur content, ppm

22600.5

(ASTM D- 4294 - 90)

Kinematic Viscosity at 40 oC, centipoise (cP).

57.8

(ASTM - 445)

Kinematic Viscosity at 70 oC, centipoise (cP).

28.56

Table 2: Conditions of upgrading Time ,hr

72

Ionic liquid wt. %

0, 0.25, 0.5, 1.0

Temperature, oC

70 - 90

Molar ratio ( IL : Metal )

1 : 0.67

Water wt %

0.1 – 12.0

Reservoir pressure

3.0-3.5 MPa


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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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Table 3: Boiling point of hydrocarbon in heavy gas oil. Carbon No.

B.P oC 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44

B.P oF -162 -89 -42 0 36 69 98 126 151 174 196 216 235 254 271 287 302 316 330 344 356 369 380 391 402 412 422 431 440 449 458 466 474 481 489 496 503 509 516 522 528 534 540 545


-259.6 -128.2 -43.6 32 96.8 156.2 208.4 258.8 303.8 345.2 384.8 420.8 455 489.2 519.8 548.6 575.6 600.8 626 651.2 672.8 696.2 716 735.8 755.6 773.6 791.6 807.8 824 840.2 856.4 870.8 885.2 897.8 912.2 924.8 937.4 948.2 960.8 971.6 982.4 993.2 1004 1013

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Table 4: Effect of water on the upgrading of crude oil.

Water wt, %

*Viscosity reduction, %

Resin, %

**Sulfur reduction, %

0.1

59.0

2.2

6.5

0.2

57.0

3.7

6.2

0.5

53.5

4.5

6.3

1

51.0

7.1

5.9

2

48.2

10.1

5.1

3

43.0

15.6

4.5

4

39.4

20.2

3.9

5

35.8

25.9

3.8

6

25.2

26.1

3

7

16.5

27.0

2

8

10.4

27.2

2.1

9

7.7

28.5

1.9

10

5.7

29.1

1.5

11

4.9

31.1

1

12

4.7

31.8

1

*viscosity reduction = **Sulfur reduction =

µ µ µ

× 100

× 100

b,a pretend to the value of property before and after treatment

Table 5: influence of Ionic Liquids wight on the Sulfur Reduction of Heavy Oil DF-ILs, wt % 0 0.25 0.5 1.0 2.0

Sulfur reduction, % 0 6.29 11.24 17.74 23.45

viscosity reduction,% 26.83 60.01 68.21 72.34 78.22

Table 6: Rate constants and half-lives for heavy oil desulfurized

[BMIM][FeCl4] ionic liquid

R2

rate const, k min-1

t1/2, h

0.981

0.018

38.50


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(a) [BMIM][Cl]

Transmittance

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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(b) [BMIM][FeCl4] Wavenumbers, cm-1


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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Figure 1: FTIR Spectra of of a) ionic liquids [BMIM][Cl] and b) modified ionic liquids [BMIM][FeCl4] based ionic liquids.


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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 ACS Paragon Plus Environment

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Chromatographic retention time (min)

Figure 4: GC spectrum of hydrocarbon in heavy gas oil before reaction.

Fid response

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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Fid response

Page 29 of 35

Chromatographic retention time (min)

Figure 5: GC spectrum of hydrocarbon in heavy gas oil after reaction With imidazolium tetracholoferrate based ionic liquid.


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0.5

290

0.45 0.4 0.35

Abs.

0.3 0.25 0.2 0.15 0.1 0.05 0 0

200

400

600

800

1000

Wave length (nm) Figure 6: Fig. 2. UV–Vis absorbance spectra of [BMIM]Cl.

3

296 nm

342 nm

2.5 2

Abs.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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1.5 1 0.5 0 0 -0.5

200

400

600

800

1000

Wave length (nm)

Figure 7: Fig. 2. UV–Vis absorbance spectra of [BMIM][ FeCl4].


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600 500

Intensity

400 300 200 100 0 0

100

200

300

400

500

600

-100 Raman shift (cm-1)

Figure 8: Raman shift of [BMIM]Cl.

1800 1600 1400

Intensity

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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1200 1000 800 600 400 200 0 -200

0

50

100 150 200 250 300 350 400 450 500 550

Raman shift (cm-1) Figure 9: Raman shift of [BMIM][ FeCl4]


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90 Viscosty Reduction (%)

80

78.63

untreated oil treated oil

70.20

70 60 50 40 26.83

30

26.83

20 10 0 1

2 Temperature, oC

Figure 10: Effect of ionic liquids on viscosity reduction 1: [BMIM][Cl] ; 2: [BMIM][FeCl4]

Viscosty Reduction (%)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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90 80 70 60 50 40 30 20 10 0

67.40

26.83

untreated oil

70.57

68.00

26.83

70

78.64

75.00

73.48

26.83

80 Temperature, oC treated oil with [BMIM][Cl]

90

treated oil with [BMIM][FeCl4]

Figure 11: Effect of temperature on the viscosity reduction


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70 60 Reduction Viscosty, wt %

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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50 40 30 20 10 0 0

1

2

3

4

5

6

7

8

9

10

Water, wt %

Figure 12: Effect of water percentage on the viscosity reduction


11

12

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Figure 13: Reaction mechanism between ionic liquids and the heavy oil.


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30

sulfur reduction, %

25 20 15 10 5 0 0

12

24

36

48

60

72

84

96

108 120 132

Time, hr. Figure 14: influence of Ionic Liquids on the Sulfur Reduction of Heavy Oil

2.5 2

ln Co/Ct

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

1.5 1 0.5

y = 0.0185x R² = 0.981

0 0

20

40

60

80

100

120

140

Time,h Figure 15: Relationship between ln(C0/Ct) and reaction time of gas oil desulfurized.


Upgrading and Viscosity Reduction of Heavy Oil by Catalytic Ionic

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