Integrated Supercritical Fluid Extraction and Fluid Thermal Conversion

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Integrated Supercritical Fluid Extraction and Fluid Thermal Conversion (ISFTC) Process: Experiment Realization and Comparison of Thermal Converted Liquids Haipeng Song, Zhiming Xu, Xuewen Sun, Linzhou Zhang, Chunming Xu, Suoqi Zhao, and He Huang Energy Fuels, Just Accepted Manuscript • DOI: 10.1021/acs.energyfuels.8b00460 • Publication Date (Web): 02 Mar 2018 Downloaded from http://pubs.acs.org on March 6, 2018

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Integrated Supercritical Fluid Extraction and Fluid Thermal Conversion (ISFTC) Process: Experiment Realization and Comparison of Thermal Converted Liquids Haipeng Songa, Zhiming Xua, Xuewen Suna, Linzhou Zhanga, Chunming Xua, Suoqi Zhaoa*, He Huangb a State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing, 102249, P. R. China b Liaohe petrochemical company of China National Petroleum Corporation, Panjin, Liaoning province, 124022, P. R. China

Abstract A new technology is proposed by directly integrated supercritical fluid extraction and fluidized thermal conversion process, which was named integrated supercritical fluid extraction and fluid thermal conversion (ISFTC) process. In the extraction unit of ISFTC, the heavy feedstock was separated into de-oiled asphalt (DOA) and de-asphalted (DAO). DOA phase is fed to a fluidized bed thermal convertor (FTC) without solvent separating, using hot coke to supply the heat. DAO will be qualified for fluid catalytic cracking (FCC) processing. The proposed process avoids feedstock quality limit for both FCC and delayed coking. It increased overall liquid yield of vacuum residue (VR) upgrading and solved the problem of solvent recovery for solvent-DOA phase at bottom of supercritical fluid extraction unit. A continuous laboratory apparatus was built to prove the concept. A Chinese petroleum residue was processed by the built apparatus at appropriate operating conditions. The total liquid yield of ISFTC, the DAO FCC liquid plus DOA FTC liquid, is by 7 wt% and 14 wt% higher than VR delayed coking and VR FTC respectively.

The bulk properties such

as molecular weight, carbon residue, density, viscosity, elemental contents of DOA converted liquid was compared to those of VR delayed coking and VR FTC. The structure parameters based

1

H-NMR were also calculated. To investigate the

molecular composition difference of acidic, non-basic and basic heteroatom species in three samples, Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FT-ICR MS) was applied with the negative and positive ion electrospray ionization (±ESI) as ion sources. The quality and compositions of DOA FTC liquid is similar to VR FTC liquid, but worse than VR delayed coking. Keywords: ISFTC; Fluid thermal conversion; Delayed Coking; Supercritical Fluid Extraction; Vacuum residue

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1. Introduction Heavy petroleum occupies a large proportion in petroleum resources around the world. But the processing efficiency of heavy petroleum still faces a various challenges in traditional refining process

[1]

. Petroleum VR is the heaviest and most

complex part of petroleum. It has high molecular weight and low hydrogen to carbon ratio. In addition, the contents of hetero-atom containing species are also high, including sulfur, nitrogen and oxygen compounds and metal organic compound. The heavy petroleum molecules also have high trend to form aggregates, which lead to fouling and precipitation problem. The chemical composition and structure of different residua have a huge difference, and there are significant differences in the difficulty of VR upgrading

[2-5]

. Hence, residue fluid catalytic cracking and even

delayed coking have specific limitation for their feedstock. Over the past decades, our group developed a supercritical fluid extraction (SFE) technology to effectively process the heavy residual oil [6-8]. In SFE process, the feedstock is separated into de-asphalted oil (DAO) and de-oiled asphalt (DOA)

[9-15]

. More than 70 % of metal, 70 % of residual carbon

precursor and 90 % of asphaltene in heavy petroleum are concentrated in unextracted DOA. Therefore, the quality of extracted fraction is significantly improved and may meet requirements for some catalytic upgrading process (e.g., fluid catalytic cracking). DOA has high softening point due to high abundance of polyaromatics and heteroatom containing species [16-20]. DOA is obtained at the bottom of extraction unit, which generally contains relative high amount of supercritical fluid. Complete recovering solvent from viscous DOA is a challenge, leading to subsequent transport and processing problem. Therefore, it is obvious that, if a direct process for DOA upgrading and solvent recovery can be followed, the economic value of supercritical fluid extraction process will be increased. Coking, especially delayed coking is the main upgrading technology for ultra-heavy petroleum fraction

[21]

. It produces light fraction with high

hydrogen-to-carbon ratio and coke with high aromaticity. Besides gasoline and diesel, a considerable amount of coker gas oil (CGO) is obtained, which could be generally fed to fluid catalytic cracking (FCC) or hydro-cracking processes to produce higher quality lighter fractions [22,23]. Comparing to hydro-treating, coking process obviously has certain advantages in the relative low investment and feedstock quality requirements. In contrast to the feedstock limitation of delayed coking, fluidized coking has much advantage in continuous operation and wide adaptability of

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feedstock. It has the ability to process the inferior feedstock which is difficult for delayed coking [24-29]. Based on the characteristics of SFE and fluid coking, an integrated process is proposed, namely integrated supercritical fluid extraction and fluid thermal conversion (ISFTC). In the process, DOA from SFE is directly fed into fluidized bed thermal conversion without solvent separation. By this routine, the feedstock upgrading and solvent recovery demands for DOA are solved simultaneously. In this paper, the concept of the integrated process was verified by the development of a continuous laboratory-scale apparatus. The properties and compositions of fluidized thermal conversion products for DOA were analyzed. The product yield and quality of the integrated process were compared with VR fluid thermal conversion and VR delayed coking. 2. Experiment 2.1 Feedstock A vacuum residue produced from Chinese Dagang crude oil (DGVR) was chosen as feedstock. The Dagang vacuun residue (DGVR) was distilled by the petroleum from Dagang oilfield, China Tianjin, around 500 ℃ in a vacuum. And the nickel content of Dagang crude oil is very high (37.5µg/g), the vanadium content is low (< 0.1µg/g), and other metal content is not high. It belongs to low sulfur intermediate base crude oil, as a result, the properties of its vacuum residuum has a certain difference and is better than other conventional crude oil vacuum residue[30, 31]. The feedstock bulk properties are shown in Table 1. It has obviously high carbon residue (CCR) and nickel content, which cannot meet requirement for FCC feedstock [32-34]. 2.2 DOA and VR ISFTC The main experiment used the self-designed apparatus of the integrated process of supercritical fluid extraction and fluid thermal conversion units. ISFTC apparatus mainly included three parts: control system, separation unit and thermal conversion unit. The flow chart of integrated process is shown in Figure 1. The integrated process capacity in laboratory scale is 300 g/h. In the integrated apparatus, the DOA outlet of separation unit directly linked with the injection port of thermal conversion unit, and then DOA with supercritical solvent was sprayed into the fluid thermal converter. The DAO was collected to test its FCC reactivity. The VR direct fluid thermal conversion evaluation is also carried out in same fluid thermal conversion unit of ISFTC. For VR fluid thermal conversion, under the condition of higher than solvent critical temperature, the feedstock VR flowed through the extractor of ISFTC to make the

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solvent evaporate from VR feedstock. And then, the VR entraining the solvent was sprayed into the fluidized convertor to carry out the thermal reaction. 2.3 Fluid Catalytic Cracking (FCC) The DAO obtained from the SFE separation unit was injected into the fluid catalytic cracking process to obtain more liquid product. The FCC experiment was based on a small fixed fluidized bed, as shown in Figure 2. The device mainly includes feedstock inlet, fluidization, reaction, control and collecting system. The operating conditions of DAO FCC are listed in Table 2. And the selected catalyst is the LDO-70 catalyst, which properties are shown in Table 3. 2.4 Delayed Coking (DC) The delayed coking reaction is performed in a high-temperature and high-pressure delayed coking reactor under the same temperature as other two thermal conversion. The device flow chart is shown in Figure 3. And this device is mainly composed of heating, cooling, gas collection and liquid collection systems. 3. Results and Discussion 3.1 ISFTC continuous experiments (1) Concept of ISFTC The process flows of delayed coking, fluid thermal conversion and ISFTC are shown in Figure 4. In the integrated apparatus, the DOA outlet of separation unit directly linked with the injection port of thermal conversion unit, and then DOA with supercritical solvent was sprayed into the fluid thermal converter. DAO extracted from the VR feedstock in the separation unit was fed into FCC. The ISFTC process coupled with FCC unit forms a combinational technique to convert VR into gas, liquid and coke. In which, the light extracted DAO can be processed by FCC to obtain higher light fuel yields. DOA and solvent mixture flowed through the extractor and was sprayed into the fluidized converter. (2) Yield and properties of DAO and DOA After times of tests, appropriate operating conditions of ISFTC were chose, which were listed in Table 4. Because the Dagang vacuum residue is different from other conventional VR, the quality is relatively better. When n-pentane is selected as the solvent, the yield of DAO is much more and the DOA is less[30]. The quality of DAO will go down and make some effect on the subsequent FCC. And the decrease of DOA will increase the percent of the entrained solvent in the feedstock of FTC unit of ISFTC. It will cause the insufficient of reaction heat and the thermal conversion products will be faster to be taken out of the reactor. So iso-butane was selected as the

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solvent to make sure the content of DOA. For direct delayed coking and fluid thermal conversion process, the VR feedstock was thermally upgraded without pre-separation. It is reasonable to presume that the liquid product yield will be higher than the thermal conversion unit of ISFTC, since more heavy fractions from DOA will suffer secondary condensation reactions in thermally process and converts to coke. At this part, we examine the product distribution and performance of ISFTC unit. And in the next part, we compared ISFTC unit with delayed coking and fluid thermal conversion processes. The first issue we concerned is the SFE unit performance. Under the selected conditions, the yields and properties of both DAO and DOA are listed in Table 5. Compared to the DGVR, it could be seen that, after SFE separation, the quality of DAO had been remarkably improved. The contents of resins and asphaltenes were significantly decreased, and saturates was summed up to 56.82 wt%. At the same time, the carbon residue reduced to 3.63 wt% and the total content of nickel and vanadium was only 10.22 µg/g. The removal effect of undesirable contaminates makes it suitable for fluid catalytic cracking processing [32-34]. In contrast, for DOA, the carbon residue value was high and the hydrogen to carbon atoms ratio was low. Meanwhile, the viscosity, density, softening point and hetero-atoms content were all relatively higher. It’s obvious that the poor qualities of DOA would bring vast difficulties in transport and upgrading. (3) Product distribution of DAO FCC and DOA FTC The DAO were fed to FCC unit and the DOA was directly sprayed into the fluid thermal convertor with the supercritical solvent. The results of products distribution are shown in Table 6 and Table 7. Based on the Table 5, the properties of DAO was improved, the huge amount of saturates and aromatics caused the high amount of liquid product products of DAO FCC unit. DOA was processed through the fluid thermal conversion unit of ISFTC. And the huge amount of resins of DOA made the content of FTC coke high (39.62 wt%). At the same time, although DOA enriched large molecules and contaminates, it produced 48.34 wt% of liquid products. The gasoline and diesel yield were low and the content of coking gas oil, CGO was 35.37 wt%. The integrated process not only produced more liquid product, but realized the efficient process of inferior DOA and solved the recovery problem of entrained solvent which could be collected from the gas product. The development of the integrated process is significant. 3.2 Product yield compared to VR DC, FTC and DOA ISFTC

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In order to show the difference between DOA ISFTC, VR delay coking and VR FTC, we also performed the last two experiments and make comparison on the product yield and quality. For direct fluid conversion of VR, the process was operated under the same reaction conditions of fluid thermal conversion unit of ISFTC. And the delayed coking was carried out under the conditions of 520 oC and 60 min. The product distribution of ISFTC and two comparative upgrading processes are shown in Figure 5. The liquid product yield of ISFTC is summed up from those of DAO FCC and DOA FTC units. And in Figure 5, the light oil of ISFTC included the gasoline and diesel, and the total liquid was made up of all four oil products. Compared to the delayed coking and fluid thermal conversion, the total liquid products yield of ISFTC is higher by 7 wt and 14 wt% than VR delayed coking and VR FTC. Particularly, the lightest products yield (LPG and gasoline) from ISFTC were significantly higher than delayed coking and fluid thermal conversion. Through the flow of fluidized medium and carrier, the liquid product was taken away ISFTC fluid thermal convertor in a short time to reduce the occurrence of secondary cracking [35, 36]

. Moreover, the DAO fraction was separated and injected into FCC unit, which

enhanced the liquid yield. The integrated process has a great advantage in liquid yield and distribution. 3.3 Thermal conversion liquid product composition of different processes Besides the product yields, we also perform comparison on the liquid products structure and molecular composition for DAO FTC, VR delayed coking and FTC. The liquid property is defined as the product ranging from gasoline to gas oil. The molecular composition of liquid product from FCC unit of ISFTC is not discussed since they showed typical FCC product composition characteristics. Obviously, the quality of liquid product of FCC with the better DAO as feedstock is better enough for follow-up treatment than DC and FTC with VR. According to the results, we could estimate that whether the properties of liquid product of FTC unit will affect its subsequent processing due to the inferior DOA. (1) Bulk Properties The properties of thermal converting liquid product of different processes with DGVR as feedstock are listed in Table 8. It could be seen that the liquid product bulk properties from DOA FTC and VR FTC were similar. They have similar carbon residue, viscosity, density, and hydrogen content. Considering the poor quality of DOA (comparing to VR, which are the feedstock for direct delayed coking and fluid thermal conversion), the product quality is acceptable. However, the quality of DOA

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FTC and VR FTC are inferior than VR delayed coking. The reason may be due to reaction time for delay coking are much longer. (2) Molecular structure parameters The methods of GPC and nuclear magnetic resonance, NMR are used to measure the relative molecular structure of three thermal conversion liquids. The average molecular structure parameters obtained by the modified Brown-Ladner method are listed in Table 9 [37, 38]. DOA FTC liquid and VR FTC liquid have similar molecular weight, which are quite higher than VR delayed coking. Obviously, the reason is because of reaction conditions difference. The feedstock difference between DOA and VR play less important roles. The structure parameters for DOA FTC and VR FTC are similar also. For the hydrogen atom fractions and aromatic-carbon ratio, on the whole, the aromatic-carbon hydrogen fractions of three liquids are all small, only about 3%~4%, β-carbon hydrogen have the highest proportion. Compared to VR FTC, DOA FTC liquid has slightly higher aromatic carbon ratio fA about 0.19. They have similar aromatic ring number RA around 1 and naphthenic ring number RN around 2. While delayed coking liquid has lower fA of 0.105, less aromatic ring number and naphthenic ring number. The average side chain length L is the same for all three liquids. (3) Molecular composition To investigate the molecular composition difference of acidic, non-basic and alkaline heteroatom species in three samples, Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FT-ICR MS) was applied with the negative and positive ion electrospray ionization (±ESI) as ion sources [39-43]. The broadband positive-ion mass spectrograms are shown in Figure 6. For fluid thermal conversion and DOA FTC, the mass distribution was very similar. The both mass spectrums mainly ranged from m/z 220 to 700, centered at m/z 480. For the delayed coking, the mass spectrum primarily distributed from m/z 200 to 600, centered at m/z 380. The negative-ion mass spectrums are shown in Figure 7. The delayed coking ranged from m/z 200 to 500, centered at m/z 300. Fluid thermal conversion and DOA FTC were both in m/z 220~600, centered at m/z 350. In two kinds of ion source, the mass spectrum and maximum peak slightly increased as the sequence of VR DC, VR FTC and DOA FTC. It can be seen that the molecular weight of liquid products from fluid thermal conversion and DOA FTC distributed in higher range than delayed coking, which is in consistent with GPC result in Table 8.

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Figure 8 shows the distributions of various class species in different thermal converting liquid products from positive and negative-ion ESI FT-ICR MS. In positive-ion ESI FT-ICR MS mass spectra, for three liquid samples, the class species identified from mass spectra all mainly included N1, N1O1, N1O2, N2, N2O1. The N1 class species were dominant and the N1O2 and N2O1 class species were the least. For the relative abundance of N1 class species (pyridine derivative compounds), DOA FTC was less than VR Delayed coking and FTC. And the relative abundance of N2 class species of DOA FTC was the highest in all three samples. In negative-ion ESI FT-ICR MS mass spectra, the class species of three samples all included N1, N1O1, N1O2, O1 and O2. For the liquid of DOA FTC, the N1 class species (pyrrole derivative compounds) had the highest relative abundance, but the O1 and O2 were significantly the least. Compared to delayed coking and fluid thermal conversion, it was seen that DOA FTC could produce more alkaline nitrides and less oxygen-containing compounds. For the N1 class species having the highest relative abundance in positive and negative-ion ESI FT-ICR MS mass spectra, the isoabundance plots of equivalent double bond (DBE) as a function of the carbon number for non-basic and basic nitrogen compounds were shown in Figure 9. The plots of liquid product of fluid thermal conversion were close to DOA FTC. For basic nitrogen compounds (pyridine derivative compounds), the DBE value mainly concentrated in 4~20, carbon number distribution was 22~42. And for pyrrole compounds, DBE value was in 8~20, carbon number distribution was 18~30. Relatively, compared to DOA FTC, the VR delayed coking had huge differences. For basic nitrogen compounds, DBE value of delayed coking was mainly in 3~12 and carbon number distribution is 22~32. For non-basic nitrogen compounds, DBE value was in 8~14, carbon number distribution was 16~24. The distribution ranges of basic and non-basic compounds of DOA FTC were both higher. For DOA FTC liquid, DBE value and carbon number of N1 class species became bigger ranges and the center of distribution also slightly increased. Figure 10 compared the relative abundance as a function of DBE value of N1 class species. Compared to DOA FTC, in low DBE value of basic and non-basic nitrogen compounds which ranges respectively are 4~9 and 6~12, the isoabundance of delayed coking was higher. But, in high DBE range, it became less. Compared fluid thermal conversion with DOA FTC, there was a more balanced distribution in overall DBE value. For basic nitrogen compounds, in low DBE value (4~10), DOA FTC had

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higher relative abundance, but in high DBE it is opposite. For non-basic nitrogen compounds, except the middle DBE value (12~15), DOA FTC was always higher than fluid thermal conversion. 4. Conclusion (1) An integrated process of supercritical fluid extraction and fluidized thermal conversion, ISFTC was developed and realized in continuous laboratory apparatus. The extracted DAO is fed into fluid catalytic cracking, FCC and DOA with extraction solvent is directly sprayed into fluidized thermal converter. Compared to VR delayed coking and VR fluid thermal conversion, the yield of total liquid product of ISFTC including DAO FCC and DOA fluid thermal conversion, FTC has been greatly increased. The integrated process not only solves the difficulties of DOA in transport and upgrading, but also achieves more oil products for heavy petroleum feedstock. (2) The properties, structure parameters and molecular compositions of DOA FTC are similar to VR FTC. Compared to VR delayed coking, the properties of DOA FTC liquid is relatively inferior, such as higher carbon VR, density, nitrogen content and lower NH/NC. At the molecular level, the FTC liquid product contains more heavier components, larger molecule, more basic and non-alkaline nitrides, less oxygen-containing compounds and more high-condensation compounds. The main reason may be the longer reaction time for delayed coking. (3) The total yield of ISFTC is made up of two parts, the DAO FCC and DOA FTC. Although the total yield is higher than VR FTC, the liquid yield of DOA FTC is lightly less and similar. The more yield of liquid product of ISFTC was supplied by DAO FCC. And due to the short time of thermal conversion in the reactor of FTC, the difference of the liquid product of structure and molecular composition between DOA FTC and VR FTC is small. And although the liquid quality of DOA FTC is inferior to VR delayed coking, the quality is sufficient for the subsequent processing. Consider the high total liquid yield, the development and research of ISFTC process is valuable. Author Information Corresponding Authors *Email: [email protected]; Notes The authors declare no competing financial interest.

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Acknowledgments This work was supported by National Natural Science Foundation of China (No. U1162204).

References [1]

Shah,

Sean; Greaves,

Amjad; Fishwick, Malcolm.

A

Robert; Wood, review

of

Joseph; Leeke,

novel

techniques

Gary; Rigby, for

heavy

oil and bitumen extraction and upgrading. Energy and Environmental Science, 2010, 3(6), 700-714. [2] Zhao S. Q., Kotlyar L. S., Woods J. R., Sparks B. D., Kung J., Chung K. H. A benchmark assessment of VR: comparison of Athabasca bitumen with conventional and heavy crudes. Fuel, 2002, 81 (6): 7372746. [3] Zhao S. Q., Kotlyar L. S., Sparks B. D., Woods J. R., Gao J. S., Chung K. H. Solids content s , properties and molecular structures of asphaltenes from different oil sands. Fuel, 2001, 80: 190721914. [4] Zhang Z. G., Guo S. H., Yan G. G., Zhao S. Q., Song L. Q., Chen, L. B. Distribution of polymethylene bridges and alkyl side chains in Dagang vacuum VR asphaltene and SFEF tailing asphaltene. Journal of Chemical Industry and Engineering (China), 2007, 58 (10): 260122607. [5] Li S., Liu C., Que G., et al. Colloidal structures of three Chinese petroleum vacuum VRs. Fuel, 1996, 75 (8), 1025-1029. [6] Shi T. P., Hu Y. X., Xu Z. M., Su T., Wang, R. A. Characterizing petroleum vacuum VR by supercritical fluid extraction and fractionation. Ind. Eng. Chem. Res., 1997, 36 (9): 398823992. [7] Yang, G. H., Wang R. A. The supercritical fluid extractive fractionation and the characterization of heavy oils and petroleum residua. Journal of Petroleum Science and Engineering, 1999, 22 (1): 47252. [8] Shi T. P., Xu Z. M., Cheng M., Hu Y. X., Wang R. A. Characterization index for vacuum residua and their subfractions. Energy & Fuels, 1999, 13 (4): 8712876. [9] Subramanian M., Hanson F. V. Supercritical fluid extraction of bitumen from Utah oil sands. Fuel Processing Technology, 1998, 45(3):25~28. [10] Brons G., Yu J. M. Solvent Deasphalting Effects on Whole Cold Lake Bitumen. Energy & Fuels, 1995, 9 (4), 641-647. [11] Rose J. L, Monnery W. D., Chong K., et al. Experimental data for the extraction of Peace River bitumen using supercritical ethane. Fuel, 2001, 80 (8), 1101-1110.

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[12] Xu C., Hamilton S., Mallik A., et al. Upgrading of Athabasca Vacuum Tower Bottoms

(VTB)

in

Supercritical

Hydrocarbon

Solvents

with

Activated

Carbon-Supported Metallic Catalysts. Energy & Fuels, 2007, 21 (6), 3490-3498. [13] Sangcheol Shin, Jung Moo Lee, Ji Won Hwang, Hyun Wook Jung, Nam Sun Nho, Ki Bong Lee. Physical and rheological properties of deasphalted oil produced from solvent deasphalting. Chemical Engineering Journal, 2014(257), 242-247. [14] Fahai Cao, Dan Jiang, Wudong Li, Ping’an Du, Guizhong Yang, Weiyong Ying. Process analysis of the extract unit of vacuum residue through mixed C4 solvent for deasphalting. Chemical Engineering and Processing: Process Intensification, 2010, 49(1), 91-96. [15] Zachariah, Ashley; De Klerk, Arno. Partial Upgrading of Bitumen: Impact of Solvent Deasphalting and Visbreaking Sequence. Energy and Fuels, 2017, 31(9), 9374-9380. [16] Zhao S., Kotlyar L. S., Sparks B. D., et al. Solids contents, properties and molecular structures of asphaltenes from different oil sands. Fuel, 2001, 80(13): 1907-1914. [17] Mannistu K. D., Yarranton H. W., Masliyah J. H. Solubility Modeling of Asphaltenes in Organic Solvents. Energy & Fuels, 1997, 11 (3), 615-622. [18] Pérez-Hernández R., Mendoza-Anaya D., Mondragón-Galicia G., et al. Microstructural study of asphaltene precipitated with methylene chloride and n-hexane. Fuel, 2003, 82 (8), 977-982. [19] Scott D. S., Radlein D., Piskorz J., et al. Upgrading of bitumen in supercritical fluids. Fuel, 2001, 80 (8), 1087-1099. [20] Trejo F., Ancheyta J., Rana M. S. Structural Characterization of Asphaltenes Obtained from Hydroprocessed Crude Oils by SEM and TEM. Energy & Fuels, 2009, 23 (1), 429-439. [21] Gray M. Fundamentals of bitumen coking processes analogous to granulations: a critical review. Chemical Engineering. 2002(80): 393-401. [22] Rodriguez Reinoso F., Santana P, Palazon E. R., et al. Delayed coking: industrial and laboratory aspects. Carbon, 1998, 36(1): 105-116. [23] Gray, M.R., Tuyet Le, William C., et al. Coupling of mass transfer and reaction in coking of thin films of an Athabasca vacuum VRs. Engineering of Chemical Research. 2001(40): 3317-3324. [24] Clayton Stanlick, Franco Berruti, Cedric Briens. Effect of mixing and vapor residence time on thermal cracking of bitumen in a Mechanically Fluidized Reactor.

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Fuel, 2017(200), 481-487. [25] Edward Furimsky. Characterization of cokes from fluid/flexi-coking of heavy feeds. Fuel Processing Technology, 2000, 67(3), 205-230. [26] Darabi, Pirooz; Pougatch, Konstantin; Salcudean, Martha; Grecov, Dana. Agglomeration of bitumen-coated coke particles in fluid cokers. International Journal of Chemical Reactor Engineering, 8 (2010). [27] Soskind D. M., Spektor G. S., Kasatkin D. F., et al. Fluid coking of heavy VRs. Chemistry and Technology of Fuels and Oils, 1982, 18(10):483-488. [28] Wang S. F., Wang H. B., Liu W. J. Preliminary exploration of fluidized coking technology. Proceedings of the 12th national chemical society annual meeting of China chemical society, 2011, 28:205-206. [29] Peter K., Saberian M., Briens C. L., et al. Injection of a liquid spray into a fluidized bed: particle-liquid mixing and impact on fluid coker yields. Industrial & engineering chemistry research, 2004, 43(18): 5663-5669. [30] Li Han, Zhi-Min Zong, Xin Jin, Yan-Qiu Wang.et al. Solubility of Dagang vacuum VR and molecular composition of the soluble fractions in different solvents. Fuel, 2008, 87(2), 260-263. [31] Wang Jun, Li Ruili, Meng Xianghai, Zhao Suoqi, Xu Chunming. Study on processing complementarity of Canadian synthetic crude oil and Dagang crude (I) properties of crudes and narrow fractions. Petroleum refinery engineering, 2008, 38(4), 9-13. [32] Xu C. M., Lin S. X. Effects of residual chemical composition on catalytic cracking reaction. Journal of petroleum, 1998,14(2):1-5. [33] Xu C. M., Zhao S. Q., Lu C. X., et al. Research on the engineering foundation of the new process of separation of heavy oil cascade. Journal of chemical engineering, 2010, 61(9): 2393-2400. [34] Niu Y. L., Ding L. H., Liu Y. F., et al. Characteristics of catalytic cracking reaction of decompression VR. Journal of petroleum university, 1997, 21(6): 63-70. [35] Richard P. D., William C., Murray R. G. Thermal cracking of Athabasca bitumen: influence of steam on reaction chemistry. Energy&Fuels.2000, 14(3): 671-676. [36] Wang H. L., Wang G., Zhang D., et al. Research on the pretreatment reaction of Liaohe vacuum residuum fluidization and heat transfer process. Modern chemical engineering. 2011, 11(30):278-282. [37] Zhao S. Q., Xu Z. M., Xu C. M., Chung K. H., Wang R. A. Systematic characterization of petroleum residua based on SFEF. Fuel, 2005, 84 (6): 6352645.

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[38] Zhao S. Q., Xu Z. M., Xu C. M., Chung K. H. Feedstock characteristic index and critical properties of heavy crude and petroleum residua. Journal of Petroleum Science and Engineering, 2004, 41 (3): 2332242. [39] Lateefah A., Kim S., Rodger R. P., et al. Characterization of compositional changes in vacuum gas oil distillation cuts by electrospray ionization Fourier transform-ion cyclotron resonance(FT-ICR) mass spectrometry. Energy & Fuels, 2006, 20(4): 1664-1673. [40] Qian K., Rodgers R. P., Hendrickson C. L., et al. Reading chemical fine print: Resolution and identification of 3000 nitrogen-containing aromatic compounds from a single electrospray ionization Fourier transform ion cyclotron resonance mass spectrum of heavy petroleum crude oil. Energy & Fuels, 2001, 15(2): 492-498. [41] Hughey C. A., Rodgers R. P., Marshall A. G., et al. Identification of acidic NSO compounds in crude oils of different geochemical origins by negative ion electrospray Fourier transform ion cyclotron resonance mass spectrometry. Organic geochemistry, 2002, 33(7): 743-759. [42] Muller H., Andersson J. T., Schrader W. Characterization of high-molecular weight sulfur-containing aromatics in vacuum VRs using Fourier transform ion cyclotron resonance mass spectrum. Analytical chemistry, 2005, 77(8): 2536-2543. [43] Panda S. K., Schrader W., et al. Distribution of polycyclic aromatic sulurheterocycles in three Saudi Arabian crude oils as determined by Fourier transform ion cyclotron resonance mass spectrum. Energy & Fuels, 2007, 21(2): 1071-1077.

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Tables Table 1. Properties of Dagang vacuum residue Properties CCR, wt% Viscosity (100 oC), mPa·s Density (20 oC), g/cm3 API° Carbon, wt% Hydrogen, wt% H/C Sulfur, wt% Nitrogen, wt% Nickel, µg/g Iron, µg/g Vanadium , µg/g Saturates, wt% Aromatics, wt% Resins, wt% C7 asphaltene, wt%

DGVR 16.80 1098 0.9672 14.26 86.85 11.62 1.61 0.26 0.78 81 44 1.2 26.22 38.45 32.12 3.21

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Table 2. Operating conditions for FCC experiments Conditions Reaction temperature, oC Valve box temperature, oC Medium preheating temperature, oC Preheating furnace temperature, oC Feed quantity, g Catalyst quantity, g Inlet rate, g/min Fluidized rate, mL/min Feeding time, s Dwell time, s Stripping time, min weight hourly space velocity, h-1

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Value 500 100~160 350 350 10 60 20 2.0 30 1.5~4 45 20

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Table 3. Properties of fresh LDO-70 catalyst Properties Ignition loss, wt% Catalyst components, wt%

Size distribution (φ), wt%

Al2O3 Na2O Re2O3 0~45.8 ηα 45.8~111.0 ηα >111.0 ηα

Wear index, %·h-1 Pore volume, mL·g1 Specific surface area, m2/g Micro-activity (800℃, 17 h), %

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LDO-70 12.7 49.0 0.12 4.2 23.5 55.4 21.1 1.8 0.40 243 70

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Table 4. Operating conditions of ISFTC Supercritical Conditions fluid extraction Conditions unit Extraction solvent iso-butane Carrier to DOA mass ratio Pressure, MPa 5 Medium flow rate, g/min Solvent to feedstock 4:1 Reaction temperature, oC Extraction temperature, oC 100 Separation temperature, oC 160

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Fluid thermal conversion unit 3:1 4 520

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Table 5. Yield and properties of DAO and DOA Yield and properties Yield, wt% CCR, wt% Softening point, oC Density(20oC), g/cm3 Viscosity(50oC), mPa·s H/C Average molecular weight Sulfur, wt% Nitrogen, wt% Nickel, µg/g Vanadium , µg/g Saturates, wt% Aromatics, wt% Resins, wt% C7 asphaltene, wt%

DAO 48.30 3.63 -0.9303 694 1.70 968 0.21 0.37 9.87 0.35 56.82 27.11 14.00 1.36

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DOA 51.70 28.44 113.8 1.0262 -1.37 2399 0.31 1.04 124 1.70 0.00 47.02 47.91 5.07

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Table 6. Product distribution of DAO FCC and DOA FTC Products yield, wt% DAO FCC DOA FTC

Coke 7.53 39.62

Dry gas LPG 6.02 8.82 9.76 2.28

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Liquid 77.63 48.34

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Table 7. Liquid product distribution of DAO FCC and DOA FTC Products yield, wt% DAO FCC DOA FTC

Gasoline Diesel 49.02 18.04 4.01 8.96

CGO 10.57 35.37

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Total 77.63 48.34

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Table 8. Basic physical properties of thermal conversion liquid products Properties CCR, wt% Viscosity(50oC), mPa·s Density(20oC), g/cm3 Carbon, wt% Hydrogen, wt% H/C Sulfur, wt% Nitrogen, wt%

VR Delayed coking 0.30 3.58 0.8350 85.68 13.27 1.85 0.21 0.35

VR FTC

DOA FTC

4.40 13.91 0.9255 86.43 12.20 1.69 0.20 0.52

4.61 7.76 0.9372 86.36 12.15 1.69 0.21 0.64

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Table 9. Liquid products average structure parameters VR Parameters VR FTC DOA FTC Delayed coking C, wt% 85.68 86.43 86.36 H, wt% 13.27 12.2 12.15 H/C 1.845 1.682 1.676 Mn 375 436 458 hA 0.03 0.04 0.04 hα 0.11 0.13 0.11 hβ 0.66 0.66 0.67 hγ 0.20 0.18 0.18 fA 0.105 0.192 0.195 fN 0.179 0.25 0.243 fP 0.716 0.557 0.561 CT 26.8 31.4 32.9 CA 2.8 6.0 6.4 HT 49.4 52.8 55.2 RA 0.47 1.01 1.11 RN 1.2 1.96 2.0 RT 1.66 2.97 3.11 CN 4.6 7.9 8.0 CP 19.2 17.5 18.5 L 5.6 5.6 5.6

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Figure Captions Figure 1. Flow sheet of supercritical fluid extraction coupling fluid thermal conversion device Figure 2. Flow diagram of fluid catalytic cracking Figure 3. Flow diagram of delayed coking device Figure 4. Flow diagram integrated supercritical fluid extraction and fluid thermal conversion (ISFTC) process Figure 5. Product distribution of different processes of DGVR Figure 6. +ESI FT-ICR MS of thermal conversion liquids Figure 7. -ESI FT-ICR MS of thermal conversion liquids Figure 8. Distribution of heteroatom types of different liquid products (a) +ESI; (b) -ESI Figure 9. DBE versus carbon number distribution of N1 class species by ±ESI FT-ICR MS Figure 10. DBE distribution of N1 class compounds

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Counterbalance Cooler Energy & Fuels Page 24 of 33 valve Feedstock pump

Heating furnace

1 Feedstock tank 2Solvent Extractor 3 tank 4 5 Solvent Cooler DOA heating 6 furnace Water 7 heating 8 furnace Fluid thermal 9 Solvent pump convertor ACS Paragon Plus Environment 10 11 Distilled Distilled water pump 12 water tank

Solvent separator

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1heating furnace Catalyst inlet 2 Stock 3 pump Gas 4 Feedstock bottle 5 FCC 6 Cooler reactor 7 ACS Paragon Plus Environment 8 9 Distilled water Liquid pump 10 water tank

Energy & FuelsPage 26 of 33 1 2 3 4 Cooler 5 Thermal 6 reactor 7 8 9 Coking gas 10 ACS Paragon Plus Environment 11 12 Coking liquid

Recycle Solvent

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Energy & Fuels Solvent Separator

1 DAO 2 3 Supercritical Fluid Residue Fluid 4 Catalytic Extraction Cracking 5 6 7 DOA 8 9 Gas 10 Liquid Fluid Coking 11 Coke 12 13 ACS Paragon Plus Environment 14 15 Integrated Supercritical Fluid ExtractionFluid Coking Technique (ISFTC)

Gas

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31.64

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CGO

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