Recent advances in supercritical water treatment of heavy oil

doi:10.16085/j.issn.1000-6613.2019-0060

Abstract

Abstract: As an environmentally solvent, supercritical water (SCH₂O) has excellent dissolution and diffusion ability for light hydrocarbon components and can be used as a reaction medium in upgrading process of heavy oil. The introduction of SCH₂O can not only strength the mass transfer, but also affect the mechanism of cracking reaction, even promote the phase behavior from liquid-liquid to the condensed emulsion or pseudo single-phase, which provides a possibility for developing new heavy oil processing technology. This paper reviewed the basic property of SCH₂O. Meanwhile, the reforming mechanism of heavy oil upgrading with supercritical water, the cracking kinetics and the transfer of phase behavior during the reaction were emphatically discussed. It was found that the pseudo single-phase of heavy oil and supercritical water can be formed under the conditions of high temperature, high pressure, vigorous stirring and high water-oil ratio which can increase conversion, decrease the viscosity and reduce coke filed. Finally, the SCH₂O development prospect and direction of SCH₂O treatment of heavy oil were outlined.

Key words: supercritical water, heavy oil, cracking kinetics, phase behavior

摘要： 超临界水作为一种对环境友好并且对轻烃组分具有良好溶解扩散能力的优良溶剂，在重油改质过程中有广泛应用。超临界水的引入不仅可以达到强化传质的目的，对热裂化机理产生影响，而且可以改变反应过程中体系的相结构，促使体系相行为从液-液两相向微乳体系甚至是拟均相转变，为开发新的重油加工工艺提供了可能。本文首先介绍了超临界水的基本性质，着重介绍了超临界水参与下重油的改质机理、反应过程中的裂化动力学以及改质过程中相行为的变化，发现在高水密度、剧烈搅拌和高水油比的条件下重油-超临界水表现出拟均相行为，能够达到改善液收、降低黏度并且减少生焦的目的。最后对超临界水处理重油的发展前景和方向进行了展望。

关键词: 超临界水, 重油, 裂化动力学, 相行为

CLC Number:

TE624

ZHANG Tingting, CHEN Xuefeng, SHEN Haiping, DA Zhijian. Recent advances in supercritical water treatment of heavy oil[J]. Chemical Industry and Engineering Progress, 2019, 38(s1): 77-85.

张婷婷, 陈学峰, 申海平, 达志坚. 超临界水在重油加工中的研究进展[J]. 化工进展, 2019, 38(s1): 77-85.

References

[1] SRIVASTAVA G, PAUL A K, GOUD V V. Optimization of non-catalytic transesterification of microalgae oil to biodiesel under supercritical methanol condition[J]. Energy Conversion and Management, 2018, 156:269-278.
[2] AKIYA N, SAVAGE P E. Roles of water for chemical reactions in high-temperature water[J]. Chemical Reviews, 2002, 102(8):2725-2750.
[3] SATO T, MORI S, WATANABE M, et al. Upgrading of bitumen with formic acid in supercritical water[J]. The Journal of Supercritical Fluids, 2010, 55(1):232-240.
[4] SATO T, TRUNG P H, TOMITA T, et al. Effect of water density and air pressure on partial oxidation of bitumen in supercritical water[J]. Fuel, 2012, 95:347-351.
[5] MORIYA T, ENOMOTO H. Role of water in conversion of polyethylene to oils through supercritical water cracking[J]. Kagaku Kogaku Ronbunshu, 1999, 25(6):940-946.
[6] CHENG Z M, DING Y, ZHAO L Q, et al. Effects of supercritical water in vacuum residue upgrading[J]. Energy & Fuels, 2009, 23(6):3178-3183.
[7] BERKOWITZ N, DUNN S R. Method for extracting and upgrading of heavy and semi-heavy oils and bitumens:US7947165B2[P]. 2011-05-24.
[8] GREGOLI A A, URIEL M O. Process for converting heavy crudes, tars and bitumens to lighter products in the presence of brine at supercritical conditions:US4818370A[P]. 1989-04-04.
[9] HE Z Q, LI L, LI L X, et al. Process and reactor for upgrading heavy hydrocarbon oils:US20080099378A1[P]. 2008-05-01.
[10] MORIMOTO M, SATO S, TAKANOHASHI T. Effect of water properties on the degradative extraction of asphaltene using supercritical water[J]. The Journal of Supercritical Fluids, 2012, 68:113-116.
[11] VILCÁ EZ J, WATANABE M, WATANABE N, et al. Hydrothermal extractive upgrading of bitumen without coke formation[J]. Fuel, 2012, 102:379-385.
[12] WATANABE M, KATO S N, ISHIZEKI S, et al. Heavy oil upgrading in the presence of high density water:basic study[J]. The Journal of Supercritical Fluids, 2010, 53(1/2/3):48-52.
[13] ZHAO L Q, CHENG Z M, DING Y, et al. Experimental study on vacuum residuum upgrading through pyrolysis in supercritical water[J]. Energy & Fuels, 2006, 20(5):2067-2071.
[14] DUTTA R P, MCCAFFREY W C, GRAY M R, et al. Thermal cracking of Athabasca bitumen:influence of steam on reaction chemistry[J]. Energy & Fuels, 2000, 14(3):671-676.
[15] SATO T, ADSCHIRI T, ARAI K, et al. Upgrading of asphalt with and without partial oxidation in supercritical water[J]. Fuel, 2003, 82(10):1231-1239.
[16] SCHLEPP L, ELIE M, LANDAIS P, et al. Pyrolysis of asphalt in the presence and absence of water[J]. Fuel Processing Technology, 2001, 74(2):107-123.
[17] KOZHEVNIKOV I, NUZHDIN A, MARTYANOV O. Transformation of petroleum asphaltenes in supercritical water[J]. The Journal of Supercritical Fluids, 2010, 55(1):217-222.
[18] RAHMANI S, MCCAFFREY W, GRAY M R. Kinetics of solvent interactions with asphaltenes during coke formation[J]. Energy & Fuels, 2002, 16(1):148-154.
[19] SATO M, GOTO M, HIROSE T. Supercritical fluid extraction on semibatch mode for the removal of terpene in citrus oil[J]. Industrial & Engineering Chemistry Research, 1996, 35(6):1906-1911.
[20] DEPEYRE D, FLICOTEAUX C. Modeling of thermal steam cracking of n-hexadecane[J]. Industrial & Engineering Chemistry Research, 1991, 30(6):1116-1130.
[21] DEPEYRE D, FLICOTEAUX C, CHARDAIRE C. Pure n-hexadecane thermal steam cracking[J]. Ind. Eng. Chem. Process Des. Dev., 1985, 24(4):1251-1258.
[22] KHORASHEH F, GRAY M R. High-pressure thermal cracking of n-hexadecane[J]. Industrial & Engineering Chemistry Research, 1993, 32(9):1853-1863.
[23] YUAN P Q, ZHU C C, LIU Y, et al. Solvation of hydrocarbon radicals in sub-CW and SCW:an ab initio MD study[J]. The Journal of Supercritical Fluids, 2011, 58(1):93-98.
[24] LIU Y, BAI F, ZHU C C, et al. Upgrading of residual oil in sub-and supercritical water:an experimental study[J]. Fuel Processing Technology, 2013, 106:281-288.
[25] SINGH J, KUMAR S, GARG M O. Kinetic modelling of thermal cracking of petroleum residues:a critique[J]. Fuel Processing Technology, 2012, 94(1):131-144.
[26] LIU Q K, ZHU D Q, TAN X C, et al. Lumped reaction kinetic models for pyrolysis of heavy oil in the presence of supercritical water[J]. AIChE Journal, 2016, 62(1):207-216.
[27] ZAFARANI M M T, SARMAD S. Measurement and correlation of phase equilibria for poly(ethylene glycol) methacrylate+alcohol systems at 298.15K[J]. Journal of Chemical & Engineering Data, 2005, 50(1):283-287.
[28] VAN KONYNENBURG P, SCOTT R. Critical lines and phase equilibria in binary van der Waals mixtures[J]. Philosophical Transactions of the Royal Society of London, Series A, Mathematical and Physical Sciences, 1980, 298(1442):495-540.
[29] BRUNNER E. Fluid mixtures at high pressures Ⅸ. Phase separation and critical phenomena in 23(n-alkane+water) mixtures[J]. The Journal of Chemical Thermodynamics, 1990, 22(4):335-353.
[30] BRUNNER E, THIES M C, SCHNEIDER G M. Fluid mixtures at high pressures:phase behavior and critical phenomena for binary mixtures of water with aromatic hydrocarbons[J]. The Journal of Supercritical Fluids, 2006, 39(2):160-173.
[31] STEVENSON R, LABRACIO D, BEATON T, et al. Fluid phase equilibria and critical phenomena for the dodecane-water and squalane-water systems at elevated temperatures and pressures[J]. Fluid Phase Equilibria, 1994, 93:317-336.
[32] AMANI M J, GRAY M R, SHAW J M. Phase behavior of Athabasca bitumen+water mixtures at high temperature and pressure[J]. The Journal of Supercritical Fluids, 2013, 77:142-152.
[33] BAI F, ZHU C C, LIU Y, et al. Co-pyrolysis of residual oil and polyethylene in sub-and supercritical water[J]. Fuel Processing Technology, 2013, 106:267-274.
[34] LIU J, XING Y, CHEN Y X, et al. Visbreaking of heavy oil under supercritical water environment[J]. Industrial&Engineering Chemistry Research, 2018, 57(3):867-875.
[35] TAN X C, LIU Q K, ZHU D Q, et al. Pyrolysis of heavy oil in the presence of supercritical water:the reaction kinetics in different phases[J]. AIChE Journal, 2015, 61(3):857-866.