Influence of Inorganic Salts on the Demulsification of Block Polyether with Seven Branches for Crude Oil Emulsion†

doi:10.7503/cjcu20130915

Abstract

Abstract:

The poly(propylene oxide)-poly(ethylene oxide) triblock polyether with seven branches(AE73) was synthesized by anionic polymerization and its demulsification for crude oil emulsion and aggregation behavior at oil/water interface were investigated in the presence of different inorganic salts. The influence mechanism of inorganic salts on the demulsification of AE73 for crude oil emulsion was studied by interfacial tension, cloud point and interfacial dilational rheology measurements. The results show that the demulsification of AE73 is enhanced in the presence of the “salting in” ions and decreased in the presence of “salting out” ions. The rate of dehydration becomes good with increasing of temperature, but the quality of dehydrated water is best at 45 ℃. This study may provide useful data for the selection and application of chemicals used in gathering and transportation of crude oil.

Key words: Branched block polyether, Crude oil emulsion, Interfacial activity, Interfacial dilational rheology, Demulsification

CLC Number:

O648

TrendMD:

YUAN Jing, ZHAI Xueru, XU Guiying, TAN Yebang, ZHANG Jian. Influence of Inorganic Salts on the Demulsification of Block Polyether with Seven Branches for Crude Oil Emulsion^†[J]. Chem. J. Chinese Universities, 2014, 35(2): 325.

Figures/Tables 9

Fig.1 Molecular structures of AE73 and hydrophobic modified polyacrylamide(HMPAM) (A) AE73, M=1.01×104; (B) HMPAM, M=1.849×107.

Fig.2 Effect of temperature on the demulsification of AE73Temperature/℃: a. 25; b. 45; c. 65.

Fig.3 Effect of inorganic salts on water quality at 60 min at different temperaturesa.Blank; b.AE73; c.AE73/NaCl; d.AE73/MgCl2; e.AE73/CaCl2; f.AE73/NaI; g.AE73/NaSCN. Temperature/℃: (A) 25; (B) 45; (C) 65.

Table 1 Effect of inorganic salt on water quality at 180 min and different temperatures

Sample	65 ℃			45 ℃			25 ℃
Sample	Oil-water interface	Dehydration water	Hang wall	Oil-water interface	Dehydration water	Hang wall	Oil-water interface	Dehydration wall	Hang wall
Blank	Indistinct	Slightly turbid	Hang	Indistinct	Turbid	Hang	Indistinct	Turbid	Hang
Without Salt	Neat	Slightly turbid	Not hang	Neat	Clearly	Slightly hang	Neat	Turbid	Slightly hang
1 mol/L NaCl	Neat	Slightly turbid	Slightly hang	Neat	Clearly	Not hang	Slightly neat	Turbid	Hang
0.5 mol/L MgCl₂	Neat	Slightly turbid	Not hang	Neat	Clearly	Not hang	Neat	Turbid	Hang
0.5 mol/L CaCl₂	Neat	Slightly turbid	Not hang	Neat	Clearly	Not hang	Slightly neat	Turbid	Hang
1 mol/L NaI	Neat	Slightly turbid	Not hang	Neat	Clearly	Slightly hang	Neat	Turbid	Slightly hang
1 mol/L NaSCN	Neat	Slightly turbid	Not Hang	Indistinct	Clearly	Slightly hang	Neat	Turbid	Slightly hang

Fig.4 Effect of inorganic salts on the demulsification of AE73 at 45 ℃—■ — Blank; —●— without salt; —▲— 0.5 mol/L CaCl2; —▼— 0.5 mol/L MgCl2; —?— 1 mol/L NaCl; —?— 1 mol/L NaI; —◆— 1 mol/L NaSCN.Inset shows the curve of the turning points enlarge.

Fig.5 Effect of inorganic salts on the cloud point (tcp) of aqueous AE73 solution

Fig.6 Interfacial tension curves of 100 mg/L AE73 in the absence and presence of inorganic salts at 25 ℃ (A) Equilibrium interfacial tension at n-heptane/water interface; (B) dynamic interfacial tension at n-heptane/water interface.

Fig.7 Dilational rheological property of AE73 at n-heptane/water interface in the absence and presence of inorganic saltsa. Without salt; b. 0.5 mol/L CaCl2; c. 0.5 mol/L MgCl2; d. 1 mol/L NaCl; e. 1 mol/L NaSCN; f. 1 mol/L NaI. ε: Dilational modulus; εd: dilational elastic modulus; ηωd: dilational viscous modulus. Dilational frequency: 0.01 Hz, cAE73=100 mg/L.

Fig.8 Schematic diagram of demulsification of branched polyether(A) and contact point and distribution of block polyether(B)Effect of salts with salting out and salting in type. Blue: PO group; Red: EO group; Green: Ether oxygen atoms; Gray balls: water-drop.

References 32

[1]	Xia L. X., Lu S. W., Cao G. Y., Chem. Eng. Commun., 2004, 191(8), 1053—1063
[2]	Wu X., Energy Fuels, 2002, 17(1), 179—190
[3]	Xia L. X., Lu S. W., Cao G. Y., J. Colloid Interface Sci., 2004, 271(2), 504—506
[4]	Li M. Y., Acta Petrolei Sinica(Petroleum Processing Section), 1995, 11(3), 1—6
	(李明远.石油学报(石油加工), 1995, 11(3), 1—6)
[5]	Wu J., Xu Y., Dabros T., Hamza H., Energy Fuels, 2003, 17(6), 1554—1559
[6]	Kang W. L., Liu S. R., Xu B., Wang X. Z., Zhang B. T., Bai B. J., Pet. Sci. Technol., 2013, 31(6), 572—579
[7]	Kang W. L., Jing G. L., Zhang H. Y., Li M. Y., Wu Z. Y., Colloids Surf. A, 2006, 272, 27—31
[8]	Tong K., Zhang Y., Chu P. K., Colloids Surf. A, 2013, 419, 46—52
[9]	Al-Sabagh A. M., Kandile N. G., Noor El-Din M. R., Sep. Sci. Technol., 2011, 46(7), 1144—1163
[10]	Mokhtari B., Pourabdollah K., Chem. Res. Chinese Universities, 2012, 28(5), 807—813
[11]	Wang J., Li C. Q., An N., Yang Y., Sep. Sci. Technol., 2012, 47(10), 1583—1589
[12]	El-Ghazawy R. A., Al-Sabagh A. M., Kandile N. G., El-Din M. R. N., J. Dispersion Sci. Technol., 2010, 31(10), 1423—1431
[13]	Qiu J., Pet. Sci. Technol., 2013, 31(2), 142—147
[14]	Cendejas G., Arreguin F., Castro L. V., Flores E. A., Vazquez F., Fuel, 2013, 103, 356—363
[15]	Xie Y. J., Yan F., Yan Z. J., Zhang J. M., Li J. X., J. Dispersion Sci. Technol., 2012, 33(12), 1674—1681
[16]	Zhai X. R., Liu T., Xu G. Y., Tan G. R., Lv X., Zhang J., Acta Phys-Chim Sin., 2013, 29(6), 1253—1259
	(翟雪如, 刘腾, 徐桂英, 檀国荣, 吕鑫, 张健.物理化学学报,2013, 29(6), 1253—1259)
[17]	Zhang Z. Q., Xu G. Y., Wang F., Dong S. L., Li Y., J. Colloid Interface Sci., 2004, 277(2), 464—470
[18]	Qin S. F., Li W. L., Oilfield Chemistry, 1988, 5(1), 6—10
	(覃守凤, 李外郎.油田化学,1988, 5(1), 6—10)
[19]	Fang X. L., Qin S. F., Li W. L., Oilfield Chemistry, 1989, 6(3), 221—225
	(方晓烈, 覃守凤, 李外郎.油田化学,1989, 6(3), 221—225)
[20]	Mei Z., Xu J., Sun D. J., Colloids Surf. A, 2011, 375, 102—108
[21]	Xia L. X., Cao G. Y., Lu S. W., Acta Petrolei Sinica(Petroleum Processing Section), 2003, 19(4), 94—97
	(夏立新, 曹国英, 陆世伟.石油学报(石油加工), 2003, 19(4), 94—97)
[22]	Zhai X. R., Xu G. Y., Chen Y. J., Liu T., Zhang J., Yuan J., Tan Y. B., Zhang J., Colloid. Polym. Sci., 2013, 291 (12), 2825—2836
[23]	Gong H. J., Xu G. Y., Ding H., Shi X. F., Tan Y. B., Eur. Polym. J., 2009, 45(9), 2540—2548
[24]	Li G.Z., Zheng L. Q., Xu G. Y., Colloid Chemistry in Petroleum Exploration and Development, Chemical Industry Press, Beijing, 2007, 47—97
	(李干佐, 郑利强, 徐桂英. 石油开采中的胶体化学, 北京: 化学工业出版社, 2007, 47—97)
[25]	Kumar S., Patel H., Patil S., Colloid. Polym. Sci., 2013, 291(9), 2069—2077
[26]	Zhao G.X., Zhu B. Y., Principles of Surfactant Action, China Light Industry Press, Beijing, 2003, 269—270
	(赵国玺, 朱王步瑶. 表面活性剂作用原理, 北京: 中国轻工业出版社, 2003, 269—270)
[27]	Wang Y.J., Aggregation Behavior of Poly(dimethylsiloxane)-ethoxylate/propoxylate at Interface, Shandong University,Jinan, 2009
	(王雅静. 聚氧乙烯聚氧丙烯二甲基硅氧烷的界面聚集行为, 济南: 山东大学, 2009)
28	[28] Zhang Z. Q., Xu G. Y., Wang F., Dong S. L., Chen Y. J., J. Colloid Interface Sci., 2005, 282(1), 1—4
[29]	Wang Z. L., Li Z. Q., Zhang L., Huang H. Y., Zhang L., Zhao S., Yu J. Y., J. Chem. Eng. Data, 2011, 56(5), 2393—2398
[30]	Ramírez P., Stocco A., Muñoz J., Miller R., J. Colloid Interface Sci., 2012, 378(1), 135—143
[31]	Zhang H. X., Xu G. Y., Wu D., Wang S. W., Colloids Surf., A, 2008, 317(1—3), 289—296
[32]	Ji G. D., Zhou G. H., Chem. Res. Chinese Universities, 2012, 28(3), 419—423