Base Oil Production Ii

This article was downloaded by:[CSIR Order] On: 18 September 2007 Access Details: [subscription number 779749116] Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK

Petroleum Science and Technology Publication details, including instructions for authors and subscription information: http://www.informaworld.com/smpp/title~content=t713597288

Base Oil Production. Part II: Dewaxing, Finishing, and Blending A. M. Al Nagar a; E. A. El Shamy a a Egyptian Petroleum Research Institute, Naser City, Cairo, Egypt

Online Publication Date: 01 July 2007 To cite this Article: Nagar, A. M. Al and Shamy, E. A. El (2007) 'Base Oil Production. Part II: Dewaxing, Finishing, and Blending', Petroleum Science and Technology, 25:7, 853 - 866 To link to this article: DOI: 10.1080/10916460500297088 URL: http://dx.doi.org/10.1080/10916460500297088

PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: http://www.informaworld.com/terms-and-conditions-of-access.pdf This article maybe used for research, teaching and private study purposes. Any substantial or systematic reproduction, re-distribution, re-selling, loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.

Downloaded By: [CSIR Order] At: 08:44 18 September 2007

Petroleum Science and Technology, 25:853–866, 2007 Copyright © Taylor & Francis Group, LLC ISSN: 1091-6466 print/1532-2459 online DOI: 10.1080/10916460500297088

Base Oil Production. Part II: Dewaxing, Finishing, and Blending A. M. Al Nagar and E. A. El Shamy Egyptian Petroleum Research Institute, Naser City, Cairo, Egypt

Abstract: Three feedstocks supplied by Alexandria Petroleum Company were adjusted to bench scale extraction as a first step in refining using N-methyl pyrrolidone (NMP) and NMP containing 10% ethanolamine at the most suitable extraction conditions. The raffinates were solvent-dewaxed under constant dewaxing conditions. Then the dewaxed oils were treated with adsorption technique or with oleum treatment followed by adsorption technique to produce finished base oils. Eight formulated blends were prepared by blending selective base oils. The base oils and blended ones were evaluated according to the standard specifications of the Egyptian Organization for Standardization (EOS) and Mobil velocite oil. Keywords: finishing, solvent dewaxing, spindle oil, textile base oil

INTRODUCTION Base oils in their various fields of applications require different specifications. These can only partly be satisfied by suitable choice of feedstock and the sequence of manufacturing processes, or even by some modifications of these processes. Lubricating oil production consists mainly of two steps: the manufacture of lubricant base oil and the blending by additives or other base oils Nowadays, lubricant base oils are made from selected crude oils by a selected refining process; these refining processes include these basic steps: 1. Distillation: to isolate individual raw lube oils fractions. 2. Solvent deasphalting: to produce heavy lube base oils that called bright stock from vacuum residue. 3. Solvent or hydrogen refining: to improve viscosity index and remove undesirable constituents. Address correspondence to Ebaa El-Shamy, Egyptian Petroleum Research Institute, Naser City, Cairo, Egypt. E-mail: [email protected] 853

Downloaded By: [CSIR Order] At: 08:44 18 September 2007

854

A. M. Al Nagar and E. A. El Shamy

4. Solvent or catalytic dewaxing: to remove wax and improve the low temperature properties such as pour point of paraffinic base oils. 5. Clay or hydrofinishing to improve the color, stability, and quality of the lubricant base stocks (Soudek, 1974; Brock, 1987; Sequira, 1994; Kramer et al., 2001). The present study deals with the production of base oils for textile machines from three feedstocks of different boiling point ranges from Alexandria Petroleum Company.

EXPERIMENTAL The schematic presentation of the processing sequence followed in this study is given in Figure 1.

Figure 1. The schematic presentation of the processing sequence.

Downloaded By: [CSIR Order] At: 08:44 18 September 2007

Base Oil Production for Textile Machines

855

The raffinates obtained under the most suitable extraction conditions (Al Nagar et al., 2004) were taken as the feedstocks for solvent dewaxing (Table 1). Solvent Dewaxing Dewaxing processes were carried out at dewaxing temperature of 15ı C using a solvent mixture composed of methyl ethyl ketone (MEK), benzene (B), and toluene (T) in the ratio of 40:30:30 by weight, and at constant solvent feed ratio of 3:1 and 1:1 for dilution and washing, respectively (El Shafey et al., 1985). Finishing The finishing process was considered the final step in refining processes. All the dewaxed oils (I to V) were treated with adsorption technique via percolation using bentonite as adsorbent at 80ıC (Figure 1). Treated oleum followed by an adsorption technique was carried out for dewaxed oils III and IV by using 10 and 25 wt% oleum for dewaxed oil IV and on using 25 wt% oleum for dewaxed oil III at a reaction temperature of 65ı C and under agitation for nearly 1 hour to remove the undesired contaminated constituents (Mikhail et al., 1971). Blending To adjust certain property and to produce various grades of textile base oils, different blends were made by mixing the following base oils: Base oil I (10–80 wt%) C base oil VI (90–20 wt%) Base oil V (10–80 wt%) C base oil VII (90–20 wt%) Blends were made in a molten state with delicate stirring at room temperature to secure homogeneous blends.

RESULTS AND DISCUSSION The raffinates are characterized by their paraffinicity nature in terms of high saturates and wax contents, the percentage of paraffinic carbon (%CP ) per molecule, and the viscosity index. The high pour point of the raffinates is related to the high wax content (Table 1). Hence, the raffinates must be subjected to solvent dewaxing to remove the high melting waxes to overcome their poor effects on the low temperature characteristic (Table 1 and Figure 1).

Downloaded By: [CSIR Order] At: 08:44 18 September 2007

856

A. M. Al Nagar and E. A. El Shamy

Table 1. Physical characteristics, hydrocarbon component analysis, and structural group analysis of the feeds of solvent dewaxing process No. of the feed Boiling range, C

I 300–350

II 350–400

The most suitable conditions of extraction Solvent NMP NMP C 10% EA Solvent feed ratio 2/1 2/1 Temperature, ı C 60 60 Characteristics Yield, wt% Refractive index, 70ı C Density, gm/cc, 70ı C Mean molecular weight Pour point, ı C Sulphur content, wt% Kinematic viscosity, cSt, 40ı C Kinematic viscosity, cSt, 100ı C Viscosity index VGC REN Wax content, wt% Component analysis Total aromatics, wt% Total saturates, wt% Structural group analysis Carbon distribution % CA % CN % CR % CP Ring content analysis RA RT RN

Raffinate I 68.10 1.4545 0.8164 334

Raffinate II 77.65 1.4585 0.8209 320

NMP

III 250–340

NMP

2/1 60

NMP C 10% EA 2/1 60

Raffinate III 68.74 1.4617

Raffinate IV 79.65 1.4651

Raffinate V 69.92 1.4568

0.8339 409

0.8389 391

2/1 50

0.8171 314

43 0.57 17.0

42 0.71 17.5

49 0.58 30.8

48 0.78 32

35 0.49 15.25

3.76

3.92

5.6

5.92

3.42

110 0.8054 0.9114 34.72

120 0.8170 0.4622 31.86

122 0.8208 0.7624 31.72

130 0.8269 0.4153 26.25

95 0.8159 1.6711 25.35

18.69 81.31

23.30 76.70

20.79 79.21

24.22 75.78

25.53 74.47

7.52 19.01 26.53 73.47

10.86 20.34 31.20 68.80

7.66 23.57 31.23 68.77

10.92 22.55 33.47 66.53

6.56 20.06 26.62 73.38

0.35 0.92 0.57

0.45 0.98 0.53

0.37 1.47 1.10

0.45 1.57 1.12

0.32 0.94 0.62

VGC D viscosity gravity constant. REN D refining effectiveness number.

Effect of Solvent Dewaxing The yield of the dewaxed oils calculated on the raffinate and the feed basis is greatly affected; it ranges from 66.14 to 73.58 wt% on the former and from 45.04 to 57.42 wt% on the latter basis, respectively, due to the separation of a great amount of wax as well as the oil inherent to such wax (Tables 2–4). It can also be observed that the yields of the dewaxed oils II and IV are

Downloaded By: [CSIR Order] At: 08:44 18 September 2007

Base Oil Production for Textile Machines

857

Table 2. Effect of the dewaxing variables on the physical characteristics, hydrocarbon component analysis, and structural group analysis of dewaxed raffinates of feed I NMP alone

Solvent of extraction Characteristics Yield on raffinate, wt% Yield on feedstock, wt% Refractive index, 70ıC Density, gm/cc, 70ı C Mean molecular weight Pour point, ı C Sulphur content, wt% Kinematic viscosity, cSt, 40ıC Kinematic viscosity, cSt, 100ıC Viscosity index VGC Color Wax content, wt% Component analysis Total aromatics, wt% Total saturates, wt% Structural group analysis Carbon distribution % CA % CN % CR % CP Ring content analysis RA RT RN

NMP C 10% EA

Raffinate I

Dewaxed oil I

Raffinate II

Dewaxed oil II

— 68.10 1.4545 0.8164 334 43 0.57 17.0

66.14 45.04 1.4640 0.8369 277 8 0.94 20.4

— 77.65 1.4585 0.8209 320 42 0.71 17.5

69.28 53.80 1.4685 0.8468 264 9 1.11 21.5

3.76

4.00

3.92

4.15

110 0.8054 — 34.72

85 0.8352 4.5 3.78

120 0.8170 — 31.86

89 0.8420 5 3.48

18.69 81.31

25.85 74.15

23.30 76.70

27.18 72.82

7.52 19.01 26.53 73.47

11.53 29.25 30.78 59.22

10.86 20.34 31.20 68.80

14.59 31.22 45.81 54.19

0.35 0.92 0.57

0.87 1.52 0.65

0.45 0.98 0.53

0.96 1.59 0.63

VGC D viscosity gravity constant. Solvent:  MEK C benzene C toluene 40:30:30. Dewaxing temperature D 15ıC. Solvent to feed ratio D 3:1.

somewhat higher than I and III, calculated on the basis of feedstock, which may be due to the higher yields of raffinates obtained by extraction with N-methyl pyrrolidone (NMP) containing ethanolamine (EA) for the former and those obtained by extraction with pure NMP for the latter.

Downloaded By: [CSIR Order] At: 08:44 18 September 2007

858

A. M. Al Nagar and E. A. El Shamy

Table 3. Effect of the dewaxing variables on the physical characteristics, hydrocarbon component analysis, and structural group analysis of the dewaxed raffinates of feed II NMP alone

Solvent of extraction Characteristics Yield on raffinate, wt% Yield on feedstock, wt% Refractive index, 70ı C Density, gm/cc, 70ı C Mean molecular weight Pour point, ı C Sulphur content, wt% Kinematic viscosity, cSt, 40ı C Kinematic viscosity, cSt, 100ı C Viscosity index VGC Color Wax content, wt% Component analysis Total aromatics, wt% Total saturates, wt% Structural group analysis Carbon distribution % CA % CN % CR % CP Ring content analysis RA RT RN

NMP C 10% EA

Raffinate III

Dewaxed oil I

Raffinate IV

Dewaxed oil II

— 68.74 1.4617 0.8339 409 49 0.58 30.8

68.32 46.96 1.4752 0.8573 314 6 1.38 39.2

— 79.65 1.4651 0.8389 391 48 0.78 32

72.09 57.42 1.4785 0.8615 311 7 1.63 40.3

5.6

5.9

5.92

6.1

122 0.8208 — 31.72

90 0.8443 8 2.94

130 0.8269 — 26.25

95 0.8480 8.5 2.86

20.79 79.21

33.65 66.35

24.22 75.78

35.44 64.56

7.66 23.57 31.23 68.77

12.72 28.54 41.26 58.74

10.92 22.55 33.47 66.53

15.89 31.57 47.46 52.54

0.37 1.47 1.10

0.91 2.11 1.20

0.45 1.57 1.12

0.99 2.17 1.18

VGC D viscosity gravity constant. Solvent:  MEK C benzene C toluene 40:30:30. Dewaxing temperature D 15ıC. Solvent to feed ratio D 3:1.

The effect of wax removal upon the nature of the raffinates is reflected by the decrease in pour point, viscosity index, and mean molecular weight and the increase of a viscosity-gravity constant (Tables 2–4). These changes result from the decrease in the saturated constituents and, consequently, the

Downloaded By: [CSIR Order] At: 08:44 18 September 2007

Base Oil Production for Textile Machines

859

Table 4. Effect of the dewaxing variables on the physical characteristics, hydrocarbon component analysis, and structural group analysis of the dewaxed raffinate of feed III NMP alone

Solvent of extraction Characteristics Yield on raffinate, wt% Yield on feedstock, wt% Refractive index, 70ı C Density, gm/cc, 70ı C Mean molecular weight Pour point, ı C Sulphur content, wt% Kinematic viscosity, cSt, 40ıC Kinematic viscosity, cSt, 100ıC Viscosity index VGC Color Wax content, wt% Component analysis Total aromatics, wt% Total saturates, wt% Structural group analysis Carbon distribution % CA % CN % CR % CP Ring content analysis RA RT RN

Raffinate V

Dewaxed oil V

— 69.92 1.4568 0.8171 314 35 0.49 15.25 3.42 95 0.8159 — 25.35

73.58 51.44 1.4636 0.8221 261 11 1.00 17.77 3.70 88 0.8209 4.5 1.04

25.53 74.47

28.82 71.18

6.56 20.06 26.62 73.38

11.05 28.07 39.12 60.88

0.32 0.94 0.62

0.83 1.47 0.64

VGC D viscosity gravity constant. Solvent:  MEK C benzene C toluene. 40:30:30. Dewaxing temperature D 15ıC. Solvent to feed ratio D 3:1.

corresponding increase in the aromatic components and sulphur content of the dewaxed oil. The carbon distribution spectrum and the ring content analysis are parallel to the above findings. The efficiency of the dewaxing process is measured by the dewaxing temperature differential—the spread between the dewaxing temperature and the pour point of the dewaxed oil. The low value of the dewaxing temperature

Downloaded By: [CSIR Order] At: 08:44 18 September 2007

860

A. M. Al Nagar and E. A. El Shamy

differential means that the process is economic from the industrial point of view. The pour point of the dewaxed oils are (6 and 7), (8 and 9), and 4ı C higher than the dewaxing temperature of 15ıC for feeds I, II, and III, respectively. It may be concluded that the process of dewaxing for feed III at a temperature of 15ıC is the most economic one.

FINISHING The dewaxed oils must be subjected to the finishing process to improve the color, color stability, and oxidation resistance.

Adsorption Treatment All the dewaxed oils were treated with adsorption technique via percolation using activated bentonite to reduce the level of trace-contaminated constituents (Figure 1 and Table 5). It is obvious from the data of the component analysis that the total aromatics are slightly decreased and, consequently, the saturates content increased with clay treatment. This behavior is also confirmed from the sulphur content of the product which decreases as the aromatics content decreases. The carbon distribution spectrum reflects the above findings; accordingly, the pour point, viscosity index, and mean molecular weight of the base oils are increased (compare Table 5 with Tables 2–4).

Oleum Treatment The two dewaxed oils III and IV are not greatly affected by adsorption treatment, as previously discussed, due to their relatively high aromatic contents (33.65 and 35.44 wt%, respectively). Therefore, they must be subjected to oleum (fuming sulphuric acid) treatment. Then the adsorption technique was carried out via percolation to remove the traces of acidity and the undesired contaminated constituents. The effect of adding oleum on the dewaxed oil is presented in Table 6. Data indicate that refractive index, density, and kinematic viscosity decrease, while the mean molecular weight, viscosity index, and pour point increase with a continuous increase in the amount of oleum added. This is in accordance with the gradual decrease in aromatics content and the gradual increase in total saturates content. The aromatics content, even so, is still high for base oil VI and VIII after 25 wt% oleum treatment (27.94 and 29.22 wt%, respectively). This may be

Downloaded By: [CSIR Order] At: 08:44 18 September 2007

Base Oil Production for Textile Machines

861

Table 5. Physical characteristics, hydrocarbon component analysis, and structural group analysis of finished base oil by clay treatment of the dewaxed raffinates of three feedstocks No. of the feed Solvent of extraction

I NMP

qquad weight Flash point, ı C Pour point, ı C Sulphur content, wt% Kinematic viscosity, cSt, 40ı C Kinematic viscosity, cSt, 100ıC Viscosity index Conradson carbon residue, wt% Color Component analysis Total aromatics, wt% Total saturates, wt% Structural group analysis Carbon distribution % CA % CN % CR % CP Ring content analysis RA RT RN

III

NMP

I I

NMP C 10% EA II II

Base oil I 74.89 33.73

Base oil II 56.82 30.57

1.4626

1.4665

1.4744

1.4768

1.4619

0.8245

0.8314

0.8548

0.8594

0.8197

Raffinate no. Dewaxed oil no. Characteristics Yield, wt% Yield on feedstock, wt% Refractive index, 70ı C Density, gm/cc, 70ı C Mean molecular

II

NMP

III III

NMP C 10% EA IV IV

Base oil III 73.79 34.65

Base oil IV 65.02 37.33

Base oil V 64.38 33.11

V V

286

281

322

319

245

221 7 0.89 19.60

225 8 1.04 20.84

241 5 1.35 38.14

240 6 1.48 39.35

161 10 0.88 16.49

3.95

4.08

6.00

6.05

3.53

90 0.02

92 0.03

94 0.06

96 0.07

88 0.02

1.5

7

7.5

0.5

24.46 75.54

25.66 74.34

32.40 67.60

34.78 65.22

23.25 76.75

10.87 27.99 38.86 61.14

13.96 30.56 44.52 55.48

11.96 28.17 40.13 59.87

15.14 30.74 45.88 54.12

10.24 27.59 37.83 62.17

0.86 1.5 0.64

0.94 1.56 0.62

0.89 2.09 1.20

0.98 2.15 1.17

0.81 1.46 0.65

1

Downloaded By: [CSIR Order] At: 08:44 18 September 2007

862

A. M. Al Nagar and E. A. El Shamy

Table 6. Physical characteristics, hydrocarbon component analysis, and structural group analysis of finished base oil by oleum clay treatment of the dewaxed raffinates of Feed II No. of the feed

II

Solvent of extraction Raffinate no. Dewaxed oil no.

NMP II III

Amount of oleum (based on oil) wt%

25

0

10

25

Base oil VI 39.25 18.43 1.4689 0.8496 371 240 1 1.004 32.87

Base oil IV 65.02 37.33 1.4768 0.8594 319 238 6 1.480 39.35

Base oil VII 51.98 29.86 1.4734 0.8542 336 237 3 1.276 37.26

Base oil VIII 37 21.24 1.4712 0.8516 367 239 1 1.140 34.05

5.92

6.05

5.98

5.94

95 0.03

96 0.07

98 0.04

100 0.03

7.5

0.5

0

27.94 72.06

34.78 65.22

31.41 68.59

29.22 70.78

8.65 28.13 36.78 63.22

15.14 30.74 45.88 54.12

13.92 30.12 44.04 55.96

11.38 30.89 42.27 57.73

0.85 1.92 1.07

0.98 2.15 1.17

0.96 2.07 1.11

0.94 1.99 1.05

Characteristics Yield, wt% Yield on feedstock, wt% Refractive index, 70ı C Density, gm/cc, 70ı C Mean molecular weight Flash point, ı C Pour point, ı C Sulphur content, wt% Kinematic viscosity, cSt, 40ı C Kinematic viscosity, cSt, 100ı C Viscosity index Conradson carbon residue, wt% Color Component analysis Total aromatics, wt% Total saturates, wt% Structural group analysis Carbon distribution % CA % CN % CR % CP Ring content analysis RA RT RN

0

NMPC10% EA IV IV

attributed to the presence of a dominant percentage of saturated structure attached to the aromatic rings, which weaken the attack of oleum. The sulphur content data for base oils are in line with aromatics content data as both decrease with the increase of oleum concentration. Accordingly, the ASTM color is greatly improved; it decreased from 8 or 8.5 to 0 units (compare Table 3 with Table 6).

Downloaded By: [CSIR Order] At: 08:44 18 September 2007

Base Oil Production for Textile Machines

863

EVALUATION AND BLENDING OF BASE OILS Evaluation of base oils, according to the Egyptian Organization for Standardization (EOS) revealed that base oils I, II, and V, which finished with clay treatment are within the limits of the standard specifications of spindle oils with high viscosity indices (88–92). According to the kinematic viscosity at 40ı C, base oils I and V are related to group (B) middle spindle oil, while base oil II is related to group (C) heavy spindle oil. Base oil III and IV are out of the limits of standard specifications of spindle oils (Table 5). According to the kinematic viscosity at 40ıC, base oils VI and VIII finished with 25 wt% oleum followed by clay treatment are within the limits of group (C) heavy spindle oil, while base oil VII, which finished with 10 wt% oleum, is higher than the limits of group (C) heavy spindle oils. According to the pour point, the three base oils VI, VII, and VIII have higher values than the limit of standard specification of spindle oils.

BLEND FORMULATION To adjust the specifications of base oils to meet the standard specifications of spindle oils related to the EOS and produce different grades of spindle oils, blends were made by mixing base oils. Blends Containing Base Oils I and VI The pour points of the two base oils VI and VIII are higher than the standard limit by 8 and 6ı C, respectively, which may be improved to attain to the standard limit by blending the base oil with one of a lower pour point, either base oil I or II or V. Thus, four formulations were made from base oils I and VI as indicated in Table 7. Data indicate that the kinematic viscosity at 40ıC for all the base oils obtained by blending base oils VI with I are within the limits of standard

Table 7. Blend formulations Group 1

Base oil no. Base Base Base Base

oil oil oil oil

IX X XI XII

Group 2

Base oil VI

Base oil I

90 60 30 20

10 40 70 80

Base oil no. Base Base Base Base

oil oil oil oil

XIII XIV XV XVI

Base oil VII

Base oil V

90 70 40 20

10 30 60 80

Downloaded By: [CSIR Order] At: 08:44 18 September 2007

864

A. M. Al Nagar and E. A. El Shamy

Table 8. Physical characteristics and hydrocarbon component analysis of blends containing base oils I and VI Base oil no. Characteristics: Refractive index, 70ı C Density, gm/cc, 70ı C Mean molecular weight Flash point, ı C Pour point, ı C Sulphur content, wt% Kinematic viscosity, cSt, 40ı C Kinematic viscosity, cSt, 100ı C Viscosity index VGC Conradson carbon residue, wt% Component analysis Total aromatics, wt% Total saturates, wt%

Base oil VI

Base oil IX

Base oil X

Base oil XI

Base oil XII

Base oil I

1.4689

1.4681

1.4659

1.4642

1.4636

1.4626

0.8496

0.8480

0.8442

0.8406

0.8396

0.8245

371

361

331

298

289

286

240 1 1.00

238 0 0.99

232 2 0.96

227 4 0.92

225 5 0.91

221 7 0.89

32.87

31.18

27.07

23.11

21.91

19.60

5.92

5.72

5.1

4.5

4.35

3.95

95 0.8364 0.03

94 0.8341 0.03

93 0.8305 0.03

92 0.8260 0.02

91 0.8235 0.02

90 0.8208 0.02

27.94

27.59

26.55

25.50

25.16

24.46

72.06

72.41

73.45

74.50

74.84

75.54

VGC D viscosity-gravity constant.

specifications of group (C) heavy spindle oil related to the EOS, while the pour points of these blended base oils are higher than the standard limit by 2–7ı C (Table 8). Meanwhile, base oils XI and XII, which have a pour point of 4 and 5ı C higher than the standard limit by 3 and 2ı C, respectively, are in accordance with the specifications of Mobil Velocite Oils (Mobil, 1995) (premium low viscosity textile machinery oils) of group CX and DX, respectively. Moreover, the blended base oils IX to XII would be blended with pour point depressant to improve their pour points to attain the standard limit of spindle oil. Blends Containing Base Oils V and VII It is of interest to improve the pour point and the kinematic viscosity at 40ı C for base oil VII by blending it with base oil V and to produce different grades of base oil to meet the standard specifications of spindle oil related

Downloaded By: [CSIR Order] At: 08:44 18 September 2007

Base Oil Production for Textile Machines

865

Table 9. Physical characteristics and hydrocarbon component analysis of blends containing base oils V and VII Base oil no. Characteristics Refractive index, 70ı C Density, gm/cc, 70ı C Mean molecular weight Flash point, ı C Pour point, ı C Sulphur content, wt% Kinematic viscosity, cSt, 40ı C Kinematic viscosity, cSt, 100ıC Viscosity index VGC Conradson carbon residue, wt% Component analysis Total aromatics, wt% Total saturates, wt%

Base oil VII

Base oil XIII

Base oil XIV

Base oil XV

Base oil XVI

Base oil V

1.4734

1.4724

1.4696

1.4670

1.4638

1.4619

0.8542

0.8513

0.8449

0.8350

0.8281

0.8197

336

327

310

282

263

245

237 3 1.28

230 4 1.24

215 5 1.16

191 7 1.04

176 8 0.96

161 10 0.88

37.26

34.91

30.52

24.16

20.24

16.49

5.98

5.72

5.40

4.50

4.15

3.53

98 0.8406 0.04

97 0.8378 0.04

94 0.8336 0.04

92 0.8266 0.03

89 0.8217 0.03

88 0.8164 0.02

31.41

30.59

28.96

26.51

24.88

23.25

68.59

69.41

71.04

73.49

75.12

76.75

VGC D viscosity-gravity constant.

to EOS (Table 7). The effect of the addition of base oil V to base oil VII is represented in Table 9. Data indicate that the kinematic viscosity at 40ı C for base oil VII (37.26 cSt) has been decreased to attain the upper standard limit of spindle oil (35 cSt) by the addition of 10 wt% of base oil V as shown for blended base oil XIII. A further increase in the concentration of base oil V gives base oils with different grades of kinematic viscosity 30.5, 24.16, and 20.24 for base oils XIV, XV, and XVI, respectively. Meanwhile, the addition of 60 wt% of base oil V to base oil VII decreases its pour point from ( 3ı C) to the standard limit of pour point for spindle oil ( 7ı C) as shown for base oil XV (Table 9). We can conclude that the blended base oils XV and XVI confirm the specifications of the spindle oil of group (C) heavy and group (B) middle spindle oil, respectively, according to the definition of the EOS. Base oil XIII and XIV confirm the standard specifications of group (C) heavy spindle oil excepting the pour points, which are 3 and 2ı C higher than

Downloaded By: [CSIR Order] At: 08:44 18 September 2007

866

A. M. Al Nagar and E. A. El Shamy

the standard limit, respectively. From an economical point of view, these base oils can be used as spindle oils in hot countries and when too low a temperature would be required.

ACKNOWLEDGMENT The authors would like to thank Prof. Dr. Amal Said Farag for her efforts, without which this work would not have been made possible.

REFERENCES Al Naggar, A. M., El Shamy, E. A., Farag, A. S., and El Azabawy, S. R. (2004). Mans. Sci. Bull. Egypt 31:165. Brock, D. V. (1987). Lubrication Engineering 43:184. Egyptian Organization for Standardization (EOS). (1964). ES 549, ARE. El Shafey, M. A., Farag, A. S., Riad, M. A., and Youssef, M. H. (1985). Bull. NRC, Egypt 10:88. Kramer, D. C., Lok, B. K., and Krug, R. R. (2001). Turbine Lubrication in 21st Century, ASTM STP1407. W. R. Herguth and T. M. Warne (eds.). West Conshohocken, PA: American Society for Testing and Materials. Mikhail, S., Rizk, N., Grigis, B., and Abdou, I. (1971). Revue de Lt’Institut Français du Petrole 26:1213. Mobil Product Data. (1995). 3057, Virginia. Sequira, A. Jr. (1994). Lubricant Base Oil and Wax Processing. New York: Marcel Dekker, Inc. Soudek, M. (1974). Hydroc. Process. 53:59.