The Solvent Extraction Method Biology Essay

Since the oil soluble compounds, chiefly low molecular weight chelates of V and Ni, were non removed by extractor method, an effort was made to take these by dissolver extraction method. Solvents chosen for this survey varied from non polar ( n-C6, n-C7 ) to polar ( ethyl ethanoate ) and extremely polar ( ethyl ethanoate with 0.1 to 1.0 % H2SO4 or H3PO4 ) . Properties of PDR are given in chapter-7.

Petroleum distillment residue was deasphalted-demetallated by n-C5, n-C6 and C7 methane seriess. Demetalation increased as C figure of n-alkanes decreased, therefore n-pentane gave highest 85 and 90 per centum V and Ni severally removal. Ethyl ethanoate gave the 2nd highest metal ( V + Ni ) remotion of 82 and 88 wt. % ( Table 10.1 and 10.2 ) . All dissolvers were found to be effectual in taking H2O soluble salts ; therefore 100 % Na from PDR has been removed by all dissolvers. It was noted that rate of demetalation was changing with samples, which was likely depending on the type of metal composite in the oil. Hence, solvent extraction by ethyl ethanoate removed 82 % V and 88 % Ni from PDR contains 35.0 ppm V and 13.0 ppm Ni, removed 73 % V and 83 % Ni from PDR contains 25.5 ppm V and 3.6 % Ni, and removed 57 % V from PDR contains 122.0 ppm V ( Table-10.3 ) .

However, when sulphuric acid was added ( 0.1-1.0 % ) in ethyl ethanoate there was no betterment in per centum metal remotion by solvent extraction. In fact it was found to diminish with addition in the sum of sulphuric acid ( 0.1 – 1.0 ) . Similarly, add-on of little sums of phosphorous acid ( 0.1 to 1.0 % ) to ethyl ethanoate did non demo any betterment for metal remotion ( Table 10.4 ) .

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Removal of V increased with clip up to 91 % , which is due to chemical demetalation of V porphyrins by H2SO4. Reaching clip less effects on remotion of Ni so on remotion of V, represent in Figure-10.1 Results of reaction clip consequence are summarized in Table 10.5.

Although solvent ratio higher than eight additions metal removal per centum, the solvent recovery losingss and procedure economic system do non prefer such ratios. The weight ratios of liquid dissolver to oil, extraction temperature, recovery of dissolver, and recovery of oil from residue are of import factors in utilizing solvent extraction methods. Furthermore, the consequences show that processes using hydrocarbon dissolvers ( nC5, nC6 and nC7 ) , used to modify the oily matrix solubility parametric quantity in such a manner that asphaltenes are separated, deasphaltation implies partial demetalation. Processes utilizing polar dissolvers, barely mixable with crude oil are able to selectively pull out from it metallic composites of heteroatomic fables ( e.g. metalloporphyrins ) .

The consequences for solvent extraction by mixtures of polar ( ethyl ethanoate ) and Non-Polar ( n-heptane ) dissolvers are presented in Table 10.6. Demetalation was found to diminish with mixture of the two dissolvers and demetalation becomes zero when ratio of n-heptane and ethyl ethanoate ranges between 70:30 and 50:50. It is besides found that demetalation by ethyl ethanoate is peers to the demetalation consequences when we extract oil with n-heptane and ethyl ethanoate at the same time.

HPCO is a high viscousness, gravitation oil contain high asphaltene V and nickel contents. This heavy Pakistani petroleum oil was demetalated and deasphalted by solvent extraction with n-pentane, n-hexane and CPCO. CPCO is a light Pakistani petroleum oil holding high copiousness of methane seriess ( particularly normal methane seriess ) . Removal of asphaltene by solvent extraction was increased as molecular weight of dissolver decreased. In same form metalo organic compounds are concentrated in asphaltenes Hence, n-pentane gave highest remotion of asphaltene 21.8 % . n-hexane removed 17.7 % and CPCO removed 13.7 % asphaltene from HPCO. Similarly highest 100 % and 97 % V and Ni were removed with n-pentane. N-hexane removed 98 % and 95 % V and Ni severally. Extraction with CPCO gave 53 % and 45 % V and Ni remotion when the mixture was non heated. Because normal methane seriess of C9 to C14 are abundant in CPCO ; it support the high reaction temperature. 99 % and 83 % V and Ni severally were removed when the mixture was furuncle for 30 proceedingss ( Table 10.7 ) .

HPCO was demetalated by 1 % maleic acid in CPCO. HPCO and 1 % maleic acid in CPCO in a ratio of 1:10 was boiled to reflux for 30 proceedingss. The mixture was cooled and filtered. Together dechealation and solvent extraction gave 100 remotions of V and Ni. Consequences are summarized in Table-10.7. Demetalation and deasphaltation with CPCO will be economical so solvent extraction with pure dissolvers. Managing and transit jobs may besides be countered with this method.

Table 10.1

Solvent Extraction of Petroleum Distillation Residue ( 35ppm Vanadium )

Vanadium ( ppm )

% Demetalation or Decrease in Vanadium

Solvent

Soluble Part

( Maltene )

Insoluble Part

( Asphaltene )

n-Pentane

5.25

595

85

n-Hexane

10.5

490

70

n-Heptane

13

464

62

Ethyl ethanoate

6.3

197

82

Table 10.2

Solvent Extraction of Petroleum Distillation Residue ( 13ppm Nickel )

Nickel ( ppm )

% Demetalation or Decrease in Nickel

Solvent

Soluble Part

( Maltene )

Insoluble Part

( Asphaltene )

n-Pentane

1.30

234

90

n-Hexane

3.25

195

75

n-Heptane

3.50

100

73

Ethyl ethanoate

1.56

215

88

Table 10.3

Solvent Extraction by Ethylacetate of three different Samples of PDR

A

Vanadium

Nickel

Sample

A

PPM

% Removal

PPM

% Removal

PDR

Vanadium =35.0 ppm, Nickel=13.0ppm

Soluble

6.3

82

0.3

88

Insoluble

197.0

54.0

PDR

Vanadium =25.5 ppm,

Nickel=3.6ppm

Soluble

6.9

73

0.6

83

Insoluble

411.0

70.0

PDR

Vanadium =122.0 ppm

Soluble

52.0

57

*

Insoluble

723.0

*

* Not analyze

Table 10.4

Solvent Extraction by Ethyl ethanoate

Reagent/Acid

% Removal Vanadium

% Removal Nickel

1

No reagent

73

83

2

H2SO4 0.1 %

74

75

3

H3PO4 0.1 %

55

67

4

H2SO4 1.0 %

66

68

5

H3PO4 1.0 %

51

55

Table 10.5

Consequence of clip on Demetallization of PDR by Solvent Extraction with Ethyl acetate 1 % H2SO4

( Solvent Sample Ratio 20:1 )

A

Removal %

A

Vanadium

Nickel

Day 1

67

A 68

Day 11

71

77

Day 30

75

79

Day 38

77

80

Day 91

91

83

Table 10.6

Solvent Extraction with mixture of polar and non-polar dissolver

Heptane: EtOAc

% Removal Vanadium

% Removal Nickel

1

100:0

62

73

2

90:10

25

25

3

80:20

5

13

4

70:30

0

0

5

60:40

0

0

6

50:50

0

0

7

40:60

18

3

8

30:70

30

17

9

20:80

48

55

10

10:90

73

80

11

0:100

82

88

Table 10.7

Solvent Extraction of Heavy Pakistani Crude Oil

( Contact Time 30 proceedingss & A ;

Sample Solvent Ratio 1:10 )

S.No

Solvent

Temperature EsC

Asphaltne %

Removal % Vanadium

Removal %

Nickel

1

n-Pentane

~36

21.84

100

97

2

n-Hexane

~69

17.60

98

95

3

CPCO

~25-30 °C

13.70

53

45

4

CPCO

~160

*

99

83

5

CPCO with 1 % Maleic Acid

~160

*

100

100

* Not look into

Figure 10.1

Consequence of clip on Demetallization of PDR by Solvent Extraction with Ethyl acetate 1 % H2SO4

( Solvent Sample Ratio 20:1 )

Figure 10.2

Solvent Extraction with mixture of polar

and non polar dissolver