Super Phosphoric Acid Catalysed Biodiesel Production Biology Essay

The conventional procedure for bring forthing biodiesel is basal accelerator and requires anhydrous status and provender stock with low degrees of free fatty acid ( FFA ) . Basic accelerator gives the higher reaction rate than acerb accelerator. However, the basic accelerators involved soap formation of free fatso acid taking to the inactivation of accelerator and high production cost. Cheap provender stocks incorporating high degrees of free fatty acid can non be straight used with the base accelerator. This work deals with the synthesis of biodiesel from high free fatso acid incorporating petroleum degummed cotton seed oil ( CDGCSO ) , utilizing 5 wt % ( weight of the oil ) super phosphorous acid ( SPA ) as accelerator and measuring the consequence of the molar ratio ( oil: intoxicant ) on per centum transition. Molar ratio 1:10 showed greater output. The acid accelerators do non organize the soap and can at the same time carry on esterification and transesterification of free fatty acid and oil to biodiesel. However, they are slower and ask higher reaction temperatures. However, acid-catalyzed procedures could bring forth biodiesel from low-priced provender stocks and take downing the cost of production.

Keywords: Super Phosphoric acid, FFA, low cost provender stock, CDGCSO, Biodiesel

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1. Introduction

Biodiesel is a nonpetroleum-based fuel that consists of alkyl esters derived from either the transesterification of triglycerides ( TGs ) or the esterification of free fatty acids ( FFAs ) with intoxicants [ 1 ] . It is an alternate to petroleum Diesel for cut downing emanations of gaseous pollutants such as CO, SOx, particulate affairs and organic compounds [ 2, 3 ] . The flow and burning belongingss of biodiesel are similar to petroleum-based Diesel and therefore, can be used either as a replacement for Diesel fuel or more normally in fuel blends [ 4 ] . It is a clean combustion fuel which is non-toxic, biodegradable and considered as the fuel of the hereafter.

Normally, biodiesel is prepared from TG beginnings such as vegetable oils, carnal fats and waste lubricating oils. There are several paths to obtain biodiesel from assorted provender stocks. But the most common method is transesterification [ 5 ] – [ 8 ] in which harmonizing to stoichiometry, 1 mol of TG reacts with 3 mol of intoxicant in presence of a strong accelerator ( acerb, base or enzyme ) , bring forthing a mixture of biodiesel ( fatty acid alkyl ester ) and glycerin ( Scheme-1 ) [ 9, 10 ] .

Scheme 1 Transesterification of triglyceride ( TG ) to Biodiesel.

The transesterification reaction requires a accelerator in order to obtain sensible transition rates. The nature of the accelerator is cardinal since it determines the compositional bounds that the provender stock must conform to. Furthermore, the reaction conditions and post-separation stairss are predetermined by the nature of the accelerator used. Presently most biodiesel is prepared utilizing base accelerator, such as Na and K methoxides and hydrated oxides. Even though transesterification is executable utilizing base accelerator, the overall base catalyzed procedure suffers from serious restrictions that translate into high production costs for biodiesel. Strict feedstock specifications are a chief issue with this procedure [ 2 ] . The entire FFA content associated with the feedstock must non transcend 0.5 wt % in instance of base catalyzed procedure. Otherwise, soap formation earnestly hinders the production of fuel class biodiesel [ 1, 11, 12 ] . Soap signifiers when the base accelerator reacts with FFAs in the provender stocks ( Scheme 2a ) . Soap production gives rise to the formation of gels, additions viscousness and greatly increases merchandise separation cost [ 9 ] . The intoxicant and accelerator must besides follow with strict specifications. The intoxicant every bit good as the accelerator must be basically anhydrous ( entire H2O content must be 0.1-0.3 wt % or less ) [ 13 ] . This is required since it is assumed that the presence of H2O in the feedstock promoted hydrolysis of the alkyl ester to FFA ( Scheme 2b ) and accordingly, soap formation.

Scheme 2 ( a ) Base accelerator reaction with FFAs to bring forth soap and H2O.

( B ) Water promotes the formation of FFAs.

To conform to such demanding feedstock specifications necessitates use of extremely refined vegetable oil whose monetary value can account for 60-75 % of the concluding cost of biodiesel [ 14 ] . Other less expensive beginnings of TG provender stocks such as rough oil, waste oil, and xanthous lubricating oils can be used to antagonize the high monetary value tickets associated with biodiesel produced from refined oils utilizing acid catalyzed system. The type of provender stock by and large selects the nature of accelerator. If the FFA content is high, acerb catalyzed esterification followed by transesterification is used. If FFA content is low the base catalyzed transesterification is most desirable and is comparatively faster than acid catalyzed transesterfication [ 15 ] . For acerb catalyzed system, sulphuric acid has been the most investigated accelerator, but other acids, such as HCl, BF3, H3PO4 and organic sulphonic acids have besides been used by different researches [ 16 ] . The influence of procedure variables on the acid-catalyzed transesterification reaction has been reported in several surveies [ 17 ] – [ 21 ] . Freedman et al. [ 17 ] and Canakci and Van Gerpen [ 18 ] examined the consequence of the intoxicant type on the acid-catalyzed transesterification of soybean oil at temperatures merely below the boiling points of the intoxicants. The consequences indicated that the consequence of the reaction temperature, instead than the type of intoxicant used, dominates the rate of the reaction and dictates the clip required to accomplish complete ester transition. Canakci and Van Gerpen [ 18 ] showed that the ester transition increased with an increasing temperature, molar ratio of intoxicant to oil and acid-catalyst concentration.

Goff et Al. [ 20 ] conducted a survey to look into the efficiency of different acid accelerators at elevated temperature under different operating conditions and determined that H2SO4 was the most effectual accelerator for the transesterification reaction. Freedman et al. [ 21 ] investigated the acid-catalyzed butanolysis of soybean oil at an intoxicant: oil molar ratio of 30:1 and 1 wt % H2SO4 accelerator concentration at different temperatures in the scope of 77-117 A°C. The consequences indicated that the complete transition was achieved in 20 hours at 77 A°C and 3 hours at 117 A°C. Zheng et Al. [ 19 ] studied the acid-catalyzed transesterification reaction dynamicss of waste frying oil utilizing MeOH: oil molar ratios in the scope of 50:1-250:1 and acid-catalyst concentrations runing from 1.5 to 3.5 mol % ( on the footing of the oil ) at temperatures of 70 and 80 A°C. The consequences demonstrated that the acid-catalyzed transesterification reaction of waste frying oil in MeOH efficaciously follows pseudo-first-order reaction dynamicss.

The demanding provender stocks specifications for base catalyzed reactions have led research worker to seek catalytic and treating options that could ease this trouble and lowers the cost of production. Methodologies based on acid catalyzed reactions have the possible to accomplish this since acid accelerators do non demo mensurable susceptibleness to FFAs. For this ground the development of acid catalyzed methodological analysiss is the focal point of this paper.

The purpose of this work is to develop the procedure by utilizing ace phosphorous acid ( SPA ) accelerator to bring forth the biodiesel from low cost provender stocks ( petroleum degummed cotton seed oil ) . A major hurdle towards widespread commercialisation is the high monetary value of biodiesel. And therefore, an effort is made to bring forth low monetary value biodiesel by utilizing rough oil. In this survey, CDGCSO incorporating 5 % FFA is chosen as a feedstock for biodiesel production. The consequence of changing oil: intoxicant molar ratios of 1:40, 1:30, 1:20, 1:10 and 1:5 with accelerator ( SPA ) amount 5 % of the weight of the oil on the transesterification reaction output were investigated.

2. EXPERIMENTAL

2.1 REAGENTS AND MATERIALS

Crude degummed cotton seed oil obtained Bhavani Oil Mill Limited, Botad, Gujarat, India. Super phosphorous acid and 1-butanol used in the present survey were purchased from S. D. Fine Chem. Limited, Vadodara, Gujarat, India.

2.2 SPA CATALYZED BIODIESEL PRODUCTION FROM CRUDE DEGUMMED COTTON SEED OIL

SPA catalyzed biodiesel synthesis were performed in a three cervix 1000 milliliter unit of ammunition underside flask equipped with scaremonger, thermometer, H2O capacitor and warming system. The biodiesel synthesis was studied at different oil:1-butanol molar ratios ( 1:40, 1:30, 1:20, 1:10 and 1:5 ) under reflux at 120OC and with accelerator ( SPA ) amount 5 % of the weight of the oil. Reactants were introduced together with the appropriated accelerator mass and clip of reaction was considered when coveted temperature ( by and large 120OC ) was reached. Samples were drawn at two hours interval and per centum transition was estimated by Gel Permeation Chromatography ( GPC ) . After completion of reaction, extra 1-butanol was wholly distilled off and the mixture was carefully transferred to a separating funnel and allowed to settle ( Fig. 1 ) . The upper bed consists of biodiesel whereas the lower bed contained glycerol and most of accelerator. The upper bed was purified utilizing hot distilled H2O and so dried over anhydrous Na sulphate ( Na2SO4 ) . Figure 2 shows the washed, dried biodiesel and petroleum degummed cotton seed oil incorporating 5 % FFA. In this method, 1.0 gram of anhydrous Na2SO4 was taken for 100 milliliter of biodiesel, stirred for 15 proceedingss and so was allowed to settled and decanted. The decanted dried biodiesel was filtered with the aid of vacuity pump for concluding remotion of solid hints. Finally, biodiesel fuel belongingss were determined with the aid of the criterion trials ( Table 1 ) .

Table 1. Specification of low cost provender stock biodiesel.

Sr. No.

Property

ASTM

Biodiesel

Unit of measurements

Free Glycerin

D6584

0.004

% mass

Monoglyceride ( MG )

D6584

0.179

% mass

Diglyceride ( DG )

D6584

0.160

% mass

Triglyceride ( TG )

D6584

0.181

% mass

Entire Glycerin

D6584

0.099

% mass

Acid Number

D664

0.45

milligram KOH/gm

Water Sediment

D2709

0.045

% vol.

Water by KF

D6308

0.075

ppm

Figure 1. Separating Funnels:

( 1 ) Upper bed – biodiesel.

( 2 ) Lower bed – glycerol.

Figure 2. Biodiesel after rinsing & A ; drying and

petroleum degummed cotton seed oil with 5 %

FFA.

Experiments were conducted as above to mensurate the transition of FFA and TGs in the CDGCSO to matching outputs of diglycerides ( DGs ) , monoglycerides ( MGs ) and biodiesel. All experiments were performed at atmospheric force per unit area till the completion of reaction. Initial analysis of reaction mixture by GPC showed that it contained FFA and TGs ( Figure 3 ) . The analysis of per centum transition of FFA & A ; TGs to DGs, MGs and biodiesel were carried out at two hours intervals utilizing GPC. At intervals of two hours samples were drawn, filtered through 0.2 Aµm Teflon syringe filters. GPC phials incorporating 0.04 gram of filtered sample were weighed and diluted with THF to do up 20 mg/mL sample solution for GPC analysis.

Figure 3 GPC of CDGCSO.

The GPC of reaction mass was done by utilizing Waters GPC instrument with Waters 600 accountant and pumps. The HPLC class Tetrahydrofuran ( THF ) was used as a nomadic stage at a flow rate of 1.0 ml/min. The GPC system was equipped with three columns: PLgel 50 A0, Oligopore and PLgel 100 A0 connected in series. Waters 2410 Refractive Index sensor and Waters 2487 Dual I» optical density sensor were used with internal temperature of 350C for peak sensing. The system was operated utilizing Waters Millennium 32 package. The running clip required for merchandise word picture was about 35 proceedingss. Calibration curves [ 22 ] were generated from the criterions: triolein ( TG ) , diolein ( DG ) , monolein ( MG ) , butyl oleate ( biodiesel ) , oleic acid ( FFA ) and glycerin ( GLY ) . The countries under the extremums in the chromatograms were used to find the per centum of the components ( TG, DG, MG, FFA and biodiesel ) nowadays in the sample. Figure 4 shows the 99.79 % transition of FFA and TGs to biodiesel at 1:10 oil:1-butanol molar ration after 10 hours.

Figure 4 GPC of Biodiesel.

3. RESULT AND DISCUSSION

The Acid catalyzed transesterification procedure does non bask the same popularity as the base catalyzed procedure. The fact that the acid catalyzed reaction is about 4000 times slower than the base catalyzed reaction has been one of the chief ground [ 23 ] . However, acid catalyzed transesterifications hold an of import advantage with regard to establish catalyzed 1s: the public presentation of acerb accelerator is non strongly affected by the presence of FFAs in the feedstock. In fact, acerb accelerator can at the same time catalyse both esterification and transesterification of FFA and TGs severally to biodiesel. The acerb catalyzed esterification of FFA follows a mechanistic strategy similar to tranesterification. Consequently, alternatively of get downing with a TG molecule, as in the transesterification reaction ( Scheme 3 ) , the starting molecule is FFA.

Scheme 3 Homogeneous acid-catalyzed reaction mechanism for the transesterification of triglycerides: ( 1 ) protonation of the carbonyl group by the acerb accelerator ; ( 2 ) nucleophilic onslaught of the intoxicant, organizing a tetrahedral intermediate ; ( 3 ) proton migration and dislocation of the intermediate. The sequence is repeated twice.

Therefore, a great advantage with acerb accelerator is that they can straight bring forth biodiesel from low cost provender stocks, by and large associated with high FFA concentrations and therefore, take downing the cost of production. As refinement of rough oil costs around $ 0.12 per litre and were applied to the concluding cost of biodiesel production [ 24 ] . To accomplish this CDGCSO with 5 % FFA concentration was used as a provender stock and the maximal output of biodiesel at optimal molar ration of oil:1-butanol were survey. The consequences of per centum transition of FFA and TGs to matching DG, MG and biodiesel are summarized in Table 2 to 6.

Table 2. Consequences of per centum transition of FFA and TGs to matching DG, MG and biodiesel ( BD ) with 1:40 oil:1-butanol molar ratio.

Sr. No.

Feed Stock

Molar ratio

( Oil:

1-butanol )

FFA

( % )

Catalyst

( SPA )

( % )

Reaction Temp. ( OC )

Chemical reaction Time

( Hrs. )

% Conversion

%

TG

% DG

% MG

% BD

CDGCSO

1:40

5

5

120

2

61.42

18.50

0.89

19.19

CDGCSO

1:40

5

5

120

4

38.14

24.08

0.74

37.04

CDGCSO

1:40

5

5

120

6

24.85

23.34

0.63

51.18

CDGCSO

1:40

5

5

120

8

16.43

21.50

0.51

61.56

CDGCSO

1:40

5

5

120

10

10.50

17.69

0.46

71.35

CDGCSO

1:40

5

5

120

12

6.76

14.32

0.32

78.60

CDGCSO

1:40

5

5

120

14

4.26

11.05

0.27

84.42

CDGCSO

1:40

5

5

120

16

2.29

7.15

0.21

90.35

CDGCSO

1:40

5

5

120

18

1.31

4.62

0.15

93.92

CDGCSO

1:40

5

5

120

20

0.72

3.22

0.09

95.97

CDGCSO

1:40

5

5

120

22

0.5

2.30

0.07

97.83

CDGCSO

1:40

5

5

120

24

0.10

0.37

0.00

99.53

Table 3. Consequences of per centum transition of FFA and TGs to matching DG, MG and biodiesel ( BD ) with 1:30 oil:1-butanol grinder ratio

Sr. No.

Feed Stock

Molar ratio

( Oil:

1-butanol )

FFA

( % )

Catalyst

( SPA )

( % )

Reaction Temp. ( OC )

Chemical reaction Time

( Hrs. )

% Conversion

%

TG

% DG

% MG

% BD

CDGCSO

1:30

5

5

120

2

52.66

16.97

0.76

29.61

CDGCSO

1:30

5

5

120

4

25.63

18.09

0.69

55.59

CDGCSO

1:30

5

5

120

6

13.72

14.28

0.56

71.44

CDGCSO

1:30

5

5

120

8

6.86

10.40

0.50

82.24

CDGCSO

1:30

5

5

120

10

3.43

6.20

0.60

89.77

CDGCSO

1:30

5

5

120

12

1.66

3.39

0.49

94.46

CDGCSO

1:30

5

5

120

14

0.73

2.11

0.36

96.80

CDGCSO

1:30

5

5

120

16

0.33

1.24

0.15

98.28

CDGCSO

1:30

5

5

120

18

0.04

0.45

0.03

99.21

CDGCSO

1:30

5

5

120

20

0.04

0.20

0.00

99.76

Table 4. Consequences of per centum transition of FFA and TGs to matching DG, MG and biodiesel ( BD ) with 1:20 oil:1-butanol molar ratio.

Sr. No.

Feed Stock

Molar ratio

( Oil:

1-butanol )

FFA

( % )

Catalyst

( SPA )

( % )

Reaction Temp. ( OC )

Chemical reaction Time

( Hrs. )

% Conversion

%

TG

% DG

% MG

%

Bachelor of divinity

CDGCSO

1:20

5

5

120

2

28.12

26.18

0.56

45.14

CDGCSO

1:20

5

5

120

4

11.50

19.11

0.59

68.80

CDGCSO

1:20

5

5

120

6

4.26

7.19

0.48

88.07

CDGCSO

1:20

5

5

120

8

1.80

3.31

0.39

94.50

CDGCSO

1:20

5

5

120

10

0.70

3.12

0.18

96.00

CDGCSO

1:20

5

5

120

12

0.50

1.32

0.09

98.09

CDGCSO

1:20

5

5

120

14

0.02

0.43

0.04

99.51

CDGCSO

1:20

5

5

120

16

0.00

0.35

0.00

99.65

Table 5. Consequences of per centum transition of FFA and TGs to matching DG, MG and biodiesel ( BD ) with 1:10 oil:1-butanol molar ratio.

Sr. No.

Feed Stock

Molar ratio

( Oil:

1-butanol )

FFA

( % )

Catalyst

( SPA )

( % )

Reaction Temp. ( OC )

Chemical reaction Time

( Hrs. )

% Conversion

%

TG

% DG

% MG

% BD

CDGCSO

1:10

5

5

120

2

8.83

10.32

0.42

80.43

CDGCSO

1:10

5

5

120

4

2.18

4.69

0.32

92.81

CDGCSO

1:10

5

5

120

6

1.80

1.58

0.27

96.35

CDGCSO

1:10

5

5

120

8

0.52

0.36

0.21

98.91

CDGCSO

1:10

5

5

120

10

0.00

0.16

0.05

99.79

Table 6. Consequences of per centum transition of FFA and TGs to matching DG, MG and biodiesel ( BD ) with 1:05 oil:1-butanol molar ratio.

Sr. No.

Feed Stock

Molar ratio

( Oil:

1-butanol )

FFA

( % )

Catalyst

( SPA )

( % )

Reaction Temp. ( OC )

Chemical reaction Time

( Hrs. )

% Conversion

%

TG

% DG

% MG

% BD

CDGCSO

1:05

5

5

120

2

12.07

10.93

0.20

76.80

CDGCSO

1:05

5

5

120

4

3.04

7.22

0.21

89.53

CDGCSO

1:05

5

5

120

6

0.54

4.80

0.07

94.59

CDGCSO

1:05

5

5

120

8

0.16

3.31

0.50

96.03

CDGCSO

1:05

5

5

120

10

0.12

1.61

0.31

97.96

CDGCSO

1:05

5

5

120

12

0.09

0.50

0.15

99.26

Canakci & A ; Van Gerpen studied how the molar ratio affected reaction rates and merchandise output in the transmethylation of soybean oil by sulfuric acid [ 18 ] . And their consequences indicated that ester formation increased with increasing the grinder ratio, making its tallness value, 98.4 % at 1:30 molar ratio. Crabe et. Al. besides determined the consequence of molar ratio within the scope of 1:3 -1:23 and concluded that the tallness molar ratio required for complete transmethylation could be found between 1:35 and 1:45 by extrapolation [ 25 ] .

In present survey best consequences were achieved with the 1:10 oil:1-butanol molar ratio. The per centum transition of oil to biodiesel was affected drastically by altering the oil:1-butanol molar ratio under the same conditions ( Figure 5 ) . Decreasing the oil: intoxicant molar ratio from 1:40 to 1:10, cut down the clip of reaction from 24 hours to 10 hours for more than 99 % transition. As 5 % FFA can acquire esterified to biodiesel, there is yield betterment by 5 % utilizing SPA catalyzed procedure from low cost provender stocks. By utilizing SPA catalyzed procedure, there is no demand for rigorous provender stock specifications, as there is no soap formation and job associated with layer separation. In short cost effectual biodiesel can be produced from low cost provender stock by utilizing SPA catalyzed procedure with minimal separation cost and without soap formation with singular betterment in overall per centum of output.

Figure 5 Consequence of molar ratio on biodiesel per centum transition with regard to reaction clip.

4. Decision

In this survey SPA catalyzed transesterification reaction of petroleum degummed cotton seed oil was investigated. As reference earlier, the oil: intoxicant molar ration is an of import parametric quantity for transesterification reaction. From the obtained consequences, it can be evaluated that 1:10 oil: intoxicant gives best consequences and reaction clip decreases with lessening in molar ratio from 1:40 to 1:10. In present survey 1:10 oil:1-butanol grinder ratio, 5 % SPA accelerator, 120OC reaction temperature and 10 hours of stirring are considered to be the best status to develop low cost method to bring forth biodiesel from petroleum degummed cotton seed oil.

As SPA catalyzed biodiesel production converts FFA and TG to biodiesel, there is no demand to do TG free from FFA and it gets converted to biodiesel therefore, increasing the per centum output and finally cut down the cost for concluding merchandise as there is no demand to take FFA from petroleum degummed cotton seed oil. Further there is lessening in molar ratio from 1:40 to 1:10 for height transition at shortest clip, there is besides cut down cost for separation and recovery of intoxicant that accounts for concluding cost of biodiesel. In short cost effectual biodiesel can be produced by utilizing SPA catalyzed procedure from low cost provender stock.