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Sustainable Chemical Processes

Table 2 Summary of microwave-enhanced biodiesel production studies

From: Microwave energy potential for biodiesel production

Sample

Reaction time (min)

Reaction temp. (°C)

Catalyst

Oil to alcohol ratio

FAEE/ FAME conv. (%)

Equipment

Mode

Ref

Vegetable/edible oils

Coconut oil*

0.5

79.5

NaOH

1:9 Ethanol

100

Domestic Microwave

Continuous

[122, 123]

0.75

82.2

NaOH

1:9 Ethanol

100

 

Continuous

1

83.4

NaOH

1:9 Ethanol

100

 

Continuous

Rice bran oil*

0.5

77.8

NaOH

1:9 Ethanol

93.5

 

Continuous

 

0.75

80.4

NaOH

1:9 Ethanol

93.2

 

Continuous

1

83.4

NaOH

1:9 Ethanol

93.1

 

Continuous

0.75

81.2

NaOH

1:9 Ethanol

83.9

 

Continuous

1

84.1

NaOH

1:9 Ethanol

90.6

 

Continuous

Vegetable oil (Triolein)

3.5

50

NaOH

1:6 Methanol

98

 

Batch

[124]

Soybean oil

10

65

Ba(OH)2 H2O

1:9 Methanol

97.8

Milestone Ethos 1600, 1000 W

Batch

[125]

Rapeseed oil

10

103

Ba(OH)2 H2O (1.5%)

1:9 Methanol

99

 

Batch

[132]

Rapeseed oil

15

60

Ba(OH)2 H2O (1.5%)

1:9 Methanol

98

 

Batch

[132]

Rapeseed oil

0.5

65

NaOH (0.1%)

1:30 Methanol

89

 

Batch

[122]

3

65

NaOH (0.1%)

1:30 Methanol

92

 

Batch

5

65

NaOH (0.1%)

1:30 Methanol

94

 

Batch

16

65

NaOH (0.1%)

1:30 Methanol

99

 

Batch

Sunflower

16

65

NaOH (1.0%)

1:30 Methanol

99

 

Batch

 

Soybean oil

20

60

NaOH (0.15%)

1:5 Methanol

98

 

Batch

[106]

Soybean oil

20

65

NaOH (0.15%)

1:9 Ethanol

98

 

Batch

[106]

Rice bran oil

20

60

NaOH (0.15%)

1:5 Methanol

98

 

Batch

[106]

Rice bran oil

20

60

NaOH (0.15%)

1:9 Ethanol

97

 

Batch

[106]

Rice bran oil

10

50

NaOH (0.6%)

1:5 Ethanol

99

 

Continuous

[133]

Rice bran oil

10

73

NaOH (0.6%)

1:5 Ethanol

99

 

Continuous

[133]

Soybean oil

10

50

NaOH (0.6%)

1:5 Ethanol

98

 

Continuous

[133]

Soybean oil

10

73

NaOH (0.6%)

1:5 Ethanol

99

 

Continuous

[133]

Vegetable oil

2

50

KOH (0.6%)

1:6 Methanol

98

CEM Mars

Continuous

[130]

Cottonseed

7

333

KOH (1.5%)

1:6 Methanol

92.4

21% of 1200W

 

[64]

Safflower seed oil

6

333

NaOH (1%)

1:10 Methanol

98.4

300W

 

[135]

Rapeseed & soybean

1

333

NaOH (1.3%)

1:18 Methanol

97

300W

 

[136]

Soybean

1

333

NaOH (1.3%)

1:27 Methanol

95

300W

 

[136]

Diphenylammonium salts:DPAMs (Mesylate) (10 molar)

 

100

  

Corn

20

150 C

DPABs (Benzenesulfonate) (10 molar)

2goil:5g Methanol

96

  

[137]

DPATs (Tosylate) (10 molar)

100

  

DPAMs (10 molar)

2goil:5g

92

   

Soybean

20

150

DPABs (10 molar)

Methanol

97

  

[137]

Soybean

60

338

Nan CaO (heterogeneous)

1:7 Methanol

96.6

-

 

[142]

Soybean

20

60

Sulfated zirconia (5%)

1:20 Methanol

90

  

[143]

Oleic acid

20

60

Sulfated zirconia (5%)

1:20 Methanol

90

  

[143]

Canola

5

100

ZnO/La2O2CO3 (1%)

1:1(W/W) Methanol

95

-

 

[148]

Camelina

-

-

BaO (1.5%), SrO (2%)

1:9 Methanol

94, 80

800W

 

[118]

Soybean

2

333

NaOH(1%)

1:6 Methanol

97.7

900W

 

[152]

Sunflower

45

-

 

H2SO4 (0.05%)

96.2

400

 

[154]

Sunflower

25

-

TiO2/SO4 (0.02%)

1:12 Methanol

94.3

300

 

[155]

Vegetable oil

2

50

KOH (0.6%)

1:6 Methanol

98

CEM Mars

Continuous

[130]

Waste vegetable oils/non-edible oils

Waste vegetable oil (domestic)

1

65

KOH

1:9 Methanol

96

Start S Milestone

Batch

[120]

Waste vegetable oil (restaurant)

1

65

KOH

1:9 Methanol

94.5

 

Batch

Kerosene used palm oil

mixture*

0.5

 

NaOH

1:9 Ethanol

70.9

  

[122]

0.75

76.5

NaOH

1:9 Ethanol

91.5

Domestic Microwave

Continuous

1

80.2

NaOH

1:9 Ethanol

91.6

 

Continuous

Used vegetable oil

0.15

 

NaOH (1%)

1:9 Ethanol

100

  

[123]

Used palm oil*

0.5

77.5

NaOH

1:9 Ethanol

82.5

 

Continuous

2.3:1.27 (g:mL)

Unknown

1

60

NaOH

Methanol

97

CEM Explorer

Batch

[129]

Waste vegetable oil

6

50

KOH

1:6 Methanol

96

CEM Explorer

Batch

[130]

Waste frying oil

5

64

NaOH (1%)

1:6 Methanol

93.36

600w

 

[138]

Macauba

15

30

Novozyme 435 (2.5%)

1:9 Ethanol

45.2

  

5

40

Lipozyme IM (5%)

1:9 Ethanol

35.8

Waste frying oil

0.5

-

NaOH (3%)

1:12 Ethanol

97

800W

 

[139]

Rapeseed

5

323

KOH (1%)

1:6 Methanol

93.7

67% of 1200W

 

[141]

Rapeseed

3

313

NaOH (1%)

1:6 Methanol

92.7

67% of 1200W

 

[141]

Karanja

150s

-

KOH

33.4% (W/W)

89.9

180W

 

[144]

Jatropha

2

65

KOH (1.5%)

1:7.5 Methanol

97.4

-

 

[145]

Palm oil

5

70

KOH (1.5%)

1:8.5 Ethanol

98

70W

 

[146]

Yello horn

10

60

Heteropolyacid (HPAs) (1%)

1:12 Methanol

96.2

500W

 

[147]

Castorbean

5

-

Al2O3/50% KOH (1%)

1:6 Methanol

95

40

 

[149]

Castorbean

30

-

SiO2/50% H2SO4 (1%)

1:6 Methanol

95

40

 

[149]

Castorbean

25

-

SiO2/30% H2SO4 (1%)

1:6 Methanol

95

220

 

[149]

Castor

60

338

H2SO4

1:12 Methanol

94

200

 

[111]

Triolin

1

323

KOH (5%)

1:6 Methanol

98

25

 

[150]

1

323

NaOH (5%)

1:6 Methanol

98

25

 

[150]

Frying oil

4

60

NaOH (0.5%)

1:6 Methanol

87

50% of 750W

 

[151]

Rapeseed

4 hr

310

-

1:2.5 Methanol

91

-

 

[128]

Safflower

16

60

NaOH (1%)

1:10 Methanol

98.4

300W

 

[135]

Maize

-

-

NaOH (1.5%)

1:10 Methanol

98

-

 

[153]

Jatropha

7

328

NaOH (4%)

1:30 Methanol

86.3

-

 

[127]

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