Table 2.
Use of co-solvents in homogeneous alkaline catalysed methanolysis.
| Co- solvent |
Catalyst | Reactor type | Feedstock | Pre- treatment |
Reaction conditions |
Yield (wt.%d) |
Ref. | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Co-solvent amount (wt.%a, v.%b, mol%c,d) |
Catalyst amount (wt.%a, mol%d) |
MeOH/ oil molar ratio |
Time (min) |
T (°C) |
Stirrer (rpm) |
Special conditions |
|||||||
| Acetone | KOH | STR | Canola oil | – | 154 v.% (25 wt%) |
1 | 4.5:1 | 30 | 25 | N/S | – | 98.30 | [39] |
| Catfish oil | – | 0.5 | 60 | 25 | 97.50 | [21] | |||||||
| – | 1 | 30 | 35 | 97.02 | [39] | ||||||||
| Jatropha curcas L. oil | – | 1 | 30 | 25 | 97.91 | [39] | |||||||
| – | 0.5 | 60 | 25 | 97.80 | [21] | ||||||||
| 1 | 92 v.% (20 wt%) |
1 | 6:1 | 30 | 40 | 90 | [40] | ||||||
| Acetone | KOH | STR | WCO | – | 154 v.% (25 wt%) |
1 | 4.5:1 | 30 | 25 | N/S | – | 98 | [39] |
| Biodiesel | KOH | STR | Soybean oil | – | 20 v.% (5 wt%) |
0.8 | 6:1 | 60 | 70 | 100 | – | ∼95e | [14] |
| DEE | KOH | STR | Rapseed oil | – | 256 v.% (100 mol%c) |
0.7 | 9:1 | 120 | 30 | 700 | – | 97.6 | [15] |
| [41] | |||||||||||||
| Microtube | Sunflower oil | – | 187 v.% (73 mol%c) |
1 | 8:1 | 93 s | 25 | -f | 92.8g | [32] | |||
| NaOH | STR | Soybean oil | – | 144 v.% (56 mol%c) |
1.07 | 5.65:1 | 30 | 34 | 500 | 98.35 | [42] | ||
| DME | KOH | Oscillating zylinder | Sunflower oil | – | 100 mol%c | 1 | 6:1 | 20 | 25 | 2.6 Hz shaking |
500 kPa | ∼99e,g | [32] |
| n-hexane | CH3ONa | STR | Castor oil | – | 15 v.% | 1 | 6:1 | 120 | 60 | 600 | – | 95.5 | [43] |
| KOH | STR |
Cyprinus carpio fish oil (fish waste) |
150 v.% | 0.60 | 5:1 | 30 | 50 | 600 | 97.24 | [44] | |||
| Pork lard | 214 v.% (65 wt%) |
2.0 | 10:1 | 120 | 50–60 | 600 | 98.2 | [45] | |||||
| Microreactor | Soybean oil (used) |
45 vol% | 1 | 33.3 v.%g | 9.05 s | 57.2 | -f | 98.8 | [41] | ||||
| NaOH | STR | Jatropha curcas L. oil | 2 | 40 v.% | 1 | 8:1 | 7 | 60 | N/S | 96.50 | [47] | ||
| Rapeseed oil soybean oil (1:1) |
3 | 5 g | 0.80 | 5:1 | 120 | 55 | 1600 | 94 | [48] | ||||
| MTBE | KOH | STR | Rapeseed oil | – | 296 v.% (100 mol%c) |
0.7 | 9:1 | 120 | 30 | 700 | – | 97.5 | [15] |
| NaOH | Microwave cell (batch) |
Rapeseed oil | 165 v.% (no ratio given) |
1.3 | 12:1 | 1 | 60 | 400 | 2.45 kHz | 95 | [49] | ||
| Soybean oil | 97 | [49] | |||||||||||
| Microwave cell (continuous) |
Soybean oil | 97 | [49] | ||||||||||
| Petro- Diesel |
NaOH | Sonication vessel | Soybean oil | – | 265 v.% (30 wt%) |
1.0 | 3:1 | 30 | 50 | -f | 20 KHz 750 W 2 s On 2 s Off |
92 | [50] |
| THF | NaCl | Electrolysis cell | Corn oil | – | 50 v.% (25 mol%c) |
0.56 | 24:1 | 120 | N/SL | -f | 18.6 V 2 wt% water |
97 | [51] |
| KOH | STR | Mahua oil | 4 | 125 v.% | 1 | 6:1 | 180 | 45 | N/S | – | 99g | [52] | |
| STR | Rapeseed oil | – | 202 v.% (100 mol%c) |
0.7 | 9:1 | 120 | 30 | 700 | 98.3 | [15] | |||
| [41] | |||||||||||||
| Oscillating bottle |
Thespesia populnea biomass |
- | 25 v.% | 1.5 | 5.5:1h | 120 | 60 | 500 | 97.8 | [53] | |||
| NaOH | STR | Jatropha curcas L. oil | 1 | 100 v.% | 0.5 | 4:1 | 10 | 40 | 200 | 98.04 | [54] | ||
| KM Micromixer | WCO | 5 | 30 v.% | 1 | 12:1 | – | 70 | -f | 60 ml/h | 97 | [55] | ||
h regarding the oil volume.
1: esterification.
2: degumming, esterification and drying.
3: neutralisation, purification and heating.
4: ethyl acetate and saturated sodium bicarbonate solution were shaken with the oil followed by settling period.
5: filtration and esterification.
a
regarding the oil weight.
b
regarding the MeOH volume.
c
regarding mole MeOH.
d
%FAME yield.
e
estimated from diagram.
f
no agitation.
g
%conversion.
h
MeOH volume to biomass weight ratio.