Comparison of catalytic performance of different heterogeneous acid catalysts for biodiesel production.
| Catalyst | Oil feedstocks | Transesterification parameters | Ester content (%) | Cycles | Ref | |||
|---|---|---|---|---|---|---|---|---|
| Temperature (°C) | Time (h) | Alcohol : oil molar ratio | Catalyst loading (%) | |||||
| WO3/SnO2 | Soybean | 110 | 5 | 30 : 1 | 5 | 79.2 | 5 | 58 |
| WO3/AlPO4 | Soybean | 180 | 5 | 30 : 1 | 5 | 72.5 | 5 | 23 |
| WO3/Zr-MCM-41 | Sunflower | 200 | 2.5 | 12 : 1 | 13.3 | 92.0 | 3 | 48 |
| WO3/ZrO2 | Soybean | 200 | 5 | 15 : 1 | 3 | 97.0 | — | 59 |
| Nb2O5/SO4 | Macaw palm oil | 250 | 4 | 120 : 1 | 30 | 99.2 | 5 | 49 |
| HPMo/TiO2 | Waste cooking oil | 190 | 4 | 90 : 1 | 5 | 94.5 | 4 | 20 |
| HPMo/Al2O3 | Macaw palm oil | 190 | 4 | 50 : 1 | 13 | 99.8 | 4 | 60 |
| HPMo/Nb2O5 | Macaw palm oil | 210 | 4 | 90 : 1 | 20 | 99.6 | 4 | 61 |
| Cs2.5PW12O40 | Used vegetable oil | 260 | 0.67 | 40 : 1 | 3 | 92.0 | — | 62 |
| WO3/CuFe2O4 | Waste cooking oil | 180 | 3 | 45 : 1 | 6 | 95.2 | 5 | This study |