Activity comparison of different CaO-ZnO catalysts.
| Entry | Catalyst | Oil | T (°C) | t (h) | M/O | CA (wt%) | Yield (%) | Reuse cycle (%) | Basic density (mmol g−1) | Ref. |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | CaO-ZnO | Jatropha oil | 120 | 3.0 | 25 : 1 | 3 | 94 | 4(80) | 1.38 | 88 |
| 2 | CaO-ZnO | Jatropha oil | 120 | 4.0 | 26 : 1 | 3.7 | 97.0 | — | — | 89 |
| 3 | CaO-ZnO | Sunflower oil | 78 | 3.0 | 20 : 1a | 3.0 | 95.0 | 3(40) | — | 90 |
| 4 | ZnO-CaO | Jatropha oil | 65 | 0.75 | 9 : 1 | 5.0 | 99 | 5(99) | — | 91 |
| 5 | CaO-ZnO | Sunflower oil | 60 | 4.0 | 10 : 1 | 2 | 95 | — | 0.28 | 92 |
| 6 | K2O/CaO-ZnO | Soybean oil | 60 | 4.0 | 15 : 1 | 6 | 81.1 | — | 93 | |
| 7 | ZnO/Ca (OH)2/KF | Soybean oil | 65 | 1.5 | 12 : 1 | 3 | 97.6 | — | 3.62 | 94 |
a
The substrate of transesterification is ethanol.