Table 1.
Ultrasound-assisted esterification of valeric acid with various alcohols (MeOH, EtOH, iPrOH, BuOH) and different acid: alcohol ratios.
| Entry | System | Alcohol | Acid:alcohol Ratio | Conversion (mol%) | Specific activity (U/g biocatalyst) |
|---|---|---|---|---|---|
| 1 | Blank | Methanol | All | – | – |
| 2 | Ethanol | ||||
| 3 | 1-Propanol | ||||
| 4 | 1-Butanol | ||||
| 5 | SiO2 material | Methanol | All | - | – |
| 6 | Ethanol | ||||
| 7 | 1-Propanol | ||||
| 8 | 1-Butanol | ||||
| 9 | Free enzyme | Ethanol | 1:1 | 75 | 583 ± 16 |
| 10 | 1:2 | 76 | |||
| 11 | 1:3 | 74 | |||
| 12 | Bio-lipase | Methanol | All | – | – |
| 13 | |||||
| 14 | |||||
| 15 | Ethanol | 1:1 | 85 | 616 ± 9 | |
| 16 | 1:2 | 90 | |||
| 1:3 | 82 | ||||
| 17 | |||||
| 18 | 1-Propanol | 1:1 | 50 | 480 ± 6 | |
| 19 | 1:2 | 60 | |||
| 20 | 1:3 | 57 | |||
| 21 | 1-Butanol | 1:1 | 73 | 585 ± 14 | |
| 22 | 1:2 | 76 | |||
| 23 | 1:3 | 75 |