Table 4.
Ethanol yield-related parameters from MW-assisted acid and alkali-pretreated cassava stems subjected to saccharification with or without detoxification chemicals (120 h) followed by fermentation for 48 h
| Treatments* | Ethanol content (g/L) | Ethanol yield (YE) | FE (%) | Volumetric ethanol productivity (g/L/h) | Ethanol recovery (ml/kg dry biomass) | |
|---|---|---|---|---|---|---|
| A* | D* | |||||
| Cassava stems | ||||||
| MW-acid (D0) | 13.66e | 0.304a,b | 59.43g | 0.285b | 166.64h | 160.00 |
| MW-acid (D+) | 16.54d | 0.331a | 64.85f | 0.345b | 201.73e | 190.00 |
| MW-alkali (D0) | 17.84c | 0.363a | 71.01e | 0.372a,b | 217.50d | 210.00 |
| MW-alkali (D+) | 21.56b | 0.401a | 78.49b | 0.449a | 262.90b | 250.00 |
| Cassava leaves | ||||||
| MW-acid (D0) | 6.43h | 0.297b | 58.18g | 0.134c | 78.40 k | 70.00 |
| MW-acid (D+) | 9.60g | 0.373a | 72.99d | 0.200c | 117.05j | 110.00 |
| MW-alkali (D0) | 12.33f | 0.371a | 72.61d | 0.257b,c | 150.41i | 140.00 |
| MW-alkali (D+) | 16.37d | 0.397a | 77.71b | 0.341b | 199.64f | 190.00 |
| Cassava peels | ||||||
| MW-acid (D0) | 14.40e | 0.384a | 75.21c | 0.300b | 175.57 g | 165.00 |
| MW-acid (D+) | 17.93c | 0.398a | 77.90b | 0.373a,b | 218.60d | 205.00 |
| MW-alkali (D0) | 20.15b | 0.402a | 78.74b | 0.420a | 245.76c | 235.00 |
| MW-alkali (D+) | 24.86a | 0.433a | 84.65a | 0.518a | 303.19a | 290.00 |
*D0: without detoxification chemicals; D+: with detoxification chemicals; statistical comparison was made within each column and values with different superscripts are significant at p < 0.05; A*: ethanol recovery based on analytical data; D*: ethanol recovery from distillation (mean from two runs)