Table 1 Coded and real values for each variable of the central composite design
− α | − 1 | 0 | + 1 | + α | ||
|---|---|---|---|---|---|---|
A | Glycerol, g/L | 20.0 | 52.5 | 85.0 | 117.5 | 150 |
B | Temperature, °C | 25.0 | 27.5 | 30.0 | 32.5 | 35.0 |
C | pH | 2.5 | 3.63 | 4.75 | 5.87 | 7.0 |
D | DOT, % | 10 | 20 | 30 | 40 | 50 |
− α | − 1 | 0 | + 1 | + α | ||
|---|---|---|---|---|---|---|
A | Glycerol, g/L | 20.0 | 52.5 | 85.0 | 117.5 | 150 |
B | Temperature, °C | 25.0 | 27.5 | 30.0 | 32.5 | 35.0 |
C | pH | 2.5 | 3.63 | 4.75 | 5.87 | 7.0 |
D | DOT, % | 10 | 20 | 30 | 40 | 50 |