Table 3 Equations for the dependent variables (gross calorific value, extraction yield and amount of hemicelluloses extracted) as a function of the independent variables (acid concentration and temperature)

Tagasaste

 (1)

GCV = 19 603.0 + 77.8 X_C + 587.5 X_T + 212.9 X_CX_C + 365.9 X_TX_T

 (2)

Yield = 69.3 − 11.4 X_C − 3.7 X_T − 3.5 X_CX_C − 3.9 X_TX_T + 5.8 X_CX_T

 (3)

HE = 62.5 + 10.8 X_C + 12.2 X_T − 2.1 X_CX_C + 12.0 X_TX_T − 8.5 X_CX_T

Leucaena

 (4)

GCV = 19 315.5 + 82.8 X_C + 274.8 X_T + 218.7 X_TX_T

 (5)

Yield = 66.4 + 5.7 X_C − 7.1 X_T + 4.7 X_CX_C − 0.6 X_CX_T

 (6)

EH = 55.2 − 1.2 X_C + 14.8 X_T + 7.5 X_TX_T + 3.5 X_CX_T

Paulownia trihybrid

 (7)

GCV = 20 186.6 + 318 X_C + 480.6 X_T + 221.8 X_CX_C + 77.8 X_TX_T − 52.2 X_CX_T

 (8)

Yield = 54.5 − 4.5 X_C − 4.5 X_T − 3.8 X_CX_C + 5.2 X_CX_T

 (9)

EH = 57.6 + 17.5 X_C + 10.8 X_T + 16.5 X_CX_C − 7.7 X_CX_T