Optimization of Hydrothermal and Diluted Acid Pretreatments of Tunisian Luffa cylindrica (L.) Fibers for 2G Bioethanol Production through the Cubic Central Composite Experimental Design CCD: Response Surface Methodology

Table 3

Theoretical matrix of cubic central composite experimental design CCD for optimization of hydrothermal pretreatment of Luffa cylindrica fibers.

	Experiments	Temperature (°C)	Reaction time (min)
A′	1	−1	−1
	2	−1	−1
	3	−1	−1
B′	4	+1	−1
	5	+1	−1
	6	+1	−1
C′	7	−1	+1
	8	−1	+1
	9	−1	+1
D′	10	+1	+1
	11	+1	+1
	12	+1	+1
E′	13	−1	0
	14	−1	0
	15	−1	0
F′	16	+1	0
	17	+1	0
	18	+1	0
G′	19	0	−1
	20	0	−1
	21	0	−1
H′	22	0	+1
	23	0	+1
	24	0	+1
I′	25	0	0
	26	0	0
	27	0	0