Table 3.

CCD matrix for the experimental design and the response for surface area and yield of activated carbon.

Run	A: Carbonization temperature (°C)	B: Impregnation ratio (1:x)	C: Activation time (min.)	Surface area (m2/g) (Y1)			Yield (%) (Y2)
				Actual	Predicted	Residual	Actual	Predicted	Residual
1	450.00	3.00	90.00	342.21	341.99	0.22	43.40	43.04	0.36
2	450.00	3.00	150.00	367.10	367.54	−0.44	23.52	23.43	0.09
3	650.00	3.00	90.00	318.40	318.09	0.31	18.76	18.61	0.15
4	450.00	1.00	150.00	402.03	402.45	−0.42	31.87	31.65	0.22
5	550.00	2.00	120.00	431.56	431.92	−0.36	56.29	56.45	−0.16
6	650.00	1.00	90.00	376.03	376.34	−0.31	21.24	21.04	0.20
7	550.00	2.00	120.00	455.01	455.32	−0.31	54.40	54.71	0.02
8	550.00	2.00	120.00	441.30	441.80	−0.50	56.43	56.13	0.30
9	550.00	0.32	120.00	271.90	271.67	0.23	43.19	43.56	−0.37
10	550.00	3.68	120.00	297.43	297.43	0.00	32.85	32.54	0.31
11	650.00	3.00	150.00	386.10	386.54	−0.44	44.26	44.07	0.19
12	550.00	2.00	69.55	291.30	291.91	−0.61	37.81	37.45	0.36
13	381.82	2.00	120.00	416.87	416.37	0.50	27.29	27.57	−0.28
14	550.00	2.00	120.00	439.12	439.52	−0.40	50.50	50.87	−0.37
15	550.00	2.00	120.00	453.21	453.61	−0.40	53.91	53.73	0.18
16	718.18	2.00	120.00	287.30	287.60	−0.30	34.13	34.54	−0.41
17	550.00	2.00	170.45	371.80	372.20	−0.40	19.76	20.20	−0.44
18	550.00	2.00	120.00	449.50	449.32	0.18	57.78	57.26	0.52
19	650.00	1.00	150.00	345.89	345.56	0.33	46.09	46.34	−0.25
20	450.00	1.00	90.00	265.34	265.06	0.28	27.34	27.12	0.22