Continuous Production of Lipase-Catalyzed Biodiesel in a Packed-Bed Reactor: Optimization and Enzyme Reuse Study

Table 1

3-level-3-factor Box-Behnken design of experiments.

	Factors				Predicted
Treatment^a	Temperature (^∘C)	Flow rate (mL/min)	Molar ratio (alcohol/oil)	Yield (%)	Yield^c (%)
no.	𝑋1	𝑋2	𝑋3	𝑌1 ± SD	𝑌2
1	1^b (60)	1 (0.5)	0 (4)	55.00 ± 2.53	58.04
2	1 (60)	−1 (0.1)	0 (4)	81.23 ± 1.49	82.26
3	−1 (40)	1 (0.5)	0 (4)	27.53 ± 1.76	26.50
4	−1 (40)	−1 (0.1)	0 (4)	70.53 ± 1.69	67.49
5	1 (60)	0 (0.3)	1 (5)	72.40 ± 1.69	71.65
6	1 (60)	0 (0.3)	−1 (3)	63.65 ± 1.49	60.34
7	−1 (40)	0 (0.3)	1 (5)	39.72 ± 0.93	43.03
8	−1 (40)	0 (0.3)	−1 (3)	41.90 ± 0.09	42.65
9	0 (50)	1 (0.5)	1 (5)	56.94 ± 1.09	54.66
10	0 (50)	1 (0.5)	−1 (3)	41.14 ± 0.41	41.42
11	0 (50)	−1 (0.1)	1 (5)	80.14 ± 2.32	79.87
12	0 (50)	−1 (0.1)	−1 (3)	79.13 ± 3.88	81.42
13	0 (50)	0 (0.3)	0 (4)	63.98 ± 1.26	63.98
14	0 (50)	0 (0.3)	0 (4)	63.22 ± 0.35	63.98
15	0 (50)	0 (0.3)	0 (4)	64.73 ± 0.71	63.98

^aThe treatments were run in random order.
^bThe values (−1), (0), and (1) are coded levels.
^cCalculated from the refined model.