Subcritical Water Extraction of Chlorella pyrenoidosa: Optimization through Response Surface Methodology

Table 3

Response values of the oil yield for given levels of variables (reaction temperature, reaction time, and biomass loading) in response surface methodology.

Run Number	Type	Independent variables			Dependent variable
		Reaction temperature, A (°C)	Reaction time, B (min)	Biomass loading, C (%)	Oil Yield, Y (g/g algae)
1	Factorial	320	5	10	0.0702
2	Factorial	320	15	3	0.1268
3	Factorial	320	5	3	0.0742
4	Axial	270	10	15	0.0250
5	Center	270	10	5	0.0659
6	Center	270	10	5	0.0497
7	Center	270	10	5	0.0624
8	Axial	170	10	5	0.0101
9	Factorial	220	15	3	0.0173
10	Factorial	220	5	3	0.0053
11	Axial	270	10	1	0.0625
12	Axial	370	10	5	0.1091
13	Factorial	220	5	10	0.0053
14	Factorial	320	15	10	0.0683
15	Axial	270	1	5	0.0118
16	Center	270	10	5	0.0543
17	Factorial	220	15	10	0.0115
18	Center	270	10	5	0.0585
19	Axial	270	20	5	0.0506
20	Center	270	10	5	0.0697