Table 4.

Analysis of the in situ transesterification factors for the yield of crude biodiesel from Scenedesmus sp. using the orthogonal array design (% w/w, based on lipid weight).

	A	B	C	D
K 1	102.13 ± 3.61	102.03 ± 4.46	97.26 ± 7.04	91.46 ± 4.71
K 2	124.24 ± 2.00	124.14 ± 2.77	124.50 ± 1.33	137.97 ± 1.13
K 3	127.42 ± 2.61	127.63 ± 0.99	132.04 ± 0.16	124.38 ± 2.38
k 1	34.04 ± 1.20	34.01 ± 1.49	32.42 ± 2.35	30.49 ± 1.57
k 2	41.41  ±  0.67	41.38 ± 0.92	41.50 ± 0.44	45.99 ± 0.38
k 3	42.47 ± 0.87	42.54 ± 0.33	44.01 ± 0.05	41.46 ± 0.79
R	8.43 ± 0.24	8.54 ± 1.16	11.59 ± 2.40	15.50 ± 1.60
Optimal level	3	3	3	2

K _i ^A = ∑ biodiesel yield at A _i .   

k _i ^A = K _i ^A/3 .  

R _i ^A = max⁡{k _i ^A} − min⁡{k _i ^A}.