Biodiesel Production Using Supercritical Methanol with Carbon Dioxide and Acetic Acid

Table 4

Results of L9 (3⁴) orthogonal array experiments on fatty acid methyl ester (FAME) and glycerol contents of biodiesel production samples.

Run	FAME content					Glycerol content
	Test 1 (%)	Test 2 (%)	AVG	SD	S/N ratio (db)	Test 1 (%)	Test 2 (%)	AVG
1	35.73	38.22	38.22	3.51	31.59	3.21	3.67	3.44
2	51.1	51.47	51.47	0.52	34.23	5.29	5.59	5.44
3	61.12	60.44	60.44	0.97	35.62	5.27	5.52	5.39
4	85.97	86.49	86.49	0.74	38.74	5.44	5.64	5.54
5	85.17	82.35	82.35	4	38.3	5.63	6.08	5.85
6	72.3	72.46	72.46	0.22	37.2	6.85	7.19	7.02
7	85.27	82.73	82.73	3.59	38.34	6.01	6.39	6.2
8	62.05	63.38	63.38	1.88	36.03	6.79	7.17	6.98
9	71.88	70.45	70.45	2.03	36.95	6.63	7.01	6.82
CT	98.17	97.48	97.83	0.49	39.81	6.74	7.22	6.98

AVG: average; SD: standard deviation; S/N: signal-to-noise ratio; CT: confirmation test.