In Situ Transesterification of Spirulina Microalgae to Produce Biodiesel Using Microwave Irradiation

Table 3

Physicochemical properties of Spirulina microalgae oil.

No.	Property	Test method	Limits ASTM D6751	Values of algal oil
1	pH	—	7-9	7
2	Specific gravity	ASTM D 941	0.86-0.89	0.877
3	Kinematic viscosity at 40°C mm^2/s	ASTM D 445	1.9-6.0	5.76
4	Acid value KOH/g	ASTM D 664	—	0.4
5	Free fatty acid value		—	0.802
6	Moisture content%	ASTM D 2709	0.050 max	7.8
7	Carbon residue %	ASTM D 524	0.050 max	<
8	Refractive index			1.365
9	Sulphur, wt%	ASTM D 5453	0.0-0.0024	Nil