Response Surface Methodology Process Optimization of Biodiesel Production from Castor Seed Oil

Table 2

Physicochemical properties of refined castor oil.

Parameters	Unit	Refined castor oil	ASTM standard value
Moisture content		3.72
Specific gravity		0.961	0.957–0.968
Viscosity (at 40°C)	mm^2/sec	12.4	6.3–8.8
Acid number	mL·KOH/g oil	2.4	0.4–4
Saponification number	mg·KOH/g oil	185.2	175–187
Iodine number	—	86	82–88
Cetane number	min	56.4	47
Heating value	MJ/kg	40.6	37.5–42.8