Table 8. Physical Properties of the Biodiesel Product Using a Double-Step Esterification Process.

			biodiesel standard		biodiesel standard in Thailanda
property	method	diesel	EU	USA	for agricultural engine	for commercial-based biodiesel	resultb
ester (wt %)	EN 14103		96.5 min			96.5 min	94.22c
density at 15 °C (kg/m3)	ASTM D1298	810–870	860–900		860–900	860–900	870
viscosity at 40 °C (cSt)	ASTM D445	1.8–4.1	3.5–5.0	1.9–6.0	1.9–8	3.5–5	5.36
flash point (°C)	ASTM D 93	52	101 min	130 min	120 min	120 min	168
copper strip corrosion	ASTM D 130	no. 1 max	no. 1 max	no. 3 max	no. 3 max	no. 1 max	no. 1a
acid value (mgKOH/g)	ASTM D664		0.5 max	0.5 max	0.8 max	0.5 max	11.78
methanol (wt %)	EN 14110		0.2 max	0.2 max		0.2 max	<0.01
monoglyceride (wt %)	EN 14105		0.8 max			0.7 max	0.69
diglyceride (wt %)	EN 14105		0.2 max			0.2 max	1.32
triglyceride (wt %)	EN 14105		0.2 max			0.2 max	0.56
free glyceride (wt %)	EN 14105		0.02 max	0.02 max	0.02 max	0.02 max	0.00
total glyceride (wt %)	EN 14105		0.25 max	0.24 max	1.5 max	0.25 max	0.25

^aRefer to Thawornprasert et al.³³

^bResults of biodiesel production from the recommended conditions.

^cPurity of ester from the GC–FID analysis method.