Tribological Performance of Si-Doped Hydrogenated Diamond-Like Carbon Coatings in Different Biodiesel

Table 3

Selected results from biodiesel analyses according to DIN EN 14214:12-11.

Feature	Limits acc. standards	RME; w/o OS	RME; 200 mg/kg OS	RME; 1000 mg/kg OS	SME; w/o OS	SME; 200 mg/kg OS	SME; 1000 mg/kg OS
Ester content	96,5%	>99%	>99%	>99%	98,1%	98,1%	98,1%
Total glyceride content	max. 0.25%	0.1%	0.1%	0.1%	0.2%	0.2%	0.2%
Sulphur content	max. 10 mg/kg	<5 mg/kg	<5 mg/kg	<5 mg/kg	<5 mg/kg	<5 mg/kg	<5 mg/kg
Cetane index	min. 51.0	52.5	52.5	52.5	57.1	57.1	57.1
Water content	500 mg/kg	64 mg/kg	64 mg/kg	64 mg/kg	127 mg/kg	127 mg/kg	127 mg/kg
Copper corrosion	1	1	1	1	1	1	1
Oxidation stability	min. 8 h	7.3 h	12.5 h	24.5 h	4.5 h	6.4 h	12.5 h
Acid number	max. 0.5 mg KOH/g	0.49 mg KOH/g	0.49 mg KOH/g	0.49 mg KOH/g	0.271 mg KOH/g	0.217 mg KOH/g	0.217 mg KOH/g