Controlling the fuel quality requirements

Despite its valuable advantages, biogenic fuels right from the start had to struggle for acceptance. Reports highlighting engine problems due to poor quality biofuels discredited the promising biogenic fuel. Not until quality standards (see table) were defined did the quality of biofuels and its acceptance improve.

If the standard is mentioned in the following table this means that Metrohm instruments meet the stipulated minimum requirements for use in the standardized test method. The character «#» stands for a check of the quality criteria using a different testing method.

Parameter / Method	Biodiesel		Bioethanol		Vegetable oil
	EN 142141 EN 142132	ASTM 6751	prEN 153763	ASTM D 48064 ASTM D 57985	DIN V 51605
Oxidation stability	EN 14112	#	-	-	EN 14112
Water content KF (coul.)	EN ISO 12937	#	prEN 15489	ASTM E 1064	EN ISO 12937
Water content KF (vol.)			prEN 15489	ASTM E 203
pH value	-	-	prEN 15490	#	-
Chloride	-	-	DIN EN 15492	ASTM D 7318 ASTM D 7319 ASTM D 7328	-
Sulfate	-	-	DIN EN 15492	ASTM D 7318 ASTM D 7319 ASTM D 7328	-
Acid number	EN 14104	ASTM D 664	prEN 15491	ASTM D 1613	EN 14104
Iodine number	EN 14111	-	-	-	EN 14111
Alkali metals and alkaline earth metals	#	#	-	-	#
Antioxidants	recommended	-	-	-	recommended

¹ Automotive fuel
² Heating oil
³ European standard for bioethanol, currently under approval.
⁴ Standard specification for denatured alcohol used as an additive to fossil fuels.
⁵ Standard specification for mixtures of bioethanol and gasoline (Ed75-Ed85).

While the analysis of sulfate is specified in a number of ASTM standards, until recently, the ASTM D 4806-06b standard – the specification for denatured fuel ethanol – provided no guidelines for total and potential sulfate. Recognizing the need for validated quality control methods, ASTM balloted and approved a sulfate specification for fuel ethanol stipulating a maximum level of sulfate in ethanol of 4 parts per million (ppm). Ion chromatography (IC) is at the leading edge of this effort.
Read more in our brochure Quality Assurance of Biofuels with Metrohm instruments (pdf)!