The Price Implications Of The Different Quality Characteristics Of Biodiesel Products

The quality characteristics of the biodiesel products vary in function of the chemical properties of the feedstock used for their production.
The most common feedstocks used in the production of biodiesel are rapeseed oil, soybean oil, palm oil, used cooking oil and tallow. From each feedstock is produced a biodiesel with a different chemical composition and different quality characteristics than others.
The fatty acid composition of the feedstock determines the physical and chemical properties of the biodiesel product, including its cold flow properties. The biodiesel products derived from feedstocks with high content of unsaturated fatty acids, e.g. biodiesel produced from rapeseed oil and soybean oil, have a lower CFPP (Cold Filter Plugging Point) than the biodiesel products derived from feedstocks with high content of saturated fatty acids, e.g. biodiesel produced from palm oil and tallow.
CFPP is the lowest temperature at which a given volume of biodiesel can pass through a filter and thus, allows the assessment of the cold temperature performance of the biodiesel products. The lower the CFPP, the better the cold temperature performance of the biodiesel product and therefore, more valuable the biodiesel product will be.
The lowest CFPP is that of rapeseed oil fatty acid methyl esters (biodiesel produced from rapeseed oil) which is in the range of – 14 and – 12º C.
The next in line is the CFPP of soybean oil fatty acid methyl esters (biodiesel produced from soybean oil) which is – 4 and – 2º C.
The third is the CFPP of used cooking oil fatty acid methyl esters (biodiesel produced from used cooking oil) which is 0º C.
The fourth is the CFPP of palm oil fatty acid methyl esters (biodiesel produced from palm oil) which is +13º C.
The fifth is the CFPP of tallow fatty acid methyl esters (biodiesel produced from tallow) which varies between +12 and 13º C.
A common feature of biodiesel products is their hygroscopic nature which involves the risk that the biodiesel cargoes can absorb atmospheric moisture during the storage and transportation by sea in case of temperature differences between the ambient temperature and the storage and carrying ship`s tanks. The biodiesel products are purchased by European fuel suppliers for blending with petroleum diesel fuel to comply with the quota imposed by the EU Renewable Energy Directive. Given the hygroscopic nature of biodiesel products, the water content of biodiesel cargoes is required to be below the maximum limit stated in EN 14214 specifications¹ (500 mg/kg) in order to avoid that the biodiesel/petroleum diesel blend end up with a water content above the saturation limit.
The lower the water content, the more valuable the biodiesel cargo will be.
The biodiesel product with the lowest water content is rapeseed oil fatty acid methyl ester which has a water content of 300 ppm.
Palm oil fatty acid methyl ester has a water content of 350 ppm.
Used cooking oil fatty acid methyl ester has a water content of 350 ppm.
Tallow fatty acid methyl ester has a water content of 350 ppm.
Soybean oil fatty acid methyl ester has a water content of 400 ppm.
The biodiesel cargoes are sold either as individual products, i.e. rapeseed oil fatty acid methyl esters, soybean oil fatty acid methyl esters, palm oil fatty acid methyl esters, used cooking oil fatty acid methyl esters, tallow fatty acid methyl esters, or as blends of biodiesel products, the type and share of each biodiesel product in the blend being in function of the CFPP and water content required by the buyers (fuel suppliers), which in turn is in function of the season and weather conditions.
The blends of biodiesel products are sold under the generic description "Fatty Acid Methyl Esters". The most common blends are Fatty Acid Methyl Esters with a CFPP of – 10º C and a maximum water content of 350 ppm and Fatty Acid Methyl Esters with a CFPP of 0º C and a maximum water content of 350 ppm.

by Vlad Cioarec, International Trade Consultant

This article has been published in Commoditylaw`s Biofuels Trade Review Edition No. 4.

Endnotes:

1. The biodiesel products are sold in Europe based on the standard specifications published by the European Committee for Standardization EN 14214, except for CFPP and water content.