performance exclusive of any difficulties. Austria was the first country in the world to define and approve the standards for rapeseed oil methyl esters as diesel fuel. As standardization is a prerequisite for successful market introduction and penetration of BD, standards or guidelines for the quality of BD have also been defined in other countries like Germany, Italy, France, the Czech Republic, and in the United States.
Quality standards are prerequisites for the commercial use of any fuel product. They serve as guidelines for the production process, guarantee customers that they are buying high quality fuels, and provide authorities with approved tools for the assessment of safety risks and environmental pollution [163]. Moreover, engine and automobile manufacturers rely on fuel standards for releasing warranties for their vehicles to be operated on BD.
In 1997, the European Committee for Standardization was mandated to develop a uniform standard for FAME fuels and come up with respective measurement procedures. The resulting standard EN 14214, which has come into picture in 2004, is valid for all member states of the European Union and thus replaces the respective national specifications. Apart from Australia and the United States of America, which have already drawn up BD quality norms, a number of countries worldwide (e.g. Brazil, Canada, Japan) are currently working on their introduction, having released drafts or preliminary specifications. Then, ASTM D 6751 and EN 14214 conditions as well as their analysis methods for BD are illustrated in Table 1.3.
The constraints that are utilized to describe the quality of BD can be divided in two groups [164]. One of them is also used for mineral diesel, and the second describes the composition and purity of fatty esters. The former includes, for example, density, viscosity, flash point, sulfur percentage, Conradson carbon residue, sulfate ash percentage, cetane number, and acid number. The latter comprises, for example, methanol, free glycerol, total glycerol, phosphorus contents, water and esters content, and other properties described in Table 1.3. Thus, ASTM D 6751 and EN 14214 specifications methods for BD are illustrated in Table 1.3.
1.10 Conclusion
Currently, the uses of BD as an eco‐friendly alternative to petrodiesel are gaining much recognition. The production of BD from nonconventional oils may simultaneously reduce dependence on imported fossil fuels and help alleviate the food versus fuel dilemma that plagues rapeseed, soybean, palm, and other oilseed crops that are also traditional oil sources. As a result of development of local BD industry and market, opportunities would be raised for the farmers to grow new oilseed crops and increase production of traditional and nonconventional oils, generating profit and income for all the stakeholders. Moreover, the establishment of local BD industry not only will generate opportunities for employment and personnel training but also might help reduce the dependence on imported petroleum and fuel derived from it, which continues to decrease in availability and affordability. More research and advancements in BD technology coupled with large‐scale cultivation of oilseed crops, especially the nontraditional crops, additional subsidies, and the relevant technological sector, may lead to further reduction of the cost of this renewable fuel. Furthermore, there is a real need to appraise the environmental benefits of producing BD and to consider such attributes while determining the cost incurred in the production of such green fuels.
Table 1.3 Biodiesel specifications according to ASTM D6751 and EN 14214 standards.
| Property | ASTM D 6751 | EN 14214 | ||
|---|---|---|---|---|
| Test method | Limits | Test method | Limits | |
| Density (15 °C) | — | — | EN ISO 3675 | 860–900 kg m−3 |
| Kinematic viscosity (40 °C) | ASTM D 445 | 1.9–6.0 mm2 s−1 | EN ISO 3104 | 3.5–5.0 mm2 s−1 |
| Flash point | ASTM D 93 | 130 °C, min | EN ISO 3679 | 120 °C, min |
| Cloud point | ASTM 2500 | Not specified | — | — |
| Sulfur content | ASTM 5453 | 0.05% (w/w), max | EN ISO 20864 | 10.0 mg kg−1, max |
| Carbon residue | ASTM D 4530 | 0.050% (w/w), max | EN ISO 10370 | 0.30% (molmol−1) |
| Cetane number | ASTM D 613 | 47, min | EN ISO 5165 | 51, min |
| Sulfated ash | ASTM 874 | 0.020% (w/w), max | ISO 3987 | 0.02% (molmol−1) |
| Distillation temperature | ASTM D 1160 | 360 °C, max | — | — |
| Copper strip corrosion (3 h, 50 °C) | ASTM D 130 | No. 3, max | EN ISO 2160 | 1 (degree of corrosion) |
| Acid number or acid value | ASTM 664 | 0.50 mg KOH g−1, max | EN 14104 | 0.50 mg KOH g−1, max |
| Iodine value | — | — | EN 14111 | 120 gI2·100 g−1, max |
| P content | ASTM D 4951 | 0.001% (w/w), max | EN 14107 | 10.0 mg kg−1, max |
| Water content | ASTM D 2709 | 0.050% (v/v), max | EN ISO 12937 | 500 mg kg−1, max |
| Oxidative stability | — | — | EN 14112 | 6 h, min |
| Methanol content | — | — |
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