Japan: Fuels: Biodiesel Fuel
Quality Assurance Law Specifications
There are two quality standards for biodiesel fuels in Japan: a mandatory standard specified in the Law on the Quality Control of Gasoline and Other Fuels (Quality Assurance Law) and a Japanese Industrial Standard (JIS).
The Quality Assurance Law was amended to allow up to 5% Fatty Acid Methyl Esters (FAME) by mass (in the USA and Europe, blending is by volume) and to prevent the use of unprocessed vegetable oils. The requirements took effect in March 2007. The diesel fuel properties specified in this law are sulfur, cetane index, T90 distillation temperature and upper limits on FAME and triglicerides. For biodiesel, additional requirements include limits for methanol, total acid number (TAN), low molecular weight acids and oxidation stability. Both diesel fuel and biodiesel/diesel blends have limits on FAME and triglicerides to clearly distinguish between the two and to prevent the use of unprocessed triglicerides. B5 blends are required to comply with the same limits as diesel fuel as well as the requirements in Table 1.
| Fuel Property | Unit | Specification | Test |
|---|---|---|---|
| Methanol, max | % mass | 0.01 | |
| Total acid number, max | mg KOH/g | 0.13 | JIS K2501 |
| Formic, acetic and propionic acids, max | % mass | 0.003 | |
| Oxidation stability, max acid number increase | mg KOH/g | 0.12 | ASTM D7545 |
JIS Standard
Table 2 shows the limits specified by JIS K2390 for biodiesel used to make B5 blends. Type 1 biodiesel is for warmer seasons and temperatures above 0°C, and Type 2 for colder, sub-zero conditions. Type 2 is formulated with lower monoglyceride levels to prevent gelling and filter clogging in cold environments. FAME must not contain polyunsaturated fatty acid methyl esters.
| Fuel Property | Unit | Limit1 | Test | |
|---|---|---|---|---|
| Type 1 | Type 2 | |||
| Ester content, min | % mass | 96.5 | EN 14103 | |
| Density @15°C | g/ml | 0.86 - 0.90 | JIS K 2249-1, -2, -3 | |
| Kinematic viscosity @40°C | mm2/s | 2.0 - 5.0 | JIS K2283 | |
| Flash point, min | °C | 100 | JIS K2265-2, -3 | |
| Sulfur, max | % mass | 0.0010 | JIS K 2541-1, -2, -6, -7 | |
| 10% carbon residue, max | % mass | 0.3 | JIS K2270-1, -2 | |
| Cetane index, min | 51.0 | JIS K2280-4 | ||
| Sulfated ash, max | % mass | 0.02 | JIS K2272 | |
| Water, max | ppm | 500 | JIS K 2275-1, -2, -3, -4 | |
| Particulate, max | ppm | 24 | EN 12662 | |
| Copper corrosion, max | 1 | JIS K2513 | ||
| Acid, max | mg KOH/g | 0.50 | JIS K2501, JIS K0070 | |
| Oxidation stability | h | 102 | EN 14112, EN 15751 | |
| Iodine number, max | g I/100g | report | JIS K0070 | |
| Linolenic acid methyl ester, max | % mass | 12.0 | EN 14103 | |
| Methanol, max | % mass | 0.20 | EN14110 | |
| Monoglycerides, max | % mass | 0.7 | 0.6 | EN 14105 |
| Diglycerides, max | % mass | 0.20 | EN 14105 | |
| Triglycerides, max | % mass | 0.20 | EN 14105 | |
| Free glycerin, max | % mass | 0.02 | EN 14105, EN14106 | |
| Total glycerin, max | % mass | 0.25 | EN 14105 | |
| Metals (Na + K), max | ppm | 5 | Na: EN 14108, EN 14538 K: EN 14109, EN 14538 | |
| Metals (Ca + Mg), max | ppm | 5 | EN 14538 | |
| Phosphorus, max | ppm | 10 | EN 14107 | |
| Pour point | °C | * | JIS K 2269 | |
| CFPP | °C | *3 | JIS K 2288 | |
|
* Agreement between producer and distributor 1 If the monthly minimum temperature for a given region is 0°C or higher, Type 1 limits apply; if it is below 0°C, Type 2 limits apply. 2 This provision shall not apply if the parties to the delivery agree that the diesel fuel (B5) blended with this product satisfies the oxidation stability requirements in Table 1. 2 B5 must comply with the applicable grade specified in JIS K 2204. | ||||
The B5 TAN limit is set at 0.13 mg KOH/g and is the sum of the contributions to TAN of the blend from the biodiesel and the diesel fuel components. The biodiesel blend stock contribution is based on the maximum TAN of 0.50 mg KOH/g for B100 meeting the EN 14214 TAN requirement. Blending it with diesel fuel at the B5 level means that it would contribute 0.025 mg KOH/g to the TAN of the blend. The diesel fuel contribution to TAN is set at 0.10 mg KOH/g to allow acid type lubricity additives used in Japan. Adding the biodiesel and diesel fuel contributions and rounding to two decimal places results in the 0.13 mg KOH/g limit.
It was found that a 0.13 mg KOH/g TAN limit on its own is not sufficient to prevent corrosion in a cup test used to test fuel tank materials [1421]. Additional requirements that limit the total concentration of formic, acetic and propionic acids (generated by the oxidation of FAME) to 30 ppm are also specified. Formic, acetic, and propionic acids can be measured with ion chromatography coupled with water extraction. Caproic acid is also of concern but is more difficult to measure by this method. Rather than include it in the limit, it is controlled indirectly through the control of formic, acetic and propionic acids.
EN 14103 is a High Performance Liquid Chromatography (HPLC) method for determining FAME content and is able to simultaneously measure FAME and triglycerides in a diesel fuel blend. The European diesel fuel standard, EN 590 uses an infrared spectroscopy technique (EN 14078) that is not able to differentiate between FAME and triglycerides. Gas chromatography (GC) as used in the European biodiesel standard EN 14214 to quantify the ester content, is unable to do a simultaneous measurement of FAME and triglycerides in a diesel fuel blend. Different measurement conditions are required to quantify both FAME and triglycerides, which greatly increases measurement time or requires two separate GCs.
An important consideration regarding the use of the GC based EN 14103 for the ester content (Table 2) of the pure biodiesel is its poor response to lauric fatty acid (short-chain) esters. Palm oil will likely be an important feedstock for Japanese biodiesel and once esterified, would contain around 38% lauric fatty acid esters. The GC based method as it is currently used is not able to measure these short-chain esters and would significantly underestimate the ester content of any biodiesel containing them. A modified temperature program and appropriate response factors would be required to use this method with biodiesel containing lauric acid fatty esters [1445].