|
|
| |
 |
CHAPTER 4. |
|
|
Technical Information of Biofuel |
|
|
|
|
|
4.1 Technological Standards (Quality Specification) |
|
|
|
Japanese automotive fuel quality standards are determined by the “Act on the Quality Control of Gasoline and Other Fuels.” |
|
|
|
|
|
4.1.1 Permitted Levels of Bio-ethanol in Automotive Fuel |
|
|
|
The permitted percentage levels of ethanol and other oxygenated compounds (containing atoms of oxygen within their molecules) within automotive fuel were added to the Act on the Quality Control of Gasoline and Other Fuels in August 2003.
Levels were set with due consideration to automotive safety and to the properties of exhaust gasses. Automotive fuels can currently contain up to 3vol% ethanol and 1.3wt% other oxygenated compounds. |
|
|
|
|
|
Table 4.1 Permitted Levels of Various Substances in Gasoline |
|
|
|
| Item |
Level |
| ○Lead |
No detection |
| ○Sulfur |
≦ 0.001vol% |
| ○MTBE |
≦ 7vol% |
| ○Oxygen Content |
≦ 1.3wt% |
| ○Benzene |
≦ 1vol% |
| ○Kerosene |
≦ 4vol% |
| ○Methanol |
No detection |
| ○Ethanol |
≦ 3vol% |
| ○Gum |
≦ 5mg/100ml |
| ○Color |
Orange |
| Octane rating |
Regular |
≧ 89.0 |
| High octane |
≧ 96.0 |
| Density |
0.783g/cm3 |
| Distillations temperature |
10% |
≦ 70℃ |
| 50% |
75 – 110℃ |
| 90% |
≦ 180℃ |
| Ending point |
≦ 220℃ |
| Quantity of residual oil |
≦ 2.0vol% |
| Copper corrosion (50℃、3h) |
≦ 1 |
| Read vapor pressure (37.8℃) |
44～78kPa(kgf/cm2) |
| Oxidation Stability |
≧ 240 min |
|
|
|
|
Note: Circled items are mandatory |
|
|
|
In order to determine the quality of ethanol permitted to be mixed with gasoline, the JASO (Japanese Automotive Standards Organisation) in consultation with the automotive, alcohol and petroleum industries and consumer groups published the following guidelines for the use of ethanol in automotive fuels (JASO M 361) in October 2006 (Table 4.2). |
|
|
|
|
|
Table 4.2 "Ethanol Quality for Automotive fuels" (JASO M 361) |
|
|
|
| Characteristic |
Specification |
| Quality |
Method of
Examination |
| Appearance |
|
Transparent |
Visual |
| Alcohol content |
vol% |
≧ 99.5% |
JAAS001 – 6.2 |
| Methanol |
g/L |
≦ 4.0 |
JAAS001 – 6.4 |
| Moisture |
mass fraction % |
≦ 0.70 |
JIS K 8101 |
| Organic impurities (excluding methanol) |
g/L |
≦ 10 |
JAAS001 – 6.4 |
| Electrical conductivity |
µS/m |
≦ 500 |
JIS K 0130 |
| Residue on evaporation |
mg/100mL |
≦ 5.0 |
JAAS001 – 6.3 |
| Coppe |
ppm |
≦ 0.10 |
JIS K 0101 – 51.2 |
| Acid degree (acetic acid) |
mass fraction % |
≦ 0.0070 |
ISO 1388/2 |
| pHe |
|
7.0 ± 1.0 |
6.10 |
| Sulfur content |
ppm |
≦ 10 |
JIS K 2541-6,2541-7 |
|
|
|
|
 |
|
|
|
Figure 4.1 Bio-ethanol Quality Specifications |
|
 |
|
|
|
|
4.1.2 Specification of ETBE Quality |
|
|
|
Although legal regulations regarding the mixing of gasoline and ETBE are not yet provided, the existing legislation concerning the amount of oxygen that is allowed in gasoline (up to 1.3%) means that gasoline can be mixed with up to 8.3% ETBE. There are currently no regulations in place stipulating the legal quality standards for ETBE. |
|
|
|
 |
|
|
|
Figure 4.2 ETBE Quality Specifications |
|
|
|
|
|
|
4.1.3 Biodiesel Fuel Quality Specifications |
|
|
|
When the “Act on the Quality Control of Gasoline and Other Fuels” was established, regulations related to the quality of nonpetroleum fuel such as biodiesel fuel were not included. However, the legal requirements pertaining to the fatty acid methyl ester (FAME) of which biodiesel is mainly constructed were established in March 2007. The fuel was examined according to properties of exhaust gas emissions and car safety. Examinations were conducted into durability, levels of gas evaporation and the effects of the substance on rubber, resin, metallic components etc. As a result of these investigations, the permitted percentage of FAME than can legally be blended with gasoline was set at 5%. The amendments to the law related to diesel oil can be seen in the Table 4.3. |
|
|
|
|
|
Table 4.3 Mandatory items of Quality Standard items for Diesel Oil |
|
|
|
| Item |
Diesel Oil blended with FAME |
Diesel Oil not blended with FAME |
Existing
regulations |
Sulfur |
≦ 0.001vol% |
≦ 0.001vol% |
| Cetane Index |
≧ 45 |
≧ 45 |
| Distillations temperature 90% |
≦ 360℃ |
≦ 360℃ |
Additional
regulations |
Fatty Acid Methyl Ester
(FAME) |
＞0.1wt%
≦ 5.0%wt% |
＞0.1wt%
≦ 5.0%wt% |
| Triglyceride |
≦ 0.01wt% |
≦ 0.01wt% |
| Methanol |
≦ 0.01wt% |
- |
| Total Acid Number (TAN) |
≦ 0.13 |
- |
Total content of Formic Acid,
Acetic Acid,
Propionic Acid |
≦ 0.003 %. |
- |
Oxidation Stability
(Acid Number Growth) |
≦ 0.12 |
- |
|
|
|
|
In addition, in October 2006 the JASO published a list of required standards related to the blending of FAME with other fuels (JASO M 360, table 4.4). The standards were set with agreement from the alcohol, automotive and petroleum industries as well as consumer groups.
It is expected that these regulations will be standardized in the future by the Japanese Industrial Standards Association (JIS). |
|
|
|
|
|
Table 4.4 "Use of Fatty Acid Mehylic Ester (FAME) in Automotive Fuel-mixtures" |
|
|
(JASO M 360) |
|
|
|
| Component |
Specification |
| Standard |
Examination method |
| Ester content |
mass fraction (%) |
96.5 or more |
EN 14103 |
| Density (15℃) |
g/ml |
0.86-0.90 |
JIS K 2249 |
| Kinematic viscosity (40℃) |
m㎡/s |
3.5-5.0 |
JIS K 2283 |
| Flash point |
deg.C |
120 or more |
JIS K 2265 |
| Sulfur content |
ppm |
10 or less |
JIS K 2541-1,-2,-6or-7 |
| 10% residual carbon |
mass fraction (%) |
0.3 or less |
JIS K 2270 |
| Cetane number |
|
51 or more |
JIS K 2280 |
| Sulfuric acid |
mass fraction (%) |
0.02 or less |
JIS K 2272 |
| Moisture |
ppm |
500 or less |
JIS K 2275 |
| Solid impurities |
ppm |
24 or less |
EN 12662 |
| Copperplate corrosion (50℃,3h) |
|
1 or less |
JIS K 2513 |
| Acid value |
mgKOH/g |
0.5 or less |
JIS K 2501,JIS K 0070 |
| Oxidative stability |
|
Agreed by the supplier and customer |
| Iodine value |
gl/100g |
120 or less |
JIS K 0070 |
| Linolenic acid methylic ester |
mass fraction (%) |
12.0 or less |
EN 14103 |
| Methanol content |
mass fraction (%) |
0.20 or less |
JIS K 2536,EN 14110 |
| Monoglycerides |
mass fraction (%) |
0.80 or less |
EN 14105 |
| Diglycerides |
mass fraction (%) |
0.20 or less |
EN 14105 |
| Triglycerides |
mass fraction (%) |
0.20 or less |
EN 14105 |
| Free glycerol |
mass fraction (%) |
0.02 or less |
EN 14105 or EN 14106 |
| All glycerins |
mass fraction (%) |
0.25 or less |
EN 14105 |
| Metals (Na+K) |
ppm |
5 or less |
EN 14108 and EN 14109 |
| Metals (Ca+Mg) |
ppm |
5 or less |
prEN 14538 |
| Phosphorus |
ppm |
10 or less |
EN 14107 |
| Fluid point |
deg.C |
Agreed by the supplier and customer |
| CFPP |
deg.C |
|
|
|
|
 |
|
|
|
Figure 4.3 Quality Specifications for Biodiesel Fuel |
|
|
|
|
|
|
4.2 Various Biofuel Manufacturing Methods |
|
|
4.2.1 Bio-ethanol |
|
|
|
The carbohydrate solution bio-ethanol is produced from organic matter containing large amounts of glucose and starch which is anaerobically fermented. Many fermentation procedures exist, and research aimed at further increasing productivity is currently being carried out.
Before fermentation, the starch in the raw material must be broken down into sucrose using an enzyme (amalayse).
Technologies of manufacturing ethanol from cellulosic raw material are being developed both within Japan and in other countries, and development has advanced in recent years. Processes using acid saccharification, enzyme saccharification or subcritical water can be undertaken to convert the cellulose or the hemicellulose in the material to sucrose ready for fermentation. In addition, the bacterium used in fermentation can be developed using genetic modification in order to increase efficiency of the fermentation process. |
|
|
|
Process (example using hextose)
C6H12O6 → 2C2H5OH + 2CO2 |
|
|
|
 |
|
|
|
Figure 4.4 Bio-ethanol Manufacturing Process Outline |
|
|
|
*Example of production in domestic plant |
|
|
|
(1) Ie island, Okinawa
Asahi Breweries, Ltd. and the National Agriculture and Food Research Center for Kyushu Okinawa Region (KONARC) have been conducting a verification test producing both sugar and ethanol on Ie island of Okinawa prefecture since 2006.
Sugarcane plants in the test have so far produced a high amount of biomass, growing quickly and strongly with more stems than average and regenerating quickly when harvested. This has increased the sugar harvest per unit area, meaning that bio-ethanol manufacturing has become possible without affecting sugar production. In addition, the amount of remaining bagasse (refuse material after sugar has been extracted) has trebled, and its use as a combustable energy source means that all necessary energy for the production of sugar and ethanol is provided.
The plant consists of both sugar and ethanol manufacturing equipment. The sugarcane is processed once to extract the first syrup, then the syrup is diluted with water until the liquid is 20-25% desity. High fermentative yeast is then added, and the liquid is fermented. Because the concentration of salt is less compared to blackstrap molasses, halotolerant yeast is not needed. |
|
|
|
 |
|
|
|
1 National Agriculture and Food Research Center for Kyushu Okinawa Region, press release
http://www.knaes.affrc.go.jp/press/20060131/jissyo.html |
|
|
|
Figure 4.5 Flow Diagram Showing Sugar and Ethanol Production from Sugarcane Containing a High Quantity of Biomass 1 |
|
|
|
(2) Sakai City, Osaka
Bio-ethanol Japan Kansai Ltd. manufactures bio-ethanol from waste construction lumber using a two stage saccharification method, which uses diluted sulfuric acid. The genetically modified fungus bacterium K011 and yeast are used in the reaction process. |
|
|
|
The genetically modified bacterium was developed in the United States and introduced to Japan by the Marubeni Corporation and Tsukisima Kikai Ltd.
The saccharification process is performed in two stages. First, pentose (mainly xylose) is collected from hemi-cellulose during the primary hydrolysis. Pentose cannot be fermented using conventional microbes, so genetically modified bacteria are used to enable fermentation to proceed. For the second stage, water and diluted sulfuric acid are added to the residue left from the primary hydrolysis in order to collect hexose from the cellulose, and this is then neutralized and fermented into ethanol using yeast. |
|
|
|
 |
|
|
|
Figure 4.6 Bio-ethanol Manufacturing Flow Diagram Showing 2-stage Process Involving
Diluted Sulphuric Acid 2 |
|
|
|
2 Terashima et. al., Bioethanol Production from Construction wood waste, Taisei Corporation Technical Center Information, Publication No. 38 2005. |
|
|
|
(3) Maniwa city, Okayama
Mitsui Engineering & Shipbuilding Co., Ltd. and Okayama prefecture have been manufacturing bio-ethanol mainly from coniferous wood chip.
After hemi-cellulose and cellulose are converted into sugar by diluted sulphuric acid and cellulolytic enzyme (cellulase), both C5 and C6 sugar are fermented into ethanol at the same time by genetically modified yeast, which is developed by VVT (Finland).
The refined ethanol is dehydrated by a high-performance zeolite film. |
|
|
|
 |
|
|
|
Figure 4.7 Bio-ethanol Manufacturing Flow Diagram Showing a Process involving
Diluted Sulphuric Acid and Cellulase Pretreatment 3 |
|
|
|
3 Mitsui Engineering & Shipbuilding Co., Ltd., Manufacturing technology of bioethanol from wood-based materials, 2006 |
|
|
|
|
|
|
4.2.2 ETBE (Ethyl Tert-Butyl Ether) |
|
|
|
Ethanol and isobutene (a side product of the oil refining process) are mixed, and ETBE is usually distilled by reacting them over heat with a catalyst.
Gasoline can be mixed with up to 8.3vol% ETBE, which is equal to 3vol% ethanol, in Japan. |
|
|
|
 |
|
|
|
Figure 4.8 ETBE Mixed Gasoline Manufacture and Supply Flow Diagram |
|
|
|
|
|
|
4.2.3 Biodiesel Fuel (BDF) |
|
|
|
Biodiesel Fuel (Fatty acid methylic ester) is created from vegetable oil which is composed mostly of Triglyceride. Triglyceride is decomposed into FAME and Glycerin by reacting methanol in a transesterification reaction. Various transesterification methods have been developed over the years, but the most common method involves using an alkalai catalyst. |
|
|
|
 |
|
|
|
Figure 4.9 Triglyceride Ester Exchange Reaction |
|
|
|
|
|
Table 4.5 Common Biodiesel Refinement Methods 4 |
|
|
|
| Refinement method |
Outline |
Catalyst |
Merits |
Problems / notes |
| Alkali catalyst |
Transesterification is carried out with An alkyl group from methanol and glycerin from used cooking oil (oils and fats) using an alkali catalyst. |
Potassium hydroxide, sodium hydroxide etc. |
Proven technology used worldwide. |
- A lot of waste fluid is produced.
- There are often impurities in the glycerin produced. |
| Acid catalyst |
Free fatty acids are esterified with an acid catalyst. |
Sulfuric acid,
fluorinated acid etc. |
Can be used in preprocessing of waste cooking oil which contains a lot of free fatty acids. |
Lengthly manufacturing process. |
| Biological catalyst |
The transesterification process is conducted through oxidation using the enzyme (lipase) fixed on resin. |
Yeast bacterium,
enzyme |
- There is no waste fluid
- The glycerin purity level is high. |
- The reaction takes a long time.
- The process is very expensive. |
| Supercritical methanol |
Supercritical methanol of 320℃ or more and 20MPa or more is mixed with oils and fats for the purpose of transesterification. |
Not needed |
- A catalyst is not needed.
- The process takes a short time (4 mins).
- feed-water and drainage equipment are not needed.
- High-melting oils and fats can be processed. |
High cost of production in small-scale facilities. |
| Fixed catalyst |
Transesterification is carried out using a fixed catalyst such as fixed base catalysts. |
Calcium oxide, barium titanate, ion exchange resin etc. |
- One to one reaction makes methonal recovery unnecessary.
- The glycerin purity level is high. |
- Durability of the catalyst.
- High cost of the catalyst. |
|
|
|
|
4 Miyazaki Prefecture Environmental Department, Biodiesel Fuel Guidebook, 2006. |
|
|
|
|
|
|
4.2.4 Biomass to Liquid (BTL) |
|
|
|
Fuel can be produced using the Fischer-Tropsch process in which carbon monoxide and hydrogen from gasification of biomass are converted into liquid hydrocarbons.
The gasification process involves pyrolyzing the biomass while using air or oxygen, water vapor, etc under normal pressure or pressurized condition in order to create synthetic gas which can be converted to liquid.
Reduction of tars, soot and char and the after-treatment influence greatly on design of the process, operational costs and operational management. |
|
|
|
Gasification reaction: CxHyOz + O2 + H2O → CO + CO2 + H2 + CaHb
FT synthesis reaction: nCO + 2nH2 → -(CH2)) N- + nH2O |
|
|
|
|
|
4.2.5 Second Generation Biodiesel Fuel (Bio Hydrofined Diesel: BHD) |
|
|
|
Oils and fats are hydrogenated using high temperatures and pressure and isomerization is induced according to need. A light oil distillate mainly containing paraffinic hydrocarbons is created. |
|
|
|
|
|
4.2.6 Straight Vegetable Oil (SVO) |
|
|
|
Agricultural products with a high oil and fat (triglyceride) content such as palm, rapeseed, sunflower, soybean, coconut etc. can be grown to produce oil. The oil is manufactured through compression, extraction, filtering and refining, after which any impurities are removed. When extracting oil from biomass with a high oil/fat content, the material is normally heated and compressed. When extracting oil from biomass with a low oil/fat content, an organic solvent is generally used. |
|
|
|
|
|
4.2.7 Biomethanol |
|
|
|
This is generally produced through a catalysed reaction from synthesis gas, which is reformed from biomass. |
|
|
|
Reaction: CO + 2H2 → CH3OH
CO2 + 3H2 → CH3OH+H2O |
|
|
|
|
|
4.2.8 Biobutanol |
|
|
|
The manufacturing process of biobutanol is similar to that of ethanol; therefore existing ethanol production facilities can be remodeled to produce bio-butanol. Ethanol, butanol and acetone can be produced by fermenting glucide in raw materials anaerobically with an acetone bacterium (Weizmann organism). |
|
|
Japanese
