Fuel and food production are mutually exclusive
Although the development of biodiesel as an alternative energy source has been favored by the industry, there are few examples of commercial production. This comes mainly from the cost of vegetable oil. Vegetable oil procurement, transportation, storage and extraction account for most of the cost of biodiesel production. However, it is also argued that because the production of biodiesel requires a large amount of vegetable oil raw materials, it is imperative to build plantations, which can drive related agricultural production.
Viscosity coefficient
Biodiesel also has some technical limitations and is not suitable for many areas. Because it has a higher viscosity than ordinary diesel, its usability will be reduced at low temperatures. Like chicken soup and braised pork put in the refrigerator for refrigeration, grease will condense into a white sticky shape. Academic terms are called “cloud” and the temperature of condensation is called “cloud point”. The cloud point of petroleum-based diesel is about 15 degrees below zero Celsius, while 100% biodiesel B100 begins to cloud at zero Celsius, and it is easy to block the oil road at low temperatures. Additives or other thermal insulation measures must be added to biodiesel in winter. In hot and humid environment, long-term storage of biodiesel also needs to take into account the inhibition of microbial and bacterial growth.
Energy value
Another disadvantage of biodiesel is that the energy content of B100 is 11% lower than that of petroleum-based diesel fuel, and the maximum horsepower output will be reduced by about 5-7%. But the gap is not big, and there is hardly any difference if 5% biodiesel is used. On the contrary, the viscosity of biodiesel is higher than that of petroleum-based diesel, which can provide better lubricity for fuel injection system and engine components and prolong the life of engine system. Many car owners have designated B2 diesel (2% biodiesel, 98% petroleum-based diesel) to help lubricate the engine. The soybean powered cars mentioned above used diesel from B5 to B30.
Development cost
In order to assist the development of biodiesel, many countries (such as Canada, Korea, etc.) will invest in the development of Biotechnology Industrial parks, through the production and development of related materials together, to reduce the development cost of biodiesel.
Low temperature gelatinization
When the ambient temperature of biodiesel falls below a certain level, some molecules in the oil aggregate and form crystals. Once the crystal becomes larger than a quarter of the wavelength of visible light, the crystallization temperature at which the oil appears cloudy is commonly referred to as “cloud point” (or “cloud point”). For example, biodiesel produced from butter and palm oil cemented at 16 ~C (61 ~F) and 13 ~C (55 ~F), respectively.
Oil pipeline blockage and sediment accumulation
After the promotion of biodiesel in Taiwan, some owners reacted that the use of B2 biodiesel often resulted in blockage of oil pipeline and engine flameout. Gas station operators also had cases of sediment accumulation in oil tank and blockage of filter in refuelling machine.
Although it is not yet possible to confirm that the production or storage of biodiesel is related to climate, vehicle owner maintenance and the management of gas station operators, on May 5, 2014, the Ministry of Economy decided to announce the amendment of the “range and mode of implementation of the ratio of petroleum refining industry to importing industry in the sale of domestic automotive diesel blended esters”, which will be compulsorily added. The order of adding more than 2% biodiesel will be changed to vehicle diesel oil to be mixed with esters. Since May 2014, the supply of B2 biodiesel has been phased out, and then it will be re-supplied after the problem has been solved.
In October 2014, the retail gas stations and the sightseeing vehicle industry jointly opposed the resumption of sales and use of biodiesel. The plenary meeting of the Tourist Vehicle Association stressed that more than 500 accidents of fire extinguishing had occurred in the past year.