Biodiesel fuel: applications, production and advantages

Biodiesl fuel is made of vegetable oil and methanol. Ethanol or isopropyl alcohol can be used instead of the latter. The process is based on transesterification of the product in the ratio of 200 kg of methanol per 1 ton of oil. Sodium or potassium hydroxide is also a component in the production process. Process occurs at 60ºС at normal pressure.

To make the fuel compliant with the quality standards, the following conditions must be met:

• content of methyl esters in the fuel must not be less than 96%;
• additional purification of methyl ester from methanol. This is due to the fact that the latter is usually used in excess for rapid and complete transeesterification;
• methyl esters must be purified from saponification products. If this is not done, the soaps will quickly clog filters, forming tar and carbon deposits. Separation and centrifuging methods are not efficient, water or sorbent wash is required;
• methyl esters must be dried. Water promotes development of microbes and formation of fatty acids, reducing the quality of the biodiesel;
• biodiesel should not be stored longer than three months. After three months the fuel may break down.

Using biodiesel

Biodiesel fuel can be used straight or blended with regular diesel. In the United states, fuels are marked as follows: first the letter B, as a general designation, then the percentage of biodiesel in the blend. B2, for instance, means that the blend contains 98% of diesel and 2% biodiesel fuel. Using high quality blended fuels does not require any design change of the engine.

Biodiesel cetane number must not be less than 51. Mineral diesel has 42-45 cetane number.

Biodiesel sources

The raw materials for biodiesel production are usually vegetable or algae oil. European producers prefer rapeseed, while the most common feedstock in the US is soybean oil, Canada mostly uses canola (a kind of rapeseed), Brazil – castor oil, Indonesia and the Philippines – palm oil. Animal fat, tallow etc can also be used.

Oil yield per one hectare (data: The Global Petroleum Club)

The world leaders in biodiesel production are the US, Germany, France, Italy and Spain. For instance, 2611 million liters of biodiesel were produced in the US in 2008. European production figures are more modest. German production at the same time period was 5302 thousand tons of the product.

Applications

If biodiesel fuel is spilled into water, it cannot harm plants and animals. It is fully biodegradable, as opposed to petroleum based fuels. Research shows that biodiesel in soil or water is completely decomposed by microbes in 28 days, making the risk of polluting rivers and lakes minimal.

Besides, the use of biodiesel significantly reduces carbon dioxide emissions into the atmosphere. High flashpoint (above 100ºC) makes this fuel relatively safe.

Biodiesel production equipment

GlobeCore has developed and supplies biodiesel production lines. GlobeCore biodiesel plants are built in production capacity range from 1000 to 16000 liters per hour, working on any type of vegetable oil or animal fat. This fuel can also be made form used vegetable oil and algae oil.

GlobeCore biodiesel production complex is designed for transesterification of vegetable oil or animal fat by highly intensive mixing with catalyst and subsequent dry polishing. The product fully complies with the European EN 14214 and the American ASTM standards.

The unique technology allows production without a lengthy process of resetting the equipment for various oils or fats. All components are built from stainless steel in ex-proof design.

The biodiesel production line consists of the following components:

• stream oil heater;
• biodiesel reactor;
• biodiesel settling tanks and output pumps;
• methanol recovery section;
• purification and filtration section.

The raw material is filtered and purified, then pumped to the oil heater to raise its temperature. The hot oil is then pumped to the biodiesel reactor. The reactor is also supplied with alkali solution and methanol. After hydrodynamic mixing and the reaction of oil with the alkali and methanol, the reactor output is crude biodiesel.

It is supplied to the settling tanks, where water and glycerin phase is separate and pumped away.

The remaining biodiesel is pumped to the methanol recovery section, where the product is dried under vacuum.

The final polishing of biodiesel occurs in the filtration and purification section. Passing through a layer of ion-exchange resin, the residual methanol is removed from biodiesel. Particulate matter is removed by a system of filters.

GlobeCore biodiesel process has the following advantages:

• low power consumption;
• near-instant transesterification reaction;
• transportation mobility and simple installation thanks to modular design;
• no waste stream. Glycerin phase can be used for many purposes: power generation, fertilizer production etc;
• simple operation and high efficiency.

What are the advantages of biodiesel?

Biodiesel fuel has the following advantages:

• good lubrication properties;
• high cetane number;
• extended engine life without upgrades;
• relative safety due to high ignition temperature;
• no harmful environmental effects.