The rise and fall of Biodiesel
Biodiesel became very popular in the recent years as the number one alternative fuel in Europe. Germany was the big promoter of biodiesel made from rapeseed oil. Thanks to a 100% fuel tax exemption the industry gained momentum. To protect the internal market and also required by car manufactures a fuel norm DIN 14214 was developed, which was later adapted by the EU as the EN 14214. Since the middle of 2008 the selling of B100 (100% biodiesel) has dropped dramatically, both in de EU as in the US. This article describes the reasons why.
What is biodiesel?
Biodiesel is an oil or fat which is converted to make it fit for use in a diesel engine. In this process of conversion or transesterification ethanol or methanol is needed. It generates some waste in the form of glycerol, soapstock and some salts. In short the conversion goes as follows:
- Vegetable oil + 18% alcohol + 0.5% Caustic Soda
- Heavy mixing and heating up to 55 degrees Celsius for about 30 min.
- After some rest, the biodiesel will stay on top of a separate layer containing glycerol.
- Cleaning the biodiesel from soaps using water or clay
In practice it is a little bit more complex as you have to deal with Free Fatty Acids, Polymers, water and other contamination in the feedstock. Vegetable oil confirming to DIN 51605 needs no pre-treatment and has only to follow the basic conversion steps as described above to become biodiesel.
Waste vegetable oils have to follow a different route. Normally they contain more than 3% FFA's and water. A pretreatment with sulfuric acid is needed to bring these values down to acceptable levels.
Methanol (300 Euro/MT) is a petrochemical product and will add 8 Eurocents per liter biodiesel due to its cost price. The total production cost for 1 liter biodiesel is about 10 Eurocents. The left over crude glycerol has to be refined before it hits any real value (from 100 to 600 Euro/MT). Crude glycerol has some value when used in Bio-methane production. For these reasons the biodiesel always is a more expensive biofuel than pure vegetable oil (SVO).
Pure vegetable oil as a Biodiesel alternative
There exist a greener German alternative for biodiesel in the form of a standardized biofuel with the specifications E DIN 51605 a.k.a. pure plant oil. In most cases the biofuel is made from (cold pressed) rapeseed, but it can be made from other resources as well. For German taxation reasons the biofuel DIN 51605 is blended with 5% biodiesel to make it inedible.
The biofuel made from rapeseed oil is only slightly different from the edible oil variety of rapeseed you can find in the supermarkets. The norm requires that the oil has undergone a process which is called degumming and deacidifing in order to meet the standards which are necessary to prevent deposits in the diesel engine and injection pump.
Straight Vegetable Oil (SVO) is the name used for pure vegetable oil in America. However, as the source can be anything from waste fryer oil to soya oil the quality of this biofuel should be tested against the DIN 51605 before using it as a biofuel.
Using some form of preheating makes the oil less thick (viscous) before it enters the injection pump or the diesel engine. In this way it will resemble closely the standard diesel viscosity. In most cases the engine is running on diesel fuel to heat up before it switches over to the pure vegetable oil. The vehicle comes with 2 tanks, one for diesel fuel and the other for the vegetable oil. It works much like the way a LPG installation does in petrol cars.
Only Elsbett systems can work on vegetable oil alone. The Elsbett systems go even further by modifying engine pistons and cylinders in order to run without the help of diesel to preheat the engine.
There are about 30.000 trucks and agricultural machines in Germany using DIN51605 as their main fuel. It is far more economic in its use than biodiesel because it is cheaper to produce. Several tests in Germany have showed that the use of 100% DIN51605 will not hurt or damage the engine in any way. Also the CO2 reduction potential or ecological savings is the highest of all biofuels.
Advantage |
Disadvantage |
|
Biodiesel DIN 14214 |
Widely accepted as alternative |
Chemical treatment necessary |
Pure Vegetable Oil DIN 51605 |
No chemical conversion needed |
Fuel delivery system of the diesel |
Hydro- |
Can be produced in existing oil |
Only works with a diesel blend |
A more recent development is the application of vegetable oil in petrochemical refineries. There it gets hydrogenated and blended with diesel. The resulting fuel is very stable, high in lubricity and Cetane Index. In this way it cannot replace the diesel fuel completely but it becomes an additive (up to 10%). Another approach is to use pyrolysis to crack the oil. The needed infrastructure already exists in the form of petrochemical refineries and therefore has a much higher production capacity than all the biodiesel factories added together.
Difficult times for the Biodiesel Industry
In the years 2007 to 2009 we saw an increase in bankruptcy of the biodiesel factories in Germany. The main reasons are:
- Cheap subsidized biodiesel imports from America
- Higher fuel taxes in Germany on biodiesel while the subsidiary ends
- Competition with cheaper DIN 51605 biofuel (rapeseed oil)
- High cost prices of feedstock for both rapeseed oil and methanol
- Sudden collapse of mineral oil price, biodiesel is traditionally sold a little cheaper to compensate for a slightly less energy content
- Less support from German car manufactures for 100% biodiesel use
The main reason the remaining biodiesel factories will stay in production is thanks to the mandatory blending of 5% biodiesel in the standard diesel (B5, DIN EN 590). The revenues for selling of 100% biodiesel are still too marginal.
For 2012 and later the original projected blending rate of 20% is lowered to 10%. Of this 10% a 7% share will be biodiesel and 3% will be hydrogenated vegetable oil. We expect the use of hydrogenated vegetable oil to increase as it is so easy to implement into the existing logistics of a petrochemical refinery. Also the oil companies will profit more in this way as they don’t have to buy the biodiesel from a competitor.
This move makes it possible for oil companies to use more vegetable oil as an additive or “Biofuel”. Biodiesel will always be more expensive than its feedstock, the vegetable oils. As the German DIN 51605 shows there is no need to convert the oil into more expensive biodiesel before using it in a diesel engine.
Biodiesel sold as a 100% replacement for diesel has lost its significance. More than 70% of the pump stations who sold biodiesel before 2009 stopped doing this. In the graph above the 2.1 million MT blended biodiesel in 2009 represents only a total of 7% replaced diesel fuel for Germany alone. Biodiesel will survive as an important additive for diesel fuel as it enhances the lubricity and helps lowering the CFPP in certain cases.
Before the popularity of “biodiesel”, Fatty-Acid-Methyl-Ester (FAME, the official name for biodiesel) was mainly used in (biodegradable) lubricants and many more chemical applications. The demand for these Bio-lubricants is still rising. Other crops like Castor bean and Camelina sativa will fill in this gap. Bio-lubricants are sold at premium prices and justify the extra costs of production by transesterification.
