Vegetable oil fuel

Area	Fuels
title	Fuels for engines suitable for vegetable oil - Rapeseed oil fuel - Requirements and test methods
Latest edition	2010-09
ISO	-

other vegetable oil fuels
other names	Vegetable oil, vegetable oil fuel, Pöl (colloquial)
Brief description	Fuels for self-igniting piston engines (diesel fuels)
origin	biogenic
properties
Physical state	liquid
viscosity	DIN 51605: 2010-09 (for rapeseed oil) ; max. 36.0 mm² / s; Sunflower oil 68.9 mm² / s (20 ° C); Soybean oil 63.5 mm² / s (20 ° C); Linseed oil 51.0 mm² / s (20 ° C); Olive oil 83.8 mm² / s (20 ° C); Cottonseed oil 89.4 mm² / s (20 ° C); Jatropha oil 71.0 mm² / s (20 ° C); Coconut oil 21.7 mm² / s (50 ° C); Palm oil 29.4 mm² / s (50 ° C); Palm kernel oil 21.5 mm² / s (50 ° C);
density	Pre-standard DIN 51605 (for rapeseed oil) ; 0.900-0.930 kg / L; Sunflower oil 0.93 kg / L (15 ° C); Soybean oil 0.93 kg / L (15 ° C); Linseed oil 0.93 kg / L (15 ° C); Olive oil 0.92 kg / L (15 ° C); Cottonseed oil 0.93 kg / L (15 ° C); Jatropha oil 0.91 kg / L (15 ° C); Coconut oil 0.87 kg / L (15 ° C); Palm oil 0.92 kg / L (15 ° C);
calorific value	9.2 kWh / L = 10.0 kWh / kg
Calorific value	Sunflower oil 34.5 MJ / L = 37.1 MJ / kg; Soybean oil 34.5 MJ / L = 37.1 MJ / kg; Linseed oil 34.4 MJ / L = 37.0 MJ / kg; Olive oil 34.8 MJ / L = 37.8 MJ / kg; Cottonseed oil 34.2 MJ / L = 36.8 MJ / kg; Jatropha oil 37.0 MJ / L = 40.7 MJ / kg; Coconut oil 30.7 MJ / L = 35.3 MJ / kg; Palm oil 34.0 MJ / L = 37.0 MJ / kg;
Cetane number	Sunflower oil 36 CZ; Soybean oil 39 CZ; Linseed oil 52 CZ; Olive oil 37 CZ; Cottonseed oil 41 CZ; Jatropha oil 51 CZ; Palm oil 42 CZ;
Flash point	Sunflower oil 316 ° C; Soybean oil 350 ° C; Cottonseed oil 320 ° C; Jatropha oil 240 ° C; Palm oil 267 ° C;
Carbon dioxide emissions from combustion	3.24 kg / L
safety instructions
GHS labeling of hazardous substances	no classification available
	no classification available
H and P phrases	H: see above
	P: see above
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Rapeseed oil fuel
other names	Vegetable oil, vegetable oil fuel, Pöl (colloquial)
Brief description	Fuel for compression ignition piston engines (diesel fuels)
origin	biogenic
Characteristic components	Rapeseed oil
properties
Physical state	liquid
viscosity	74.0 mm² / s (20 ° C) (max. 36.0 mm² / s)
density	0.92 kg / L (15 ° C)
calorific value	9.7 kWh / L = 10.5 kWh / kg
Calorific value	39.5 MJ / kg
Cetane number	40 CZ
Flash point	317 ° C
safety instructions
GHS labeling of hazardous substances	no classification available
	no classification available
H and P phrases	H: see above
	P: see above
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Vegetable oil fuel (abbreviated PÖK , colloquially also Pöl ) is a biologically renewable energy source . Untreated vegetable oil can be used as a fuel for diesel engines in mobile and stationary applications. A distinction must be made between vegetable oil fuel and biodiesel , which is produced by transesterifying vegetable oil.

history

The idea of using vegetable oils as engine fuel goes back to Rudolf Diesel , the inventor of the diesel engine . The availability of cheap petroleum was the reason why more expensive alternatives such as vegetable oil were not used as fuel for a long time.

It was only after the oil crises of the 1970s that the search for alternative fuels increased. The increasing environmental and climate protection awareness at the end of the 20th century brought renewable energy sources back into the discussion.

Usable vegetable oils

In Germany, rapeseed oil is mostly used as a vegetable oil fuel . However, there are many thousands of oil crops around the world that could be used as fuel. In principle, all types of vegetable oil and also animal oils are suitable for use in converted vehicles. Occasionally, drivers also use filtered waste oils and liquid edible fats . However, they must be carefully cleaned, drained and, if necessary, neutralized before use. When using vegetable oil as fuel, high quality standards must be observed in all cases.

Although camelina oil has better properties, the share of rapeseed oil predominates on the market, as the farmers can neither derive a financial advantage from cultivating mixed crops, nor could they use the pressed residues as feed, as this was prohibited until 2009 due to Annex 5 No. 31 of the Feed Ordinance .

properties

Vegetable oil is one of the densest forms of energy that are created through photosynthesis . At 37 MJ / kg, the calorific value is lower than that of gasoline (43 MJ / kg) and diesel fuel according to EN 590 (42.5 MJ / kg), but higher than that of hard coal (30 MJ / kg). The volume-related energy density is around 9.2 kWh per liter and is thus between gasoline with 8.6 kWh / L and mineral diesel oil with 9.6 kWh / L.

Pure vegetable oil consists mainly of triacylglycerides, i.e. H. Glycerine - esters of long-chain fatty acids (i.e. not from alkanes ) and is more difficult to ignite (see flash point ) than diesel. The ignitability ( cetane number ) is generally limited, since unheated vegetable oil is not sufficiently atomized in the combustion chamber by the injection nozzle (therefore pre-engine and swirl chamber engines are more suitable). Due to its higher viscosity , which increases even further as the temperature drops, the flow resistance in the fuel lines, the injection pump and the injection nozzles increases compared to that of diesel fuel. Some injection systems such as common rail or pump nozzle therefore work with vegetable oil outside of their specification, which can lead to abnormal wear and tear or even total failures.

use

Due to the higher viscosity and the lower cetane number compared to diesel fuels, adaptation measures are usually necessary on conventional diesel engines. These consist, for example, in the heating of the fuel in order to reduce the viscosity immediately before it enters the injection system. This technology is already known from multi-fuel engines .

The regulation is the DIN standard DIN 51605 as a quality standard for vegetable oil fuel made from rapeseed oil.

Motors and heaters suitable for vegetable oil

The city of Aachen's leaf vacuum truck powered by vegetable oil

Mini block-type thermal power station , suitable for operation with cold-pressed rapeseed oil

When using vegetable oil, the emission of soot particles is roughly halved compared with the use of diesel. The emission is only visibly increased when the engine is cold and there is insufficient atomization in the cylinder. There are fewer emissions of fine dust than with diesel operation. Contamination by sulfur and heavy metals is largely eliminated.

In addition, vegetable oil can be used as fuel for heating systems in stationary areas.

Only a few older engines can be run on vegetable oil without any problems. These are usually pre-chamber diesel engines. The quality of the injection pump is important. In-line injection pumps have proven themselves, for. B. the company Bosch . Modifying these engines is also very easy. The following conversion steps are required:

Installation of a heat exchanger, for example to heat the fuel filter with the aid of the cooling water.
A fuel line with a larger cross-section
Installation of a new filter
In winter operation, the vegetable oil must be supplied with at least 10% winter diesel .

The conversion costs for self-installation are around 200 to 600 euros.

Specially developed engines such as the Elsbett engine or other multi-fuel engines have not been able to establish themselves because of the higher costs.

Modern engines are equipped with common rail injection or pump-nozzle injection . Corresponding conversions are now available for this, which are complex and (correspondingly) expensive. However, these are safe and well-proven. After the conversion it is then possible to use vegetable oil as fuel in addition to (mineral oil) diesel. The current technology compensates as much as possible for the high viscosity in winter and the lack of ignition. For this purpose, the vegetable oil is heated to 60 ° C by a heat exchanger . With a cold start this happens electrically, with a warm engine via the cooling water. The manufacturers report starting problems below −8 ° C in winter. Preheating and starting then take a little longer. There is a risk of "freezing" in winter operation. Since the solidification of the fuel begins in the lowest area of the tank, where the fuel emerges, the continuous continuation of the fuel supply cannot be guaranteed. It is therefore advisable to add mineral oil diesel fuel ("winter diesel") at low temperatures.

The conversion can be made to a 1-tank or 2-tank system:

When single-tank , the fuel for the engine is in a single tank, and at lower temperatures diesel parts are admixed to the vegetable oil during refueling. Helpful modifications include an enlarged pipe cross-section for the fuel, a system for preheating the feed pipes, the fuel filter and the injection pump . Depending on the design and thermal environment of the motor, only some of the measures are required.

With the two-tank system , the engine is started and warmed up with diesel fuel from a separate tank. The resulting waste heat from the diesel engine preheats the rest of the system. Then it is switched to the vegetable oil tank manually or fully automatically. For phases of low load, such as idling speed or in the partial load range, diesel should be used. In the full load range, up to 100% vegetable oil can be used. Before switching off the engine for a long time, you should switch over in good time so that the injection system is filled with diesel again when the engine is restarted.

For several years now there have been offers to convert diesel engines for direct operation with vegetable oil. With names like "BB.drive", "BEAM-Plus", "eoil", "Poeltec" and the like. a. conversions are offered on the Internet that not only rely on heated, but also carefully degassed rapeseed oil. Even a tiny gas content, so it is claimed externally, causes vapor bubble formation ( cavitation ) in a modern high-pressure injection system , which destroys the material in the vicinity. It should be noted, however, that conventional diesel fuel also contains a certain amount of gases. For this reason, processes that rely only on degassing, such as. B. the eoil system, highly controversial. It should also be considered that - if the ultrasonic degassing method is used - the ultrasound itself can be the cause of cavitation due to the strong pressure fluctuations generated, cf. ( Cavitation : cavitation can occur in the pressure minima of the vibrations). This means that the ultrasound method would trigger exactly what it claims to avoid in the sonicated system. In addition, cavitation arises from the vapor bubbles of a liquid; Air, mixed with a vapor bubble, and as such not condensable at normal temperature, would, on the contrary, dampen the collapse of the vapor bubbles while generating heat, so it would be advantageous to avoid the damaging effects of cavitation.

In addition to the Internet offers, there are engineering offices that specialize in converting commercial vehicles to alternative fuels such as vegetable oil, animal fat, and biodiesel. The products, such as the "bioltec system", are constantly being further developed in order to use vegetable oil in diesel engines with the latest emission standards. From a technical point of view, modern commercial vehicle engines can be operated with biogenic pure fuels - in compliance with the current emission regulations Euro 5 or EEV.

With the current state of the art, the conversion makes the most sense mainly for trucks, utility vehicles and agricultural machines, because the conversion pays for itself within a few months due to the high specific consumption of these vehicles.

The company Deutz AG has at Agritechnica 2007 in Hanover its Natural Fuel Engine presented. This makes it the first major engine manufacturer to offer a diesel engine with full warranty and engine management optimization for operation with rapeseed oil in accordance with DIN 51605. This engine is to be sold primarily in the agricultural sector.

In a fleet test, around 200 heavy commercial vehicles are currently testing vegetable oils in practical use in Germany by the end of 2015. It is based on the DIN SPEC 51623 standard, which defines optimal fuel properties on a broad basis of vegetable raw materials. The aim is the industrial feasibility, across brands in current commercial vehicles under economic aspects. Started at the IAA Commercial Vehicles 2012, the special focus is on compliance with the Euro 6 emissions regulations. For the field test, the vehicles are equipped with special dual-fuel technology.

Problems in use

Change in engine oil

Unburned fuel gets into the engine oil - especially during a cold start and at high speed - and worsens its lubricating properties or polymer chains form in the engine oil, which can clump together and clog lines and filters. This problem occurs particularly with the use of modern fully synthetic lubricating oils, apparently fully synthetic oils bind foreign substances (free radicals) particularly well, which is what they should - if there aren't too many of them.

Pure diesel fuel begins to evaporate at approx. 55 ° C. If the engine oil reaches this temperature while driving, the diesel fuel evaporates from the engine oil. Since vegetable oil, in contrast to diesel, only begins to evaporate from approx. 220 ° C and the engine oil never reaches this temperature, vegetable oil inevitably accumulates in the engine oil. Converting the vehicle to run on vegetable oil can only slow down this process, but not prevent it. It is therefore advisable in all cases to check the oil level regularly and to halve the oil change intervals.

viscosity

Vegetable oil is much more viscous than diesel fuel, but the engine's injection system is designed for thinner diesel fuel. The flash point of vegetable oil is approx. 165 K higher than that of diesel fuel. Both properties have a decisive influence on combustion.

A conversion must therefore either adapt the engine to use with vegetable oil and / or change the vegetable oil so that it comes as close as possible to the properties of diesel. In order to ensure the most complete combustion possible, it is necessary to atomize the vegetable oil just as finely as diesel fuel when injecting it. To do this, either the viscosity of the vegetable oil must be adapted to that of diesel fuel or the injection pressure must be increased. In practice, both options are usually used.

The viscosity of vegetable oil is strongly temperature dependent, i. In other words, the further the vegetable oil is heated, the thinner it becomes. At room temperature, the viscosity of vegetable oil is around 100 times greater than that of diesel, which would lead to enormous forces in unmodified injection pumps. Vegetable oil only reaches the viscosity of diesel at around 150 ° C. Usually, however, Pöl is only heated to 65–85 ° C with a cooling water heat exchanger.

Theoretically, it would also be possible to increase the injection pressure accordingly, but the effort is very high, which is why the injection pressure is only increased slightly. In older injection systems, this can easily be achieved by changing the opening pressure of the injection nozzles. Since the injection pump then takes a little longer to build up the higher pressure, the fuel is injected later; the injection timing must then be reset.

Admixture of diesel / petrol

In addition to heating, adding diesel or gasoline is also a way of changing the viscosity and flash point of the vegetable oil. This technology is used by some retrofitters such as B. "Klümper vegetable oil technology" and "Danhag" are used. In this context, the so-called must Schur mixture ( Schur mixture , SCHUR-ECOFUEL) are mentioned, in addition to gasoline as an essential component around ten percent by volume isopropyl alcohol contains (IPA).

Vegetable oil is thicker than diesel. Therefore, a mixture of diesel and vegetable oil, regardless of the mixing ratio, can never reach the viscosity of diesel fuel. A combination of admixing and heating has proven itself in practice. On the one hand, the vegetable oil is much thinner at the same temperature than without the addition of diesel, and on the other hand, the flash point of the mixture drops to a value between 55 ° C (diesel) and 220 ° C (vegetable oil), which results in better combustion .

Gasoline is thinner than diesel, so a vegetable oil-gasoline mixture can reach the viscosity of diesel. This is the case with a mixing ratio of approx. 60% PO oil to 40% gasoline. The anti-knock agents added to the gasoline, however, inhibit the self-ignition of the mixture in the diesel engine. H. the cetane number drops sharply, so that the engine starts poorly and does not provide full power. In this case, ignition-improving additives that increase the cetane number must therefore be added. In addition, the addition of gasoline deteriorates the lubricating properties of the vegetable oil, which can damage the injection pump. The addition of two-stroke oil helps here. A mixture of 59% PO oil, 39.5% gasoline, 1% two-stroke oil and 0.5% ignition-improving additive had an HFRR value of 160 µm in a study by the University of Rostock in September 2011 , which is almost three times as good as it does EN 590 prescribes for diesel fuel (460 µm).

storage

Vegetable oil should be stored as cool and dark as possible. They can be stored in above-ground and underground tank systems without any problems, with underground systems having advantages due to their relatively constant low temperature.

The advantage of the good biodegradability of the vegetable oil goes hand in hand with a poor aging resistance and deteriorates the shelf life. Bacterial contamination , oxidation and water build-up are the main problems. Therefore , when storing vegetable oil, care must be taken to prevent chemical reactions that degrade the quality of the vegetable oil, such as

the oxidation ,
the hydrolysis ,
the polymerization and
the enzymatic degradation.

Storage must therefore be dark, cool (between 5 and 10 ° C), dry and with little contact surface with atmospheric oxygen. The tanks, pipes and fittings must be made of stainless steel (without catalytically active alloy components such as copper) or opaque plastic (e.g. HDPE ) and contain a water-separating filter for ventilation. Underground tanks are cheap because of the usually low storage temperature. The tanks should be cleaned regularly, as the sediments from contaminants accelerate the progress of the deterioration in quality through chemical reactions (see above).

The following storage combination is common for the production of vegetable oil in the oil mill:

The first tank stores the vegetable oil from ongoing production
The second storage tank stores the vegetable oil, the samples of which are quality tested
The third tank contains the vegetable oil, which after the quality approval can be given to the end customer for immediate consumption.

Osh

Vegetable oil is non- toxic .

Denatured vegetable oil can smell or taste unpleasant. A study by the Federal Research Center for Agriculture funded by Shell , Daimler-Chrysler , Volkswagen and the Association of the German Biofuel Industry came to the conclusion that the emissions of a diesel truck engine powered by pure rapeseed oil were around 30% compared to an engine powered by conventional diesel. times are more carcinogenic. With reference to this study, experts from the Federal Environment Agency demand that trucks no longer run on pure rapeseed oil. The employees in the truck workshops in particular are at risk. These statements have meanwhile been refuted in a current study by the Technologie- und Förderzentrum (TFZ), Straubing and the bifa environmental institute in Augsburg.

This study found:

Compared to diesel emissions, vegetable oil emissions when using bioltec technology showed a mutagenic effect that was roughly halved. The mutagenic effect is a measure of the carcinogenic potential of the exhaust gases.
The fine dust emissions are also roughly halved when using load-dependent defined vegetable oil / diesel mixtures compared to pure diesel operation.
The result was confirmed several times in the investigation with different measurements and control measurements.

Taxation in Germany

Pure vegetable oil ( rapeseed oil ) as a fuel is subject to the Energy Tax Act (EnergieStG) , like any fuel . The basic taxation is 470.40 euros per 1000 liters ( Section 2 EnergieStG), which corresponds to 47.04 cents per liter of fuel. With the introduction of the Energy Tax Act in June 2006, which replaced the old Mineral Oil Tax Act (MinÖStG), “reliefs” were enacted, which lower the taxation of pure vegetable oil fuel. These reliefs, which are only granted on rapeseed oil, which corresponds to the quality standard DIN V 51605, amounted to a full 100% in 2006 and 2007, which means that no taxes were incurred for these vegetable oil fuels ( Section 50 (3) No. 2 EnergieStG). Other vegetable oil fuels that do not meet the quality standard are subject to the full tax rate.

Over the years, this relief was gradually lifted, which increases the taxation for fuel. In addition to the introduction of the law on August 1, 2006, adjustments were made to the years 2008, 2009 and 2013. For 2013, the relief is still 21.40 euros per 1000 liters (2.14 cents / liter), which is a relief of 4.55 % equals.

The following table shows the taxation for pure vegetable oil fuels.

from date	Basic taxation in cents per liter	Relief in cents per liter by EnergieStG	Net tax in cents per liter	rel. Share for basic taxation
August 1, 2006	47.06	47.06	0.00	0%
January 1, 2008	47.06	38.89	8.15	17.3%
January 1, 2009	47.06	30.49	16.55	64.8%
January 1, 2013	47.06	2.14	44.90	95.4%

Biodiesel and vegetable oil for use as fuel in agriculture is tax-free. Biodiesel and vegetable oils that are used as heating fuels were tax-free until December 31, 2009 ( Section 50 (1) No. 5 EnergieStG ). Since 2010, like light heating oil, they have been taxed at 6.135 cents per liter in accordance with Section 2 Paragraph 3 No. 1 in conjunction with Paragraph 4 EnergieStG.

Quality standards

The properties of vegetable oil differ depending on which plant they were obtained from. For example, camelina oil is longer liquid than rapeseed oil. While uniform quality standards can be guaranteed for diesel fuels, this is not so easy with vegetable oil. It is not available as a standardized liquid and there is still no large-scale market that relies on central processing and would enable the controlled mixing of oils from different origins and thus constant quality.

In order to create uniform quality standards for the very frequently used rapeseed oil, the "LTV decentralized vegetable oil production, Weihenstephan working group " formulated a "quality standard for rapeseed oil as fuel (RK quality standard)" as a guideline . This has been replaced by DIN 51605: 2010-09 Fuels for engines suitable for vegetable oil - Rapeseed oil fuel - Requirements and test methods :

Properties / ingredients	unit	Limit values		Test procedure
Properties / ingredients	unit	min	Max
Density at 15 ° C	kg / m³	900	930	EN ISO 3675, EN ISO 12185
Flash point according to P.-M.	° C	220	-	EN 2719
calorific value	kJ / kg	36,000	-	DIN 51900-1, -2, -3
Kinematic viscosity at 40 ° C	mm² / s	-	36.0	EN ISO 3104
Cold behavior	-	-	-	Rotational viscometry (test conditions are being developed)
Ignitability ( cetane number )	-	39	-	(Test method is being developed)
Coke residue	Dimensions-%	-	0.40	EN ISO 10370
Iodine number	g / 100 g	95	125	EN 14111
Sulfur content	mg / kg	-	10	ISO 20884/20864
Total pollution	mg / kg	-	24	EN 12662
Acid number	mg KOH / g	-	2.0	EN 14104
Oxidation stability at 110 ° C	H	6.0	-	EN 14112
Phosphorus content	mg / kg	-	3	EN 14107
magnesium	mg / kg	-	1	EN 14538
Calcium	mg / kg	-	1	EN 14538
Ash content	Dimensions-%	-	0.01	EN ISO 6245
Water content	Dimensions-%	-	0.075	EN ISO 12937
So far, these values have been a draft standard .

The volume consumption and the performance characteristics are approximately the same for both (diesel and rapeseed oil) fuels. Vegetable oil burns a little “softer”, however, as the combustion takes place more slowly. The engine manufacturers see the coke residue as problematic, as a result of which there are no or hardly any approvals for vegetable oil. In addition, vegetable oil tends to polymerize in connection with the additives in engine oil, i.e. the formation of solid compounds and lumps. This is caused by the inevitable entry of unburned vegetable oil through the cylinder wall into the engine oil, especially when driving short distances.

Market and cost

In Germany alone, according to a more recent estimate by the VCD, there are around 20,000 vehicles that run on vegetable oil. At vegetable oil filling stations or at oil mills, the price for pure vegetable oil including the tax component is usually at a similar price level as diesel fuel at regular filling stations.

In contrast to conventional fuels, rapeseed oil is only available at a few hundred filling stations in Germany. There are also many suppliers and oil mills who offer vegetable oil in quantities that are common for refueling.

Refueling with vegetable oil from 1-liter retail bottles is possible everywhere (food refined oil corresponds to DIN 51605), but it is inconvenient. Furthermore, you are obliged to pay the tax charges to the tax office afterwards. Many vegetable oil drivers therefore operate a storage tank with a pump on private property (farm gas station). A common size is around 1 m³. Small storage tanks are sometimes available for around 50 euros.

For agricultural producers, rapeseed oil is cheaper than agricultural diesel . In 2001, a "100 Tractor Program" funded by the Consumer Protection Ministry with DM 5.6 million was started: A total of 111 farm tractors from various manufacturers, whose engines correspond to the technological standards of the EURO I and EURO II emissions standards, were upgraded to vegetable oil Plant converted to gain experience. The project ran from April 2001 to October 2005 and was supervised by the Institute for Energy and Environmental Technology at the University of Rostock .

The costs (including VAT) for a retrofit range from € 360 (1-tank) or € 1,500 (2-tank) to € 4,000 per engine, vehicle or stationary unit, depending on the method. For self-installers, sets are available from € 260 (1-tank) or € 600 (2-tank). In some regions, public subsidies are also offered up to half of the net renovation costs.

Availability in Germany

Many suppliers offer vegetable oil in large quantities that can be temporarily stored in domestic tanks. Refueling with vegetable oil from food retailers (salad oil bottles) is possible, but inconvenient and, due to the small packaging units, also very waste-intensive. In addition, some supermarket chains have introduced a maximum sales volume. Spontaneous demand can be covered by normal diesel from the filling station.

In addition, it should be borne in mind that vegetable oil purchased in the food retail trade, if it is filled into the tank of a vehicle, is determined by this act as fuel in the sense of energy tax law ( Section 1 (2) No. 1 Energy Tax Act), which is a manufacturing act according to the Energy tax law ( Section 6 (1) of the Energy Tax Act), so that - since it happens outside of a manufacturing facility - the energy tax (in the amount of 47.04 ct / l; Section 2 (1) no. 4 letter b in conjunction with para 4 sentence 1 of the Energy Tax Act) (see Section 9, Paragraph 1 of the Energy Tax Act). In addition to prior notification to the competent main customs office (Section 9 (1a) of the Energy Tax Act), a tax return must be submitted immediately (Section 9 (2) sentence 2 of the Energy Tax Act).

Vegetable oil can be produced locally by farmers with the help of smaller, inexpensive oil presses at affordable costs. Because of the sharp rise in the tax burden on vegetable oil as a fuel in Germany from 2008 onwards, it is to be expected that the production of vegetable oil will become significantly less attractive for farmers and that the number of refueling options will therefore rapidly decrease. For the filtration of vegetable oils to fuel quality, cheap and high-quality filter systems are on the market today.

Environmental impact

The use of vegetable oils as a fuel has ecological advantages and disadvantages that cannot always be offset against each other. The German Federal Environment Agency (UBA) said in 1999: "From the point of view of environmental protection and for economic reasons, the promotion of the use of rapeseed oil and RME in the fuel sector is still NOT to be advocated." ( Lit .: Kraus et al., P. 21 ). On the other hand, in March 2007, the UBA's website for the keyword "biodiesel" states: "Biodiesel or the cultivation of rapeseed can make a small contribution to conserving fossil energy resources and protecting the climate."

Climate protection

The use of vegetable oils as fuel is not CO ₂ -neutral in the broader sense. It is true that only the amount of CO _{2 is} released during combustion that the plants previously removed from the atmosphere through photosynthesis . In most cases, however, a small percentage of electricity or mineral fuel is consumed during production (pressing) and, strictly speaking, a small amount of carbon dioxide is released. In addition, the ordering of the cultivation areas including the energetic expenditure for the extraction and logistics of the fertilizer or the spray (pesticides and agents for disease, pest and weed control) and the harvest requires energy, which also leads to the release of carbon dioxide.

The use of naturally produced energy sources leads to a lower CO ₂ pollution over a large area and in the long term compared to crude oil. The carbon dioxide produced during combustion is absorbed by the renewable producer plants and converted into new energy.

The energy balance in the production of vegetable oils is u. a. presented by Poel-Tec. Accordingly, the PÖL factor is more favorable than that of biodiesel (~ 1.48), but less favorable than that of conventional fuels, which is ~ 8.6. However, this representation does not take into account that with conventional diesel, chemically bound energy (crude oil) has to be added, which is taken from a finite reservoir. In the case of vegetable oil and biodiesel, on the other hand, the sun's radiation energy is neglected, which is available anyway and practically inexhaustible. ${\ displaystyle k = \ mathrm {{\ frac {Energy yield} {Energy expenditure}} = {\ frac {37 \, MJ / kg} {16 \, MJ / kg}}} = 2 {,} 31}$

Resource protection

In view of the depletion of fossil resources , raw materials for energy supply as well as for the chemical industry, which are increasingly produced by agriculture, will become more important in the future. The mineral oil companies also take this development into account and invest in corresponding research.

Water protection

The risk of water pollution (including groundwater) is not as great with vegetable oil as with conventional petroleum-based fuels . Whether vegetable oil that is not used as food or animal feed is considered hazardous to water depends on its composition. The main stock of vegetable oils is with the code no. 760 in appendix 1 of the administrative regulation water-endangering substances (VwVwS) listed and therefore "not water endangering": Triglycerides (technically untreated or hydrogenated; fatty acid residues saturated and unsaturated, with an even, unbranched C chain and C number ≥ 8). Since vegetable oil is not a pure substance, but a mixture of substances , the mixing rule of the VwVwS applies. Thereafter z. B. Components of water hazard class 1 only contain less than 3%, so that the substance is classified as "not hazardous to water". Therefore, depending on the type of plant and the oil extraction process, the oil can be hazardous to water if it contains too much triglycerides with short-chain fatty acids, too much free fatty acids (if these do not correspond to code no. 661 in Appendix 1 of the VwVwS) or other contaminants. In June 2007 the Federal Environment Agency held a technical discussion on the subject of “Water pollution from biogenic oils”. Thereupon the commission for the evaluation of water-polluting substances, which advises the federal government, determined that biogenic oils are to be classified as slightly water-polluting in the WGK 1, as far as no further hazard properties occur.

Natural substances can also damage rivers, lakes and groundwater. For example, Section 5 of the Water Resources Act requires "the due care required in the circumstances to avoid a detrimental change in the properties of the water". A classification as “not hazardous to water” only means that the special requirements of Sections 62 and 63 of the Water Management Act and the ordinances issued thereafter do not apply.

Fire protection

The risk of fire is low compared to diesel oil or EL heating oil , because due to the flash point of 220 ° C (see chapter Quality standard below) it is not flammable at normal temperature and cannot form explosive gas / air mixtures.

Space requirement

In order to calculate the theoretical land requirement for the production of vegetable oil as fuel, the energy expenditure is added to the net energy yield:

${\ displaystyle \ mathrm {Total energy yield} \ = \ mathrm {Net energy yield} \ + \ \ mathrm {Energy expenditure} \ = \ mathrm {Net energy yield} \ \ cdot {\ frac {k} {k-1}}}$

For a net energy yield of 1 and k = 2.31, 2.31 / 1.31 = 1.76 of total energy must be used. This factor is important to calculate what area is actually required for energy generation. So you have to order 1.76 m² of arable land in order to provide one square meter of energy for a use other than the generation of energy by agriculture, the national economy. Further details on space requirements can be found under the keyword biodiesel .

Agricultural and regional policy effects

Vegetable oil fuel can also be produced by small oil mills close to the agricultural producer with relatively simple means . When there is increased demand, the recultivation of abandoned agricultural areas is an option . The transport route from producer to consumer is comparatively short. Even the by-product of production, the oil or press cake, can be used as animal feed as a high-quality protein and energy source. The sales market has been falling sharply in recent years. In 2007 it was 800,000 tons, but by 2009 it had fallen to 100,000 tons. In the 2009/2010 biofuel report this is explained by the competitive situation with biodiesel. Associations see the reason in the Merkel II government's biofuel policy, which no longer promotes existing pure fuels.

Differentiated effect of the cultivation methods

The type of cultivation is of central importance both for the ecological balance and for the profitability of the use of vegetable oil. A distinction can be made between two types:

Cultivation in monoculture with mineral fertilizers
Cultivation in mixed culture with organic fertilizers

Most of the scientific arguments (such as the UBA's report) are based on the assumption that the necessary quantities of vegetable oil can only be obtained in intensive agriculture through rape cultivation in monocultures with high levels of fertilizer and pesticide use.

Since 1997, experiments with mixed crop cultivation in organic agriculture in Bavaria have been less known to the public . This means growing a mixture of different crops in the same field at the same time. If leaf plants with crops, deep roots with shallow roots or plants with different nutrient requirements grow together in one field, they complement each other. A beneficial effect for camelina or rapeseed with peas, wheat or barley has been proven. Mixed cultivation requires less fertilizer (the peas provide the nitrogen) and makes the use of herbicides against weeds unnecessary. In the case of grain, due to the lower weed pressure, the same area yield was achieved with a higher-quality grain with an additional yield of approx. 80 to 150 liters of vegetable oil per hectare.

The core of the biological approach is the extensive use of all resources. Due to the mutual benefit of the plants, fertilization can be largely dispensed with in addition to pesticides. The crops are sorted directly in the harvesting machine. Leftover plant material can serve as a basis for fiber materials or be processed into energy as biomass . The press cake obtained from the oil can be used as animal feed and can then ultimately be used as liquid manure for biogas production . The digested residues can then also be used again as fertilizer. The proponents point out here that the cultivation of oil plants should not simply exclude their material and energetically valuable by-products. With this holistic approach, the superiority of modern bio-technology over mineral oil products becomes clear.

According to the proponents, another possibility would be the extensive cultivation of erucic acid-rich natural rapeseed, which is more suitable as a fuel than the erucic acid-free rapeseed currently being grown (so-called OO varieties, the breeding goal of which is to produce a good edible oil).

It is further argued by proponents that in the discussion other oil plant cultivars extensively in Germany would tillable as sunflower , garden rocket , radish , mustard , turnip rape , false flax , linseed or hemp , are drawn too little into consideration.

literature

Katja Kraus, Guido Niklas, Matthias Trappe: Current evaluation of the use of rapeseed oil / RME compared to diesel fuel . Texts. Federal Environment Agency, Berlin 79.1999, ISSN 0722-186X
N. Makowski, D. Brand: Mixed cultivation of camelina and peas is attractive. ( Memento from June 26, 2003 in the Internet Archive ) (PDF) Institute for Energy and Environmental Technology Munich. unpublished Ms. 2000.
M. Winkler: DEUTZ engines for rapeseed oil operation. DEUTZ AG, 2008, (ppo-eu.org ; PDF).

Web links

FNR: Biofuels Basic Data Germany. (PDF; 526 kB) October 2008.
Emissions of biodiesel and vegetable oils in comparison (PDF; 1.45 MB) Presentation.
Poel-Tec Infoportal for vegetable oils as fuel
Bio in the tank - opportunities, risks, side effects. ( Memento from December 10, 2005 in the Internet Archive ) (Reader for a symposium 2005)
Flue gas measurement when burning vegetable oil.
Shear Mixture (Retrieved May 5, 2020)

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k FNR: Biofuels Basic Data Germany. (PDF; 526 kB) October 2008.
↑ ^a ^b ^c ^d ^e DIN 51605 Fuels for engines suitable for vegetable oil - Rapeseed oil fuel - Requirements and test methods.
↑ handelshaus-runkel.de (PDF).
↑ ^a ^b This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
↑ Sustainable commercial vehicle of the future (PDF; 2.6 MB).
↑ Commercial vehicles between economy and ecology (PDF; 1.6 MB).
↑ Schurmischt , PDF file with a text by H. Schur, accessed on May 5, 2020.
↑ Raiffeisen: Safety Data Sheets ( Memento of the original from September 9, 2006 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2
^ Institute for Prevention and Occupational Medicine of the German Social Accident Insurance Institute of the Ruhr University Bochum (IPA): Genotoxicity of particulate diesel engine emissions (DME): Influence of designer fuels under development , December 2006.
↑ Results of the rapeseed oil operation of a truck engine (PDF). ( Memento from September 29, 2007 in the Internet Archive )
↑ Tests on the mutagenicity of soot from the combustion of biogenic and fossil fuels ( Memento from February 10, 2013 in the web archive archive.today ) Examination conditions: To test the exhaust gas behavior of diesel engines, as well as the measurement of exhaust gas components and their carcinogenic effects, one of the Well-known mineral oil companies examined a truck of the latest design according to the currently toughest emissions standard EURO 5 with diesel and standardized vegetable fuel (ESC 13-stage test). The exhaust gases were analyzed neutrally by bifa using the internationally standardized AMES test according to OECD guideline 471. The exhaust gas components are collected and their mutagenic effects on Salmonella strains are examined. A system type "ultimate" from bioltec evolv-ram GmbH was used for fuel management. This fully automatically determines the operating status of the engine and supplies it with the optimal fuel or fuel mixture.
↑ Changes to § 50 EnergieStG
↑ ( Page no longer available , search in web archives: www.rerorust.com )@1@ 2Template: Dead Link / www.rerorust.com
↑ Poel-Tec: Diesel-rapeseed oil-biodiesel comparison - life cycle assessment, page from September 9, 2006.
↑ Administrative regulation water-endangering substances (VwVwS) of May 17, 1999 and amendment administrative regulation of July 27, 2005.
↑ opinion KBwS to biogenic oils ( Memento of 8 September 2013, Internet Archive ).
↑ dip21.bundestag.de (PDF).
^ Opinion on BtL fuel. ( Memento from January 31, 2012 in the Internet Archive ) (PDF).
↑ IG mixed fruit cultivation .
↑ Ernst Schrimpff: Vegetable oils - not ecologically sensible? Comment on negative BUA reports regarding PÖL, January 1, 2003.

[FNR-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k FNR: Biofuels Basic Data Germany. (PDF; 526 kB) October 2008.

[DIN_51605-2] DIN 51605 Fuels for engines suitable for vegetable oil - Rapeseed oil fuel - Requirements and test methods.

[3] shaus-runkel.de (PDF).

[NV-4] This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.

[5] Sustainable commercial vehicle of the future (PDF; 2.6 MB).

[6] Commercial vehicles between economy and ecology (PDF; 1.6 MB).

[7] Schurmischt , PDF file with a text by H. Schur, accessed on May 5, 2020.

[8] Raiffeisen: Safety Data Sheets ( Memento of the original from September 9, 2006 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2

[9] Institute for Prevention and Occupational Medicine of the German Social Accident Insurance Institute of the Ruhr University Bochum (IPA): Genotoxicity of particulate diesel engine emissions (DME): Influence of designer fuels under development , December 2006.

[10] Results of the rapeseed oil operation of a truck engine (PDF). ( Memento from September 29, 2007 in the Internet Archive )

[11] Tests on the mutagenicity of soot from the combustion of biogenic and fossil fuels ( Memento from February 10, 2013 in the web archive archive.today ) Examination conditions: To test the exhaust gas behavior of diesel engines, as well as the measurement of exhaust gas components and their carcinogenic effects, one of the Well-known mineral oil companies examined a truck of the latest design according to the currently toughest emissions standard EURO 5 with diesel and standardized vegetable fuel (ESC 13-stage test). The exhaust gases were analyzed neutrally by bifa using the internationally standardized AMES test according to OECD guideline 471. The exhaust gas components are collected and their mutagenic effects on Salmonella strains are examined. A system type "ultimate" from bioltec evolv-ram GmbH was used for fuel management. This fully automatically determines the operating status of the engine and supplies it with the optimal fuel or fuel mixture.

[12] Changes to § 50 EnergieStG

[13] ( Page no longer available , search in web archives: www.rerorust.com )@1@ 2Template: Dead Link / www.rerorust.com

[14] Poel-Tec: Diesel-rapeseed oil-biodiesel comparison - life cycle assessment, page from September 9, 2006.

[15] Administrative regulation water-endangering substances (VwVwS) of May 17, 1999 and amendment administrative regulation of July 27, 2005.

[16] KBwS to biogenic oils ( Memento of 8 September 2013, Internet Archive ).

[17] 21.bundestag.de (PDF).

[18] Opinion on BtL fuel. ( Memento from January 31, 2012 in the Internet Archive ) (PDF).

[19] IG mixed fruit cultivation .

[20] Ernst Schrimpff: Vegetable oils - not ecologically sensible? Comment on negative BUA reports regarding PÖL, January 1, 2003.