Ethanol fuel
|
DIN 51625 |
|---|---|
| Area | Fuels |
| title | Automotive fuels - Ethanol fuel - Requirements and test methods |
| Latest edition | 2008-08 |
| ISO | - |
Ethanol fuels are petrol with different high proportions of ethanol . The mixtures are named after the proportion of ethanol in gasoline, e.g. B. E85 with 85% ethanol. The E10 mixture with 10% ethanol, which is controversially discussed in Germany, or the mixture of gasoline with only a small amount of ethanol added (E5 with 5% ethanol) is still referred to as gasoline.
In Germany, requirements and test methods for ethanol fuel are standardized in the DIN standard DIN 51625.
Pure ethanol is a chemical compound and therefore always has the same physical properties regardless of its production. There is no chemical difference between ethanol made from fossil carbon compounds or bioethanol made from vegetable raw material sources. Bioethanol has a significantly higher proportion of the radioactive carbon isotope 14 C , which is negligible in terms of its physical properties. From a global perspective, alcohol produced from fossil sources (for example by hydration of ethene derived from coke oven gas ) is of no importance today ; Of the amount of biologically produced ethanol, around 35% is produced as neutral alcohol for beverages and food as well as for other technical purposes and around 65% for use as fuel. In Germany the ratio is around 50:50.
The biologically produced ethanol only for fuel purposes as an additive to gasoline in different mixture concentrations is now called bioethanol , it is important in the context of the energetic use of renewable raw materials . Bioethanol for blending with gasoline is mixed with denaturing substances such as gasoline, ETBE or methanol. Common denaturants, such as those added to spirit or alcohol for cosmetic purposes, for example MEK ( methyl ethyl ketone ), must not be used in fuels according to EN 228. While bioethanol has so far only been obtained from sugar and thus mainly from sugar beet and starch-containing grain, newer methods mainly use biomass from cellulose-containing raw materials such as Chinese reed , switchgrass and wood ; the result is cellulosic ethanol .
→ see main article biofuel
history
As early as the 1860s, Nikolaus August Otto used "spirit" ( potato spirit , ethyl alcohol ) as a knock-proof fuel ( octane number at least 104 RON) in the prototype of his internal combustion engine. During the First World War, this fuel was used as an engine spirit for high performance requirements such as fighter planes.
As early as the Weimar Republic , the Reichskraftsprit-Gesellschaft added around 25% potato fuel to gasoline from 1925 and sold the mixture under the name Monopolin . Until the 1950s, ethanol was mixed with various other fuels such as benzene , methanol , acetone and nitrobenzene to form very knock- resistant racing fuels , which are banned today due to the toxic effects on people and the aggressive effects on the material.
Due to the supply situation with gasoline, there was in Germany with the Reichskraftsprit (RKS) founded in 1925, a manufacturer of alcohol ( potato schnapps ) for use as gasoline . However, the use served less as a means to increase the knock resistance , but rather to support the growing agriculture. RKS sold its gasoline mixture with an approx. 25 percent share of alcohol under the brand name Monopolin . 1930 came into force in Germany the purchase regulation for alcohol for fuel purposes for all fuel companies. 2.5 percent by weight of the amount of fuel produced or imported was to be obtained from the Reich monopoly administration and added to the petrol. This quota increased gradually to 10% by October 1932.
In the decades that followed, oil remained the main source of energy. It was not until the oil crises of the 1970s that ethanol found new interest as a fuel. Starting in Brazil and the USA, the use of ethanol from sugar cane and grain ( bioethanol , 1st generation biofuel ) as fuel for cars, as well as other alternative fuels based on renewable raw materials, was increasingly supported by government programs. A global expansion of these efforts came about as a result of the Kyoto Protocol . Due to the possible competition for land in the cultivation of energy crops, efforts are being made to be able to produce 2nd generation biofuels ( cellulose ethanol ) and 3rd generation biofuels ( BtL fuel ), which have a clearly positive environmental balance sheet.
The technology of ethanol-powered engines is now well advanced. For example, the 838 kW (1140 hp) super sports car Koenigsegg Agera , which went into series production in 2013, runs on E85 and E100 (85% and 100% ethanol). Even with a consumption of 25 l / 100 km, the Agera emits less CO 2 than most electric cars with a German electricity mix. The CO 2 pollution, calculated on the basis of the biofuel sustainability ordinance, is equivalent to 64 g CO 2 / km when driving with the E100 and 165 g CO 2 / km with the E85 fuel.
E85
Bioethanol is sold with a content of 85% (for summer fuel) to 15% normal petrol, known as E85. Flexible fuel vehicles (FFV, dual fuel, multi fuel) can be operated with this fuel mixture. It is possible to retrofit other vehicles with petrol engines, but some restrictions must be observed. In Brazil, Sweden, the Czech Republic and the USA, the E85 has been on the market for a long time, and FFV models are offered there as standard. They are mostly suitable for any fuel composed of bioethanol and petrol. In Germany these vehicles are currently u. a. distributed by Ford , Volvo , Renault and VW . Independent petrol stations have been continuously expanding their range in Germany since 2005 . Studies on this show an additional consumption of up to 30% for E85. The cause is the different air mass required for the stoichiometric combustion air ratio lambda = 1. While super petrol can burn approx. 14.7 kg of air with 1 kg of fuel, pure bioethanol only needs approx. 9.0 kg of air with 1 kg Fuel. Converted to liters, this results in a theoretical additional consumption of 42% of E85 compared to super petrol. However, since the oxygen content, octane number ( knock resistance ) and heat of evaporation also play a role, the practical value is reduced to 15–25%, depending on the engine design.
criticism
Ethanol fuel is a biofuel , the advantages and disadvantages of which are in the scientific and political debate. There is criticism, for example, of the climate footprint, possible competition effects for the provision of food or the possible threat to rainforests.
See also
Individual evidence
- ↑ Company page on Koenigsegg Agera
- ↑ gs-500.info: Information on converting a motorcycle
- ↑ Archived copy ( memento of the original from August 26, 2011 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Advantage bioethanol , Association of the German Biofuel Industry e. V.
- ↑ Additional consumption E85 , e85-fahren.ch
- ↑ Combustion air ratio ( Memento of the original dated November 7, 2011 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , Calculation of the combustion air ratio
- ↑ Calculation of additional consumption E85 ( Memento of the original from June 23, 2012 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. , Theoretical calculation of the additional consumption of E85
- ↑ http://www.e85-fahren.ch/faq.php#12
Web links
- Handbook for Handling, Storing, and Dispensing E85 (5.36 MB; 54 pages; English), National Renewable Energy Laboratory, US Department of Energy
- Table of contents of DIN 51625: 2008-08 at Beuth-Verlag