How are ethanol and gasoline mixtures called

Free travel for alcohol

"So, the tank is empty. We have to fill it up first. Let's open the filler cap as normal. So, pump. Let's fill it up a little now."

Free travel for alcohol.

"You can fill up here as you would at any normal petrol station. You pull up the vehicle, pull out the tap, open the filler neck and fill up."

To the perspectives of alternative fuels.

"So, the tank is full. That's it. [TAPFHAHN] Let's close everything. And now we can drive off."

A broadcast by Volker Mrasek.

"Completely normal car. Completely normal tank. The only additional thing is preheating. When it drops below 20 degrees, you can preheat the engine. Then the engine starts better. It is designed because the cars mainly driving in Sweden so far. It's getting a bit colder there. "


"Well, start up normally. Runs normally too. If you buckle up, please!"

A small city tour in Bad Homburg, north of Frankfurt am Main. The car is only a few weeks old, its owner a dentist in Bad Homburg - and a revolutionary: Hartmut Papke drives the first bioethanol car in Germany. A 1.8 liter Ford Focus. The engine can justifiably be described as a hybrid: It runs on both premium gasoline and - schnapps ...

"I knew just as little about bioethanol as most people either. And today I am constantly being asked: What is bioethanol actually?"

Super, normal, diesel. But what is bioethanol? Or even ethanol?

Spirits! Nothing else. The high percentage in our spirits, also called "drinking alcohol".

"Bioethanol is alcohol that is produced from renewable raw materials."

The agricultural engineer Berthold Nolte, managing director of Südzucker Bioethanol GmbH in Zeitz near Leipzig ...

Fuel from the field instead of from the oil refinery. Nolte's company recently commissioned Europe's largest bioethanol production facility to date. Elsewhere in Germany, too, gasoline replacement capacities are being expanded.

"Today, bioethanol is made from raw materials containing sugar or starch. Raw materials containing sugar are, for example, sugar beet or sugar cane. Raw materials containing starch can be potatoes or all types of grain Beer production by saccharifying starch and then fermenting it. "


Maybe another four decades and the age of oil will draw to a close. Black gold will become much more expensive even earlier. And with it super, normal and diesel fuel. One can assume that.

Another problem is even more pressing: climate change. Burning the fossil fuels oil, natural gas and coal releases enormous amounts of carbon dioxide, a greenhouse gas that retains heat in the atmosphere. According to the unanimous opinion of climate researchers, CO2 emissions must be reduced rigorously in the coming decades in order to avoid dangerous changes in the climate. Transport should also play its part.

The following applies to fuel made from sugar cane or cereal grains: The CO2 that is released during combustion is previously removed from the atmosphere by the plants - while they are growing. With regard to the raw material, bio-fuel burns "climate-neutrally", as they say. Emissions only arise from field cultivation and the processing of energy crops.

In Europe, therefore, there is a declared political will to place non-fossil fuels more strongly in the market ...

"This new market was initiated by the European biofuel directive, which provides that 5.75 percent of fuel is to be covered in the form of biofuels by 2010. The biodiesel and bioethanol processes are currently ready for practice."
Biodiesel made the start. The fuel is obtained from rapeseed oil. Numerous commercial vehicle fleets, but also private cars, have been running on pure rapeseed oil methyl ester, as biodiesel is also known, for years. Almost 2,000 filling stations now offer this alternative fuel nationwide, the mineral oil companies are now mixing it with conventional diesel - up to five percent. Biodiesel already accounts for an estimated six percent of total diesel sales in Germany.

The development of gasoline is only just beginning. Bioethanol has similar prospects here as biodiesel does for self-igniting. The alcohol can be mixed with petrol fuels and thus partially replace petrol from fossil sources. Bioethanol is thus the second alternative fuel that is gaining a foothold in traffic and is currently enjoying the greatest attention - not just in Germany, by the way.

Manfred Wörgetter, proven expert for biofuels at the Austrian Federal Institute for Agricultural Engineering.

"When it comes to biofuels, one speaks of the first and second generation. The first generation are those that have already been launched on the market from a technical point of view, that is bioethanol made from starch and sugar, biodiesel mainly made from rapeseed oil. The next step will then be fuels the second generation. The best chances are currently given to synthetic fuels via the step of biomass gasification, the synthesis of fuel. "
Petroleum is a desolate mixture of innumerable different hydrocarbons. This is also noticeable in the gasoline and diesel produced from it: in the end they still contain hundreds of different carbon compounds. These include unwanted ones. For example, those that produce harmful exhaust gases when they burn in the engine.

The next generation of synthetic fuels is completely different. They can be composed, as it were. Something like this: You take wood waste, gas it at high temperature and, through intermediate steps, obtain clean, so-called synthesis gas. No wild mixture of substances as with the fossil raw materials, only carbon monoxide and hydrogen. This gas can be further processed and liquefied, resulting in tailor-made fuels that only contain the desired ingredients.

Experts speak of BTL or designer fuels. BTL stands for biomass to liquid - for the conversion of biomass into liquid fuel.

"If that works, then we will be between 2010 and 2025. How things will continue afterwards are pure visions. The visions are the way to hydrogen."

Hydrogen! The fuel for fuel cell vehicles in which CO2 or toxic benzene no longer oozes out of the exhaust pipe, only water vapor.

Hydrogen! An energy source that is not available per se, but has to be generated first. And which requires a completely new infrastructure. For storage and provision in gaseous form at temperatures beyond minus 250 degrees Celsius.

Hydrogen! Individual buses or car prototypes may already be powered by fuel cells today. But hydrogen is only a third generation of alternative fuels.

"From today's perspective, we know that in the foreseeable future, and by that we mean the next 20 years, hydrogen can only play an extremely small role."

Wolfgang Staiger, development engineer at VW in Wolfsburg, where he is responsible for new drive concepts. Like Staiger, other energy experts say:

Hydrogen can only be expected as an energy carrier in car traffic in the long term.

BTL fuels should be available in the medium term.

And in the short term we end up with biodiesel and bioethanol. And so again in Bad Homburg in Hesse. At the local Ford dealership.

Here Hartmut Papke not only bought the first bioethanol car in Germany that was registered for a private person. Not only mechanics will take care of the vehicle inspection here. This is also where the currently only public petrol pump for the high percentage fuel is located. And next to that, Volker Bissing, employee of the car dealership.

"This is our bioethanol filling station. We are Germany's first manufacturer to open this filling station. If I drive to a large filling station today, of course, I have several options with regular, premium, diesel, 100 octane As I said, now only our bioethanol in there. "

Anyone who already drives a bioethanol car today does not necessarily have to stop for fuel in Bad Homburg:

"The vehicles have the special option of refueling: bioethanol or super unleaded. Customers can choose to refuel. So, they don't need to be afraid. They can refuel with super unleaded elsewhere at any time. he can then refill bioethanol normally again. "

Flexible fuel vehicles are called the two swallowers: "fuel-flexible vehicles", short: FFV. It doesn't differ much from the normal gasoline engine. The valves are extra hardened and the tank is specially protected against rust. But the most important thing: FFV models have a sensor on board that automatically detects what's in the tank: super, bio-ethanol, or a mixture of both. The engine management adjusts the ignition times in the combustion chamber accordingly. They need to be adjusted because ethanol evaporates faster than gasoline.

E85 flows from the brand new gas pump in Bad Homburg. The fuel is so named because it consists of 85 percent ethanol. And only 15 percent from gasoline. One would not expect gasoline engines to have a higher alcohol content because this could lead to problems with a cold start in winter. And in the summer with the volatility of the fuel, ethanol has disadvantages compared to gasoline. On the other hand, the alcohol increases the octane number. As a result, petrol becomes more knock-resistant and the engine gains more power.

So far, only Ford offers two FFV models in Germany. But other brands will follow suit. The Swedish manufacturer Saab has already announced this for spring. It is also believed that Volvo could soon follow suit.

However, it has to be said that if the bioethanol boom should come about in Europe, it will happen very late. In a country like Brazil, alcohol has long been processed into fuel. Schnapps has been pouring into the petrol tank there for 20 years. Manfred Wörgetter has followed the development from the beginning:

"Brazil is clearly the number one pioneer in the biofuel sector. They opted for bioethanol from sugar cane very early on. In Brazil, up to 26 percent of ethanol is added to gasoline. All cars run on this ethanol-gasoline mixture Flexible fuel vehicles that can run on both gasoline and ethanol in any composition. "

Another important overseas bioethanol market is the US. There the mineral oil companies sell E5, for example - a gasoline that contains five percent bioethanol. This is also how the alcohol consumes enormous amounts:

"In the United States, soon after the Brazilians, people began to focus on producing ethanol primarily from corn. And in the United States there are currently 96 large ethanol plants in operation. 23 new ethanol plants are under construction. that in 2006 the US has a capacity of 20 million cubic meters of ethanol. These are huge plants. "
Now the spark has also spread to Europe. Sweden is the beginning.

As soon as the Brussels Biofuels Directive was passed, the government in Stockholm decided to exempt bioethanol from the tax. Even more: Anyone who drives an FFV model generally does not pay a parking fee in city centers. Despite a lack of production capacities in their own country, Sweden has no supply bottlenecks: The Scandinavians import their bioethanol from Brazil.

Biochemist and fuel expert Ann Segerborg from the Swedish National Environment Agency:

"In 2004 we started with around 18,000 vehicles filling up with the E85. Next year it should be well over 50,000. The 300th filling station in Sweden recently installed a bioethanol pump. Every tenth newly registered vehicle in Sweden will soon be be an FFV model.

"The vehicles have recently also been marketed in Great Britain and France. They are hardly more expensive than pure gasoline models. The price difference is only a few hundred euros. You can also save on fuel. E85 is exempt from mineral oil tax, so the liter is almost half a euro Cheaper than premium gasoline. On the other hand, bioethanol does not have such a high calorific value, so a car that runs on E85 uses around 30 percent more fuel.

"Whether the FFV and E85 will hit the ground running in Germany is not yet clear," says Edmund Brück, board member at Göhler, one of the largest German tank system manufacturers based in Hösbach, Bavaria:

"The chances are greater than with any other fuel. I don't need to solve the chicken-and-egg problem like with the other fuels, so that I first have to build a huge infrastructure for natural gas, liquid gas, or whatever the other fuels are called . It now depends on how strongly this is forced. "

Of course, ecological criteria also play a major role. Switching to alternative fuels only makes sense if it actually reduces climate-damaging CO2 emissions. In addition, bioethanol and biodiesel should not produce more pollutants than fossil fuels - rather less. All of this has to be scientifically assessed. A case for the accompanying energy and fuel research.

"Next I switch on our eddy current brake. The eddy current brake simulates the load on the motor. For example, we simulate a full load drive. And nobody is able to hold the motor when it is running under full load. That's why we add a brake . The brake circuit is running. The tank circuit is in operation. Everything lights up green. Now I'll switch on the suction system. "

Early morning in Braunschweig. At the FAL, the Federal Research Center for Agriculture. The FAL maintains its own engine test bench, housed in a spacious workshop hall. The adjoining room, on the other hand, is hardly the size of a garage. In it a total of five computers, circuit diagrams on the screens, displays with glowing red digits on the walls that change hectically: this is the connected control room.

Jürgen Krahl tests the emission behavior of diesel fuels here. The chemist is head of research in the Department of Biosystems Technology at the FAL. At the same time, he teaches at the Coburg University of Applied Sciences in Northern Bavaria. A six-cylinder truck engine, typical for a 7.5 or 12-ton truck, is on the test bench.

"We run the engine with different fuels. With biodiesel, with diesel. We are also testing the new branded fuels that mineral oil companies have offered in recent years. And look: What impact does a biogenic component have on emissions compared to a fossil component, that is Exhaust gases, and also their effects. "

As a professor, Krahl is not constantly on the test bench. The job is done by Thomas Berndt, a student of physical technology in Coburg and seconded to Braunschweig for a practical semester.

"Next I'll go to the ignition here with the mouse. And now I can start the engine."


"The engine is now running, and I now, for example, speed 1,100 revolutions per minute. Of course, I also have to accelerate! And you can hear the engine slowly coming up."

"We run a 13-step test. This is a test standardized in Europe that is supposed to simulate the typical operating points of a truck. It takes 28 minutes. During this time, it runs a measurement program, during which we then take samples for the exhaust gas analysis. "

With such series of measurements on the engine test bench, researchers like Krahl know what oozes out of the exhaust pipe of an alternative fuel such as biodiesel.

In the case of diesel, there has been a conflict over alleged damage to health for a long time. It's about dust particles that are released when burned and are so fine that they penetrate the lungs. About particles that are mutagenic, i.e. have the potential to become a cancer focus at some point. According to Krahl's analyzes, biodiesel does better:

"One can say in a nutshell that biodiesel leads to a significant improvement in most of the emissions. Especially with the carcinogenic substances, especially the mutagenic substances, especially the total particle mass, that we can clearly formulate advantages for biodiesel."

The situation is similar with bioethanol. Older studies have shown that alcohol burns cleaner than conventional gasoline. In particular, a fuel like E85 with a very high proportion of ethanol has an advantage over classic super. However, it remains to be clarified to what extent the higher consumption of E85 reduces this eco bonus.

The first bioethanol cars will be on the market, more filling stations are only a matter of time. Politically, too, a greater spread of the gasoline substitute is wanted in Germany:

"If we want 5.75 percent alternative fuels by 2010, then we will not get past the bioethanol story."

That much is clear, says Martin Kaltschmitt, managing director of the Institute for Energy and Environment in Leipzig and a recognized specialist in renewable energies.

An assessment that is shared by the new federal government. She wants the statutory admixture requirement. Soon only petrol and diesel with 5 percent organic content should be available at the filling stations.

The petroleum industry has already taken this path with diesel. And in principle there is nothing against it when it comes to petrol, says Axel Graf Bülow, General Manager of the Federal Association of Independent Petrol Stations:

"According to the German standard, that is, according to the DIN standard, you can add up to five percent bioethanol to the fuel if you comply with the criteria of the standard. You don't even notice that. That's standard fuel. You notice that in the car too no. They have no difference in operation. "

According to Bülow, some free petrol stations already offer E5. On the other hand, there was no such thing as a result of the large oil companies. You don't want gasoline with an admixture of ethanol. Because such a fuel needs separate bearings and pump nozzles. It is problematic when E5 and conventional Otto fuels come into contact with each other, argues Klaus Picard, General Manager of the Mineral Oil Industry Association and a trained agricultural engineer:

"When I mix fuel containing ethanol with pure gasoline, I have the problem that the vapor pressure jumps up due to the chemical-physical properties, which means that the fuel goes out of specification and is therefore no longer for sale."

This is what is known as the vapor pressure problem. Bioethanol advocate Berthold Nolte does not deny it either:

"Of course, with mixtures of gasoline and ethanol, the vapor pressures must be adhered to, as they correspond to the fuel standard. But this can be made possible by producing the 95 percent gasoline in a different specification ...".

... which, according to Nolte, is not very popular with the large oil companies ...

"... because it simply increases the cost of gasoline."

Association chief Picard emphasizes that there are also other ways of introducing ethanol into gasoline fuel. Not in pure form, but as part of a new anti-knock agent. ETBE is the abbreviation for this connection. In fact, almost half of it consists of ethanol and has largely replaced an additive that was used in the past. Scientists like Martin Kaltschmitt hardly see any further development potential:

"The problem is that the possibilities of adding ETBE have actually already been exhausted."

So it can really only boil down to adding pure bioethanol. So on E5. And - if pure biofuels remain tax-privileged - also on E85.

"But here, too, ethanol production is relatively energy-intensive, relatively inefficient in terms of what I can get down per hectare, [which] really makes it appear more like - let's say - an intermediate stage with regard to future alternative fuels . And then the question is: what comes next in the 2nd generation? "

The next generation of car fuel is already available. Not on the market, but from the pilot plant. At the Chorén company in Freiberg, Saxony ...

"Please follow! We go a few steps further. We follow the path of the wood. The wood is here in the dosing bunker and is now being fed into the first process stage of our gasification process. This is the so-called low-temperature reactor, one and a half meters in diameter." "

Jochen Vogels is an engineer at Chorén. He is drawn to the third level of the four-story steel structure, which is teeming with reactors, compressors and compressors. Here, nine meters above the ground, Vogels can best get hold of the high-temperature carburetor. The technical operations manager, Mirko Roth, is already waiting there ...

"You have to imagine a large, vertically set up container. So it goes almost to the bottom of the foundation. This is the heart of our gasification plant, in which the biomass flows are converted into the / actual raw synthesis gas."

In the Freiberg plant, wood residues are gasified in stages. In the first process step, carbonization gas and something like charcoal dust are created. Both are reintroduced into the process at a later point. A nifty trick: This is how you finally get a tar-free, clean raw or synthetic gas. This can easily be liquefied - in a catalytic reaction that chemists know as the Fischer-Tropsch synthesis. In the end, Chorén extracts pure hydrocarbons in this way, which can be further processed into diesel or gasoline.

This is then the designer or BTL fuel that was already mentioned. And about the bird says:

"Well, at the moment we are convinced that it will be the fuel of the future."

Chorén is determined to expand production further. In the meantime, the Shell oil company is also investing money in the project. Car manufacturers such as Volkswagen and DaimlerChrysler are already busily testing the new biofuel and are aligning their future engine concepts accordingly. VW development engineer Wolfgang Staiger:


"Today we have around two to three thousand individual molecules in fuel, of which we don't even know half. With synthetic fuels, we still have ten molecules."

No annoying sulfur compounds, no aromatic hydrocarbons or other accompanying substances that prevent the fuel from burning evenly ...

"The designer fuels now enable the development of new combustion processes. And we have the clear intention of developing a successor process that includes the advantages of both diesel and gasoline engine combustion technology. These are homogeneous compression-ignition gasoline engines that are now inevitably have consumption levels comparable to those of today's diesel engines. There is practically no difference anymore. "
Grain grains have to be harvested for the production of bioethanol, and rapeseed seeds for biodiesel. In contrast, future BTL refineries will use whole plants. Or just their crop residues. For example, straw or wood bark. This is another plus point for future biomass fuels: the more efficient use of the raw material.

This aspect is extremely important. Because of course the question arises: Where should all the energy crops for alternative fuels come from? To take bioethanol as an example:

"If we want to meet the European biofuel directive today to replace 5.75 percent of gasoline, we would need around seven million tons of grain if we were to produce it in Germany from grain."

An enormous amount for which Bertholt Nolte comes up. But German farmers alone harvested 50 million tons of wheat every year, says the agricultural engineer. Up to a third are still exported today. In the future, however, it will no longer be worthwhile. So there is enough grain available to turn it into biofuel, which is expressed in Nolte's estimate ...

"... that Europe has enough raw materials from these so-called surplus raw materials to replace 20 to 25 percent of current gasoline requirements with bioethanol. That is a huge potential."

But you shouldn't overestimate it either. Sufficient wood, straw, grain and other biomass to completely replace fossil fuels is definitely not available. Today's consumption quantities are simply too large for that.

There are experts who say that future BTL fuels will only be able to cover a sixth of the gasoline and diesel requirements in the passenger car sector - not to mention commercial vehicles and airplanes.

Bio-fuels can therefore reduce dependence on fossil fuels, but only to a limited extent. You can make traffic lower in CO2 and thus more climate-friendly - but you cannot turn it upside down.

There is no alternative to the rapid market launch of bio-fuel, says Manfred Wörgetter. But this alone cannot be the solution, the engineer from Austria warns:

"It is high time the world went in the direction of an energy turnaround. This limitless consumption of limited resources! On the other hand, you have to be completely clear that bioenergy can only cover a relatively small proportion of the energy hunger. Bioenergy likes the alternatives play the biggest role in the medium term, but in the long term the only thing that can be done is to reduce energy consumption, which will not be avoidable.


They heard "Clear the way for organic juice. The prospects for alternative fuels." A broadcast by Volker Mrasek. Speakers: Marietta Bürger and Jürg Löw. Production: Axel Scheibchen. The director was Uli Blumenthal.