Scientists at the Vienna University of Technology have developed an internal combustion engine that can use two fuels in parallel thanks to the so-called dual-fuel combustion process. Compared to conventional diesel engines, was through the use of bio- ethanol engine efficiency can be increased, leading up to 39 percent lower CO2 – emissions entails.
Prof. Bernhard Minder from the Institute for Vehicle Drives and Automotive Technology explains that “it has long been common in some countries to add large amounts of ethanol to gasoline . So far, this was only possible to a minimal extent with diesel engines. ”
Mixed operation with diesel and bio-ethanol reduces CO2 emissions by up to 39 percent. Fine dust emissions are even reduced by 99 percent. In the medium term, this could make truck traffic significantly more environmentally friendly.
Reduced CO2, fine dust and soot:
During the experiment, the bioethanol content in the fuel was gradually increased to 70 percent. According to Aleksandar Damyanov from the Vienna University of Technology, an efficiency increase of up to 6.1 percent was achieved, which already improves the environmental balance of the engine. If you also take into account that the CO2 balance of bioethanol is significantly better than that of diesel, which is produced from petroleum due to the production from renewable raw materials , the CO2 emissions are reduced by a maximum of 39 percent. On average, the CO2 emissions from the use of bioethanol were 31 percent lower than the CO2 emissions that are emitted from pure diesel operation.
Ignition problems with diesel-ethanol mixture:
This is because a mixture of bioethanol and diesel directly in the tank would cause the ignition to stop working in conventional vehicles. For this reason, the scientists developed the dual-fuel combustion process, which, as explained in less detail, “ignites with a direct-injected diesel jet as with ordinary diesel engines”. The bio-ethanol is mixed with the intake air during operation before it enters the engine. Once there, it is ignited by the diesel ignition process. In this process, Diesel works “like a spark plug for bioethanol.”
What about Improvement:
The improvement in engine efficiency and the lower CO2 emissions were found during the experiment in speed ranges from 1500 rpm to 3000 rpm. Efficiency rose by an average of 1.9 percent, with a maximum of 6.1 percent higher efficiency. NOx emissions (nitrogen oxide) were also reduced by an average of 13 percent through the use of bioethanol, with a maximum of 36 percent less. The greatest differences were in particulate emissions, which decreased by a maximum of 99 percent.
Less summed up that the “results clearly show that bio-ethanol can be used successfully as a substitute fuel in a dual-fuel diesel engine, and that this concept brings considerable benefits to the environment.” The developers of the drive technology hope that diesel engines In some areas, such as truck traffic, where they cannot be replaced in the medium to long term, the use of dual-fuel technology will make them more environmentally friendly.
has been present there for 59 years, today with ten brands and seven plants. Last year, the South American subsidiary of the German Volkswagen AG manufactured exactly 828,400 vehicles (excluding MAN and Scania) for sale in Brazil and for export. Every fourth vehicle in Brazil is now a VW.
Make ethanol acceptable again as a fuel alternative
After that, there were many attempts to make ethanol acceptable again as a fuel alternative. The Brazilian was faced with the choice: I would buy a car that filled with alcohol or ran on petrol, roughly comparable to the decision to buy in Germany: petrol or diesel. The situation changed in 2003 when VW made a breakthrough with Flex Fuel technology. Bosch was brought on board during the development. “Thanks to the electronic injection process, the new engine was able to burn in any ratio, like all Volkswagen ethanol (E 100), gasoline (E 22), or a mixture of both, manufactured in Brazil,” explains Dr. Feichter. In the new Gol, for example, the 1.6-liter engine with ethanol produces 76 kW / 104 PS, petrol flows into the injection, 74 kW / 101 PS.
A second big success, according to the interlocutor , was VW with a special heating of ethanol-fueled vehicles, so that they start without problems even in the colder temperatures that occur in the south of the country. The premiere vehicle was the Polo. “This has given VW a great competitive advantage in Brazil,” emphasizes Dr. Feichter.
Alcohol or gasoline – the Brazilian refueledhis car today mostly according to the motto: look, calculate, fill up. The prices vary widely from region to region, but are comparatively far below the EU level in view of the domestic currency (2.62 real – one euro). However, if you consider the real income in Brazil, the minimum wage is the equivalent of 350 euros, the gasoline price is significantly above the European level. “It wasn’t so long ago that the liter of ethanol cost 99 centavo, so under one real. So the decision to refuel was easier, ”says Dr. Feichter. In the 15 million metropolis of Sao Paulo with its approximately seven million registered cars, the liter prices between ethanol and petrol change on almost every street corner – from 1.49 real for ethanol to 2.58 real for petrol to 1.98 real 2.88 real. In any case, gasoline is always significantly more expensive.
The direct hit of a total of 22 models:
The Gol from Volkswagen do Brasil, including the Fox and Polo series and the Passat. Similar to the Golf in Germany, it is the sovereign market leader in its segment in Brazil, which is 24 times larger. Gol stands for goal in Portuguese: that is probably why VW won the Brazilian soccer star and striker Neymar at the Motor Show in Sao Paulo for the presentation of the sixth variant of the compact front-wheel drive. The Gol, which has been available since 1980, has been the best-selling vehicle in Brazil for 26 years and has been produced over seven million times. Like all Brazilian VW models, the Gol runs on ethanol, petrol or in a mixture. “The prerequisite for this was that we launched Flex Fuel technology in 2003, with which 86 percent of all new cars registered in 2012 are on the road in Brazil, ”emphasizes development chief Dr. Egon Feichter from Volkswagen do Brasil.
Brazil and that from 100 percentEthanol produced from sugar cane is an interesting story, also with a view to the current bio-fuel discussion in Germany. In 1973, the government at the time pushed for a “Programa National Alcohol” due to the oil crisis. Shortly afterwards, VW developed the first engines for this. Series production of the first ethanol-powered Volkswagen began in late 1979 with the Sedan 1300. “Up to 95 percent pure alcohol cars were on the road in Brazil in the mid-1980s,” says Dr. Feichter. Ethanol was subsidized and vehicles were taxed less. But at the end of the 1980s, they were no longer competitive – world sugarcane prices rose and approvals fell to zero. Cars were bought that fueled petrol. “Diesel is still not permitted for cars in Brazil, only for vehicles with a payload of more than a ton,” adds Dr.