Hope for diesel vehicles
Diesel is considered dirty. Nevertheless, biodiesel has hardly been able to get anywhere. A breakthrough could now be achieved by a German research team ,with a modifiable biofuel.
Diesel vehicles are currently causing a headache for most people. The owners of diesel cars have to fear driving bans in German city centers, and the manufacturers of diesel engines are gradually turning away from the fuel.
Lastly, Volvo announced in May this year not to develop any new diesel engines. But whoever calls for the use of diesel vehicles is ahead of its time.
Firstly, studies have shown that gasoline engines with direct injection are at least as dirty as old diesel engines. And secondly, the development of biodiesel is advancing. If too slow.
Production of biodiesel in Germany
In Germany, last year around 3 million tons of biodiesel were produced, estimates the association of the German biofuel industry.
Most producers used rape (62%), cooking oil (25%), soya, palm and other fats. Of the produced biofuel, however, only 2.15 million tonnes were sold in the country, as the Federal Office for Economic and Export Control reported.
The share of diesel cars that drive with biodiesel has thus fallen to just under 5.7%.
The biofuel is politically promoted in Germany and the petroleum industry mixes it with the conventional petro diesel in order to improve its pollutant values. For example, in the EU every diesel fuel may be called “biodiesel”, which contains at least 7% fatty acid methyl ester admixture.
This is defined by the EU standard for modern diesel engines EN 590, which also provides an increase to 10% by 2020.
A project which is technically difficult to understand from a chemical point of view.
Biodiesel usually boils at higher temperatures than petrodiesel.
The only partial combustion of the fatty acid methyl ester, or Fame, creates residues which settle, for example, on engine parts or the particulate filter.
“Cars that are fueled with pure biodiesel therefore need specially designed engines,” says Lukas Gooßen, Evonik’s founder professor for organic chemistry at the Ruhr University Bochum.
This is on the one hand the reason why pure biodiesel vehicles have not yet been implemented and on the other hand the justification for the necessary further development of conventional biodiesel.
Together with a researcher from Kaiserslautern and Rostock, Gooßen has now presented a procedure that can be used to tune conventional biofuels.
As a raw material, the researchers used rapeseed oil, the basis of most Fame biodiesel, but in the end their mixture had characteristics like conventional petro-diesel.
Researchers succeeded in correlating the boiling point of Biodiesels with that of the Petro Diesel
It was important to the researchers that the biodiesel comes as close as possible to the boiling point curve of diesel fuel from mineral oil. This means that as much as possible of the newly obtained product mixture evaporates at the same temperature as Petro Diesel.
“This is the case for the diesel fuel, for which a motor is ideally suited,” explains Gooßen.
So he took this curve and compared the values of the new mixture with it again and again. Until ,after three years of work, the match was perfect.
The new biodiesel thus corresponds to the conventional petro diesel in its combustion properties and thus to the EU standard.
The future of Diesel saved?
This does not change anything for drivers. This is because these findings are derived from the basic research, the fuel is still a few years away from an application.
Not bad, says Gooßen, because he and his colleagues have now made a solution suggesting the way to a more environmentally friendly fuel.
“We have demonstrated what needs to be developed to solve the problem, but with very expensive catalogers and in very small quantities,” says Gooßen.
A first step. After all!
The study “Biofuel by isomerizing metathesis of rapeseed oil esters with (bio) ethylene for use in contemporary diesel engines” appeared in the American trade magazine Science Advances.