The year 2035 will mark a before and after for the automotive sector in Europe. As of this date, EU countries will only be able to sell new cars and vans without emissions. Dealers will be prohibited from selling cars that are powered by diesel and gasoline, but this does not mean that it will mean the end of thermal engines. The European Union yielded to pressure from Germany - the largest community vehicle manufacturer - and will allow the sale of cars that use synthetic fuels or e-fuels despite initial reluctance.
This decision adopted in extremis by the European Parliament opens the door to look for all kinds of alternatives to diesel and gasoline that go far beyond synthetic fuels. In this new horizon that is already glimpsed in the distance, ammonia looms as a possible new power source for internal combustion engines.
Ammonia, a household product found in most Spanish homes, was already used as fuel in Europe in the middle of the last century. In the midst of World War II and faced with fuel shortages, Belgium adopted this chemical element as fuel to continue the passenger transport service. In 1943 the first ammonia-fueled bus entered service and over the next few months the Belgians managed to put eight more vehicles into operation to cover various transport lines.
Precedents such as Belgium, as well as its current use in electric motors in maritime transport, show that ammonia could become an alternative to traditional fuels to save a mechanic that comes from many years ago. But is it technically viable today?
"There are basic scientific difficulties that would first have to be resolved in order to firmly affirm that ammonia is a viable fuel for internal combustion engines," says Xavier Giménez, professor of Environmental Chemistry at the University of Barcelona (UB). “Perhaps in twenty years we can say that it is viable, but today it is not. Technological development is still necessary to be able to reach this new stage”, says the teacher.
The process used to obtain ammonia is the Haber-Bosch process that was first carried out by chemists Fritz Haber and Carl Bosch in the early 20th century. This process consists of the reaction of nitrogen and hydrogen in gaseous form. Nitrogen is obtained from the atmosphere while hydrogen comes from natural gas.
Studies carried out on the use of ammonia as fuel reveal that the best results have been obtained in engines that work with a mixture of ammonia and hydrogen. At the same time, it has been detected that the greenhouse gas emissions generated by these engines are up to a third less than those generated by a diesel or gasoline engine.
Despite the fact that the process for obtaining ammonia is totally ecological, that is, free of emissions, Giménez considers that today it is not an applicable solution in the automotive world. "First of all, obtaining ammonia is just as expensive or more than oil, therefore, we would not be saving anything."
However, the factor that definitively rules out ammonia as a fuel is the need to solve "a basic scientific problem" such as the low intensity of its flame. “With ammonia it is more complicated to produce a flame that has the same heating property as gasoline or diesel, therefore it is useless”, says the UB professor.
Giménez only contemplates the use of ammonia in the automotive industry in "the energy transition towards the hydrogen economy". Being an easy gas to transport and store, he believes that ammonia could play an important role in solving the problem of transporting hydrogen on a large scale. The professor explains that “once ammonia is introduced as a fuel, it is very easy to obtain hydrogen. It is a natural process that is obtained in a spontaneous and clean way”.
The chemist consulted by Moveo believes that despite the pressure from the lobby of the main car manufacturing countries -Germany, Italy and France- to save the internal combustion engine, the future of mobility is electric. “Electric motors are much more efficient than internal combustion engines and if Europe has given up on its initial idea of shelving internal combustion engines, it has only been due to the pressure it has received from the leading countries in the production of this type. of technology, not by its efficiency.
