Hydrogen gas is the lightest of all the elements in the universe, it is about 14 times lighter than air and this means that the hydrogen spreads very quickly in the event of a leak. Hydrogen consists of two hydrogen atoms and therefore has the chemical designation H₂. It is colorless, odorless, non-toxic and even then highly flammable. Hydrogen is the most abundant chemical substance in the universe and makes up approximately 75% of all normal matter. Down on earth, it is significantly rarer, only 0.15% of the mass, it is found bound in various forms of matter, for example in water, H₂O.

Production of hydrogen

The first documented time that hydrogen was produced artificially was at the beginning of the 16th century with acids that reacted on various metals. Today, there are a number of ways to produce hydrogen, the different ways affect the environment more or less, and work is constantly being done to try to produce it as green as possible. What we know today that is best for the environment is if you can use solar energy or wind turbines, but even these methods have a certain negative effect on the environment.[1]

 

Here, only one of the ways will be explained in a very simplified way. You can say that it is done in such a way that you separate the oxygen and the hydrogen from each other. This is done by charging the water with electricity. Salt water is an advantage to use because it conducts electricity better, it can also be called splitting the water. What then happens is that oxygen and hydrogen gas come out, but separated from each other. In this chapter, we will not delve too much into how the production itself goes beyond the fact that it can actually be done at home, if you have the right equipment. At the same time, you have to remember that it is a very flammable gas you are dealing with.[1]

 

Different types of vehicles

Development has come a long way and the use of hydrogen in all possible types of vehicles can be seen today. Most of the major vehicle manufacturers around the world are testing their cars where they have developed engines that run on hydrogen only, or rather modified them to run on only hydrogen. What should be added here is that development moves at such a high speed that it is difficult to be completely up-to-date on the subject, and what is written here today may be old tomorrow. Buses have been successfully driven with hydrogen with traditional combustion engines in various parts of the world.

 

One of the issues is that it is not completely zero emissions, because the carbon oxide content, CO, and carbon dioxide content, CO₂, is almost non-existent. But, on the other hand, the nitrogen oxide content, NOx, you struggle with in different ways to bring it down to an acceptable level. In a combustion process, air is used and the nitrogen in the air is then converted into nitrogen oxide, which means that these vehicles do not meet the requirements to be classified as a vehicle with zero emissions, but research continues to succeed in this too. We will come to this later and explain how to work with this. Also, within the other sector of heavy vehicles, research is being conducted into using hydrogen as fuel for the already existing internal combustion engines. Long-distance traders that have been completely dependent on fossil fuels soon won't have to be. 

Already today, in theory, you can drive completely fossil-free and only use hydrogen as fuel. The engines have proven to work at least as well on hydrogen as on diesel, and the engine output, torque and fuel efficiency are just as good as before, some developing companies in the fuel injection fields even claim that their product puts out higher figures on both the effect and the torque.   Furthermore, the problems that electric car owners have with regard to charging stations and the time it takes to charge are completely avoided, because time is precious in this transport sector.

In shipping, it is the same development, in addition, here you will reach an even greater environmental goal since there are no restrictions on the fuel that is used, there is also no purification of what comes out, several shipping companies are already testing hydrogen today.

Aviation is also developing alternative sources of propulsion for aircrafts, and one alternative is hydrogen. It has recently made successful attempts at flights with hydrogen, it was in this case with a mixture of another fuel called electrofuel. Electrofuel is a collective name for carbon-containing fuels produced by electricity as the main energy source. The carbon atoms in the fuel come from carbon dioxide collected from the air, the sea or from fuel gasses from power plants, you can call it a form of carbon dioxide recycling.

Space shuttles have also used hydrogen but then in liquid form, together with oxygen also in liquid form. The tanks were 15 stories high and held 530,000 liters of liquid oxygen and 1.5 million liters of liquid hydrogen. These are gasified in a combustion chamber and provide propulsion for the rocket. All this amount of fuel was used up in 8 minutes and 20 seconds.[1]

 

In short, it can be stated that the fuel hydrogen can definitely be used in more or less all types of vehicles and crafts. However, it seems that development has not really taken off in the passenger car sector, at least not yet today, but there are prototypes that appear here and there from various manufacturers around the World. 


[1](KSC, n.d.)


[1](Office of Energy Efficiency & Renewable Energy, 2019)


[1]Kumar (2016)