Haber-Bosch-Verfahren / Die Ammoniaksynthese

Today we have already briefly mentioned the Haber

bosch

ammonia synthesis several times, but because it is so important and because you are also interested in it, we are now preparing a separate video. The Haber

bosch

ammonia synthesis was developed by Fritz Haber and Carl Bosch. These are them. Both players here also received the Nobel Prize in Chemistry for their synthesis, so it was quite an achievement, but what exactly happens and what conditions must prevail? The principle is that nitrogen molecules react with three times as many hydrogen molecules. to form two molecules of ammonia. Now it sounds like a real one.

But it's not like that? If, for example, you create hydrogen and introduce nitrogen to it, no ammonia is created, at least not under normal conditions. So they must have changed something. and first we look at a catalyst, that is, a substance that accelerates the reaction without being consumed and To do this, in the Haber Bosch process, iron oxide 23 is used, that is, Fe3 Fe4, a mixture of two iron oxides FMO and iron oxide 3 Fe2O3. Used. This is also called magnetite. To become active, hydrogen on the surface is later revealed to be the standard modification of pure iron, reducing service revealed as the actual catalyst of the reaction, but this reduction has nothing directly to do with the formation of ammonia. itself, it simply happens in parallel and prepares the catalyst, so to speak.

By definition, a catalyst does not change as a result of catalysis and the good thing is that the catalytic converter becomes more effective. the higher the temperature, it would be great to increase the temperature and then the reactions would develop faster. But from here we come to a problem and the second condition: the reaction is external in general, so energy is released and there Here we have an equilibrium reaction. When the temperature increases, the reaction takes place preferentially and consumes heat. But that would be the reverse reaction, so the hotter it gets, the more the equilibrium shifts to the left on the element side.

This means that we are faced with a dilemma: temperature too low so the equilibrium is good but the reaction is slow temperature too high here the reaction is fast but the equilibrium was allowed so they found a temperature of around 500 degrees Celsius at which Most of the ammonia is produced depending on the temperature and the catalyst used. But there is another way to influence the reaction, namely the pressure, which of course was also adjusted. Why does that help? Well, if the balanced reaction equation we have four gas particles on the side of the starting materials, on the other only two.

If the pressure now increases, the equilibrium shifts in such a way that it avoids the external force, that is, the concrete thing here is that it shifts towards the side of the smaller starting materials. volume, that is, to ammonia, so an impression of about 300 bar is created. How can we now clearly imagine the reaction of nitrogen obtained from air and hydrogen? The master is obtained from natural gas and reaches the catalyst. "Both are absorbed on the surface and then stored. Then the bonds between the molecules are broken because the addition weakens the bonds of the elementary molecules.

Now the nitrogen molecules can gradually react with the absorbing hydrogen molecules until they form ammonia. Then ammonia dissolves from the surface." "It is also said to defect and you get ammonia in the gas phase. This only works until an equilibrium of about 18 percent is reached. Now you just have to separate the gas mixture of nitrogen, hydrogen and york. This is This is achieved by cooling, since at 33 degrees Celsius below zero ammonia becomes liquid, the remaining gases, that is, nitrogen and hydrogen, are returned to the reaction vessel and can react there. That is why the process is also called cycle.

Until here the process itself. , but why does this production of ammonia occur? Great, in fact, so good that it deserves a Nobel Prize. This is because ammonia is used to produce fertilizers that contain nitrogen. At first no It sounds very exciting, but without the fertilizer that comes from this work, the world's population could not be fed, so a vital invention could lead to more important chemical discoveries. Here in our top 15, check it out if you liked the video , leave a like or a comment and be sure to check out your partner's other channels, his free internet tutoring, otherwise come on in and take care of yourself until then and ciao