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Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: fidu13 on December 01, 2023, 04:30:53 AM

Title: Chemical reactions during the synthesis of synthetic Ammonia using Strotium
Post by: fidu13 on December 01, 2023, 04:30:53 AM
Hei everyone :)

I am investigating a possible route of synthetic ammonia production using strotium and would like to simulate this using Cantera. As I understand it, I need to create the mechanism file for this reaction, which I am currently struggling with. I would like to investigate the following main reactions:

Nitration :
2 Sr + N2  ::equil:: 2 SrN(s)
Hydronation:
2 SrN(s) 2 3H2  ::equil:: 2 Sr + 2 NH3
I started to put my mechanismus file together out of different sources (https://github.com/jiweiqi/CollectionOfMechanisms/tree/master/Nitrogen) but I am still missing any information about any reaction involving  Strontium. Where could I find such information? Is it possible to derive such information from other reaction involving other metals such as Ni, Al, Mg and Fe? Or is there anywhere a large libary/summary in a book I am not aware of?

I very much appricate any comment and help you are able to give me :)

Best,
David Kaeser
Title: Re: Chemical reactions during the synthesis of synthetic Ammonia using Strotium
Post by: Hunter2 on December 01, 2023, 01:46:24 PM
First the chemical equation is wrong.
Why using Strontium. Hydrogen will not able to react. But water would do.
Title: Re: Chemical reactions during the synthesis of synthetic Ammonia using Strotium
Post by: fidu13 on December 04, 2023, 10:10:51 AM
Dear Hunter2

Sorry for the wrong equation, now it should be correct in my opinion:
Nitration :
2 Sr + N2  ::equil:: 2 SrN(s)
Hydronation:
2 SrN(s) + 3H2  ::equil:: 2 Sr + 2 NH3

I am investigating sustainable ways of producing synthetic ammonia using thermochemical processes. Can I ask why you suspect that hydrogen will not be able to react? The reason why I want to use Strotium is that it has been shown in experiments to preform good in this reaction in low pressure regiem. Also the reaction has nitration and hydronation regimes which are seperated by temeperatures.
Title: Re: Chemical reactions during the synthesis of synthetic Ammonia using Strotium
Post by: Corribus on December 04, 2023, 10:42:10 AM
Unclear what information you are looking for. What does " any information about any reaction involving  Strontium" mean? That's incredibly vague.
Title: Re: Chemical reactions during the synthesis of synthetic Ammonia using Strotium
Post by: fidu13 on December 04, 2023, 10:57:35 AM
Dear Corribus,

Thanks for the question. I am looking to complete my mechanism file to us it in Cantera as an input file for my reaction. Similiar to those files here (https://github.com/jiweiqi/CollectionOfMechanisms/tree/master/Nitrogen), just with the added information for the Strontium reaction.

This would mean the activation energy and the Arrenius constants of all possible/likely reaction of Strontium with O, H, N and Ar. Here, Strontium would we in a solid form at the begining of the reaction and everything in gaseos form. I am struggling currently with two tasks:


I hope this clarifies my problem a bit more :) Thanks for the help !
Title: Re: Chemical reactions during the synthesis of synthetic Ammonia using Strotium
Post by: Hunter2 on December 04, 2023, 12:11:52 PM
Dear Hunter2

Sorry for the wrong equation, now it should be correct in my opinion:
Nitration :
2 Sr + N2  ::equil:: 2 SrN(s)
Hydronation:
2 SrN(s) + 3H2  ::equil:: 2 Sr + 2 NH3

I am investigating sustainable ways of producing synthetic ammonia using thermochemical processes. Can I ask why you suspect that hydrogen will not be able to react? The reason why I want to use Strotium is that it has been shown in experiments to preform good in this reaction in low pressure regiem. Also the reaction has nitration and hydronation regimes which are seperated by temeperatures.
The equation is still wrong
In which group do you find strontium and in which group nitrogen?
Title: Re: Chemical reactions during the synthesis of synthetic Ammonia using Strotium
Post by: fidu13 on December 05, 2023, 04:11:13 AM
Dear Hunter2

Sorry for the wrong equation, now it should be correct in my opinion:
Nitration :
2 Sr + N2  ::equil:: 2 SrN(s)
Hydronation:
2 SrN(s) + 3H2  ::equil:: 2 Sr + 2 NH3



I am investigating sustainable ways of producing synthetic ammonia using thermochemical processes. Can I ask why you suspect that hydrogen will not be able to react? The reason why I want to use Strotium is that it has been shown in experiments to preform good in this reaction in low pressure regiem. Also the reaction has nitration and hydronation regimes which are seperated by temeperatures.
The equation is still wrong
In which group do you find strontium and in which group nitrogen?

Thanks for pointing out the error in my equation, you were absolutly right it did not write down the correct chemical reaction. Sorry for that. I meant the following two reactions:
Nitration :
2 SrH2 + 0.5 N2  ::equil::  Sr2N + 2 H2
Hydronation:
Sr2N + 3.5 H2  ::equil:: 2 SrH2 + NH3
Title: Re: Chemical reactions during the synthesis of synthetic Ammonia using Strotium
Post by: Hunter2 on December 05, 2023, 04:31:31 AM
They are still wrong

It's 3 Sr +  N2 => Sr3N2

To develop ammonia it's in my knowledge only possible with water


Sr3N2 + 6 H2O => 3 Sr(OH)2 + 2 NH3

Title: Re: Chemical reactions during the synthesis of synthetic Ammonia using Strotium
Post by: fidu13 on December 05, 2023, 10:17:34 AM
They are still wrong

It's 3 Sr +  N2 => Sr3N2

To develop ammonia it's in my knowledge only possible with water


Sr3N2 + 6 H2O => 3 Sr(OH)2 + 2 NH3

Thanks for your reply and your help. In my understanding it should be also be possible with the above written reactions. May I ask why this equation are in your opinion wrong? And is there a way to derive all possible pathways and species which could occur from a set number of elements? Sorry if this is a dumm question, my background is mechanical and not chemical engineering....:)
Title: Re: Chemical reactions during the synthesis of synthetic Ammonia using Strotium
Post by: Hunter2 on December 05, 2023, 10:22:52 AM
Check a periodic system table of elements.
Look up Strontium

It is in 2nd. Group. It can only Sr2+ in compound.

Nitrogen is in 5th. Group. As anion it can only 8-5 = 3 as N3-

So if you want combime both its only possible as Sr3N2

3*(+2) + 2*(-3) =0
Title: Re: Chemical reactions during the synthesis of synthetic Ammonia using Strotium
Post by: Borek on December 05, 2023, 01:51:07 PM
In my understanding it should be also be possible with the above written reactions.

Just because you can write a reaction equation and balance it, doesn't mean substances will react. Actually finding out which reactions can occur and in what conditions is what most of the chemistry is about. Absolute minimum is some kind of chemistry 101 course, that will give you some basic understanding of what is possible and what is unlikely.
Title: Re: Chemical reactions during the synthesis of synthetic Ammonia using Strotium
Post by: fidu13 on December 06, 2023, 03:51:09 AM
Check a periodic system table of elements.
Look up Strontium

It is in 2nd. Group. It can only Sr2+ in compound.

Nitrogen is in 5th. Group. As anion it can only 8-5 = 3 as N3-

So if you want combime both its only possible as Sr3N2

3*(+2) + 2*(-3) =0
Ok thanks. I understand that the ideal and stable constilulation would like to represent a state of an ideal gas. But other constilation do appear as well in reaction due to the Gibbs energy as I understand it, such as Sr2N and so on under specific conditions. Shouldn't there be a way to figure out all possible reaction based on the entropy and enthalpie? And is there maybe an list, table or programm out there which has already summarized all possibility based on temperature or so and the specific elements involved? Or do I misunderstand here some basics?
Title: Re: Chemical reactions during the synthesis of synthetic Ammonia using Strotium
Post by: fidu13 on December 06, 2023, 03:57:42 AM
In my understanding it should be also be possible with the above written reactions.

Just because you can write a reaction equation and balance it, doesn't mean substances will react. Actually finding out which reactions can occur and in what conditions is what most of the chemistry is about. Absolute minimum is some kind of chemistry 101 course, that will give you some basic understanding of what is possible and what is unlikely.

Thanks for the reply. I absolutly agree, that's why I would like to build on already known reactions. I would of course love to find some literature explaining it as well as listing possible reactions. If this is not possible I would like to build on other reaction involving abmentioned metals in order to derive somewhat the behavior of Sr instead of the metal. Would something like that be feasible? And is there a way to derive kinetics of the reaction based on known values such as enthalpie and entropy?