Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: smart on 28/08/2016 13:10:35

Title: What is a zeolite catalyst ?
Post by: smart on 28/08/2016 13:10:35
The synthesis of zeolites from coal fly ash could be used to develop high density jet fuels with low aromatics
concentration:

Quote
PRODUCTION OF HIGH DENSITY AVIATION FUELS
VIA NOVEL ZEOLITE CATALYST ROUTES
http://www.dtic.mil/dtic/tr/fulltext/u2/a216444.pdf

Aromatics concentrations must be less than 20 volume percent 2 because high aromatic fuels produce smoke which excessively heats jet engine components. There exists an added complication for military aircraft related to the visible contrail behind the plane, due to the smoke produced from the combustion of aromatics.

Title: Re: What is a zeolite catalyst ?
Post by: Bored chemist on 28/08/2016 13:55:36
Why do you ask about zeolites and then highlight a passage that essentially says "We don't want the enemy to see thick black soot trails behind our aircraft"?

Why not just search for what zeolite catalysts are?
https://en.wikipedia.org/wiki/Zeolite#Petrochemical_industry

Title: Re: What is a zeolite catalyst ?
Post by: smart on 28/08/2016 14:39:27
Why do you ask about zeolites and then highlight a passage that essentially says "We don't want the enemy to see thick black soot trails behind our aircraft"?

I certainly hope that the "enemy" is not humanity but rather a minority of corrupted sociopaths attempting to cover up their crimes as "geoengineering"..

Moreover, it is essential to characterize how theses advanced jet fuels produces "synthetic contrails" to provide evidences that clandestine geoengineering activity is based on advanced technology with potentially harmful effects on human health.
   
Title: Re: What is a zeolite catalyst ?
Post by: Bored chemist on 28/08/2016 15:00:22

Moreover, it is essential to characterize how theses advanced jet fuels produces "synthetic contrails"
 
Not really.
As the abstract says, the military have an interest in getting the stuff to burn cleanly.
So it will nearly all burn to CO2 and water.
Title: Re: What is a zeolite catalyst ?
Post by: smart on 31/08/2016 12:17:37
Could a zeolite catalyst oxidize aromatic hydrocarbons to an alcohol or a ketone?
Title: Re: What is a zeolite catalyst ?
Post by: Bored chemist on 31/08/2016 22:08:55
No
But, if you mean could a zeolite catalyse the oxidation of aromatic hydrocarbons to an alcohol or a ketone by air at high temperatures?

Then the answer is "probably".
There are lots of different zeolites so it's a bit like asking "Could a metal catalyse this oxidation?"
Yes, some metal under some condition would probably do it.

Why do you ask?
Title: Re: What is a zeolite catalyst ?
Post by: smart on 01/09/2016 18:16:54
No
But, if you mean could a zeolite catalyse the oxidation of aromatic hydrocarbons to an alcohol or a ketone by air at high temperatures?

Then the answer is "probably".
There are lots of different zeolites so it's a bit like asking "Could a metal catalyse this oxidation?"
Yes, some metal under some condition would probably do it.

Why do you ask?

Could a coal-based aluminosilicate catalyst produces a high density aerosol (aluminium oxide) under ambiant air when burned with kerosene jet fuel?

"chemtrails" are also called "warm contrails"?

Title: Re: What is a zeolite catalyst ?
Post by: chiralSPO on 01/09/2016 23:38:19
No
But, if you mean could a zeolite catalyse the oxidation of aromatic hydrocarbons to an alcohol or a ketone by air at high temperatures?

Then the answer is "probably".
There are lots of different zeolites so it's a bit like asking "Could a metal catalyse this oxidation?"
Yes, some metal under some condition would probably do it.

Why do you ask?

Could a coal-based aluminosilicate catalyst produces a high density aerosol (aluminium oxide) under ambiant air when burned with kerosene jet fuel?

"chemtrails" are also called "warm contrails"?

If an aluminosilicate catalyst is turning into an aluminum oxide aerosol, it is not a catalyst.
Title: Re: What is a zeolite catalyst ?
Post by: smart on 02/09/2016 11:44:19
No
But, if you mean could a zeolite catalyse the oxidation of aromatic hydrocarbons to an alcohol or a ketone by air at high temperatures?

Then the answer is "probably".
There are lots of different zeolites so it's a bit like asking "Could a metal catalyse this oxidation?"
Yes, some metal under some condition would probably do it.

Why do you ask?

Could a coal-based aluminosilicate catalyst produces a high density aerosol (aluminium oxide) under ambiant air when burned with kerosene jet fuel?

"chemtrails" are also called "warm contrails"?

If an aluminosilicate catalyst is turning into an aluminum oxide aerosol, it is not a catalyst.

could the kerosene-based hydrocarbon jet fuel produce a exothermic reaction with the zeolite catalyst: the vapor-phase oxidation of aluminosilicate powder will make a plume of aluminium oxide when burning hydrogen?

 
Title: Re: What is a zeolite catalyst ?
Post by: chiralSPO on 02/09/2016 14:31:40
could the kerosene-based hydrocarbon jet fuel produce a exothermic reaction with the zeolite catalyst: the vapor-phase oxidation of aluminosilicate powder will make a plume of aluminium oxide when burning hydrogen?

no
Title: Re: What is a zeolite catalyst ?
Post by: Bored chemist on 02/09/2016 18:48:45




could the kerosene-based hydrocarbon jet fuel produce a exothermic reaction with the zeolite catalyst: the vapor-phase oxidation of aluminosilicate powder will make a plume of aluminium oxide when burning hydrogen?
The answer to this bit is no
"could the kerosene-based hydrocarbon jet fuel produce a exothermic reaction with the zeolite catalyst"
The answer to this bit is no
" the vapor-phase oxidation of aluminosilicate powder"
And the answer to this bit is no
" make a plume of aluminium oxide when burning"

Stop posting gibberish. Either go and learn some basic science or just stop posting.
Title: Re: What is a zeolite catalyst ?
Post by: smart on 02/09/2016 20:28:52
All you can say is "no" without a valid explanation. At least explain why you think the vapor-phase oxidation of hydrocarbons could not yield aluminium oxide nanoparticles if using a zeolite catalyst.
Title: Re: What is a zeolite catalyst ?
Post by: evan_au on 03/09/2016 02:01:14
Quote from: tkadm30
At least explain why you think the vapor-phase oxidation of hydrocarbons could not yield aluminium oxide nanoparticles if using a zeolite catalyst.
The definition of a catalyst is a substance which promotes a chemical reaction, without being consumed by that reaction.

Hydrocarbons (at least the expensively refined ones used in jets) contain Hydrogen + Carbon =Hydrocarbon.
- Cheaper fuels (eg for shipping) contain some hydrocarbon compounds including the occasional sulphur, nitrogen or other trace elements.
- They do not contain aluminium to any significant extent.

So the only way you could end up with a plume of Aluminium Oxide is if you burnt the zeolite to produce Aluminium Oxide.
- If you burn it, it is being consumed, so it is not acting as a catalyst, by definition.

See: https://en.wikipedia.org/wiki/Catalysis
Title: Re: What is a zeolite catalyst ?
Post by: smart on 03/09/2016 11:51:01
Quote from: tkadm30
At least explain why you think the vapor-phase oxidation of hydrocarbons could not yield aluminium oxide nanoparticles if using a zeolite catalyst.
The definition of a catalyst is a substance which promotes a chemical reaction, without being consumed by that reaction.

Hydrocarbons (at least the expensively refined ones used in jets) contain Hydrogen + Carbon =Hydrocarbon.
- Cheaper fuels (eg for shipping) contain some hydrocarbon compounds including the occasional sulphur, nitrogen or other trace elements.
- They do not contain aluminium to any significant extent.

So the only way you could end up with a plume of Aluminium Oxide is if you burnt the zeolite to produce Aluminium Oxide.
- If you burn it, it is being consumed, so it is not acting as a catalyst, by definition.

See: https://en.wikipedia.org/wiki/Catalysis

Thanks for the info, evan.

1) Could the synthesis of zeolites and aluminium oxide hydrate from coal-based jet fuel (JP-900) be used to produce aluminium oxide nanoparticles?
2) Could you tell me more on the vapor-phase oxidation of alcohols and if hydrogenation of hydrocarbons result in smoke generation?
Title: Re: What is a zeolite catalyst ?
Post by: Bored chemist on 03/09/2016 15:33:03
All you can say is "no" without a valid explanation. At least explain why you think the vapor-phase oxidation of hydrocarbons could not yield aluminium oxide nanoparticles if using a zeolite catalyst.
No
It's not true to say that "all (I) can say is no".
That's all I did say because I wasn't going to waste my time explaining stuff to you because you are too lazy or dumb to research it for yourself.
The very simple answer is that hydrocarbons don't contain aluminium and so oxidising them can not give aluminium oxide.
All the elements apart from oxygen in zeolite catalysts are already fully oxidised and thus can not be oxidised to anything.
Why not go and learn some science?
Come to think of it, given that you ask stuff like
" Could the synthesis of zeolites and aluminium oxide hydrate from coal-based jet fuel (JP-900) be used to produce aluminium oxide nanoparticles? "
why don't you go and learn some logic?
Jet fuel doesn't have (more than tiny accidental traces of ) aluminium in it.
So you can not possibly synthesise zeolites or aluminium oxide hydrate from it.
Therefore you can't produce aluminium oxide nanoparticles from it.
Title: Re: What is a zeolite catalyst ?
Post by: smart on 04/09/2016 13:12:23
Quote
Aluminium should displace hydrogen from water because of its positive oxidation potential, but does not normally do so because of the protection by a surface layer of oxide. This oxide has the same density as the metallic aluminium, so it does not crack or wrinkle when it is formed, a lucky thing.
http://mysite.du.edu/~jcalvert/phys/alumin.htm

So, does this mean hydrated aluminium oxide can increase hydrothermal stability? How can the zsm-5 catalyst produces low aromatics/high density jet fuel from coal ?
Title: Re: What is a zeolite catalyst ?
Post by: Bored chemist on 04/09/2016 13:33:02
"So, does this mean hydrated aluminium oxide can increase hydrothermal stability?"
No

"How can the zsm-5 catalyst produces low aromatics/high density jet fuel from coal ?"
The simple answer is that, if you take straight distilled petroleum like fuels and heat them until they start to fall apart, then let the mixture of bits cool down they settle into different chemicals from what you started with.
The petroleum distillates will be largely long chain molecules. the products from smashing them and putting the bits together are branched chains so they take up a bit less space .
That lets you get more weight of fuel into a given size of tank.

The trick with the zeolite catalysts is that they provide a "framework" for the  bits to reassemble onto which favours the production of the sorts of molecules you want (aromatics and branched chains).They also provide strongly acid sites that help break up the incoming hydrocarbons.

Title: Re: What is a zeolite catalyst ?
Post by: smart on 06/09/2016 11:15:34
Since alcohols and phenols can be alkylated to alkyl ethers, could the vapor phase alkylation of hydrocarbons yield a alkene?

https://en.wikipedia.org/wiki/Alkylation#Electrophilic_alkylating_agents

https://en.wikipedia.org/wiki/Alkene
Title: Re: What is a zeolite catalyst ?
Post by: smart on 06/09/2016 11:52:56
Vapor phase alkylation in presence of crystalline aluminosilicate catalyst: https://www.google.ch/patents/US3755483

Is methylcyclohexane an alkylaromatic (saturated) hydrocarbon ?
Title: Re: What is a zeolite catalyst ?
Post by: Bored chemist on 06/09/2016 21:21:23
This
"Since alcohols and phenols can be alkylated to alkyl ethers, could the vapor phase alkylation of hydrocarbons yield a alkene? "
is like asking "since wood can be made into tables, would burning oil make smoke?"

"since wood can be made into tables"
Well, OK it can.
"would burning oil make smoke?"
well, it might, but it has nothing to do with the first bit.

"Since alcohols and phenols can be alkylated to alkyl ethers,"
Well OK they can
"could the vapor phase alkylation of hydrocarbons yield a alkene? "
Yes, it can (as long as the hydrocarbon you started with was an alkene, but even that doesn't guarantee it)
 but it has nothing to do with the first bit.



"Is methylcyclohexane an alkylaromatic (saturated) hydrocarbon ?"
It is impossible for an aromatic hydrocarbon to be saturated.

Why not go and learn some science?

https://www.khanacademy.org/science/organic-chemistry
Title: Re: What is a zeolite catalyst ?
Post by: chiralSPO on 06/09/2016 21:33:48
This
"Since alcohols and phenols can be alkylated to alkyl ethers, could the vapor phase alkylation of hydrocarbons yield a alkene? "
is like asking "since wood can be made into tables, would burning oil make smoke?"

"since wood can be made into tables"
Well, OK it can.
"would burning oil make smoke?"
well, it might, but it has nothing to do with the first bit.

"Since alcohols and phenols can be alkylated to alkyl ethers,"
Well OK they can
"could the vapor phase alkylation of hydrocarbons yield a alkene? "
Yes, it can (as long as the hydrocarbon you started with was an alkene, but even that doesn't guarantee it)
 but it has nothing to do with the first bit.

amen!

"Is methylcyclohexane an alkylaromatic (saturated) hydrocarbon ?"
It is impossible for an aromatic hydrocarbon to be saturated.

For the record, methylcyclohexane is a saturated (unless you count the ring as an unsaturation). It is not aromatic, and, as pointed out by Bored, aromatic hydrocarbons and saturated hydrocarbons are exclusive groups. One must be either or neither, but cannot be both.
Title: Re: What is a zeolite catalyst ?
Post by: smart on 07/09/2016 11:46:06
Is it possible to convert long-chains alcohols (aromatics) to an electrophilic alkene ??

 
Title: Re: What is a zeolite catalyst ?
Post by: chiralSPO on 07/09/2016 12:34:32
long chain alcohols are also NOT aromatics
Title: Re: What is a zeolite catalyst ?
Post by: smart on 07/09/2016 12:54:03
Quote from: chiralSPO
long chain alcohols are also NOT aromatics

Then, what is a alkyl aromatic hydrocarbon?
Title: Re: What is a zeolite catalyst ?
Post by: chiralSPO on 07/09/2016 16:15:45
Quote from: chiralSPO
long chain alcohols are also NOT aromatics

Then, what is a alkyl aromatic hydrocarbon?

I have never heard the term before, but presumably it would be intended to mean hydrocarbons that contain both aromatic and aliphatic components. For instance, toluene, ethylbenzene, xylenes, mesitylene, tri-tert-butyl benzene, 2-octylnaphthalene etc.

some definitions:

hydrocarbon--a compound that is composed only of hydrogen and carbon (so no ethers, alcohols, esters amines etc.)

aliphatic (alkyl): part of a molecule composed of one or more tetrahedral (sp3-hybridized) carbons connected together as a chain, branched chain, ring, multiple rings, or combination of rings and chains.

aromatic (aryl): part of a molecule composed of at least 3 trigonal (sp2-hybridized) carbons connected together as a ring or multiple rings such that the pi system has 4n+2 electrons in it.
Title: Re: What is a zeolite catalyst ?
Post by: Bored chemist on 07/09/2016 21:03:30
Is it possible to convert long-chains alcohols (aromatics) to an electrophilic alkene ??

https://www.khanacademy.org/science/organic-chemistry
Title: Re: What is a zeolite catalyst ?
Post by: smart on 08/09/2016 12:15:25
Quote from: chiralSPO
long chain alcohols are also NOT aromatics

Then, what is a alkyl aromatic hydrocarbon?

I have never heard the term before, but presumably it would be intended to mean hydrocarbons that contain both aromatic and aliphatic components. For instance, toluene, ethylbenzene, xylenes, mesitylene, tri-tert-butyl benzene, 2-octylnaphthalene etc.

Thanks for this info.

1) So does a zeolite-based catalytic vapor-phase alkylation of benzene (alkyl) produce ethylbenzene ?
2) What chemical reaction can possibly yield "alkyl polycyclic aromatic hydrocarbons" in the atmosphere?
 
3) Can you explain what is a (aluminium) halide ?

Thx.
Title: Re: What is a zeolite catalyst ?
Post by: chiralSPO on 08/09/2016 12:58:11
Thanks for this info.

1) So does a zeolite-based catalytic vapor-phase alkylation of benzene (alkyl) produce ethylbenzene ?
2) What chemical reaction can possibly yield "alkyl polycyclic aromatic hydrocarbons" in the atmosphere?
 
3) Can you explain what is a (aluminium) halide ?

Thx.

You're welcome.

1) Yes, it is possible for zeolites to catalyze the formation of ethylbenzene and related compounds from benzene and sources of alkayl substituents.

2) I am not entirely sure about the alkyl part, but certainly incomplete combustion of hydrocarbons is known to produce polycyclic aromatic hydrocarbons.

3) a halide is any halogen (fluorine, chlorine, bromine or iodine) with a charge of negative one (fluoride, chloride, bromide or iodide). So an example of an aluminum halide is aluminum chloride. While aluminum halides might be important for the synthesis of zeolite catalysts (I assume this is where the question comes from), it is important to note that catalysts are not consumed during the course of the reaction, so it is unlikely that the products of zeolite catalysis contain any significant amount of zeolite or zeolite components, especially if the products are then going to be fed into a jet engine (if there were any aluminum compounds in jet fuel, it would almost certainly form aluminum oxide junk inside the jet engine, and ruin the engine after only a short period of use, which would like be very expensive, if not dangerous to those in an under the aircraft)