Navy plans to make jet fuel from sea water

[KitemanSA]

PS: I never argued is reaction NO+NH3=> N2+ H2O exo or endo, stating that is less significant for energy balance and therefore less interesting for me at this (current) level of discussion.

]But I am not still not catching up about your belief that injection of ammonia for reduction of NOx emission is exothermic.

I suppose this could just be a language issue, but it could be that yet again "Joey the jeneous" is changing toons when demonstrated he is yet again WRONG.

Yes, I am still not catching up about your belief that this is exothermic reaction and never argued and am not arguing even now.
As I am still stating that this reaction is less significant for energy balance.
You have about 0.1% (about 1000 ppm) by mass of NOx in exhaust gas. What improvement in efficiency can give reaction decreasing this number even if that is exothermic?

I never stated or implied any condition where adding ammonia to exhaust would increase the output of an engine. That was your contention, not mine. I merely stated that I believed the reaction was exothermic. It is nice to have my belief validated.

[Joseph Chikva]

That relates to Mr. Kiteman's proposal to use the so called "Selective catalytic reduction" for decreasing of NOx level in any type of fuel burning exhaust gas. Including fossil fuel, ammonia, hydrogen, etc. As NOx present anywhere where air as an oxidizer is used.

Not mine, but I could wish it were so.

http://www.amazon.com/BLUE-DEF-DIESEL-E ... rds=adblue

Certainly, not your idea.
But your interest to that is that reaction exo or endo means that you wish to gain more power from exhaust gas. This is quite logical wish. Please explain your interest.

And I asked how practical would to attach that device for injection of this fluid e.g. to iarcraft's nozzle?
As this topic's name is "Navy plans to make jet fuel from sea water".
Please, explain.

[Joseph Chikva]

I merely stated that I believed the reaction was exothermic. It is nice to have my belief validated.

By the person who was mistaken in 500 tymes in hydrogen molar mass?

[KitemanSA]

Replies in red.

That relates to Mr. Kiteman's proposal to use the so called "Selective catalytic reduction" for decreasing of NOx level in any type of fuel burning exhaust gas. Including fossil fuel, ammonia, hydrogen, etc. As NOx present anywhere where air as an oxidizer is used.

Not mine, but I could wish it were so.

http://www.amazon.com/BLUE-DEF-DIESEL-E ... rds=adblue

Certainly, not your idea.
But your interest to that is that reaction exo or endo means that you wish to gain more power from exhaust gas. Your reply here demonstrates conclusively that your English comprehension is too impaired to carry on a meaningful conversation. This is quite logical wish. Please explain your interest. I was answering Dan's question.

And I asked how practical would to attach that device for injection of this fluid e.g. to iarcraft's nozzle? Since I have repeatedly stated I was NOT talking about aircraft, by what twist of your demented imagination would you consider such an action?
As this topic's name is "Navy plans to make jet fuel from sea water".
Please, explain. READ my first post, and several other since. Like the article linked, I am talking about using ammonia for SHIPS.

[KitemanSA]

I merely stated that I believed the reaction was exothermic. It is nice to have my belief validated.

By the person who was mistaken in 500 tymes in hydrogen molar mass?

Was he talking gram-mole or kilogram-mole?

[Joseph Chikva]

Like the article linked, I am talking about using ammonia for SHIPS.[/color]

[/quote]
I understand that for ships. And after discussion are you still stating that your proposal makes sense?
As yesterday you cried something like "Help, anyone"

Can you today provide number on available space in carrier's size ships?
Can you provide number what electric power you need?
Can you provide number how much installed power you can fit on aircraft size ships, how big space is required for electrolize section, ammonia making section, air separation section and storage tank? As I proved you that your idea is worthless.
Are you not agree?

[Joseph Chikva]

I merely stated that I believed the reaction was exothermic. It is nice to have my belief validated.

By the person who was mistaken in 500 tymes in hydrogen molar mass?

Was he talking gram-mole or kilogram-mole?

Ask him yourself.

[Blankbeard]

I merely stated that I believed the reaction was exothermic. It is nice to have my belief validated.

By the person who was mistaken in 500 tymes in hydrogen molar mass?

Was he talking gram-mole or kilogram-mole?

No, he's correct. I made a silly mistake. SI units are KILOGRAM/mole but the common expression is GRAM/mole. I feel a bit stupid over that. I should have caught that mistake when I when through the second time.

Thank you for pointing that out, Joseph.

It should make a HUGE difference in the outcome but I was consistent. I built in a fudge factor of 20 in and I overestimated the volume of water by the same 1000 times. And I vastly underestimated how much you could fit on a single vessel. Still, you're going to need more power (in the very rough neighborhood of 3-5 GW electric and 10-15 GW Thermal) and will still have to increase the number of ships by at least a couple.

Even before this, I wasn't convinced it was actually workable. After correcting for my mistake, I'd say it's on the limits of plausibility. You could probably run it off from say four or five supertanker type hulls which have more usable internal space with a Gen IV/LFTR/Fusion reactor that can run the hydrogen production section at 800-900 Celcius.

Even so, this is on the limits of plausibility. Supertankers aren't exactly agile and they would be tempting targets. You'd still need smaller oilers (ammoniers?) to do the actual refueling. I think it would be more cost effective to do your fuel production on land and tank it out in small oilers.

Also, I noticed earlier you said jet fuel was a small part of fuel use. The links I posted earlier suggest it's actually more than half. Given that ammonia has only about 2/3 of the energy density of jet fuel, the loss in range (or increased requirements for drop tanks with corresponding drop in mission loadout) may be a deal breaker.

As always, I am not an expert. I make mistakes. This is opinion.

I think this is a cool idea, but I'm not sure it can be done effectively.

[Joseph Chikva]

No problem, Blankbeard.
All we can make mistakes.
Good luck,
Joseph

[Blankbeard]

A skilled engineer should know that fuels are exothermic.

Only when you have corresponding quantity of oxidizer. You can inject extra (above stechiometric ratio) fuel into a flame with reducing of temperature.
For example stechiometric ratio for gasoline/air is about 1:13.5 (by mass) and all extra quantity of fuel above this ratio will not be exothermic.

English is my fourth language and is not so good as I wish.

Irrelevant on the issue of oxidizer. Nitrogen oxides are the oxide. If they're not present, that reaction won't take place. That doesn't change the fact that the reaction is exothermic when it takes place.

On the english issue, understood. I didn't want to criticize you over a language issue.

For example stechiometric ratio for gasoline/air is about 1:13.5 (by mass) and all extra quantity of fuel above this ratio will not be exothermic.

This is wrong. Adding fuel beyond the stiochiometric ratio results in incomplete combustion and increased emissions. This is called running an engine rich and is used to control engine heat.

And the ratio for gas is 1:14.7 by mass (What else would it be? By volume? That's a huge number. Gas vs liquid) not 1:13.5

http://en.wikipedia.org/wiki/Air-fuel_ratio

[KitemanSA]

Like the article linked, I am talking about using ammonia for SHIPS.[/color]

I understand that for ships. And after discussion are you still stating that your proposal makes sense?
As yesterday you cried something like "Help, anyone"

Another example of your inability to read?

[Joseph Chikva]

A skilled engineer should know that fuels are exothermic.

Only when you have corresponding quantity of oxidizer. You can inject extra (above stechiometric ratio) fuel into a flame with reducing of temperature.
For example stechiometric ratio for gasoline/air is about 1:13.5 (by mass) and all extra quantity of fuel above this ratio will not be exothermic.

English is my fourth language and is not so good as I wish.

Irrelevant on the issue of oxidizer. Nitrogen oxides are the oxide. If they're not present, that reaction won't take place. That doesn't change the fact that the reaction is exothermic when it takes place.

On the english issue, understood. I didn't want to criticize you over a language issue.

For example stechiometric ratio for gasoline/air is about 1:13.5 (by mass) and all extra quantity of fuel above this ratio will not be exothermic.

This is wrong. Adding fuel beyond the stiochiometric ratio results in incomplete combustion and increased emissions. This is called running an engine rich and is used to control engine heat.

And the ratio for gas is 1:14.7 by mass (What else would it be? By volume? That's a huge number. Gas vs liquid) not 1:13.5

http://en.wikipedia.org/wiki/Air-fuel_ratio

Yes, nitrogen oxide is an oxide but reduction is a process in which nitrogen reduces its "valentity" (I do not know the proper English term) thus oxidizing hydrogen in ammonia molecule.
So, NOx there is oxidizer and NH3 is fuel.

Rich and poor mixes are the example when more oxidizer for poor mix would not provide more energy (lack of fuel) and more fuel would not also be exothermic when we have lack of oxidizer.
Regardless to what products we will get as result.

14.7 vs. 13.5? May be. This is the same order of magnitude and changes nothing.

[Blankbeard]

Yes, I aware with turbochargers. Also I aware with belt driven chargers (superchargers).

I didn't make the claim turbochargers were the only or even the best way to improve engine efficiency. I made the claim that turbocharging was an instance where adding energy to an exhaust stream was useful. You said there was no reason to do so.

Hehe, that "crazy" idea to get extra power from exhaust system follows from your smart "belief" that reduction reaction is exothermic.
If you did not think to get extra power, does not matter is that reaction exo or endo.

His smart belief was right. So was the crazy idea. And then you claimed you needed a bulky heat exchanger to use that energy on a jet engine. This is wrong. A turbocharger is one instance of a small device that utilizes exhaust heat to do useful work. An afterburner is another.

If you think that turbochargers improve efficiency in internal combustion engines because they take energy from exhaust gas, that's right. But not totally.
As more significant is dependence of engine's efficiency on compression ratio.

You are aware a forced induction engine (super/turbo -charged) usually run at a lower compression ratio than a normally aspirated version of the same engine, correct? Higher compression ratios are better but the increased fuel and higher air charge temperature make detonation and engine damage more likely. Intercoolers and water injection lower the charge temp and let you run at a better compression ratio. Computers can also detect when detonation is likely and adjust conditions to prevent it, allowing you to run a higher compression ratio without destroying your engine. Ford's Coyote engine runs at 11:1 NA. The Aluminator version recommended for forced induction runs at the same ratio but has a thousand dollar higher price tag due to internal strengthening.
(You can go FI on a stock engine cause they're strong and modern ECUs are pretty effective but you're going to risk your engine with too much boost. Safety factor and all)

I snipped the bit about superchargers because they don't have anything to do with claims I have made.

Engineering, my friend, is a permanent compromise between mutually exclusive things.
And your wish to use more energy loosing at this moment with exhaust gases does not mean that you able to propose technically attractive solution. For example, I doubt in your or Kiteman's such ability.
Without any offense too.

None taken. If you want to recover energy from an exhaust stream, turbochargers are the technically attractive solution. Heat exchangers work too if weight isn't an issue or the exhaust temperature is low.

And once again, here was talk about reduction of NOx, very common number of which is about 1000 ppm.

Wait. You're the engineer here. Why didn't you point out that ammonia combustion doesn't produce oxides of nitrogen under normal circumstances? The flame temperature is way below the decomposition point of N2.

If you wish to get more power from its reduction reaction - I wish you all the best.
Can you estimate an efficiency improvement - how much extra % can you get in the best case?
As this is a school grade task too.
Good luck in your homework.

Commercial turbocharged engines regularly exceed 75% increase in power for a tiny increase in weight. An ammonia afterburner could easily increase power by 50% or more. An ammonia rocket sent the X-15 to the highest speeds ever reached by a powered aircraft at the time.

Note: the drawing uploaded by me was related namely to "NOx Catalytic reduction" that was proposed by Kiteman. As I understand he strongly advocates this method. See the link in wiki from which that diagram was taken.

Then rather than arguing whether a reaction was exothermic or not or whether it's efficient to inject more ammonia into an exhaust stream you should have pointed out that burning ammonia doesn't produce NOx in amounts worth worrying about.

[KitemanSA]

Blankbeard,
You will soon detect that it doesn't matter what you say, you are always wrong in Joey's eyes. He will read something you write, add tonnes of excess, unrelated concepts springing solely from his imagination, and condemn you for "your" idea which is not yours at all.

Sometimes I wish he would stick to his first three languages and leave us in peace. (Sometimes = 99.99999% of the time?)

[Blankbeard]

But your interest to that is that reaction exo or endo means that you wish to gain more power from exhaust gas. This is quite logical wish. Please explain your interest.

No, whether the reaction is exothermic or not has to do with whether you can use it as an effective fuel or not. Extracting power from an exhaust stream is a side issue that, as far as I can tell, you brought up on page 3, post 7.

You pointed out an error of mine and I admitted to it. Now, I've pointed out an error of yours. Will you admit to it?

And I asked how practical would to attach that device for injection of this fluid e.g. to iarcraft's nozzle?

I don't think that has an answer because the whole discussion has been wrong. You don't need to reduce output of NOx in an ammonia burning engine normally because it doesn't produce much. Still, there are valid reasons to use excess fuel in an engine and under some circumstances it may be useful to use excess fuel to heat an exhaust stream.