Why not ammonia, NH3, as liquid fuel?

Discussion in 'Chemistry' started by Billy T, Feb 26, 2007.

  1. dixonmassey Valued Senior Member

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    So, what does it have to do with its feasibility as a magic fuel? BTW, zinc no more in just 30 years, no zinc catalysts - no massive production of ammonia as we know it.


    that was truly perceptive and ahead of the time.


    Ammonia powered car was made 27+ years ago, so I've read, ammonia is extremely toxic and corrosive. Ammonia car has NO chance to conquer the streets considering litigation possibilities. Heat of ammonia combustion is half of that for diesel. Sounds like a winner evil oil companies keep from eager plebeians.

    So does burning shit.


    First, you'll have to come up with the process transforming nonpolluting (are you crazy?) nuclear energy into ammonia. Good luck. Second genius, you should know that heat required for synthesis of substance X is equal to the heat of dissociation of that substance. Considering all kinds of energy loses and efficiency of the machinery involved, energy released by burning ammonia will unlikely cover even 50% of energy spent to manufacture it.

    Third, mankind doubled concentration of active nitrogen in the nitrogen cycle which does nasty things to all kind of rivers and estuaries, etc. Burning ammonia is a really smart idea to boost those imbalances.



    Please, call back when you invent iron based fuel cells or iron based catalysts for NH3 production. Until then ...

    The bottom line question, will ammonia engines save fossil fuel or accelerate its consumption. At this time the answer is obvious even for chemically challenged - NH3 substitution will accelerate depletion of oil, gas and rare metals.
     
    Last edited by a moderator: May 10, 2009
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  3. Trippy ALEA IACTA EST Staff Member

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    *** Moderator Note***
    I've removed some un-neccsarry, and unwanted name calling, if it continues, I'll start deleting posts and warning users.

    On a side note, and without the Moderator hat on, Arthur C Clarke proposed the idea of using Ammonia as a storage medium for Hydrogen in 2001 A Space Odyssey, and 2010 The Year we make Contact.

    The reason given, essentially is that the Ammonia has a better density - you can fit more Hydrogen into a tank the same size, than storing liquid hydrogen, it leaks slower, and is easier to maintain at an appropriate temperature.

    In 2010, the Chinese opt for a system that uses water, instead of Ammonia, because that means that they can land on Europa and refill their tanks, enabling them to take a much higher energy, and much more direct path to Jupiter.

    And finally, 2061 is (partially) set on a space liner that uses water as it's fuel source, essentially because it's more fun for the passengers, probably becasue its more widely available in the solar system, and can be used for more than one purpose (in the book, they wind up using one of the geysers from Halley's Comet to refill their tanks to make a rescue in the Jovian system).
     
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  5. Trippy ALEA IACTA EST Staff Member

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    Another point I would like to make is this.

    The point that adding additional Nitrogen to an already overloaded system leading to increased eutrophication of fresh water and marine environments was made, but, it occurs to me that the conditions under which nitrates may be converted back into ammonia are well known, so, does it not stand to reason that this perhaps represent a way of remediating some of the eutrophication.

    Observe.

    First, we can extract the Ammonia directly from the waterways, it's present in many water ways, especially where intensive dairying occurs, in concentrations between 0.1-1 ppm.
    Secondly, we can use anerobic metabolism to convert nitrates back into ammonia, and extract that directly from the water as well.

    This ammonia can then be stored, and removed from the environment from which it was extracted, broken down into Nitrogen and Hydrogen, the hydrogen used for power, the nitrogen discharged safely to the atmosphere.

    cif:
    \(C_6H_{12}O_6+3NO_3^-+3H_2O\to6HCO_3^-+3NH_4^+ \Delta G^0=-1796 kJ\)
     
    Last edited: May 10, 2009
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  7. Trippy ALEA IACTA EST Staff Member

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    I should also point out his paper:
    http://aiche.confex.com/aiche/2005/preliminaryprogram/abstract_25627.htm
    Which says that direct electrolysis of Ammonia into Nitrogen and Hydrogen consumes only 1.55 Wh/g of Hydrogen, where electrolysis of Water into Hydrogen and Oxygen consumes 33 Wh/g of Hydrogen.
    In otherwords, producing a Kilo of Hydrogen over the course of an hour consumes about the same energy as running a 1 bar heater for an hour and a half.
     
  8. Nasor Valued Senior Member

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    While I agree that there was name calling, I'm not sure it was unnecessary.
     
  9. Trippy ALEA IACTA EST Staff Member

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  10. rwendell Registered Member

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    Dixonmassey, rag dab it! Read the posts, especially mine at 05-08-09, 11:38 PM. Platinum is a dead end, but there are much cheaper catalysts in vast supply that are better than platinum. Read! Learn! Quit spewing out uninformed garbage! The Monash University discovery is just one of at least two alternatives to platinum in fuel cells.
     
  11. dixonmassey Valued Senior Member

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    The rule of a big thumb - NEVER trust a grant hunter, NEVER, even if it's an unrelated subject. Discovery you say, I know how hyping up works, let's wait for a REAL fuel cell made of something really inexhaustible , because it looks like we are heading into exciting times. Don't get so worked up over my posts, save that energy, you'll need it to beat crap out of Monash University researchers who got your hopes way too high, if they'll be around in 20 years

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  12. rwendell Registered Member

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    Way too cynical...

    dixonmassey, you're far to cynical for my taste. :bugeye: First, Monash U isn't the only breakthrough scenario for platinum substitutes. I guess you WANT platinum to be the only way to go so you can keep on saying fuel cells are no solution as long as you can possibly get away with repeating it? You make yourself right this way, of course, and can continue doing so until technology develops to the point you can't convince anyone else of it any longer.

    Making yourself right is not a very laudable goal, by the way. Try finding out what's actually going on as an at least slightly superior substitute. Maybe you could invoke a little historical memory to recall how just about every "sane" person in the world thought heavier-than-air flight was the pipe dream of Utopian fools? This mode of thought is highly counterproductive. It's fundamentally a can't-do attitude. Please forgive me for proposing that this isn't what the world needs right now.
     
  13. rwendell Registered Member

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    Going nuclear...

    Oh, and on another issue brought up by others in earlier posts, nuclear energy, even if it's theoretically ideal and totally clean fusion energy, is not a long-term solution. I realized this personally decades ago and people thought I was nuts. However, I recently read an article in a scientific journal that corroborated that thinking. It showed that with current economic growth estimates based on the usual, non-thinking, simplistic projections of economic growth from what we've already been doing, we will ruin the planet with straight thermal pollution even if we magically went carbon neutral overnight tonight.

    Given an unaltered albedo (which would take some serious geo-engineering to change) and the earth's rate of radiating energy back into space, pumping that much energy beyond what comes from the sun into the terrestrial environment will raise the equilibrium temperature enough to send all earthlings into oblivion in fairly short order. Even totally clean nuclear fusion energy is not a solution. This clearly implies that a fully sustainable solution cannot involve any energy that doesn't originate in the sun.
     
  14. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    From the context, I understand you mean increasing Earth's albedo cannot be done.

    That may be more feasible than you suggest by spraying ocean water into the air to form clouds, at least that has been proposed. (But not near night fall as that would retain IR.) Unfortunately, a much greater change in the albedo, in the wrong direction, is taking place in the arctic with the melting of polar ice. Also to some extent incomplete combustion (soot particles selling on high abeldo lands) are reducing the albedo too, but this is very complex as they can also increase cloud formation.
     
  15. Trippy ALEA IACTA EST Staff Member

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    Changing the earths albedo is another one of these large scale geo-engineering projects that I think is a bad idea.
     
  16. rwendell Registered Member

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    Geo-engineering

    Yes, Billy T and Trippy. Never said the albedo can't be changed; just that it takes some major geo-engineering. Most scientists consider that a last-ditch option. BUT, as Billy T says so well, we ARE doing some major geo-engineering...in roughly the same way a 3-year-old with matches might just re-engineer your house.

    "To be negative about the future you don't have to know anything. To be positive you have to know a great deal."
    - R.Buckminster Fuller

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  17. Trippy ALEA IACTA EST Staff Member

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    Yes, yes.
    I get all that, I understand completely what you're saying.

    My objection has entirely to do with possible versus probable outcomes.
    My objection has to do with commiting us to a long term solution that may have unexpected side effects.
    My objection has to do with an apparent lack of accurate knowledge.

    Yes, I get that we're currently undertaking a Geoengineering project in the sameway a three year old might undertake an engineering project with your house, and a box of matches (see my other posts over in earth science) HOWEVER I don't think that we should nececssarily be going out there and painting the planet white just yet.
     
  18. rwendell Registered Member

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    On the same page...

    Good, Trippy. So just so you know, we're on exactly the same page on these issues.

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    Never recommended geo-engineering. Unexpected consequences can be too easily overlooked and some could easily be irreversible. We're getting close enough to that already with our unwitting contributions to geo-engineering. I'm not at all in favor of adding to that with good intentions that go awry.
     
  19. Trippy ALEA IACTA EST Staff Member

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    Exactly, it's happened so many times before?
    Fuel additives leaching into ground water in california (I forget which one it was - supposed to replace lead.
    DDT.
    POP's.
    CFC's.
    To name a few examples, okay, they're not geoengineering projects gone wrong, however, unintended large scale environmental consequences.
     
  20. dixonmassey Valued Senior Member

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    There is a thin line between can do attitude and delusion. Besides "can do" attitude is a crock of BS in the first place. Most technological advances are OPPORTUNISTIC, they are NOT a result of "can do" chanting. "Can do", however, is always used by puppet controllers to keep status quo (i.e. to perpetuate the plunder of environment and labor to make a tiny minority truly blessed).

    Yup, the mind of a hairless monkey is truly unstoppable, boundless, majestic, holding mysteries of universe in its greasy gray matter. Is that so? Visit freaking Monash University and look in the eyes of the lab rats (human), you'll see the limits (if you don't see them yet). Does heavier than air airplanes prove warp drive, for example, or unified theory of everything? Common.

    Earth is finite, nonrenewable energy sources are limited in quantity, "renewable" energy consumption is limited by Earth heat balance. More efficient energy converters = higher per capita energy consumption = higher total energy consumption. What's the freaking point?

    A technological advance as a rule results in a HIGHER energy density of a product/action. Trucks versus rickshaws, spades versus tractors, automated car plants versus Ford's Highland park, and so on. Energy supplies are limited. Looks like a suicidal path. We really got to be sure warp drive is possible before beating in the "can do" drum.

    Without possibility of a warp drive (or without remaking societies, even more unrealistic) EVERY technological advance is just a step to our early grave. Did I mention First, Second laws of thermodynamics? Shall we try "can do" spirit on those two bastards first?

    Of course, all of the above has little to do with an engine working on NH3, a silly idea with marginal to nonexistent benefits (in the best case).
     
  21. rwendell Registered Member

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    Well, "can-do attitude" in the context I used it referred strictly to the idea of a hydrogen fuel cell without platinum. Is there something wrong with thinking that is a realistic possibility? Is that really just a pipe dream, or do you just want it to be? You sound more like a propagandist for the oil industry than a green energy supporter.

    More importantly, is there something wrong with deciding a priori that this ISN'T a possibility? My answer to the last question is an unqualified "yes". Motivation is absent when you've decided up front that something is impossible. So poop on that all you want, my friend, but only if, when it happens, you're willing to recycle your waste via your prolific mouth.

    By the way, unified field theory and the underlying assumption that all the fundamental fields can ultimately be explained as manifestations of a single underlying field represent ideas that have driven development of the most successful, comprehensively powerful theoretical framework in physics that can be found in any branch of science to date. After all, the essential purpose of ANY theory is to discover underlying principles that conceptually unify otherwise isolated data points and thereby allow us to project new data points that experiment accurately confirms. This whole approach to understanding implies an at least tacit if not explicit assumption that nature is fundamentally unified.

    The intellect and its ability to reason have practical value ONLY as they depart from what is ultimately subjective human experience and return to it successfully in their results. Reason has zero intrinsic value ultimately, unless it is based on unprovable axioms that derive from experimental evidence. Note the intimate relationship between the words "experiment" and "experience".

    Human experience is by definition ultimately subjective. Yet it by necessity must form the basis for all reason. Scientific method is ultimately nothing more than a method of reducing the social noise in the communication of human subjectivity with nature. We can use all the instrumentation we like, but ultimately the observer who reads the meter or whatever data source and interprets it is still using subjective experience at the end of the chain.

    Science uses experimental design (noise filtering) and replication (the redundancy necessary in any communications channel to reliably transfer useful information in a noisy environment) to provide what we label "objectivity". This directly implies that we can know nothing that is not a subjective impression, and that what we label as objective is actually no more than the communication of subjective human observation with nature via a social noise reduction technology that provides a superior degree of reliability. Scientists and the meta-science (underlying philosophical orientation) that guides their theoretical interpretations too often tacitly ignore what should be this simple, self-evident fact.
     
  22. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Certainly Earth is finite and all energy resources, renewable or not, are limited, but after those truths you are too general to be fully correct. For example, installation of typical photo-voltaic cell now probably does result in decrease in Earth's albedo (more solar heat absorbed) but this need not be the case. They could be designed to have high reflectivity for all wavelengths longer than those equal to the band gap energy. Only photons which have energy greater than the band gap can lift an electron from the valance band to the conduction band. Only those photons produce electrical output. In the case of silicon, (and the spectrum for the star we call the sun) these useful photons are only 22% of the solar energy. Thus in principle 78% of the solar energy could be reflected back into space. In most locations, this is a net negative heating of the Earth for each kWh produced and probably about neutral if located in a desert area (I don't remember the albedo of the typical desert, but doubt it is more than 0.78) In the case of wind power or tidal power it is surely always wrong as their energy will turn to heat and if the process has a detour thru electric power first then that is some fossil fuel not burned for energy. Thus your statement is usually very wrong as too general and for some renewable sources it is ALWAYS WRONG.

    Compared to burning coal for power, which typically generates two units of heat (not to mention the GHG trapping of solar heat) for every unit of electric energy produced. I cannot think of any renewable source that is not vastly superior when just considering the direct heat release effects. Perhaps you should not be so dogmatic with your ignorance?

    I doubt this, but it is not easy to demonstrate that it too is false. Certainly, the US energy use per capita is greater than when only Indians were living here so that supports your POV, however, I bet you are wrong with some of your examples. For example are you sure that moving a ton from A to B (say separated by 40 miles) takes less energy if done by rickshaw than if done by truck? Certainly, if done by train (steel wheel on steel rails are very efficient.) the extra food energy the rickshaw pullers would need is greater than the increment of energy in the diesel the train used for that ton. It is not the technology, but the vastly different life styles that make the typical American consume more energy than the Indians his civilization has displaced. Yes, it would be possible to return to that lower energy level per capita of hunting and gathering, but about 99.9% of Americans need to volunteer for executions first. Would you be one of them?

    No, it may be the best hope that a hydrogen economy is possible. For years I have noted in posts that the major oil companies have promoted H2 cars as a diversion from any serious efforts to reduce oil use. They (and I) were confident that the storage problems of H2 would make an H2 economy only a pipe dream, but with a lot of promotional effort they persuade many ignorant people that we need not worry about the excessive consumption of oil because H2 powered cars would soon be available. It now appears that via NH3, the storage problems may have a practical solution, especially as the vapor pressure of the very toxic gas can be so greatly reduced. See post with photo below of solid solution of NH3 being held in a hand for more details at:
    http://www.sciforums.com/showpost.php?p=2203128&postcount=52

    Danish Technical University, DTU, is developing: Amminex

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    “…ammonia-based solid-state hydrogen storage solution: a tablet that can be held in your hand. The tablet is a metal ammine complex that stores 9.1% hydrogen by weight in the form of ammonia absorbed efficiently in magnesium chloride: Mg(NH3)6Cl2. The storage is completely reversible
     
    Last edited by a moderator: May 17, 2009
  23. rwendell Registered Member

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    Amminex

    "Danish Technical University, DTU, is developing: Amminex"...Exactly, Billy T. That's precisely what I was trying to point everyone toward in my initial reference to Amminex, but was unable to post any links.
     

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