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New Process Promises Ammonia From Air, Water, and Sunlight
The synthesis of ammonia is one of the globe's most significant industrial applications of chemistry. PhysOrg reports the publication in the August issue of Science (sadly, article is paywalled) the description of a low-energy process to syntheize ammonia for fertilizer using just air, water, and sunlight, by zapping with electricity water bubbling through a matrix of iron oxide, and sodium and potassium hyroxide. Electricity isn't free, though — "Low energy" in this case means two-thirds the energy cost of the long-in-use Haber-Bosch process. Researcher Stuart Licht is getting some of the energy to run this reaction from a high-efficiency solar cell he's created, which creates hydrogen as a byproduct.
Along with the elimination of the need to produce hydrogen from natural gas, the overall emissions are reduced quite significantly. The whole process also takes place at milder conditions, not requiring 450C and 200 times atmospheric pressure as the Haber-Bosch process does. ... But even with Licht's method, [University of Bristol electrochemistry professor David] Fermin points out that we are far away from being able to replicate nature's efficiency at converting nitrogen from the air to useful chemicals, which is done by nitrogen-fixing bacteria. "What is truly remarkable is that nature does it incredibly efficiently at low-temperature," Fermin added.
And yet, if something more efficient can replace the Haber-Bosch process, it would lower the energy input of the production of one of the worlds most important chemicals and lead to a notable reduction in global CO2 emissions.
so we don't need to mine asteroids or comets or whatever.
Then we can eliminate big oil from ethanol, someday in the far future when I can put ethanol in my hovercar.
This tech combined with the ammonia=>hydrogen tech mentioned here http://www.engadget.com/2014/06/27/hydrogen-fuel-cell-breakthrough-ammonia/ could mean cheaper/safer/easier hydrogen for all sorts of uses including fuel cells for homes and hydrogen fuel stations for cars
How about we reuse all the fixed nitrogen we already made instead? Right now water in Toledo, Ohio is undrinkable because of algae blooms in Lake Eerie. I'm sure we use a lot of energy in the Haber process, but I think that's a trivial concern compared to the environmental problems we can cause if we keep pumping organic nitrogen into the environment. It could turn out to be a very very bad thing to do overall. I think we'd be way better off if we reduced ammonia production, rather than switching to a more efficient way to make ammonia. I'm all for innovation generally, but to me, this idea reeks.
You can help. Off yourself. Now git.
Fuck systemd. Fuck Redhat. Fuck Soylent, too. Wait, scratch the last one.
Something not mentioned here is that ammonia is suitable as a fuel in internal combustion engines. Ammonia is liquid under modest pressures (like propane), is easily transported, and will burn inside an engine.
If we made ammonia out of nitrogen and water vapor, then it would become nitrogen and water vapor again when burned. It's a closed cycle that would not alter the composition of the atmosphere at all.
It probably wouldn't be suitable as a fuel for your car, because of safety issues (if you hammered a hole in the fuel tank, the fuel inside would flash boil and could shoot out into your eyes causing a chemical burn). However it would probably be fine for trains, airplanes, ships, and so on, where special handling procedures could be enforced and people could be required to wear goggles before working on the fuel tank.
While it is theoretically more energy efficient to get our hydrogen from electrolysis than from methane, we mostly don't do so. Why? Because we can skip the whole burning fuels to create electricity steps, and go directly to making hydrogen. If we count the inefficiency of creating electricity then electrolytic efficiency decreases substantially.
This new method uses electrolysis to generate a mixture of ammonia and hydrogen. This will likely be very useful in the future as solar and wind become widely deployed, and the price of fossil fuels increases. It might also be useful for space colonization. Overall, I think for once the editors have given us something that won't be vaporware, even if it likely won't be used for quite a while.
Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
Here's some background on the Bosch Haber process.
Whether a reaction will occur is based on whether energy is required and whether the reaction increases entropy. In the case of nitrogen+hydrogen => ammonia, the reaction is both exothermic and increases entropy at room temperature and pressure. If one could somehow ignite the process it would be self-sustaining.
The problem is, to ignite the reaction you first need to break N2 molecules into individual N atoms, and this requires a great deal of initial energy which is regained in subsequent steps. Something like 7eV per molecule to break them apart. The molecules in normal air have a bell-curve spread of energies, but very few of them reach energies this high: the reaction happens at room temperature, but very *very* slowly. A handful of molecules per second will react.
To get around this you can raise the temperature, increasing the probability that molecules will have enough energy to break apart. The entropy produced is inversely proportional to temperature, so when you start to have N2 molecules with enough energy to break apart, the reaction is no longer favored because it would result in an entropy decrease.
Since 4 moles of reactants result in 1 mole of product, increasing the pressure of the reactants will tend to favor the products, so you can use this to offset the deficit in entropy.
The Bosch-Haber process tries to find a "sweet spot" by increasing the temperature to get a reasonable number of N2 molecules to break apart, and high pressure to make the process favor the products.
At 200 ATM and 400 degrees, the yield is 15% (!).
Reaction vessels for this pressure and temperature are expensive, and the process requires multiple cycles of compression, decompression, removal of ammonia, and recompression. This takes a *lot* of energy and uses *very* expensive compressors which wear out over time and have to be replaced.
I haven't read the paywalled article yet, but if I'm understanding the abstract, they are breaking apart the nitrogen electrochemically. Just as running a current through molten NaCl will break it into atomic sodium and chlorine, running a current through nitrogen dissolved in KOH and NaOH breaks it apart and the reaction then proceeds at normal conditions. The reaction also supplies its own hydrogen by breaking apart water.
Much of the "green revolution" is due to the use of nitrate fertilizers, and the source material is finite: guano from Peru, for example.
If this process is as efficient as the abstract suggests and can be industrialized, it would be *huge*. It would give us an essentially infinite source of nitrogen-based fertilizer and reduce the worldwide consumption of energy by a couple of percent.
Coupled with a source of renewable energy, it would mean that the world could sustain its food production at current levels indefinitely.
This could be really, *really* big news.
Still here, wasting food and oxygen, or it is just (say) brown people in far away countries unlike you that are useless?
http://m.earth.org.uk/
That's about as interesting as a police chase in a Geo Metro.
Just the ones that refuse to become members of VEHMT, easily spotted when they go "I wanna be a grandparent!"
So, how does this process compare economically to just growing nitrogen-fixing bacteria?
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
billions of useless mouths
If you want to reduce the population, feel free to start by offing yourself, Adolf.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
"Not me, of course. I mean those other useless people." - Suiggy
Before I get slammed by a P-Chem major, here's what's really going on with the entropy.
The reaction is exothermic, and this release of heat increases the entropy of the universe. At the same time, 4 atoms of source become 1 atom of product, so this aspect of the reaction *decreases* the entropy of the universe. (There's more ways that 4 atoms can be arranged in a box than there is to arrange 1 atom.)
At room temperature, the entropy increase from the release of heat is greater than the entropy decrease from the reduction in states, so the reaction is favored.
The entropy from the release of heat is inversely proportional to temperature. Double the [absolute] temperature and you halve the increase in entropy from the release of heat. With higher temperatures, the entropy increase from "release of heat" is smaller than the entropy decrease from "change of states", the total change of entropy is negative, and the reaction is no longer favored.
I wrote a simpler/shorter explanation to avoid losing sight of the main point.
It's Science. Accessible through any respectable library.
After someone's worked out a decent design for a pilot plant for the process that question will look a lot less like "I can't buy it at Walmart NOW? Then why waste my time?". For the moment it's just as irrelevant and likely to get at best polite answers from people attempting not to be patronising, although that's going to leave people unaware of how stupid such questions are very early in development of a new technology so I think it's better to be blunt.
"by zapping with electricity water bubbling through a matrix of iron oxide" should say "by zapping water bubbling through a matrix of iron oxide, with electricity".
Idiots.
Would be develop a way to make air, water, and sunlight into petroleum without needing all the time it takes nature to do the same thing.
Did you know 80 to 90% of the moderators on slashdot wouldn't recognize a troll even if one dragged them under a bridge.
I was referring to how the above poster can find out about the relative danger of propane and ammonia and get some real understanding. Got it now?
And yes, I DO know what the article is about and know far more about how much effort is required to make ammonia using current methods than I ever wanted to know (around 1999 I spent about six weeks working all over a fertilizer plant during a shutdown including inside a lot of vessels - and I did some other stuff there at other times). This new process does sound very interesting.
When I hear about clever-but low energy processes that have low yield because -- and only because -- the scientists feel the need toss a stock photo of a windmill or solar cell into the paper to trigger that warm fuzzy feeling, I think to myself, "How cute."
Decades of cuteness now. It's not cute any more.
The world needs less cuteness and more large scale thinking. Gigawatts not milliwatts. We also need to get into reverse osmosis in a big way, so we can start to manufacture fresh water from salt and pipe it inland. This requires massive amounts of energy.
Real Humans do not need to wait for rain, real humans need not wait for oil and gas to diminish in order to achieve the next step. Real humans better wake up and resume the industrial revolution. We are smart enough to keep it clean.
Follow us down the rabbit hole...
<blink>down the rabbit hole</blink>
I have a device that produces ammonia from water and air already. It's called a "cat".
This is a first step. Ten years from now our cars will run on synthetic gasoline, created from CO2, H2O and electricity from sunlight.
no, I don't have a sig
While anhydrous (dry) ammonia gas is lighter than air, will rise in dry air, and will dissipate. However, in the presence of moisture (such as high relative humidity), the liquefied anhydrous ammonia gas immediately forms heavier-than-air compounds that roll along the ground smothering and killing (ammonia compounds are strongly basic) most anything in their path.
The Houston Ammonia Truck Disaster 11976.
Scroll down and read what Mike Read says about it - he was in the Houston Post newspaper building when it happened. The occupants of the Houston Post newspaper building saw the ammonia gas cloud unfold and roll toward their office-and-printing building near the freeway site of the accident. Luckily someone in the building had the wherewithal to shut off the air-conditioning and air circulation system and those inside remained unhurt as the cloud enveloped the building and then slowly dissipated. During the following days the grass around the Post building died and turned black. Many died and many were injured.
For decades the EPA has limited use of ammonia inside heavily-populated areas for good reason.
Russia has been using natural gas in efforts to economically blackmail various parts of Europe for a while now.
One of the effects of this is to cause prices of fertilizer and as a result grain production and food costs in Eastern Europe to vary quite a bit depending on the political situation. This innovation would help considerably.
Another nice aspect of this is that China is using a lot of coal in fertilizer production because for them it's a cheaper source of hydrogen than natural gas. This would help China reduce CO2 emissions quite a bit.
Grandparent is wrong about CUTE solar. TFA was about an invention by the same people who invented a kind of solar cell and the grandparent naively thought that it wasn't an opportunity to show off their other tangentially related invention... it was only about being "cute."
Solar is not too expensive and it is extremely reliable!
1) Solar costs less than nuclear. It's upfront cost is high (like nuclear) but it has zero fuel costs for it's lifespan unlike everything else except wind and hydro. (Nuclear fuel is cheap. Spent fuel is another matter and becomes highly speculative as to the real costs.)
2) Solar is extremely reliable. Sunlight is predictable; humans knew precisely how much sun they'd see way before the discover of electricity; including the eclipses. How much sunlight... that is intermittent but it does not completely disappear; you still get energy. It is not dark everywhere all at once (except at night,) just as traditional power generation required a GRID which could shift power for frequent planned and unplanned downtime as well as shifts in demand; future power will require the same planning and mitigation but we will need MORE of it. 100s of miles from my 1 local coal and 1 nuclear plant are other fallback coal plants which are routinely relied upon. It is unlikely low solar output here is also low, we are not talking about running power any further than we already do.
3) Net costs are often ignored and people ALWAYS ignore the indirect costs such as the harm pollution causes. Asbestos and Pb paint are great but their indirect costs eventually were great enough to overcome the objections of industry. (Just look to Asbestos, Canada where they still defend Asbestos.) It cost more to transition away from them but we did. Investment in power storage has huge potential for side benefits while expensive "base load" investment does not.
Example: Making ICE for cooling is an already cheap way to buffer energy demands which handles the biggest spikes in demand and has been deployed for years to save money on the cheap coal powered grid in the USA; solar has nothing to do with it. Storage/buffering systems can save money on their own already and that market has barely started with no demand (other than some businesses wanting to save money) as energy becomes diversified and distributed the demand for buffering will grow. That is where the wise investment is.
Democracy Now! - uncensored, anti-establishment news
Why reduce the population when you can run away into outer space, and make a lot of room for everybody there? It's gonna be a while before we run out of room in outer space, unlike down here on the surface of this planet. Maybe we just need to find ways to stack people on top of each other more efficiently. Like in a downtown area, when room gets expensive, everything grows upwards, towards the sky, and you get sky scrapers from it. Or even on chicken farms, the chicken sit on top of each other, like 4 layers high, and it's more cost efficient like that, less property tax needed (as I think property tax and real estate tax is the real reason why chickens have to suffer like that, it's not even real estate price, because there is a lot of that go go around in some places, but the continuous price of having too much real estate, and the taxes over it.) So in the future once we hit 10 billion people, we're gonna say, that's it people, the planet is full, we gotta build a 2nd floor throughout the planet, and put all the new people on the 2nd floor, til we hit 20 billion, then we need a 3rd floor, and so on, and people are not allowed to fuck and reproduce until they complete the 2nd floor to put the new people in their area. Farming becomes an issue though, as it's hard to see how a multistory farm can efficiently distribute and share sunlight to where the productivity of each floor does not drop to say 1/3, or by 66%, for each floor, but, by, say, only 10%.
More specifically the symbiotic bacteria that they host. Nature has solved this problem already (and more than once) - no high pressures or temperatures needed.
http://en.wikipedia.org/wiki/Azolla