Unfortunately this looks to be mostly puff-press since we are dealing with a trifecta of minority-in-startupland (black, female, third-world country)
This weird contraption obviously uses more power to make hydrogen than it takes to run it. (Unless we are breaking some laws of physics?)
I also see no mention of why using urine is better/worse than just using regular water. I am guessing because "Putting electricity in water generates hydrogen" is a less exciting title.
> I also see no mention of why using urine is better/worse than just using regular water. I am guessing because "Putting electricity in water generates hydrogen" is a less exciting title.
This is not electrolysis of water. In theory, they are decomposing urea to get their hydrogen, which uses far less energy. This is the same principle that would cause a hydrogen economy to be run off of natural gas. Sometimes a little knowledge is a dangerous thing. Or, in the words from Spinal Tap, there's often a thin line...
I point this out in another comment, but that's a good point I hadn't taken into account. Getting hydrogen from urea is better than electrolysis, but there's not that much urea. Still, if the entire village contributed, it might be enough to charge cell phones and run LED reading lights, which would still be a huge boon.
> Still, if the entire village contributed, it might be enough to charge cell phones and run LED reading lights, which would still be a huge boon.
If you think people in undeveloped countries need to generate power from their urine to charge their cell phones, you really need to get out and see the world.
Not all villages in developing countries are dirt-poor and desperate for the slightest technology. Cheap cell phones are used quite a bit in many rural areas in Africa, for example: http://www.cnn.com/2012/09/13/world/africa/mobile-phones-cha.... For example, farmers can use them to look up weather forecasts and price information for their crops.
I would assume running wires to a few cell towers considerably cheaper than running wires to many villages. Indeed, isn't that why cell phones themselves are much more common than landlines in rural Africa?
No, it's because many developing countries "skipped" a technology. They missed out on land-lines because they were undeveloped, and now they have electricity and infrastructure, they jump straight to cell phones.
Jeesh, it's like you're missing the trees for the forest here. Skipping technologies is the pattern but there's a reason for pattern.
Developing countries don't skip technologies out of a desire for hopscotch or something. They skip wired tech because copper wires are expensive, their expense doesn't go down over time in contrast with the increasing sophistication of chips. Conventional phone lines and electrical power are both wired tech. Thus both are harder in third world conditions.
That doesn't help. If you electrolyze water with 3% urea the vast majority of your energy is used to split water, and only a small portion of it will split the urea.
But electrolyzing water, and then burning hydrogen is a net loss in energy, and the 3% urea does not give enough advantage to offset this.
Maybe if you had some way to preferably electrolyze just the urea and leave the water alone, but then you have to deal with batch process (instead of just continually adding liquid), and the lower voltage makes the reaction too slow.
The technical paper linked from the article[0] explains how this is done. The electrolysis of urea does compete with the electrolysis of water, but it happens at a lower voltage.
You still have to input energy to get hydrogen from urea, so why not just use that energy directly?
The only good reason to extract hydrogen is for storage. For example, solar energy could be used to extract the hydrogen from urea, which could then be burned at night to continue to generate power.
On it's own, any technology that requires extraction of hydrogen will result in a net loss. Sometimes a HUGE net loss.
Urea is easier to break down than water. (0.37V as opposed to 1.2V) I'm no chemist, but I think that making an unstable chemical into a stable(er) one gives off energy.
Also, if it wasn't a viable way to get energy than it wouldn't run at all. I don't see any wire going into a wall socket or anything, so I assume if they had it run for six hours like the article implies there has to be /something/ there.
My main issue with it is having what looks like a gasoline generator run on hydrogen. Doing the necessary tweaks raises the technical complexity of this by an order of magnitude.
Uh, are you implying that urine is mostly urea? If that were the case, then our urine wouldn't be liquid, but more like bird poop. (The white part contains uric acid.) Urea is solid at room temp and is dissolved in water in our urine. Also, it's CO(NH2)2, so there is hydrogen there you don't have to get from water.
What's more, they're leading small (?) quantities of hydrogen into a metal container which (presumably) hasn't been vacuum-emptied beforehand, and so will after a while contain an air+hydrogen mixture, which while technically not oxyhydrogen, can still be ignited and make the metal gas tank explode like a pipe bomb.
The first time I tried to write this comment, I was a little flip, because I'm not sure if you're trolling.
Purging the container is very easy and requires nothing more than fire (which I think Africans have), water (I am sure they have this), a vessel for boiling the water (ditto), and a moment's thought (the linked article seems to suggest this is locally available too). It does not require any vacuum pumps.
Step 1: Fill the vessel with water and start a fire
Step 2: Fill the hydrogen container with water and invert (so the open side is down)
Step 3: Hold the hydrogen container so that the opening is just below the surface of the water-to-be-boiled
Step 4: Wait for water vapor to fill the hydrogen container.
You now have a hydrogen container filled with water vapor and trace amount of atmospheric gases (the ones dissolved in the water and the ones adsorbed to the surface of the container). Since the urea electrolysis process produces only "dryish" hydrogen gas (the borax stage is used to remove water vapor from the as-produced hydrogen), it does not matter that the hydrogen container initially contains water vapor.
At this point, the user can either cap the hydrogen container (which will produce a poor vacuum as the water condenses) or immediately start filling it with hydrogen.
If conservation of borax is important (probably not, since I suspect that it can be dried fairly easily) one could prime the system by purging the hydrogen container with as-produced hydrogen to reduce the water content to an acceptable level before connecting it to the borax stage.
I dont feel I am calling anyone out (except perhaps the website/author). I was trying to convey that this article is only getting traction /because/ of that. It is a deceptive invention that uses more power than it creates.
This is contrary to the article which would have you believe if you piss in a can you could have 6 hours of generator power.
Quite literally this device is nothing more than a fraud as it is currently written.
Article title is : "These four African girls have created a pee-powered generator"
1: It is not a generator
2: You are mistaken. Its the article author who calls out front and center they are in 3 different minorities (see the title above) - I am simply responding to that.
They use nickel catalyst in the process and achieve 36% cheaper hydrogen production than water electrolysis. I don't know if the results explicitly means that it could be used as a sustainable power source. The original article doesn't mention that. The main point is cheaper way of producing hydrogen fuel while denitrificating waste water.
Amen to that. Sewage gas, on the contrary is used with great success to generate energy, both in the developing world and in the developed world. This urea-electrolysis thing, on the other hand, is plain weird, to generate hydrogen you must put energy in that you won't ever recover, thermodynamics tells you that, and hydrogen isn't something that's easily stored or transported.
This weird contraption obviously uses more power to make hydrogen than it takes to run it. (Unless we are breaking some laws of physics?)
I also see no mention of why using urine is better/worse than just using regular water. I am guessing because "Putting electricity in water generates hydrogen" is a less exciting title.