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Microbes Churn Out Hydrogen at Record Rate
FiReaNGeL writes to mention that Penn State Researchers have improved on their original microbial electrolysis cell design bringing the resulting system up to better than 80 percent efficiency when considering all energy inputs and outputs. "By tweaking their design, improving conditions for the bacteria, and adding a small jolt of electricity, they increased the hydrogen yield to a new record for this type of system. 'We achieved the highest hydrogen yields ever obtained with this approach from different sources of organic matter, such as yields of 91 percent using vinegar (acetic acid) and 68 percent using cellulose,' said Logan. In certain configurations, nearly all of the hydrogen contained in the molecules of source material converted to usable hydrogen gas, an efficiency that could eventually open the door to bacterial hydrogen production on a larger scale."
I have a high hydrocarbon yield from beer. Does that help?
Cabbage consumption increases yield dramatically!
I have something in common with Stephen Hawking...
Yes, but the bacteria are producing it from decaying plant material. You'd have to see how much greenhouse gases are being produced by the bacteria as they decompose the vinegar/cellulose/whatever before calling this a better solution than conventional electrolysis.
How can I believe you when you tell me what I don't want to hear?
Relax, dude. We've fixed them up with an excellent simulation of their society at the peak of its development. They'll go happily about their simulated lives, and never know they are just sitting in a vat generating power for us.
I don't care if it's 90,000 hectares. That lake was not my doing.
The 80% figure is impressive. But beware of the efficiency numbers they quote. This isn't the full fuel cycle. You've still got to compress and distribute hydrogen, which takes a lot (gases take lots of work to compress). For a vehicle, burning it isn't too efficient maybe 30-40%, and fuel cells aren't quite there yet.
Additionally, with any kind of electrolytically-driven process like this one, there's a HUGE efficiency penalty once you increase the flow rates to be anything substantial. And you need to, because otherwise the amount of hydrogen produced per fuel cell area would be tiny. And then, at that point, you've got the problem of lots of carbon to dispose of. Guess what -- this working microbial fuel cell takes C,H,O in as vinegar or cellulose, and outputs H2 and CO2! Do you really call that 'carbon neutral' as a fuel source? It's still dumping CO2 into the atmosphere, just less of it per Joule of useful energy.
Still, this is a great direction for them to keep going... there are very interesting things you can do with hydrogen, even to extend existing liquid fuel stocks (i.e. crude oil to gasoline) by hydrogenation. (Much cheaper than building lots of fuel cells... but not carbon-neutral.)
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Educational microcontroller kits for the digital generation.
It's 0 sum with how much greenhouse gas is being captured by growing the plant.
The only thing that ISN'T 0-sum would be pulling greenhouse gases out from hundreds of feet underground; Which we already do.
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Uhm, but you are aware that the decaying plant material can't give off more CO2 or other Carbon-based greenhouse gases than it originally consisted of. Close cycle and such.
Grow a tree. Burn a tree. No increase in greenhouse gas.
As long as you don't use your conventional gas-powered buzz saw to bring it down and an F350 to haul it to your place...
In America, researchers apply a jolt of electricity to their wastewater bacteria. In Soviet Russia, the brew tases you! Don't Tase me, brew!
"The most sensible request of government we make is not, "Do something!" But "Quit it!"
It's ending up in our lakes, rivers and streams! Why aren't more people focused on this crisis??
Hydrogen beats the crap out of batteries as far as energy storage
;)
Not currently it doesn't. Top-of-the-line hydrogen-powered vehicles are about on par, range-wise, with top-of-the-line lithium-ion powered vehicles (for vehicles released this fall, say, compare a Roadster with an Equinox -- both 200 mile range). But they're notably less thermodynamically efficient and have worse performance. Honda has a prototype FCX that they say will be able to get 350 miles by using an undisclosed storage material, but storage materials always raise issues of their own (such as how much energy it takes to get the hydrogen in and out -- thus hurting the thermodynamic efficiency even more), and if you want to count vehicles that don't exist yet... Of course, if your energy source is hydrogen *to begin with*, sure, hydrogen would be a better choice present-day. We'll have to see how each respective technology advances. Personally, I'd rather we be driving largely on grid power instead of trying to store all our energy on the vehicle
Getting this sort of tech as a backyard/rooftop energy generator could be insanely useful
You want them to eat your roof? You did read the article (or even the summary) and realize that these aren't photosynthetic bacteria, right? That will almost certainly come in the future, but that's not what we're dealing with here.
A biological system would (probably) be lower setup than a solar system as well, at least given current tech.
But maintenance can be very tricky. Bacteria mutate, get attacked, and so on. Plus, you need to keep feeding them and removing waste products. This is certainly viable, present-day, in industrial scale applications, but it probably won't scale down very well any time soon.
I will agree with you on one thing:
Wow. And 80% efficiency is pretty damn good, for a line of research that is still pretty primitive.
It sure is.
And I'd like to be the king of all Londinium and wear a shiny hat.
Here's one possible solution:
Bubble it into water in which you release into shallow man-made ponds in order to accelerate algae growth. Harvest the resultant algae, squeeze the oil out of it and make biodiesel. Put the leftovers from that into a fermenter and get what amount of ethanol you can from it. Then dump whatever is leftover from that onto fields to decompose and enrich the soil.
Yes, you are eventually liberating the carbon again in multiple paths, but it comes down to whether you want to actually sequester the carbon, or are willing to recycle it through a number of diversified fuels as many times as possible.
There are a few reasons to not worry about this:
(1) The volume of the earths oceans is enough that if we were destroying water in them at the rate at which we burn oil, it would take a few hundred million years to run out. We wouldn't be destroying it at that rate (I would guess, since you can make a lot of hydrogen from just a little water), but even if we were we have a while to figure out a solution.
(2) Hydrogen and ozone react really well -- the hydrogen wouldn't make it out of the atmosphere before it got bound back up as water.
The down side of (2) is that we could damage the ozone layer with leaked hydrogen (http://gcep.stanford.edu/research/factsheets/effects_climate.html)
Why are you comparing batteries to fuel cells in "thermodynamic efficiency". Batteries do not have "thermodynamic efficiency". A battery is not an engine, it's a container of an electrical potential that was put there probably by burning coal. You do realize that's where something like 80% of grid power comes from right? The battery's analog in current automotive propulsion is the gas tank in your Honda or whatever. Find out what the "thermodynamic efficiency" of the process of creating the electricity and then getting it into your lithium ion batteries, and then we can start making useful comparisons to other systems for automotive propulsion. Also, talking about range as if the range of a fuel cell vehicle was directly comparable to the range of a simple/straight EV (ie no production of power on bard, only storage) has limited validity too -- hydrogen vehicles are able to refill their hydrogen tanks about as fast as current gas cars fill their's, if not faster. EV's on the other hand, need to sit at a charger for a minimum of a couple hours, and if battery longevity is desired, really need to charge over an entire night. By the way, for those of you who don't know about it the Fuel Cell Equinox is extremely impressive. It's a mass produced, production fuel cell vehicle with the full interior room of a normal Equinox, that'll be driven by 1000 "owners" in the 3 major cities next year. It's been quite a wakeup call to the rest of the auto industry.