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The team used xylose -- a simple plant sugar

Virginia Tech researchers have found a way to produce large amounts of hydrogen inexpensively using a simple plant sugar.

Y.H. Percival Zhang, study leader and an associate professor of biological systems engineering at Virginia Tech, and his team have produced large quantities of hydrogen in an effort to lessen the dependence of fossil fuels.

Zhang and his team used xylose in the study, which is a sugar first isolated from wood. Not only is this form of hydrogen production inexpensive and environmentally friendly, but it can also occur using any source of biomass. 

Up until now, producing hydrogen gas from biomass was a costly process that didn't yield very much in the end.


For this study, Zhang and his team liberated the hydrogen under normal atmospheric pressure and mild reaction conditions at 122 degrees. A group of enzymes -- which were isolated from various microorganisms at extreme temperatures -- were used as biocatalysts to release the hydrogen.

The team used xylose to release the hydrogen, which hasn't been used much in the past because most scientists use natural or engineered microorganisms. These cannot create large quantities of hydrogen because the microorganisms grow and reproduce instead of splitting water molecules for the creation of pure hydrogen.

The energy stored in Xylose splits water molecules, thus creating very pure hydrogen that can be used by proton-exchange membrane fuel cells.

The team separated some of the enzymes from their native microorganisms to create a special enzyme mixture.  When the enzymes were combined with xylose and a polyphosphate, a large amount of hydrogen was liberated from the xylose.

In fact, the team produced about three times as much hydrogen as other hydrogen-producing microorganisms.

“Our new process could help end our dependence on fossil fuels,” said Zhang. "Hydrogen is one of the most important biofuels of the future.”

Source: Virginia Tech News



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One problem...
By inperfectdarkness on 4/7/2013 9:17:43 AM , Rating: 2
Hydrogen is not a fuel compatible with existing internal-combustion engines. Unlike ethanol, engines cannot even be retrofitted with relatively little work required.

Forgive my cynicism, but ethanol derived from waste biomass would seem to present a more logical alternative--though granted, I don't know about the yields of one process versus the other.

Beyond that, I'm still worried about the ability to store hydrogen in a passenger car in such a way that it cannot generate an explosion in the event of a severe accident. Modern cars have several features which mitigate the problem with gasoline/diesel tanks--but a hydrogen tank would require significant pressurization to achieve any type of reasonable MPG. And liquid hydrogen would be even more dangerous, cost-prohibitive and (due to the requirements of maintaining -253C) extremely energy-hungry.




RE: One problem...
By StevoLincolnite on 4/7/2013 11:03:20 AM , Rating: 2
I fixed my problem with oil years ago.

That's LPG gas, compatible with current engines, cheap, readily available, mileage drops a little, but when it's less than half the price, you can give it that concession.

And... Works with current petrol engines.

Not sure what availability or price is like in the US, but I honestly can't believe more people don't use it.


RE: One problem...
By Lord 666 on 4/7/2013 11:49:34 AM , Rating: 3
Right on, Mad Max. Agreed that the US is slow to change, but its partially protectionism of big business. I'm a US citizen, just calling it how I see it.

Actually, we are slowly/quickly (depends on who you ask) destroying our environment here by fracking for NG. Next up is scrapping for shale/oil sands.


RE: One problem...
By Ammohunt on 4/8/2013 11:34:15 AM , Rating: 1
Destroying the environment a mile below the earths surface? Puhlese anti-fossil fuel whack jobs will make up any nonsense in order to keep us in the stone age or keep us chasing the mythical green energy unicorn.Splitting hydrogen from water only to combine it again to produce energy for locomotion with water as the byproduct makes sense ethanol,solar,wind etc.. doesn't.


RE: One problem...
By random2 on 4/9/2013 4:35:32 AM , Rating: 1
Ever hear of a water table?


RE: One problem...
By Ammohunt on 4/9/2013 1:41:32 PM , Rating: 3
Every study geology? if the water table is a mile under the ground chances are you are aren't pulling well water from it...


RE: One problem...
By deltaend on 4/7/2013 11:48:14 PM , Rating: 2
quote:
I fixed my problem with oil years ago.


Right, because LPG gas isn't derived from oil at all... You are simply trading one oil product for another here. We need to be off of oil, not swapping our dependence from one type to another.


RE: One problem...
By Tibbz on 4/9/2013 9:23:54 AM , Rating: 1
^^This i was scratching my head at that comment. Though US has an overwhelming abundance of Natural Gas and that will be a good patch if its further developed; but only to drive down fuel costs and overseas dependancy.... not much of an environmental benefit for what it is worth. Other than that Hydrogen is the way to go


RE: One problem...
By mars2k on 4/8/2013 8:31:18 AM , Rating: 2
Good for you Zhang, there was a post last week about some auto maker giving up on hydrogen as a hydrocarbon fuel substitute because they "just couldn't see how". Thank God others can. No matter what the arguments are this is just one ray of hope among many. We have to get off the carbon tit.


RE: One problem...
By Stuka on 4/10/2013 11:03:10 AM , Rating: 2
I agree. Electric is a great endgame, but I don't see battery tech being able to keep pace with hydrogren tech. Hydrogen viability is hinged on production costs, battery viability is hinged on materials science. The former being far more tangible than the latter.


RE: One problem...
By danjw1 on 4/7/2013 11:32:34 AM , Rating: 5
So, neither do batteries, but people are putting them in cars. I see EVs as away from fossil fuels. They are step in the link to fuel cells, which create electricity, not mechanical energy. Fuels cells have two big problems right now the cost (power needed) to produce and the flammability of hydrogen. This moves forward on the production side of the issue. We still need to deal with how to store it safely. Internal combustion engines are at best 30% efficient while a fuel cell is generally 40-60% efficient.

No reasonable person could expect us to move from a fossil fuel economy to a hydrogen one quickly. That does not negate the value of research such as this.

Also, why do people only think of cars when talking about fuel cells? They are a way to produce energy, it isn't only useful in vehicles. I know that some data centers are using them as a backup power source and even to offset their external energy use.

You read a technology blog. So, I assume you aren't one of those people who put their head in the sand and ignore scientific research as useful.


RE: One problem...
By Solandri on 4/7/2013 3:53:06 PM , Rating: 2
quote:
Internal combustion engines are at best 30% efficient while a fuel cell is generally 40-60% efficient.

When we're talking about pumping fuel out of the ground, then engine/cell efficiency is all that matters (assuming they use the same fuel).

When we're talking about manufacturing fuel from another source (e.g. plant matter), then you need to take into account the efficiency of that process as well.

Currently, manufacturing hydrogen is about 25% efficient. 40% efficiency to generate the electricity needed for electrolysis, 60-65% efficiency for the electrolysis process itself. Multiply that by the ~50% efficiency of a fuel cell and the overall efficiency for hydrogen is a pathetic 12.5%. That's why hydrogen cars haven't made any progress - overall efficiency is still much lower than ICE cars.

In the context of this article, the efficiency you need to compare is not just engine efficiency, but also production efficiency. What's the efficiency of converting plant matter to ethanol? Multiply that by the efficiency of an ethanol-powered engine. What's the efficiency of this new process to convert plant matter to hydrogen? Multiply that by the efficiency of a hydrogen fuel cell. Then compare the two. Just because fuel cells are more efficient doesn't automatically make them better. If the production efficiency of manufacturing hydrogen is less efficient than manufacturing ethanol, then ethanol can still be the more efficient solution overall despite the engine being less efficient.

(Arguments about storage, safety, cost, etc. while relevant are independent of efficiency so can be considered separately. That said, nearly all of these other factors favor ethanol-powered engines over both EVs and hydrogen fuel cells. So it's even possible for ethanol-powered ICEs to have a lower overall efficiency, yet a better solution overall.)

quote:
Also, why do people only think of cars when talking about fuel cells? They are a way to produce energy, it isn't only useful in vehicles. I know that some data centers are using them as a backup power source and even to offset their external energy use.

About 40% of U.S. energy consumption is for transportation (mobile applications where you're disconnected from the electrical or natural gas grid). So that's where changes in power source are going to make the biggest impact.

While the use of fuel cells in data centers is interesting, it's a negligible part of overall energy consumption. In fact, in general, energy consumption for static applications is not a problem worthy of consideration. Electrical transmission is over 95% efficient, so any advances in production can be adopted at the power plant instead of at the point of consumption (like a data center). About the only static application where electricity would be non-optimal is heating. But that's because heaters are by definition 100% efficient, so there's literally no room for improvement over a wood/gas/oil furnace.

So it's really only mobile/transportation applications where there's potentially a lot to be gained from advances in energy storage.


RE: One problem...
By kyuuketsuki on 4/7/2013 7:11:47 PM , Rating: 3
Where are you getting all those numbers for the efficiency of various stages of hydrogen production? Seems to me like you're just pulling those out of thin air. Plus, even if they are accurate, you're obviously not taking into account the efficiency of the new process described in the article, since it's not a current manufacturing process.

Plus, what are the numbers for the various stages of extracting/transporting/burning gasoline and ethanol? You claim that both are more efficient than hydrogen, yet don't provide any proof.

Really, if hydrogen can be produced efficiently, then the only issue left is storage, which is an engineering problem that would be solved fairly quickly, I think, once hydrogen is feasible as a fuel in the first place. We've had tanks full of explosive fuel in our vehicles forever, and we already have vehicles running on a pressurized flammable gas (CNG).


RE: One problem...
By Solandri on 4/7/2013 9:49:33 PM , Rating: 1
quote:
Where are you getting all those numbers for the efficiency of various stages of hydrogen production? Seems to me like you're just pulling those out of thin air.

I'm getting them from years of mulling over and learning about these different technologies. 40% is about the efficiency of a modern coal plant. Coal produces most of our electricity.

60-65% is the efficiency of electrolysis of water. You can get higher - up to 80%-95%, but that usually comes at the cost of (much) slower conversion rates. Unfeasible for wide-scale production of hydrogen.
http://en.wikipedia.org/wiki/Electrolysis_of_water...

quote:
Plus, even if they are accurate, you're obviously not taking into account the efficiency of the new process described in the article, since it's not a current manufacturing process.

Well that was my point. You can't just point to this new hydrogen production method and say "Look! Hydrogen is free now!" You have to compare it against an alternative use of that plant matter - conversion into ethanol. You always have to compare against opportunity costs, not against a vacuum.

quote:
Plus, what are the numbers for the various stages of extracting/transporting/burning gasoline and ethanol? You claim that both are more efficient than hydrogen, yet don't provide any proof.

Isn't it obvious? Gasoline and ethanol can be stored and transported as a liquid at room temperature and normal atmospheric pressure. Hydrogen either needs to be compressed or chilled. And due to H2 being a tiny molecule, hoses and fittings which can carry gasoline and alcohol without leaking cannot carry hydrogen without leaking. So the storage and transportation cost of hydrogen will always be higher than for gasoline and ethanol.

quote:
Really, if hydrogen can be produced efficiently, then the only issue left is storage, which is an engineering problem that would be solved fairly quickly

If you know anyone who works in a lab which uses H2 gas (or He gas, which is an even smaller molecule), please have a chat with them. The stuff leaks out of even well-designed storage tanks and hoses/fittings.

The entire reason petroleum and alcohols are preferred as fuels is because they bind hydrogen into a molecule which is much easier and safer to store and handle, while only giving up a little of the energy. The difficulty with storing and transporting hydrogen gas is driving some hydrogen fuel cell researchers to try out methane and methanol as fuels instead of pure hydrogen gas. Well, if you keep going down that path, you arrive right back at where we started - petroleum and alcohol as the optimal way to store and transport energy in hydrogen atoms.


RE: One problem...
By Alexvrb on 4/7/2013 10:55:02 PM , Rating: 2
Up until now, producing hydrogen gas from biomass was a costly process that didn't yield very much in the end. But now... with this latest breakthrough... producing hydrogen gas from biomass is a costly process that yields a bit more.


RE: One problem...
By Kyuu on 4/8/2013 1:03:46 AM , Rating: 2
Okay... fair enough. Thanks for the info.

It looks like there are at least a couple of promising technologies under development for mobile hydrogen storage, though, like cryo-compression and metal organic frameworks.


RE: One problem...
By JediJeb on 4/8/2013 6:24:31 PM , Rating: 4
quote:
the flammability of hydrogen. This moves forward on the production side of the issue. We still need to deal with how to store it safely.


I have worked with cylinders of compressed hydrogen for over 20 years in the lab and never had any problems. My college professor made a perfect statement about using hydrogen as a fuel for vehicles; if you rupture a hydrogen tank you release the hydrogen and it rises, if it ignites you get a fireball above the vehicle, if you rupture a tank of gasoline you release the fuel and it makes a puddle under the vehicle, if it catches fire, well your cooked.

If either explodes violently you are dead either way. Precautions handling both are similar for keeping things safe. Possibly the biggest worry with hydrogen is that it is both invisible and odorless, which would make a leak more difficult to find, but even in the lab we have leak detection systems for such things.

Fill a balloon with hydrogen and put a match to it(from a distance of course) and you get a loud pop and a flame that lasts a few seconds at most, put a few ounces of gasoline in a gallon jug and do the same, you get a pop that tears the jug apart and you get a flame spread out over everywhere the gas flew that can burn for several minutes until all the gasoline is gone. Of course everyone tries to bring up the Hindenburg fire, but if you look at those films it doesn't burn very long at all, and can you say it is any worse than the fires produced when an airplane crash lands and catches fire? The plane usually burns much longer. The safety aspect of using hydrogen as a fuel for vehicles in either a combustion role or fuel cell role is something that can be overcome with a little engineering, but the public perception of the safety aspect will need lots of media hype to overcome, just like that of nuclear energy.


RE: One problem...
By shaidorsai on 4/7/2013 4:00:59 PM , Rating: 4
Your assuming the hydrogen has to go into a cars gas tank...not necessarily. Why not use the hydrogen in place of fuels like coal to produce cheap abundant electricity. As electric/hybrid cars advance and their range improves they become a viable alternative to gas/diesel cars and by resolve many of our fuel problems all at once.


RE: One problem...
By silverblue on 4/8/2013 2:51:52 AM , Rating: 2
There is that, though I'd argue to supplement rather than replace altogether, at least in the short term.

Personally, I would think it's far safer having the H2 on a secure site rather than sitting in the middle of every car on a busy road, and besides which, there's a reduced cost for distribution as it's only going to the power plants.

The only thing we're not solving is the spiralling production of batteries, however one would argue that we were heading this way regardless. That's a discussion for another point in time, anyway.


RE: One problem...
By BRB29 on 4/8/2013 9:23:05 AM , Rating: 2
If we can fuse hydrogen into helium like the sun AND be able to control the energy, then we don't ever need to worry energy production again.

Interstellar space travel will actually be possible and humans then can start colonizing space. Global warming will be a thing of the past and electric cars will be mainstream.


RE: One problem...
By kyuuketsuki on 4/7/2013 7:16:56 PM , Rating: 4
Why does it matter if it's compatible with current internal combustion engines? In fact, it's better if we get away from ICE because electric drivetrains are simpler, more efficient, and require less maintenance than ICE drivetrains. Electric motors also provide near-instant peak torque, unlike ICEs which only provide peak power over a small range of RPMs. Correct me if I'm wrong, but don't hydrogen vehicles simply use the hydrogen to produce electricity and then use an electric drivetrain?


RE: One problem...
By silverblue on 4/8/2013 2:59:39 AM , Rating: 2
Yes, and I'd argue that not having the fuel cell (i.e. burning the H2 elsewhere and using the grid to charge the car up, albeit slower than the 5 minutes it takes to fill an FCX Clarity) would provide a little more space for batteries as well.


RE: One problem...
By Hammer1024 on 4/8/2013 12:43:25 PM , Rating: 2
Err... Actually, it is: C8 H18 is just one of the "CxHx" groups in the gasoline soup.

Where do you think the water in an auto's exaust comes from? Add O2 from the air, and you get CO2 + H2O from combusiton.

And since you're not a history fan, I'd like you to be made aware that internal combustion engines have loved H2 since the initial experiments of the 1960's!

I still remember watching a VW Bug get a compressed hydrogen treatment! The experimentor, who started and drove the car out on the street, got out, put a glass under the tail pipe and drank the water that was dripping out!


RE: One problem...
By JediJeb on 4/8/2013 6:30:44 PM , Rating: 2
That is correct, it was a simple conversion on a car using a carburetor, much like setting one up to run on propane back then. Could be just as easy to set it up using fuel injectors to let the hydrogen into the cylinders. You can actually just take a cylinder of hydrogen with a regulator and a hose and hold it over the intake of an engine and once you get the hydrogen flow correct it will run just by sucking in the hydrogen/air mixture, crude but simple.

The only reason I would not really like to drink that exhause though is from the oil that would contaminate it from the crankcase. It would be a trace amount, but it would still be there.


"So if you want to save the planet, feel free to drive your Hummer. Just avoid the drive thru line at McDonalds." -- Michael Asher














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