Solar gases: A parabolic trough can focus sunlight on nanostructured titania, improving the efficiency of a new system for generating hydrogen by splitting water.
John Guerra, Nanoptek
A new process uses sunlight and a nanostructured catalyst to inexpensively and efficiently generate hydrogen for fuel.
Nanoptek, a startup based in Maynard, MA, has developed a new way to make hydrogen from water using solar energy. The company says that its process is cheap enough to compete with the cheapest approaches used now, which strip hydrogen from natural gas, and it has the further advantage of releasing no carbon dioxide.
Nanoptek, which has been developing the new technology in part with grants from NASA and the Department of Energy (DOE), recently completed its first venture-capital round, raising $4.7 million that it will use to install its first pilot plant. The technology uses titania, a cheap and abundant material, to capture energy from sunlight. The absorbed energy releases electrons, which split water to make hydrogen. Other researchers have used titania to split water in the past, but Nanoptek researchers found a way to modify titania to absorb more sunlight, which makes the process much cheaper and more efficient, says John Guerra, the company's founder and CEO.
Researchers have known since the 1970s that titania can catalyze reactions that split water. But while titania is a good material because it's cheap and doesn't degrade in water, it only absorbs ultraviolet light, which represents a small fraction of the energy in sunlight. Other researchers have tried to increase the amount of sunlight absorbed by pairing titania with dyes or dopants, but dyes aren't nearly as durable as titania, and dopants haven't produced efficient systems, says John Turner, who develops hydrogen generation technologies at the National Renewable Energy Laboratory (NREL), in Golden, CO.
Nanoptek's approach uses insights from the semiconductor industry to make titania absorb more sunlight. Guerra says that chip makers have long known that straining a material so that its atoms are slightly pressed together or pulled apart alters the material's electronic properties. He found that depositing a coating of titania on dome-like nanostructures caused the atoms to be pulled apart. "When you pull the atoms apart, less energy is required to knock the electrons out of orbit," he says. "That means you can use light with lower energy--which means visible light" rather than just ultraviolet light.
The strain on the atoms also affects the way that electrons move through the material. Too much strain, and the electrons tend to be reabsorbed by the material before they split water. Guerra says that the company has had to find a balance between absorbing more sunlight and allowing the electrons to move freely out of the material. Nanoptek has also developed cheaper ways to manufacture the nanostructured materials. Initially, the company used DVD manufacturing processes, but it has since moved on to a still-cheaper proprietary process.
With catalysts created by an MIT chemist, sunlight can turn water into hydrogen. If the process can scale up, it could make solar power a dominant source of energy.
Researchers have found a cheap and easy way to store the energy made by solar power.
Splitting water at a small particle creates not only hydrogen but also oxygen, at that particle. The result is not a fuel but an explosive. Water needs to be split in separate compartments, as in (in fact highly efficient) electrolysis, so that the two gases are collected separately.
several options for hydrogen-permeable membranes exist that are impermeable for oxygen.
the selectivity + flux requirements seem impossible to meet with membranes - the safety issues with compressed stoichiometric mixtures of oxygen and hydrogen make this scheme totally impractical
I wonder, will a gas furnace adapt to hydrogen? I notice the first two comments are negative; sigh.... 1. Of course there's a price consideration and 2. I'm sure none of the scientist-developers have thought of the oxygen production that occurs each and every time one separates water.
The most important question is what is the yield per m^2 (or hectare, acre, mi^2, whatever) per year? Concentrated Solar Power in the desert (e.g. sunlight at 2700 kWh/m^2/year) and 30% efficiency (i.e. 800 kWh/m^2/year) and hydrolysis at 60kWh/kg (maybe 50kWh/kg someday) gives 16 kg/m^2/year. What is the kg/m^2/year for Nanoptek?
The other question is what pressure hydrogen is produced? (Is a separate compression step required?)
Forgive my ignorance as I have no knowledge of this technology. I am curious if splitting water to make hydrogen will essentially be competing with human consumption as ethanol does? I realize that the emissions revert back to water, but to what degree? We already have shortages and this type of process seems to contribute to them.
Re: What about water consumption
maybe it works with salt water? if so, it shouldnt be an issue.
Re: What about water consumption
If it works with salt water, then perhaps large fields can be deployed to generate some hydrogen, but to some extent it can be used as a desalinization tool too. Pipe salt water into some useless desert areas, and make some gas with the sunlight Ingnite it and make some water. Leave the sodium behind!
Re: What about water consumption
Now this is a good idea. Anybody out there with a million or two to make it happen?
Re: What about water consumption
Water consumption is *not* an issue:
1) Just to grow corn for ethanol production you need 100s of times the amount of water per unit of ethanol. This process needs just 10 units of water for 1 unit of hydrogen.
2) Water can be desalinated cheaply in energy terms. 1kg of hydrogen (which needs 10kg of water to be made) contains enough energy to desalinate 4000l of water.
Re: What about water consumption
Or, to put it in more easily understood terms: the same amount of water you use for a single shower (100l+) can be used to drive your SUV over 200km (120 miles) once converted to hydrogen. Seriously, water consumption is not an issue. Cost of this technology might be.
Re: What about water consumption
When the fuel is used - water is recreated
The article hints at the cost, saying it nearly matches SMR, which is well above reasonable targets for the "hydrogen economy."
The amount of water - salt water does not work - would be enormous. Recall that 89% of the weight of water is Oxygen, so it takes 10 pounds of water to get a pound of Hydrogen, assuming perfect efficiency.
Virtually every technique employed to improve renewable hydrogen does a much better job improving PV cell efficiency, which is already well above any hydrogen technology. Anyone putting up the cash would likely spend it on PV cells or better, which need no water.
Also, the oxygen produced with hydrogen is caustic, so many of these ideas literally fall apart.
Beyond that, what do you do next? As one post mentioned, there would be compressors and pipes and storage tanks, followed by more pipes and electric generators (in the case of storage) or a hypothetical fuel cell.
Unless I can put one of these things on my roof and safely fill my vehicle, I'm going to be a slave to the Oil Companies. Please, we need to be able to fill our energy powerd vehicle at the end of an extention cord.
Hydrogen is what powers the Electric Grid. If the Oil Companies want to be part of this let them buy the Electric Companies.
Let George do it? We been dare, dun dat, no hope. Now, with a Bell Mason jar, some electronics, the good sence not to blow your (self) off the planet, and a weekend's work, you just may have a means to free us all from that slavery you are so quick to embrace.
An obvious near term application is to use this technology to create liquid fuels. A hydrogen intense liquid fuel, such as butanol (C4-H10-O) could be created using a modified syngas FT approach or possibly even be carried out in-situ.
Sourcing the carbon would never be much of an issue (one could always resort to biomass). Methane could also be easily created.
Another option would be creating a synthetic high performance aviation fuel.
While I'm ranting, I'll go ahead and make the obvious statement that the oxygen is also a valuable by product. Stored/transported seperately it (O2) will be of extreme value in organic rankine cycle turbines in the near future.
Re: Good for synthetic fuels...
Alkanes may make more sense than alcohols. Considering FT isn't very efficient, how about drawing CO2 from the air (zeolite?) and combining the hydrogen with it to make methane (CH4). Much higher process efficiency, and the methane infrastructure is common (natural gas). Methane is a pretty good fuel and transports and handles easier than hydrogen. Could be burned in CCGTs or in CNG vehicles or for heating purposes or even as a metallurgical reducing agent. If necessary, the methane can be upgraded to propane/butane fairly efficiently. Much better perspective than hydrogen IMHO.
Of course, it mostly depends on what the economics are like.
I liked two of the points at the end of the article. Siting the equipment near it's users and using hydrogen to store solar power overnight make a great deal of sense. In this way, small communities could take charge of their own electric generation the way they are trying now to take charge of their communications. These plants could be placed near the community as a solar power farm. Some of the received light would be used and the rest stored. Water use would not be an issue as the hydrogen would be recycled back into water at night.
Best of all, TimG, the oil cmpanies will REACT to any MASS ASSERTION of a COMMITMENT to this technology on a GRASSROOTS level. I am in full process of finding how to heat water and cook with this HHO (generated) fuel. You ought to do the same.
Aluminum can generate hydrogen on demand. Aluminum solves both the storage and generation problem. You can make hydrogen from Aluminum safely and instantly at home, without the use of caustic soda.
http://www.instructables.com/id/SODA-CAN-HYDROGEN-GENERATOR/
The oxygen is useful in the gasification of biomass for producing pure syngas(Hydrogen and carbon monoxide).
hydrogen is a by product of pebble bed technology for new nuclear reactors...10,000 tons a day...
Here's an idea.
Let's form a company to develop hydrogen production using direct solar.
Let's get the public to fund the initial research by investing in a lobyist.
Then let's get venture capitalists to fund the production R&D.
We can patent it (using the US legal system of course) then license the manufacture offshore (avoiding the high labor costs and legal exposure to that same legal system we wanted to protect our patent and intellectual property) and then sell it to the US consumer and never pay the public a penny.
Then we can buy a G5, avoid the airport security, screw our hookers enroute, and generally live a well deserved priviledged life, while the rest of the rodents squirm to put a meal on the table.
Sounds good to me.
Little known fact; 0.9% of the US population holds 94.6% of the US equity.
Minus the sarcasm in the previous statement, I think the idea is a great one; to start a company now and take advantage of the tremendous opportunities in store for this emerging technology. I personally would love to be a part of a start-up company that produces inexpensive and clean energy. This has been a dream of mine - to be a part of the hydrogen revolution - for the past 35 some years, since I was very young. Realistically speaking - how would one go about switching careers into this industry? I am ready!
People badmouth this guy for knowing how the REAL world works. Sarcasm? The naysayers are the same people who naively voted the people into office who perpetuate the "system" because it's the only way to survive as a politician. That nice couple next door who harp about family values & the like sscare the hell out of me. Chances are, they are referring to THIER values.
Here on planet Earth, you CAN screw your way to the top! And you should! Just emulate the ones who have gone before us-Vanderbilt, Rockefeller, etc. Me? I'll take the G-5, The hookers and champagne.
Seriously dude, point well made, and humorously so. You can't possibly be an engineer!
this is Randy Lewis is Fla, I have a vision of creating a selfsustaining system from home using solar to create hydrogen to fuel personal vehicles. You new system sounds like it might be appropriate to use at home as long as one has good sunlight.
Are you selling these units yet? If so what kind of costs are involved? I am working up a grant proposal for funding so hopefully in a few months I will have the funding and can purchase a system.
Thanks and God bless,
Randy
941-240-1060
It certainly is great to see there are so many constructive posts. Even though there are many alternatives to oil, it is my belief that we are going to be using all of them and they will be refined to near perfection in time.
I am a gearhead and love internal combustion engines. My kids do, too. Their kids won't have the sound and feel ingrained in their body and soul, which will make them feel more comfortable with silent or near silent propulsion.
I believe, and hope, that hydrogen will be the next automotive fuel, as do so many others.
I'm no scientist and can't provide any facts and figures. I am a part of the majority and respect and support the abilities of the scientists and technicians that are going to solve this thing.
In my heart, I have a feeling that this will happen--and sooner than we think.
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tsaidak
18 Comments
How nice...
This sounds great except....
How much does this hydrogen COST!??
I can't judge the technology unless they state a price per unit. Is this $20.00/gal of gasoline equivalent or $2.00/gal of gasoline equivalent? Until someone can state a price, this is no different then the pie in the sky claims for nuclear reactors in the 1950's.
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mkogrady
423 Comments
Re: How nice...
Actually, this is a nice development. The rutile material is a type of sand. We probably have more of this stuff on the Hawaiian Islands and Pacific North Beaches than we know what to do with. Possibly much less expensive than the materials used to make solar cells, and if I read the article properly, the purity levels to be useful are much lower making mass production easier.
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