ORNL researchers developing biohybrid photoconversion system to convert visible light into hydrogen
03 February 2011
Researchers at the US Department of Energy’s (DOE) Oak Ridge National Laboratory are developing a biohybrid photoconversion system based on the interaction of photosynthetic plant proteins with synthetic polymers that can convert visible light into hydrogen fuel.
In a step toward synthetic solar conversion systems, the ORNL researchers have demonstrated and confirmed with small-angle neutron scattering analysis that light harvesting complex II (LHC-II) proteins can self-assemble with polymers into a synthetic membrane structure and produce hydrogen. The researchers envision energy-producing photoconversion systems similar to photovoltaic cells that generate hydrogen fuel, comparable to the way plants and other photosynthetic organisms convert light to energy.
Making a self-repairing synthetic photoconversion system is a pretty tall order. The ability to control structure and order in these materials for self-repair is of interest because, as the system degrades, it loses its effectiveness. This is the first example of a protein altering the phase behavior of a synthetic polymer that we have found in the literature. This finding could be exploited for the introduction of self-repair mechanisms in future solar conversion systems.—Hugh O’Neill, ORNL Center for Structural Molecular Biology
Small angle neutron scattering analysis performed at ORNL’s High Flux Isotope Reactor (HFIR) showed that the LHC-II, when introduced into a liquid environment that contained polymers, interacted with polymers to form lamellar sheets similar to those found in natural photosynthetic membranes.
The ability of LHC-II to force the assembly of structural polymers into an ordered, layered state—instead of languishing in an ineffectual mush—could make possible the development of biohybrid photoconversion systems. These systems would consist of high surface area, light-collecting panes that use the proteins combined with a catalyst such as platinum to convert the sunlight into hydrogen, which could be used for fuel.
The research builds on previous ORNL investigations into the energy-conversion capabilities of platinized photosystem I complexes and how synthetic systems based on plant biochemistry can become part of the solution to the global energy challenge.
We’re building on the photosynthesis research to explore the development of self-assembly in biohybrid systems. The neutron studies give us direct evidence that this is occurring.—Hugh O’Neill
The researchers confirmed the proteins’ structural behavior through analysis with HFIR’s Bio-SANS, a small-angle neutron scattering instrument specifically designed for analysis of biomolecular materials. “Cold source” neutrons, in which energy is removed by passing them through cryogenically chilled hydrogen, are ideal for studying the molecular structures of biological tissue and polymers.
The LHC-II protein for the experiment was derived from a simple source: spinach procured from a local produce section, then processed to separate the LHC-II proteins from other cellular components. Eventually, the protein could be synthetically produced and optimized to respond to light.
O’Neill said the primary role of the LHC-II protein is as a solar collector, absorbing sunlight and transferring it to the photosynthetic reaction centers, maximizing their output. However, he noted, this study shows that LHC-II can also carry out electron transfer reactions, a role not known to occur in vivo.
The research team, which came from various laboratory organizations including its Chemical Sciences Division, Neutron Scattering Sciences Division, the Center for Structural Molecular Biology and the Center for Nanophase Materials Sciences, consisted of O’Neill, William T. Heller, and Kunlun Hong, all of ORNL; Dimitry Smolensky of the University of Tennessee; and Mateus Cardoso, a former postdoctoral researcher at ORNL now of the Laboratio Nacional de Luz Sincrotron in Brazil.
The work, published in the journal Energy & Environmental Science, was supported with Laboratory-Directed Research and Development funding. HFIR is supported by the DOE Office of Science.
Mateus B. Cardoso, Dmitriy Smolensky, William T. Heller, Kunlun Hong and Hugh O’Neill (2011) Supramolecular assembly of biohybrid photoconversion systems. Energy Environ. Sci., 4, 181-188 doi: 10.1039/C0EE00369G
At least they are using neutrons at Oak Ridge which produces about thirty for each proton that goes through its billion volt accelerator into a jet of mercury.
Solar energy at the earths surface is about a kilowatt of heat and light per square meter limited to a few hours a day. Oak Ridge has had devices that have produced millions of watts per square meter.
The people there should devote their time to projects that produce small reactors that can be buried for ten years and still produce heat which can be used like artificial geothermal energy. Hyperion could use such support and should be testing an actual uranium hydride model right now as well as their alternate design. The IDAHO lab did many experiments but now things have to be perfect and approved by all the plumbers in the US before there can be chain reaction.
Every propane tank is a mega disaster waiting, but Chernobyl only killed far less than a hundred people even after waiting on thyroids for thirty years and Bhopal chemicals a few thousand or more in a few days.
Even the guy purposely poisoned with polonium 210 lasted for several days. Seconds is all you get with potassium cyanide. Methyl mercury gave the researcher with the tiny glove leak a few days. A single anthrax organism can kill a person.
Potassium atoms are exploding at a rate of four thousand a second in every 70 kg of you and even your great-great-grand mother in her crypt if she was a royal.
Oak Ridge should test reactors; but a failure to operate one at Oak Ridge or the associated one near Chicago for more than a few hours as ordered, delayed the production of plutonium at Washington for months because fission product poisoning by iodine was not discovered by an ordered long run of one of the first operating reactors that was not done. Many tens of thousands of Japanese died in fire bombings because the only effective bomb to convince the Emperor was delayed.
How many people must die prematurely before nuclear power reactors are allowed to quickly supply abundant, cheap and efficient energy. Many will not even know that they died hungry and cold because nuclear waste was not perfectly safe, according to a senators opinion, for a billion years in deep holes in Nevada. The same senator and many others who are against the deep holes spread uranium and radioactive potassium on their lawns which was bought from a garden store and are sprinkled with rain containing radioactive elements from coal fired power plants. No rock and no soil is free of uranium and radium which can leach into the water table. The US government lied to the power companies when it said that much money was needed for holes in Nevada for used fuel when it could have been reprocessed for much less money and the fission products buried in deep sea clay.
There is even an approved operating facility for the most active elements to be stored in New Mexico. But the politicians do not wish to inform the public that military used fuels can be stored in such facilities and they are deemed and court approved for any isotope.
What is being stored at nuclear reactor sites is not worthless but 96 or more percent of it can be used again. If used in heavy water reactors, it might supply all the uranium fuel needed for the next 20 to 50 years.
The truth is that extracted fission products could be sprayed evenly over the entire area of Nevada, or at least the remote unpopulated areas, and not cause an increase in the radioactivity of any area as measured by Geiger counters. The highly absorbable iodine is long since gone. ..HG..
Posted by: Henry Gibson | 03 February 2011 at 03:50 PM
"Every propane tank is a mega disaster waiting, but Chernobyl only killed far less than a hundred people even after waiting on thyroids for thirty years.."
"Russia, Ukraine, and Belarus have been burdened with the continuing and substantial decontamination and health care costs of the Chernobyl accident. Fifty deaths, all among the reactor staff and emergency workers,
are directly attributed to the accident. It is estimated that there may ultimately be a total of 4,000 deaths attributable to the accident, due to increased
Question: When it will be safe to return to resettled villages?
R.T. Kudlenok, 56, resident of the Krasnogorye district
Answer: The population was evacuated from settlements contaminated by long-lived radionuclides. It is hardly possible to expect recovery of abandoned villages in 50 years to come considering the high degree of contamination
and long half-life period, which stands at 90 to 1,000 years.
Posted by: kelly | 03 February 2011 at 05:44 PM
Question is how MUCH H2 is produced by these LHC-II proteins. And how is it captured.
An interesting area to investigate. But we`d wonder how effective this system will be compared to the LENR work of the gentlemen in Bologna claiming a power gain of 31X:
Posted by: Reel$$ | 03 February 2011 at 07:12 PM
HG, some of your arguments are comical. "Even the guy purposely poisoned with polonium 210 lasted for several days."
You're not going to win anyone over with points like that.
Posted by: danm | 03 February 2011 at 08:21 PM
Casualties for any emissions from the nuclear industry are calculated according to the LNT model, Linear No Threshold, which means that there is assumed to be a level of risk associated with any emissions at all.
This is simply an assumption, and evidence in fact points to radiation at low levels providing some immunity to illness, which is not too surprising as we evolved to cope with background radiation which is in any case far, far greater than man-made emissions.
The coal industry however is not forced to work against an assumption of LNT, and freely distributes around the same amount of radioactive material from a single large plant as all the nuclear reactors in the US emit.
Given a level playing field the coal industry would not exist, and neither would very much of the renewables industry, which is utterly dependent on fossil fuel burn to cover up the fact that it cannot actually do the job.
Posted by: Davemart | 04 February 2011 at 01:48 AM
Davemart, Nobody in their right mind would argue with your comments about the coal industry, or renewables (yet). But the nuclear industry has a higher hill to climb because of the threat of catastrophic failure.
Unfortunately the first generation of nukes was not failsafe, and that created a negative image.
If the next generation can appear failsafe and be built on time/on budget, nuclear will get a second chance. If just one of the newer, smaller reactors could get built it would open the door.
Posted by: danm | 04 February 2011 at 11:31 AM
The general public was correct to be cautious about nuclear energy, with it's association with risks for bombs etc.
However, that initial caution and the public's technological unsophistication and difficulty understanding risk analysis has been ruthlessly exploited by an unholy alliance of greens who are ideologically driven and the fossil fuel industry, who know that they are quite safe from obsolescence whilst renewables are the preferred alternative, as they are actually entirely incapable of replacing fossil fuels.
To that end the risks of nuclear power have been exaggerated by several orders of magnitude, whilst the ongoing environmental and health disaster which is the present energy system's risks are ignored.
We are supposed to wait until we are able to replace fossil fuels with pixie dust and ground up unicorns horns, and meanwhile are evermore committed to paying for financial scams in the shape of wind turbines and solar panels which are going to provide power, in so far as they manage it at all, at a multiple of the price that nuclear would cost.
Posted by: Davemart | 04 February 2011 at 02:33 PM
When they are sitting in the dark freezing to death people will fear nuke power a smidge less.
Posted by: wintermane2000 | 04 February 2011 at 09:17 PM
Interesting comments. Agree on the alliance of some green and fossil interests in vilifying nuclear - which in breeder configurations is a "renewable." Clearly a new generation of reactors should and will be a part of the North American energy portfolio. France is a convincing example of how this works and works well. And the French are just as sensitive to environmental hazard as most N. Americans.
The wild card in the mix IMO is small business and residential CHP units. Initially running on NG, these units will provide distributed electric energy to residences and light business. The startup Bloom Box is a prime example of SOFC systems actively saving money by generating local electric energy.
The new Bank of America tower in NYC is another example. Their 4.6MW CHP system provides 65% of the electric demand, along with heat and hot water and cooling in summer. It is another player in the energy portfolio that will gain acceptance as people begin to grok the meaning of Energy Independence.
Posted by: Reel$$ | 05 February 2011 at 10:37 AM
Reel, CHP units should increase dramatically as they get smaller and more affordable. These could make a huge difference in places that are hurricane prone, where the grid might be down for a week or more. The NG lines usually are still pressurized.
Posted by: danm | 05 February 2011 at 12:44 PM
Recent studies indicated that NG power plants pollute almost as much as large coal fired power plants. Shall Gas (SG) power plants, due to high unreported leaks, can pollute more than many coal fired power plants.
CHP using SG could pollute even more. It may not be be the solution unless leaks can be reduced up to 3000 times less than current level.
Posted by: HarveyD | 06 February 2011 at 10:20 AM
NG has no particulate (of significance) which is the major health issue with coal. Look at what coal is doing to nearly one million Chinese EACH YEAR:
NG, though still a fossil, emits far less real pollutants than coal:
CO, NOx, SO2, SO4, mercury and other heavy metals average 75% LESS than coal. (EIA 1998)
Posted by: Reel$$ | 06 February 2011 at 09:06 PM
You have to consider the complete cycle including all methane gas leaks.
Posted by: HarveyD | 07 February 2011 at 03:11 PM
Harvey, are you talking about leaks at the extraction point?
Posted by: danm | 07 February 2011 at 04:23 PM