Hydrogen Production By Photosynthesis

http://www.osti.gov/energycitations/...sti_id=6660456

http://unisci.com/stories/20013/0823013.htm

Photosynthesis Redirected To Produce Hydrogen As Fuel

Hydrogen holds great promise as the "green" energy source of the future.
Though ubiquitous, it rarely exists in a pure form in nature. Present
methods of producing hydrogen for fuel -- such as extraction from natural
gas -- are energy inefficient and polluting.
Hydrogen's potential as a "clean" fuel cannot be fully realized until it can
be generated from renewable resources.

In an article published in the June 2001 issue of Photochemistry and
Photobiology, researchers from the University of Tennessee's Center for
Environmental Biotechnology (CEB) and the Oak Ridge National Laboratory
(ORNL) demonstrate that photosynthesis -- the process that plants use to
make food from sunlight -- can be redirected to produce hydrogen.

The team of CEB researchers -- including undergraduate student Jennifer
Millsaps, UT/ORNL professor Elias Greenbaum and UT professor Barry Bruce
(biochemistry, cellular and molecular biology) -- extracted intact
photosynthetic complexes (Photosystem I) from spinach plants and coated one
side of each isolated complex with platinum atoms.

In the presence of an added electron donor, this "platinized complex" was
able to use visible light to produce hydrogen.

Photosynthesis results from the cooperation of two photosystems called
Photosystem I (PSI) and Photosystem II (PSII) that are coupled together in
the plant's chloroplast by an intermediary complex.

The green plant normally reduces carbon dioxide to carbohydrates in PSI in a
complex set of enzymatic reactions powered by the electrons produced when
water is split in PSII.

The UT/ORNL experiments uncoupled PSI from PSII, removing PSII and the
intervening complex and redirecting PSI reactions to produce molecular
hydrogen.

This is the first time platinized PSI has been used to generate hydrogen,
and represents the smallest nanoscale hydrogen-evolving system ever created.

So far, diversion to hydrogen production must be supported by feeding PSI a
high-energy donor such as ascorbate. The next step is to extract PSI and
PSII separately, and then join them back together head to toe, allowing PSII
to directly supply PSI with electrons derived from splitting water.

If done successfully, this nanoscale photosystem could produce a constant
supply of hydrogen and oxygen, a fuel that when burned produces heat --
leaving only water as the waste product.

Jennifer Millsaps, the undergraduate student from Maryville College who
acted as lead author on the article, was supported by the Professional
Internship Program (PIP) of the Oak Ridge Institute of Science and Education
(ORISE). The research was supported by the U.S. Department of Energy.

In April 2004, we are pointed to an article of Aug 23, 2001
(http://unisci.com/stories/20013/0823013.htm)
and to an article on the energy citations
database dated January 1, 1981.
(http://www.osti.gov/energycitations/...sti_id=6660456)

The 1981 database entry points to a conference
"5. annual IGT meeting on energy from biomass and wastes; 26 Jan 1981; Lake
Buena Vista, FL, USA "

held 23 years ago.

Why is this news today?

Yes, photosynthesis is old, and could produce
hydrogen.

If we harness this in the same way as the living things do
(produce directly hydrogen from the sun) it *would*
be news indeed.

It *will* be news, anyway. I am sure humans will follow
this lead. We have to stop polluting, that's the only
way out.

On Wed, 28 Apr 2004 17:07:58 -0700, The_Sage wrote:

Reply to article by: *
Date written: Wed, 28 Apr 2004 15:15:05 GMT
m

We've been over this before, hydrogen isn't free, it isn't cheaper than oil,
hydrogen refineries are huge and waste lots of land space and use lots of water
and other resources more valuable than oil.

Then why is the oil industry using hydrogen to manufacture gasoline?

"The_Sage" a écrit dans le message de
news
Reply to article by: *
Date written: Wed, 28 Apr 2004 15:15:05 GMT


We've been over this before, hydrogen isn't free,

Of course not. Energy is not free. You have to produce it. An so what?


it isn't cheaper than oil,

Yes, it is. If you take into account the cost of cleaning up the atmosphere,
the cost of the many thousands of deaths yearly because of oil pollution,
and all the hidden costs of oil, hydrogen is several thousand times cheaper.

And it is not "cheaper" what counts, but ENVIRONMENT FRIENDLY!

hydrogen refineries are huge
So what? They could take the place of oil refineries that aren't
small either!

and waste lots of land space and use lots of water
and other resources more valuable than oil.
Water? More valuable than oil? With 75% of the planet
covered by oceans?

This is the type of reasoning behind the oil industry :-)


Try another blind faith mantra, please.


Yes, let's go on using yours:

OIL IS FOREVER!
LET'S POLLUTE UNTIL WE DIE!

The last issue of Scientific American has an article about
just this, the economics of Hydrogen based transportation.

One of the issues is the cost of transportation ( $ / Watt-delivered ),
this is high for Hydrogen because it is a gas. There are considerable
costs associated with compressing gas to economicaly viable pressures.

Another is the cost of production, this is not low. Some oil refineries
use Hydrogen as fuel because it is a by-product of gasoline production.
This is essentially free. This does not change Hydrogen's overall
economic position because the amounts involved are small compared to
our total energy budget.

Like many engineering solutions Hygrogen will have some areas where
it makes sense and others where it doesn't. Read the article ( and
its' references ) to see where the problems and opportunities lay.

tom

--
We have discovered a therapy ( NOT a cure )
for the common cold. Play tuba for an hour.

On Thu, 29 Apr 2004 11:51:28 -0500, (Tom Kirke) wrote:

economics of Hydrogen based transportation

Hydrogen doesn't need to be transported to provide electricity to homes.

On Thu, 29 Apr 2004 11:51:28 -0500, (Tom Kirke) wrote:

Some oil refineries
use Hydrogen as fuel because it is a by-product of gasoline production.
This is essentially free.

Nope, oil refineries are the world's largest user of hydrogen which is used
to *manufacture* gasoline.

In article , *
wrote:

On Thu, 29 Apr 2004 11:51:28 -0500, (Tom Kirke) wrote:

economics of Hydrogen based transportation

Hydrogen doesn't need to be transported to provide electricity to homes.

The article was about Hydrogen based *transportation*.

tom

--
We have discovered a therapy ( NOT a cure )
for the common cold. Play tuba for an hour.

On Wed, 28 Apr 2004 17:07:58 -0700, The_Sage wrote:

Reply to article by: *
Date written: Wed, 28 Apr 2004 15:15:05 GMT
m

We've been over this before, hydrogen isn't free, it isn't cheaper than oil,
hydrogen refineries are huge and waste lots of land space and use lots of water
and other resources more valuable than oil.

What about this don't you understand?

http://www.alternatefuels.com/hydrogen.htm

Background /Common uses: Free hydrogen is found only in very small traces in
the atmosphere, but solar and stellar spectra show that it is abundant in
the sun and other stars, and is, in fact, the most common element in the
universe. Hydrogen is already used to produce countless products and to
enhance many industrial processes. The U.S. produces 100 billion cubic feet
per year of hydrogen for industry and for the space program. The largest
user of hydrogen is the petroleum industry for converting crude oil into
gasoline and hundreds of chemicals. Sometimes used in welding torches for
welding or cutting metals.

On Thu, 29 Apr 2004 18:18:55 -0700, The_Sage wrote:

Reply to article by: *
Date written: Thu, 29 Apr 2004 02:06:00 GMT
m

We've been over this before, hydrogen isn't free, it isn't cheaper than oil,
hydrogen refineries are huge and waste lots of land space and use lots of water
and other resources more valuable than oil.

Then why is the oil industry using hydrogen to manufacture gasoline?

The oil industry uses electricity to manufacture gasoline, that doesn't prove it
is free or cheaper than oil.

What about this don't you understand?

http://www.alternatefuels.com/hydrogen.htm

Background /Common uses: Free hydrogen is found only in very small traces in
the atmosphere, but solar and stellar spectra show that it is abundant in
the sun and other stars, and is, in fact, the most common element in the
universe. Hydrogen is already used to produce countless products and to
enhance many industrial processes. The U.S. produces 100 billion cubic feet
per year of hydrogen for industry and for the space program. The largest
user of hydrogen is the petroleum industry for converting crude oil into
gasoline and hundreds of chemicals. Sometimes used in welding torches for
welding or cutting metals.