On Jan 10, 2009, at 10:31 AM, Jones Beene wrote:
Horace
Unless it was all just unfounded hype, a better solution (pun) may be
at hand from Daniel G. Nocera, the Henry Dreyfus Professor of Energy
at MIT. See announcement:
Whoa. I do not see the situation as "either/or". This is apples-to-
oranges in a way.
In fact both solutions have merit, and possibly even some crossover
synergy.
Yes, Nocera's catalysis should be able to aid any electrolysis
scheme, including those I've posted. I expect the rotating capacitive
blade linkage designs I posted about 10 years ago might work better
than the magnetohydrodynamic methods (same advantage, only mechanical
power input).
For one thing, the MIT announcement requires electricity up front,
whereas magnetolysis does not!
Bockris suggested an 11 T superconducting magnet was necessary. That
puts it way outside the economic ballpark. He also said the high cell
resistance had to be overcome.
Huge difference ! The Nocera "breakthrough" did contain a hepingly
large measure of hype. Let's face it. Many experts say that it is
still a yawner, without more.
That is far from certain. Besides, it is still being touted by
various independent parties as one of the most significant
developments of 2008 (references already provided.)
It only addressed
the problem of splitting oxygen in the half-cell and with an
photo-electro-catalyst
Actually it is just a catalyst. No light is involved - except to run
a solar array to drive the thing. It can be run by ordinary DC.
using abundant (i.e. potentially lower - but not low cost)- cobalt
electrodes for the half cell oxygen side. That is a good start!
yes, but it also can possibly be applied elsewhere, even to
magnetolysis perhaps; which in the end, needs only wind, not high
value electrical current.
Therefore it is clear that the MIT advance solves only part of the
problem - and therein lies the large (massive) dose of hype coming
out of that school - where they should require some extra homework
in science for their journalism majors, who often do not have a
clue. Anne is one of the worst.
The hydrogen electrode
used *platinum* (in Nocera's cell).
Platinum is also used for *anodes only* in many commercial
electrolysers - only a thin coating is required. However, most
anything can be used for a cathode, because cathodes don't erode like
anodes. There is a wide range of cheap materials for cathodes. See
the appended post below for more comments.
Opps! read that as $1000++ per ounce. Deal-buster. Exactly the same
deal-buster that has kept fuel cells out of automobiles, so far.
OTOH - they "think" they can avoid platinum (Pd etc) in the future
- but there is not much evidence that they can do so in practice
and maintain the same efficiency AFAIK. NREL has stated before that
"Finding a cheaper catalyst for making hydrogen shouldn't be
too difficult" but they have failed to show it. They have been
eying nickel - so where's the beef, NREL?
All in all, I beg to disagree with rating the Nocera R&D as even a
significant "breaktrough," let alone in the top 10,000.
There is no accounting for taste. 8^)
Put an efficient magnetolysis
There is no such thing yet in existence.
windmill to work in North Dakota - and then IMHO you will have the
real numero-uno advance of the decade.
For now, the MIT stuff remains a significant advance for one half
of the photocatlysis water-splitting problem, and even so - the
larger problem is that it is still that it is only functional for
8-10 hours a day and only converts one form of energy into
another-- whereas a real breakthrough will be system using nickel
electrodes for the other side and producing hydrogen at better than
95% Faradaic efficiency in the sun, and at least 80% when not in
the sun. And they have NOT done this yet or even come close.
My money (if I had any) would be clearly on magnetolysis-windmills
for hydrogen generation - but maybe that kind of attitude (out-of-
step with MIT) relates to why I don't have any ;-)
Jones
On Aug 1, 2008, at 10:30 AM, Horace Heffner wrote:
Consider the following.
From:
http://tinyurl.com/5hw4jd
page 2: "Nocera's catalyst is made from cobalt, phosphate and an
electrode that produces oxygen from water by using 90 percent less
electricity than current methods, which use the costly metal
platinum."
The above statement must mean the anode interface potential drop
has been reduced by 90 percent. I say this in part because the
photos of the experiment show a typical three electrode scheme for
measuring half cell potentials. Dropping one of the half-cell
potentials by 90 percent is a HUGE advancement. This is drop in
the anode interface potential, which is about half the cell minimum
potential drop, therefore represents roughly a 45 percent overall
improvement over other technologies, assuming the plate gap is
maintained sufficiently small and the gas bubbles are sufficiently
handled, in a manner similar or better than typical commercial
electrolysers. In fact, if this potential drop assumption is true,
it changes the baseline for the method of even measuring
electrolytic voltage efficiency. The 1.24 V baseline is moved down
to about 0.7 V. Typical commercial electrolysers run (or at least
used to run) at about 1.9 V, or 65% voltage efficiency. The 0.6 V
drop for the anode would drop the overall required voltage to 1.3 V
for similar hydrogen production, and thus, by the old measuring
standard, would cause the cell to operate at nearly 100% voltage
efficiency.
Further, the anode no longer needs to be made of platinum in order
to avoid anode digestion because it is continually recoated (with
phosphorous I assume) by the electrolysis process. Electrolyser
cathodes are already made fairly efficiently using thin platinum
coatings, though stainless steel works pretty well too.
This eventually will present a major threat to various battery
companies that are in or moving into the renewable energy
transmission power management field. It also represents a huge
opportunity for developing solar powered fertilizer production,
especially in sunny desert regions. This can free up natural gas
for other uses, like vehicle propulsion.
Lastly, the cell components are not highly corrosive, expensive, or
even resource limited, so this permits wide use of the technology
in small distributed systems and in third world countries. The
timeline for this is greatly reduced by similar recent advancements
in fuel cells.
It appears to me this is a world changing development. I expect it
will not take 10 years to see it applied to utilities power
management. I don't see why it wold not be possible to just change
out the electrolyte in order to significantly benefit some
electrolysers. If true, then it is only intellectual property
rights that might get in the way of progress, and that is
explicitly to be avoided according to statements by MIT.
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
