Sunday, March 7, 2021

Wind, Solar, Now Hydrogen -- Third Time The Charm? Saudi Arabia Pivots -- March 7, 2021

Link here. 

For the archives.

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Hydrogen

I don't have much interest in hydrogen as a fuel source over the next few decades, but it's quite a story, now that I understand the "holy grail" of energy, as it were.

It begins with photosynthesis. 

There are two components:

  • photosynthesis I, requires light; e.g., daylight;
  • photosynthesis II, does not require light; can continue throughout the night;

Photosynthesis II requires an oxygen-evolving complex -- the complex sits at the very edge of the Photosynthesis II system itself, facing the outside world, and gives a sense of being 'tacked on.' It's shockingly small. The complex is a cluster of four manganese atoms and a single calcium atom, all held together by a lattice of oxygen atoms. And that's that.

That was from Life Ascending: The Ten Great Inventions of Evolution, Nick Lane, p. 85.

Lane goes on:

... until 2006, we did not know the structure of the manganese cluster in atomic resolution, ... but now we know ... Whether the original oxygen-evolving complex was simply a bit of mineral that got wedged in Photosystem II, we don't know ... Like a few other metal clusters found at the heart of enzymes, it is almost certainly a throwback to the conditions found billions of years ago in a hydrothermal vent. Most precious of all jewels, the metal cluster was wrapped in a protein and held in trust for all eternity by the cyanobacteria.

However it formed, this little cluster of manganese atoms opened up a new world, not only for the bacteria that first trapped it, but for all life on our planet. 

Once it formed, this little cluster of atoms started to split water, the four oxidized manganese atoms combining their natural avidity to yank electrons from water, thereby releasing oxygen as waste. 

Stimulated by the steady oxidation of manganese by ultraviolet radiation, the splitting of water would have been slow at first. But as soon as the cluster became coupled to chlorophyll, electrons would have started to flow. 

Getting faster as chlorophyll became adapted to its task, water was sucked in, split open, its electrons drawn out, oxygen discarded.

One a trickle, ultimately a flood, this life-giving flow of electrons from water is behind all the exuberance of life on earth

We must thank it twice -- once for being the ultimate source of all our food, and then again for all the oxygen to burn up that food to stay alive.

It's also the key to the world's energy crisis. We have no need for two photos systems, for we're not interested in making organic matter. We only need the two products released from water: oxygen and hydrogen. 

Reacting them together again generates all the energy we'll every need and the only waste is water. 

In other words, with this little manganese cluster, we can use the sun's energy to split water, and then react the products back together to generate water -- the hydrogen economy. 

Chemists around the world are racing to synthesize this tiny manganese cluster in the lab, or something similar that works as well. Soon, surely, they will succeed.

And then it can't be long before we learn to live on water and a splash of sunshine.

Perhaps something that Sophia will see someday.

Right now, as readers tell me, it is incredibly expensive the way humans use electricity to make hydrogen.

What amazes me is that the Japanese and Chinese are able to reverse engineer American inventions, but American inventors are not able to reverse engineer what nature has done.

2 comments:

  1. Concept is easy to understand. Making it work profitability at industrial high quantities is the real challenge.

    ReplyDelete
    Replies
    1. Agree completely. What amazes me is nature figured it out two billion years (?) ago and we have not been able to reverse engineer what nature accomplished with with chloroplasts/chlorophyll.

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