Extract hydrogen from plants in large quantities

[jean.caissepas]

Hello,

Hope for "clean" energy that could reduce our oil needs.

source:

http://www.enerzine.com/6/15568+extrair ... lite+.html

Good reading !

[Ahmed]

The big current problem is not the scarcity of energy sources, but their too great abundance, abundance which makes it possible to destroy nature happily: a new source of energy which would have no quantitative limitation and a low impact ( *) on the environment would be even more formidable than those we know.

* An energy extracted from plants would immediately raise the question of the allocation of arable land and balances with food crops.

[chatelot16]

blah ... very complicated ... there is a way to make hydrogen with wood and almost everything that has been burning for more than a century ... of course it does not make pure hydrogen but a mixture of hydrogen and carbon monoxide ... it's 2 combustible gases which burn as well as the other

this means is the gasifier

damage to the fuel cell carbon monoxide pollutes it, but no matter the fuel cell is expensive is at a lousy performance ... the good old combustion engine has the same performance but does not cost more than a scrap cylinder and a piston

[Did67]

Basically this is not "logical":

a) plants, thanks to photosynthesis, store energy in the form of hydrocarbon molecules (often symbolized by glucose: C6H12O6).

b) in these molecules, C and H are "oxidizable"; during this oxidation, they release the stored energy and return to the state of "oxidized" waste: CO² and H2O

c) efficient use of the stored solar energy therefore supposes oxidizing both the carbon and the hydrogen, one in the form of CO², the other in the form of H2O.

This is what happens in a cell, which "gently" oxidizes glucose, it is what happens in a combustion (fire), it is what happens in an explosion (methane CH4 in a group cogeneration).

So "extracting H² from plants" means doing the job halfway. And it is indeed complicated existence indeed, given the "simple" methods (fire, pyrolysis ...), even natural (methanization) that exist ..

[hic]

Biological production of hydrogen by algae
*** http://fr.wikipedia.org/wiki/Production ... des_algues ***

To see
And if 'natural' hydrogen turns out to be exploitable (as well as helium)
'Natural' geological hydrogen
- hydrogen / methane hydrogen / nitrogen
*** http://www.enerzine.com/12/15593+et-si- ... sersPage=1 ***

The first work of IFPEN confirmed the existence of locally significant fluxes of H2 on the largest massive peridotites, on a global scale; but above all they have demonstrated the ubiquity of hydrogen flow in the intraplate zone. Diffused in most of the sites, these flows locally present substantial accumulations. The various natural fluids studied can have more than 80% of H2. This gas is associated with methane, sometimes *** with nitrogen, and locally with helium in economically exploitable quantities (while the world supply of this rare gas which finds high-tech applications is also currently very tense).

Basically this is not "logical":

a) plants, thanks to photosynthesis, store energy in the form of hydrocarbon molecules (often symbolized by glucose: C6H12O6).

b) in these molecules, C and H are "oxidizable"; during this oxidation, they release the stored energy and return to the state of "oxidized" waste: CO² and H2O

c) efficient use of the stored solar energy therefore supposes oxidizing both the carbon and the hydrogen, one in the form of CO², the other in the form of H2O.

This is what happens in a cell, which "gently" oxidizes glucose, it is what happens in a combustion (fire), it is what happens in an explosion (methane CH4 in a group cogeneration).

So "extracting H² from plants" means doing the job halfway. And it is indeed complicated existence indeed, given the "simple" methods (fire, pyrolysis ...), even natural (methanization) that exist ..

[Did67]

OK, nth version of the delusions which simply show a crass ignorance of a few basic principles. But you can make foam with anything.

Just this:


The researchers selected xylose because it has less than 30% of cell walls.

So let's resume:

Xylose (wood sugar or birch sugar) is an aldopentose.

It is a dare made up of a chain of 5 carbon elements (pentose) as well as an aldehyde function (aldose).
It is in the form of a white crystalline powder stable in air and soluble in water. It is not fermentable4.
D-xylose is often present in wines (contents from 0 to 440 mg · l-1).

Quick Wikipedia quote.

So here we are at the molecular level.

So that a fairly simple mocecule "has only 30% of cell walls" leaves me perplexed (because here we are at the cellular level, which can be seen under an optical microscope!).


That then we can catalyze the destruction of the xylose poiur by freeing it from the hydroigen, let us admit.

But that still begs the question: what becomes of C, which is also a source of energy in its reduced form.

And so wouldn't it be easier to burn xylose?

AND by the way, where would all the xylose come from to meet our energy needs? [knowing that when we burn, anaerobic digestion, ... etc ... biomass, we value most of the organic molecules, which all come from phostosynthesis, and which are all solar energy in "bars" !).

Finally, I remind brilliant researchers that sugar (beet, cane, vine) ferments on its own, turns into alcohol, which is a fuel or a fuel ... It's very simple!

The problem is that we don't have enough space to grow the plants we need to meet our needs, without starving the world.

Even more attractive, as this reaction takes place at low temperature, the production of hydrogen energy is greater than the chemical energy stored in xylose and polyphosphate. This results in energy efficiency of over 100% - a net gain in energy.


The stroke of the miracle enzyme which "catalyzes" a reaction which produces more energy than it consumes, there too, we have already read. And this can only "amaze" the ignorant (or believers).


In short, thus drafted, it is a little anything.

If indeed the catalysis of xylose of one or the other waste not or not currently valued could be something to consider, I am missing an element of the puzzle to understand the stake of this "find".

Until proven otherwise, fermentation seems to me much simpler and much better recover energy from waste. See : http://www.aui.ma/personal/~M.Baha/asli.pdf

This article seems to me to be situated in the general excitement around the production of H² as the "fuel" of tomorrow, forgetting that H² is only a "vector" (like electricity). You need a source of energy at the start: solar ... (in biomass, wind, photovoltaic, hydraulic ...) or nuclear.

[chatelot16]

it's a lot of brainstorming to make hydrogen that we still don't know how to store in a vehicle

we only know how to store it efficiently if it is liquid in large quantities ... but liquid on the scale of a car it is lost at any speed

the gasifier works with any burning biomass, without any requirement on the composition

it produces a mixture H2 and CO which is the raw material to make fuel by the synthesis of fischer tropsh: it therefore makes real fuel lique storable

it worked in germany during the last war

it works again in the GTL gas to liquid factories, which transform methane into artificial petroleum, to recover the methane leaving with petroleum in countries where there is no way to transport methane

it is often believed that the gasifier is a partial combustion which wastes part of the energy of the fuel: no the energy of the partial combustion of C a CO is used to decompose H2O into H2 and O2 which is immediately used to burn carbon