Methanation (H2 + CO2 -> CH4) to smooth EnR production

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Christophe
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Methanation (H2 + CO2 -> CH4) to smooth EnR production




by Christophe » 08/05/12, 18:06

Interesting interview on the stabilization of renewable (green) electricity production by the development of a "regulating" methanization network with respect to the electricity network and other more unstable renewable sources (solar and wind).

The instability of production is one of the major problems of renewable energy (especially for solar)

Methanation, a solution for the future to overcome the variability in renewable energy production

Jean François Papot, associate director of the Les EnR design office, offers us an expert opinion on the usefulness of methanation for storing energy and alleviating the variability in the production of renewable energies.

"Yes, but what do you do when the sun and wind are gone?" This simple question too often ends the debate on the massive integration of renewable energies into our energy mix. Worse, it is often followed by a stereotypical spiel about the need to relight coal-fired power stations or the evocation of a return to the candle. The main criticism against renewable energies is indeed the intermittence of their production.

Renewable energy mix: the question is no longer "if" but "when"

Faced with the shortage of fossil fuels and the growing unacceptability of nuclear power, the massive use of renewable energies to produce our electricity is no longer seen as an ecological utopia but indeed as a necessary transition both from the point of view economic than environmental. From this need arises another: to provide an answer to the intermittency of renewable energies to store the surplus of the periods of production and respond to peaks of consumption.

Intermittence is expected: it's even a job!

First of all, it should be remembered that intermittence does not mean unpredictability. It is thus quite possible, on a regional scale for example, to predict the production of a wind farm or photovoltaic power plants several hours in advance. As any network operator already anticipates peaks in consumption, the most innovative (in Spain, Germany, etc.) have learned to integrate an energy mix with a strong renewable component (occasionally greater than 100%) and therefore to manage this famous intermittence. When production is greater than consumption, it is thus common to “store” electricity via, for example, pumped storage energy transfer stations (STEP) to “lift” water drawn from it. downstream to upstream of a hydraulic dam. This water can then be reconverted in a conventional manner into energy by the dam at the cost of a loss of yield of the order of 20 to 30%. This intermittent management (production by storage and consumption by demand response) is one of the challenges of future smart grids, which currently mobilize enormous financial, technical or industrial resources.

Methanation: building a bridge between gas and electricity

Despite this, the massive use (i.e. close to 100%) of renewable energies requires finding new storage methods. Some elegant tracks exist but come up against technical (regulation of charge / discharge cycles for electric batteries), quantitative (STEP, compressed air storage, etc.), environmental (exploitation of materials for batteries) or safety limits. (hydrogen storage) and therefore will not allow, even by combining them, to respond satisfactorily to the problem as a whole.

One of the great strengths of the negaWatt scenario is to have responded to this problem by highlighting the necessary complementarity between gas and electricity. It is classic to think of gas to produce electricity (cogeneration) but a known and French concept also makes it possible to reverse the paradigm to create an equivalence, with the loss of yield close, between these two energies: methanation.

Sabatier's formula: CO2 + 4 H2 = CH4 + 2 H2O

(...)



Source continued: http://www.actu-environnement.com/ae/ne ... 15627.php4
Last edited by Christophe the 11 / 10 / 15, 21: 05, 2 edited once.
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by dedeleco » 08/05/12, 18:57

In summary, they propose to store electricity by making methane by electrolysis in H2 then methane, 60% yield they say!

To redo electricity, it falls to 60% x 30% = 18% max.
If this electricity is photovoltaic panels yield 15% is recovered after electricity only 18% of the 15% of the starting sun is 2,7% in stored electricity of the sun fallen on the panels !!!

A little weak, it seems more efficient to concentrate solar thermal (more than 50% yield) and to store in the various various possibilities, such as melted salts or in the earth in solar geothermal form (similar to the hot volcanic underground volcanoes where it is stored. solar heat) to recover 80% of these 50%, to heat or to make electricity with thermal machine that gives 30% of 50% is 15% in electricity of night and day, 15% of the sun of departure, also although the photovoltaic panels, them without any capacity of storage, with this output !!!

For the electricity of wind turbines, with methane storage complex, have recovered 18% of the original electricity, while by pumping storage in dams height is recovered 50 70%.

Methanization seems very complicated and has a fairly low yield.
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by Christophe » 08/05/12, 19:29

Rahh this dedicated always to scratch!

a) Renewable energy that cannot be stored or used directly is lost, so the storage yield is (much) less important to me than a return on the use of fossil energy!

b) The article talks about 60% of storage yield which is not bad

dedeleco wrote: or, 2,7% in stored electricity of the sun fallen on the panels !!!


c) Completely ... but see a) and compare with the overall storage yields of solar energy by the best biofuels which do not exceed ... 1% !! (finding a study would be good)

d) We can also consider that biogas can be stored ... to meet peak periods! Without storage conversion!

So yes the conversion via CH4 seems to me as complicated to set up ...
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by chatelot16 » 08/05/12, 20:46

do not waste your energy making methane with solar energy!

you just have to store the methane from the methanization, to transform it into electricity only when the non-controllable producers like wind and solar do not do enough

when a methanizer exists, adding a large methane storage gasometer is quite easy ... and a remote control of electrical production by EDF ... in exchange for a higher price than what is produced when electricity is lacking

and do not forget also the other means of stabilizing the network: there are all kinds of factories that have equipment that could be ordered to consume preferably when there is energy available on the network
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by Christophe » 08/05/12, 20:52

chatelot16 wrote:you just have to store the methane from the methanization, to transform it into electricity only when the non-controllable producers like wind and solar do not do enough


This is completely my d) previously! 8)
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by Ahmed » 08/05/12, 21:14

a) Renewable energy that cannot be stored or used directly is lost, so the storage yield is (much) less important to me than a return on the use of fossil energy!

Certainly, Christophe, but the investment which is used to fill the production gaps in renewable energies, then induces an extremely high marginal cost ...
Is speculation about candles a good idea? : Mrgreen:
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by dedeleco » 08/05/12, 22:17

At this yield:

c) Completely ... but see a) and compare with the overall storage yields of solar energy by the best biofuels which do not exceed ... 1% !! (finding a study would be good)


much let nature free to make plants and trees to store the sun for free in logs, just cut, for a photosynthesis yield around%, without any investment no fatigue, apart from cutting up !!!!

In the same desert with the algae in ponds in the sun, to harvest and dry, to have quasi oil !!!!
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by chatelot16 » 08/05/12, 22:33

why oppose solutions which are not concurrent but complementary!

wood gasifier is the best way to use wood for electricity

anaerobic digestion is the best way to use methanisable waste

as by hazar the 2 gases can end up in the same engine!

the same electric factory with internal combustion engine can use biogas that can be stored on a few days and wood that can be stored year-round
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by Fakir » 08/05/12, 23:58

dedeleco wrote:In summary, they propose to store electricity by making methane by electrolysis in H2 then methane, 60% yield they say!

To redo electricity, it falls to 60% x 30% = 18% max.
If this electricity is photovoltaic panels yield 15% is recovered after electricity only 18% of the 15% of the starting sun is 2,7% in stored electricity of the sun fallen on the panels !!!

A little weak, it seems more efficient to concentrate solar thermal (more than 50% yield) and to store in the various various possibilities, such as melted salts or in the earth in solar geothermal form (similar to the hot volcanic underground volcanoes where it is stored. solar heat) to recover 80% of these 50%, to heat or to make electricity with thermal machine that gives 30% of 50% is 15% in electricity of night and day, 15% of the sun of departure, also although the photovoltaic panels, them without any capacity of storage, with this output !!!

For the electricity of wind turbines, with methane storage complex, have recovered 18% of the original electricity, while by pumping storage in dams height is recovered 50 70%.

Methanization seems very complicated and has a fairly low yield.

Totally agree, today there are two solutions with constraints:
The most efficient method is lead battery storage.
The second is the Hydrogen vector method (see the different posts on H²)
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by Fakir » 09/05/12, 00:07

Christophe wrote: a) Renewable energy that cannot be stored or used directly is lost, so the storage yield is (much) less important to me than a return on the use of fossil energy!
I really do not agree with this reasoning. Today, we can drive with sunflower oil in Diesel. Sunflower oil is 100% renewable and yet it is completely utopian to imagine that we roll with it even by covering all of France with sunflowers. The yield is very bad (I calculated it younger ... but there it is late :-))

The efficiency of the energy chain is essential and the investment per m² as well.
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