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#1 2019-11-17 21:10:27

tahanson43206
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Registered: 2018-04-27
Posts: 1,634

Hydrogen Production Moving to Mainstream Green solution

For SpaceNut ... I checked for this title all the way back to 2005 and did not find it.

Hopefully this topic will win some updates in the current period.

The article at the link below reports on industry efforts to learn how to use hydrogen for heat intensive processes that until now have relied upon fossil fuels.

Apparently there is a level of stockholder and stakeholder pressure that is incentivizing some industries to look for ways to make hydrogen without generating CO2.

The connection I see to the Mars enterprise is that increased production of hydrogen and reduced costs may help to reduce costs to launch payloads to LEO and beyond.

https://www.yahoo.com/finance/news/fuel … 28443.html

(th)

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#2 2019-11-18 10:37:20

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 17,382

Re: Hydrogen Production Moving to Mainstream Green solution

The green creation of hydrogen has been an ongoing for a couple of decades now wit the cost of CO2 being the issue for why do it as the global warming has been said to be not real by many that make no money from going against its alternative energy sources. The fuel cell topics contain materials on where we have gone with the regulations, handling and explosiveness of its use. Much like propane, natural gass we would need to add in an odor to allow for detection of leaks. We will need to add in other safe guards to the tank which holds the gas as we will be using it under pressure. Possibly some solutions will have a blend of gasses mixed with the hydrogen to aid in making it less hazardous.
A title that comes to mind in the hydrogen economy where the gas is made from solar for home use and for hybird cars which use a fuel cell to creat power for driving.
What makes it green is the no use of fossil fuels in any form to create the hydrogen to work from.

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#3 2019-11-18 13:01:25

tahanson43206
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Registered: 2018-04-27
Posts: 1,634

Re: Hydrogen Production Moving to Mainstream Green solution

For Louis re topic ...

Louis, at present, the cost of production of hydrogen from wind, solar power, or solar power satellites (probably or almost certainly) exceeds of the cost of production of hydrogen from fossil fuel sources.  However, in light of the perceived need by some humans to eliminate the use of fossil fuels altogether, I'm wondering what the green premium might be? 

In other words, what do you think the business case might be for taking the risk of investing in green hydrogen production facilities in light of the potential demand for green hydrogen?

(th)

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#4 2019-11-18 16:47:39

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 17,382

Re: Hydrogen Production Moving to Mainstream Green solution

Related topics
Fuel Cell Development, Application, Prospects

Hydrogen Car Powered by Expansion of Liquid H2

Hydrogen bad for the environment?

The itemized cost of each when you figure in the equipment maintenance, storage, the source of water quality, are just some of the things that are never put into the numbers. The fact is most only see the fact that the source to make the device work as being the only free aspect to the gain.

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#5 2019-11-18 17:35:05

louis
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From: UK
Registered: 2008-03-24
Posts: 5,333

Re: Hydrogen Production Moving to Mainstream Green solution

If we are talking about a hydrogen economy on Earth, I don't really see hydrogen as the real green solution.  Hydrogen storage is problematic from lots of points of view, meaning it ends up being v. expensive. Just adding a bit of hydrogen to methane supply is not really a game-changer.

It might be possible to have central hydrogen facilities for electricity generation (to even out wind, solar and other green energy sources).

I see methane manufacture as the way forward, as in many countries we already have a methane-based infrastructure, so you can use it for heating as well as electricity generation (to even out intermittent energy sources). I think if you can get green energy costs down to 1 cent per KwH, it will definitely be possible to manufacture methane at a marginal cost that makes green energy cost-competitive across the board. It might be possible now in some climates with even higher costs...some climates have fairly consistent wind or solar, and so you need to cover fewer lengthy gaps in generation.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#6 2019-11-19 16:25:05

elderflower
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Registered: 2016-06-19
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Re: Hydrogen Production Moving to Mainstream Green solution

For a liquid fuel, it is easy to manufacture methanol which will work in most of our liquid fuelled devices with relatively minor modifications and which can be reformed to give Hydrogen and CO. The CO is burned to heat the reformer and the hydrogen is fed to a fuel cell for electricity production. CO2 is released and must be recaptured.

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#7 2019-11-19 18:49:45

SpaceNut
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From: New Hampshire
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#8 2019-11-20 17:30:53

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 225

Re: Hydrogen Production Moving to Mainstream Green solution

Hydrogen has poor cycle efficiency as an energy storage medium.  First, about a third of electricity is lost as heat in the electrolysis stack.

The energy cost of storing hydrogen depends upon its mode of storage.  It is relatively cheap to store in a lightly pressurised gasometer arrangement.  But capacity is limited.  Compressing hydrogen to 300bar would consume another 10% energy content and the hydrogen would gradually leak through seals.  Liquefaction allows hydrogen to be stored long-term as a liquid at 20K.  But the energy cost is equivalent to about one third of the energy content of the liquid hydrogen.  Ultimately, electrical power can be recovered in a fuel cell or, more likely, a combined cycle gas turbine plant.  Both have realistic efficiency of about 50%.  Add all efficiencies together and you get 22-33%.

In terms of bulk energy storage, it might be cheaper to store thermal energy in rock by means of electric heating elements.  This can be recovered as steam passing through pipes in the hot rock, which generates electricity in a turbine.  Storage efficiency would be 30-50%.  Whilst this is better than hydrogen, it is still not fantastic.  But the system is simpler overall and a single cubic metre of basalt heated to 1000C would store nearly 3GJ of energy.

In terms of whole system cost, thermal energy storage is hard to beat.  Hydrogen has the advantage of being a useful chemical reagent.  If you want to reduce metal ores or manufacture plastics, hydrogen is an intermediate product that is likely to be useful.  Storage isn't very important, because the hydrogen is likely to be used rapidly after it is produced.

Last edited by Calliban (2019-11-20 17:37:41)


Interested in space science, engineering and technology.

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#9 2019-11-20 17:49:34

louis
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From: UK
Registered: 2008-03-24
Posts: 5,333

Re: Hydrogen Production Moving to Mainstream Green solution

There are plenty of elevated craters on Mars. They would probably make perfect reservoirs for pumped storage. They might need to be lined with clay. They might need to be covered with a floating aerogel layer to help retain heat and keep the water liquid...that could also be achieved by using fixed reflectors to shine light on to the crater.

Calliban wrote:

Hydrogen has poor cycle efficiency as an energy storage medium.  First, about a third of electricity is lost as heat in the electrolysis stack.

The energy cost of storing hydrogen depends upon its mode of storage.  It is relatively cheap to store in a lightly pressurised gasometer arrangement.  But capacity is limited.  Compressing hydrogen to 300bar would consume another 10% energy content and the hydrogen would gradually leak through seals.  Liquefaction allows hydrogen to be stored long-term as a liquid at 20K.  But the energy cost is equivalent to about one third of the energy content of the liquid hydrogen.  Ultimately, electrical power can be recovered in a fuel cell or, more likely, a combined cycle gas turbine plant.  Both have realistic efficiency of about 50%.  Add all efficiencies together and you get 22-33%.

In terms of bulk energy storage, it might be cheaper to store thermal energy in rock by means of electric heating elements.  This can be recovered as steam passing through pipes in the hot rock, which generates electricity in a turbine.  Storage efficiency would be 30-50%.  Whilst this is better than hydrogen, it is still not fantastic.  But the system is simpler overall and a single cubic metre of basalt heated to 1000C would store nearly 3GJ of energy.

In terms of whole system cost, thermal energy storage is hard to beat.  Hydrogen has the advantage of being a useful chemical reagent.  If you want to reduce metal ores or manufacture plastics, hydrogen is an intermediate product that is likely to be useful.  Storage isn't very important, because the hydrogen is likely to be used rapidly after it is produced.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#10 2019-11-20 18:49:10

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 17,382

Re: Hydrogen Production Moving to Mainstream Green solution

Calliban Is correct about heat lose of conversion from water to gas and then to compress it for later use but for mars we can recapture that low energy heat with pellitier devices. These work create power from the heat differential from the surface of the electrolysis unit to the cold of mars and the same can be had with the tank storage as well as the compressor.
The next factor for both with the creation of heatis the speed of raction and of compressing values as the smaller the delta is the lower the temperatures will be.

https://en.wikipedia.org/wiki/Liquid_hydrogen
http://hyperphysics.phy-astr.gsu.edu/hb … phase.html

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#11 2019-11-22 00:55:32

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 225

Re: Hydrogen Production Moving to Mainstream Green solution

Methane-oxygen would appear to be problematic as a bulk energy storage solution, on Earth or Mars.

https://en.m.wikipedia.org/wiki/Sabatier_reaction

"A variation of the basic Sabatier methanation reaction may be used via a mixed catalyst bed and a reverse water gas shift in a single reactor to produce methane from the raw materials available on Mars, utilising carbon dioxide in the Martian atmosphere. A 2011 prototype test operation that harvested CO2 from a simulated Martian atmosphere and reacted it with H2, produced methane rocket propellant at a rate of 1 kg/day, operating autonomously for 5 consecutive days, maintaining a nearly 100% conversion rate. An optimised system of this design massing 50 kg "is projected to produce 1 kg/day of O2:CH4 propellant ... with a methane purity of 98+% while consuming 700 Watts of electrical power. Overall unit conversion rate expected from the optimised system is one tonne of propellant per 17 MWh energy input.[25]"

By my reckoning, even an optimised system will have an efficiency of 18%.  If the methane is then burned in an IC engine or gas turbine with an efficiency of 30%; overall efficiency drops to around 5.4%.  Not something that would be affordable as anything other than a niche application, maybe used in emergencies.

Pumped storage has better efficiency on the face of it.  However, water will not be cheap on Mars.  It must be melted and pumped from deep buried glaciers at an energy cost of 1MJ per kg.  It must also be kept liquid, which implies either heating it or storing it as brine, which would suffer corrosion problems.  On Earth, in places where pumped storage is used, the water is available for free and it remains liquid at typical temperatures.  A Martian system might use liquid CO2.  But this must be kept under a pressure of at least several bars to remain liquid.  That implies that the storage lake is built at a pressure vessel.

We have already discussed hydrogen.  On Mars, we must keep both hydrogen and oxygen in separate pressurised containers.  This would require either steel or polymer vessels, or underground reservoirs that are excavated and covered over with a mass of covering material.  Either way, it is a lot of effort and a lot of embodied energy.

All things considered, the storage of energy would appear to be expensive, however it be done.  On Earth, we tend not to do things this way.  Most bulk energy supply is controllable according to demand.  Wind and solar power are simply extensions of the fossil fuel energy system.  Fossil fuels are used to refine and smelt the metals used to make these systems.  They are used to transport and assemble the machines.  And when power is produced by a wind or solar power plant, it offsets the output of another controllable (fossil) power plant.

Last edited by Calliban (2019-11-22 01:21:24)


Interested in space science, engineering and technology.

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#12 2019-11-22 03:50:40

Terraformer
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From: Lancashire
Registered: 2007-08-27
Posts: 3,161
Website

Re: Hydrogen Production Moving to Mainstream Green solution

Compressed gas energy storage discussion

There was a thread about storing power by freezing CO2 during the night and expanding it during the day, as well. It had better than 100% efficiency as storage, so we would actually be getting slightly more power back out than it took to freeze/liquefy the CO2.


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

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