Naked Science Forum
General Discussion & Feedback => Just Chat! => Topic started by: Europan Ocean on 21/05/2021 08:57:47
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The NSW state government plans to build a new power station in case the green powers sources temporarily under supply. People complain that natural gas is a fossil fuel. But could a station that burns gas also be designed to burn Hydrogen?
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But could a station that burns gas also be designed to burn Hydrogen?
Yes.
Where do you plan to get the hydrogen from?
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Unlimited renewables, of course. Or cucumbers.
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renewables, of course
That's obviously possible.
You can pass steam through hot charcoal to get hydrogen, but it's not practical because you could just burn the charcoal in a conventional power station.
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You can pass steam through hot charcoal to get hydrogen, but it's not practical
Indeed, so impractical that it provided the main source of fixed domestic and light industrial power including street lighting, in the western world for about 150 years.
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You can pass steam through hot charcoal to get hydrogen, but it's not practical
Indeed, so impractical that it provided the main source of fixed domestic and light industrial power including street lighting, in the western world for about 150 years.
So, you don't realise that coke is different from Pepsi and from charcoal.
Here's a hint; one is renewable and was not used much to make hydrogen.
The other is a fossil fuel.
But it would still be impractical anyway- since you could burn the coal/ coke/ charcoal in a power station without the wasted effort of making hydrogen.
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Coke is not much different from charcoal. It's coal from which all the useful volatiles has been distilled, leaving about 70 - 90% carbon. As you say, it is totally impractical to pass the resulting gases through pipes to be burned in ovens and engines, which is why the Victorians did it on such a large scale.
Manufacturers of gas engines include Hyundai Heavy Industries, Rolls-Royce with the Bergen-Engines AS, Kawasaki Heavy Industries, Liebherr, MTU Friedrichshafen, GE Jenbacher, Caterpillar Inc., Perkins Engines, MWM, Cummins, Wärtsilä, GE Energy Waukesha, Guascor Power, Deutz, MTU, MAN, Fairbanks-Morse, Doosan, and Yanmar.
All hopeless fools with no engineering credibility at all.
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Yes.
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Coke is not much different from charcoal.
Radiocarbon date them and get back to me.
Or just stop trying to pretend that you screwed up on the relevant issue of "renewable ness".
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You missed the point. The process is entirely practical, whether you use charcoal (made by distilling all the pollutants from fresh biological material) or coke (ditto, fossil material) but not particularly efficient if you are going to use the hydrogen to generate electricity. Either way you produce lots of carbon dioxide, which is a mortal sin.
Only problem with burning charcoal directly in a power station is that the energy required to harvest, transport and reduce fresh biowaste to carbon is currently more than the electrical energy it generates!
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Either way you produce lots of carbon dioxide, which is a mortal sin.
No.
In one approach you return CO2 to the atmosphere which was there recently, and in the other you dump ancient carbon into the atmosphere.
just stop trying to pretend that you screwed up on the relevant issue of "renewable ness".
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You missed the point. The process is entirely practical, whether you use charcoal (made by distilling all the pollutants from fresh biological material) or coke (ditto, fossil material) but not particularly efficient if you are going to use the hydrogen to generate electricity. Either way you produce lots of carbon dioxide, which is a mortal sin.
Only problem with burning charcoal directly in a power station is that the energy required to harvest, transport and reduce fresh biowaste to carbon is currently more than the electrical energy it generates!
Hydrogen is an exellent way to ween people off oil and powerstations of gas. Sience and industry do not mix. What is scientifically achievable and industrially worthwhile are two very different things. After aceptance you can introduce the hydrogen fuel cell etc. Infrastru ture is a very expensive thing to implement.
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No.
In one approach you return CO2 to the atmosphere which was there recently, and in the other you dump ancient carbon into the atmosphere.
Blasphemy! Apostasy!
If the carbon was once there, the planet must have survived its presence. So putting it back won't do any serious harm.
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No.
In one approach you return CO2 to the atmosphere which was there recently, and in the other you dump ancient carbon into the atmosphere.
Blasphemy! Apostasy!
If the carbon was once there, the planet must have survived its presence. So putting it back won't do any serious harm.
It wasn't all there at the same time.
it wasn't all there when there were humans
it wasn't all there when the Sun's activity was as high as it currently is.
Quote from: Bored chemist on 21/05/2021 23:21:34
just stop trying to pretend that you screwed up on the relevant issue of "renewable ness".
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It wasn't all there at the same time.
It was surely (nearly) all there when the first carbon-sequestering organisms evolved, and the quantity of atmospheric CO2 generally decreased with time as coal and oil deposits were laid down. The presence of humans is fairly irrelevant to the ultimate fate of the planet, though you can reasonably argue that we are restoring the air towards its pre-Carboniferous composition.
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It was surely (nearly) all there when the first carbon-sequestering organisms evolved,
it wasn't all there when there were humans
Quote from: Bored chemist on Yesterday at 17:09:27
Quote from: Bored chemist on 21/05/2021 23:21:34
just stop trying to pretend that you screwed up on the relevant issue of "renewable ness".
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I repeat, the planet has survived much higher CO2 concentrations, up to 6000 ppm. It is toxic to most mammals at around 3% (30,000 ppm) so it doesn't pose a chemical threat to humans at current or even prehistoric concentrations.
The problem for humans is that our society is not sufficiently robust to accommodate significant climate change, and has not been for thousands of years, with coastal communities either being swamped or finding themselves a hundred miles from where the sea used to be, and deserts encroaching on farm land. Getting excited about a whiff of CO2 isn't going to solve the human problems caused by overpopulation and a reliance on climate stability.
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I repeat, the planet has survived much higher CO2 concentrations, up to 6000 ppm.
And I repeat that we haven't.
The presence of humans is fairly irrelevant to the ultimate fate of the planet,
If you are so sure that you (as a human) are irrelevant, why not shut up?
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Getting excited about a whiff of CO2 isn't going to solve the human problems caused by overpopulation and a reliance on climate stability.
Not fixing CO2 emission doesn't help those issues either- it makes them worse.
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True, but whilst we will run out of fossil fuel eventually and thus resolve that obsession, if we carry on as usual the human population will continue to grow until disaster strikes or we all agree to live in overcrowded misery.
Just because humans have no cosmic significance is no reason why life should not be pleasant for our descendants.
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if we carry on as usual the human population will continue to grow until disaster strikes or we all agree to live in overcrowded misery.
Have you noticed that, in much of the "developed" world, the birth rate had fallen dramatically before global warming became an issue.
True, but whilst we will run out of fossil fuel eventually
Quite possibly not.
We might find better ways to get feedstocks.
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Climate change has always been an issue. Whilst the postwar UK birthrate was at its maximum, global cooling was an issue. I'm not interested in fashionable names for the current climate process.
But populations increase at both ends: increased infant survival and increased longevity. Life expectancy in the UK has increased about 18% in my lifetime and childhood mortality is about 25% of its value in the 1950s. Whilst the birthrate is 30% lower the population is now 34% higher than in 1950.
We might find better ways to get feedstocks.
and thus increase atmospheric CO2. Not a good idea, surely?
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The government wants to be a zero Carbon emissions country by 2050. I think solar power and sea water is an option to extract Hydrogen, and maybe by product Oxygen, and sea minerals like Potassium and Gold... Then transport and storage are issues.
Hydrogen leaks through Cobalt... we could lose a little Hydrogen constantly. Best metal for holding it is something like Platinum, but I saw a new invention, being a powder that worked better than a cylinder.
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The government wants to be a zero Carbon emissions country by 2050. I think solar power and sea water is an option to extract Hydrogen, and maybe by product Oxygen, and sea minerals like Potassium and Gold... Then transport and storage are issues.
Hydrogen leaks through Cobalt... we could lose a little Hydrogen constantly. Best metal for holding it is something like Platinum, but I saw a new invention, being a powder that worked better than a cylinder.
So, you are saying that we could use electricity to split sea water to get hydrogen which we could use in a power station to make electricity.
Well, yes we could.
But it would expensive and inefficient.
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The government says, the gas power station, is for use only when wind and solar are insufficient. When the wind doesn't blow. Gas in a powder or cylinder, can be transported to a plant.
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The government says, the gas power station, is for use only when wind and solar are insufficient. When the wind doesn't blow. Gas in a powder or cylinder, can be transported to a plant.
Given so little of our energy is in electric and so little electric from gas fired electric it makes you wonder what the problem with coal is. They are just rearranging the deckchairs on the titanic.
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I can't understand why these arguments are going on, about power generation.
Isn't the answer blindingly obvious:
1. To generate mass power to service the centres of civilisation, such as cities - use nuclear power stations.
2. To generate individual power for vehicles, such as cars, and aircraft - use hydrogen-fuelled combustion engines
Both of these methods, need not contaminate the Earth's environment.in the slightest.
The waste from nuclear power stations, could be dumped into the deep ocean. Which would shield the radiation.
And the waste from hydrogen cars would be just water-vapour, which might actually be beneficial to combat the desiccating effects of Global Warming.
It all seems so obvious, so what's all the fuss about?
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The waste from nuclear power stations, could be dumped into the deep ocean.
Where they would dissolve contaminating essentially the whole planet.Both of these methods, need not contaminate the Earth's environment.in the slightest.
Yeah- right.
https://en.wikipedia.org/wiki/Nuclear_and_radiation_accidents_and_incidents
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So, you are saying that we could use electricity to split sea water to get hydrogen which we could use in a power station to make electricity.
Well, yes we could.
But it would expensive and inefficient.
In energy terms, certainly inefficient, but in terms of value for money it's way ahead of battery storage and much more adaptable than pumped hydro. And the intermediate products of H and O are themselves valuable.
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So, you are saying that we could use electricity to split sea water to get hydrogen which we could use in a power station to make electricity.
Well, yes we could.
But it would expensive and inefficient.
In energy terms, certainly inefficient, but in terms of value for money it's way ahead of battery storage and much more adaptable than pumped hydro. And the intermediate products of H and O are themselves valuable.
Yep that 80 percent threshold is certainly lower than losses in the grid, exess generation, battery inefficiencies and storage losses. As this is just chat I am being sarcastic, I think that it is only reasonable to point this out.
Hydrogen is slightly dangerous to generate and store though in large quantities, many many more gasometers tha n the uk ever had would be needed just for enough to power the uk for 1 hour. Hydrogen gas is even worse than lithium batteries for energy density. Liquid fuels have so much more appeal than gas or solid.
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Hydrogen is slightly dangerous to generate and store though in large quantities, many many more gasometers tha n the uk ever had would be needed just for enough to power the uk for 1 hour.
But the gasometers the UK used to have, powered the UK for 100 years on 50% hydrogen. One of my old bosses was assigned to fire watch on top of a gasholder during the Blitz. He said that tracer bullets just produced a steady flame which was extinguished with a bit of sticky rubber like a tyre patch.
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Hydrogen is slightly dangerous to generate and store though in large quantities, many many more gasometers tha n the uk ever had would be needed just for enough to power the uk for 1 hour.
But the gasometers the UK used to have, powered the UK for 100 years on 50% hydrogen. One of my old bosses was assigned to fire watch on top of a gasholder during the Blitz. He said that tracer bullets just produced a steady flame which was extinguished with a bit of sticky rubber like a tyre patch.
Tell it to the hindenburg.
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Analysis of the Hindenburg film footage shows that the aluminium-coated fabric caught fire and spread it. Hydrogen balloons and airships did not generally burst into flames when flying.
Wikipedia has an interesting example
The Gasometer Oberhausen is a former gas holder in Oberhausen, Germany, which has been converted into an exhibition space......... During World War II, the Gasometer was hit by bombs several times, but kept operating. When it was shelled by allied forces it did not explode, but the gas burned up and the pressure disc slowly descended.
But why let facts spoil a good argument?
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Analysis of the Hindenburg film footage shows that the aluminium-coated fabric caught fire and spread it. Hydrogen balloons and airships did not generally burst into flames when flying.
Wikipedia has an interesting example
The Gasometer Oberhausen is a former gas holder in Oberhausen, Germany, which has been converted into an exhibition space......... During World War II, the Gasometer was hit by bombs several times, but kept operating. When it was shelled by allied forces it did not explode, but the gas burned up and the pressure disc slowly descended.
But why let facts spoil a good argument?
Yes, also propane will not explode unless mixed with air and wheat dust if mix with air will explode also. Outside of these limits ignition will not take place. But still, the Hindenburg.
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....did not explode but burned from the outside.
Petrol vapor explodes quite nicely when mixed with air and ignited, and diesel fuel doesn't even need a spark! It may eventually dawn on you that the whole point of a thermal fuel is that it combines with oxygen and releases a lot of energy. The trick is to ignite it only when you want to, and for the most part the civilised world managed very well with piped 50% hydrogen for 150 years.Indeed if it hadn't been mixed with carbon monoxide, we'd probably still be using it, like the good citizens of Kirkwall.
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But still, the Hindenburg.
Roughly two thirds of the people on the Hindenburg survived.
That's better odds than a lot of modern aircraft disasters.
The paranoia about gas holders isn't new.
It first came to light when the gasometers were proposed.
The guy who invented them reportedly addressed people's fears of explosions with a burning torch and an axe.
He demonstrated that , if the gas coming out of a hole in the side caught fire, there wasn't a problem- you just got a flame and a waste of gas.
What he was careful not to address was the issue where you get a hole, a build up of gas mixed with air, and then ignition- in which case you get a massive explosion. It's not clear, but hydrogen may produce less of a problem from that perspective. It tends to rise rather than mix.
Indeed if it hadn't been mixed with carbon monoxide
If that had been the problem then this would have been the solution
https://en.wikipedia.org/wiki/Water-gas_shift_reaction
The driver for the change was the availability of North Sea Gas,
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....did not explode but burned from the outside.
Petrol vapor explodes quite nicely when mixed with air and ignited, and diesel fuel doesn't even need a spark! It may eventually dawn on you that the whole point of a thermal fuel is that it combines with oxygen and releases a lot of energy. The trick is to ignite it only when you want to, and for the most part the civilised world managed very well with piped 50% hydrogen for 150 years.Indeed if it hadn't been mixed with carbon monoxide, we'd probably still be using it, like the good citizens of Kirkwall.
Very good. Why do oil rigs burn off their propane gas? Remember the uk uses 6. 6 twh of gas per day. That is 20 peta joules. Hydrogen gas has 10MJ per m2, meaning we need to manufacture through electrolysis at least 2 sqkm per day and store much more. That is producing the fuel and the oxygenator all in one place. I think this may be more tricky than the gasometers piping it from a coking plant
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Very good. Why do oil rigs burn off their propane gas?
They don't. They vent a mixture that's mainly methane.
https://en.wikipedia.org/wiki/Routine_flaring
Because the value per Kg is very roughly the same as for oil, but the volume of a gas is about 100 to 1000 times bigger.
So, if you have a given size of pipe...
Incidentally, would a grown up please tell petrochemicals that sometimes, another part of the answer is something he was too childish to read when I wrote it before
you get a hole, a build up of gas mixed with air, and then ignition- in which case you get a massive explosion.
In some cases, it's safer to always have a fire going.
That way you can't get a build up of gas.
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Hydrogen gas has 10MJ per m2, meaning we need to manufacture through electrolysis at least 2 sqkm
Petrochemicals thinks it is "repetitive antagonism, " when I point out things like his use of stupid units.
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What he was careful not to address was the issue where you get a hole, a build up of gas mixed with air, and then ignition- in which case you get a massive explosion. It's not clear, but hydrogen may produce less of a problem from that perspective. It tends to rise rather than mix.
The trick with a gasometer is the heavy lid and collapsible sides. The gas inside is always above ambient atmospheric pressure so you don't get explosive mixing through a puncture - the escaping gas is burning in an excess of oxygen until the whole structure collapses.
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Pheww, thank goodness for that
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Pheww, thank goodness for that
You do realise that a book shop will explode if you drop a bomb on it, don't you?