Gas crackers
A team from the Karlsruhe Institute for Technology claims to have made a breakthrough on the energy front. They have developed a process to "crack" methane, removing the hydrogen, which can be used as a fuel, and leaving behind black carbon rather than carbon dioxide.
My initial reaction to this was to wonder what we would do with all that black carbon, but the press release has this to say:
It is already widely employed in the production of steel, carbon fibres and many carbon-based structural materials. The black carbon derived from the novel cracking process is of high quality and particularly pure powder. Its value as a marketable product therefore enhances the economic viability of methane cracking. Alternatively, black carbon can be stored away, using procedures that are much simpler, safer and cheaper than the storing of carbon dioxide.
It would be interesting to do the maths here - just how much black carbon might be produced, how much energy would be required to turn it into structural materials and so on. At the moment I remain somewhat unconvinced that this is the breakthrough claimed.
Reader Comments (49)
It's wise to be sceptical, but also hold a little flame of hope. Technological breakthroughs will be the way through this in the end, not hand-wringing and social engineering.
BUCKY BALLS!
....well, could be used for them, I suppose.
My initial reaction to this was to wonder what we would do with all that black carbon
Er, burn it in power stations?
It'll be similar to the ground up coal they burn in power stations, so just chuck it in there...
Far better to get the H2 from water. Essentially it's like charging up a battery as when you burn the H2O you get the water back...
Seems like they would make a lot of hydrogen. It is difficult to store even if liquified and dangerous as a gas ( see Hindenburg disaster) and as yet can't be used in internal combustion engines - although I understand it is technically possible it would require a re-building of the fuel supply infrastructure.
Also as you say one would end up with a whole heap of black carbon.
Watch the space but don't expect an overnight transformation.
No mention of the energy required to crack the methane but it does say it is heated to 750C and above.
""...Notably, we assume that some of the produced hydrogen is used to generate the required process heat....""
It appears to be another perpetual motion machine.
They say the process requires a temperature of 750 degrees without specifying how they achieve that.
This sounds a bit like sunbeams from cucumbers to me.
PS
The phrase "perpetual motion" wandered into my mind as well, Ivor.
The result would be a fine mountain of black carbon. Besides the applications listed, black carbon can also be used to improve soils -- and then you can gainfully dispose of a large volume of the stuff.
Only if one were worried about CO2 is this a breakthru.
I am just an engineer, but does carbon actually burn? Seems to me that when you burn stuff, you get carbon! Mind you, I suppose if you add a mxture of 3 parts pixie dust along with a few greenalists left over from Paris, we may produce some useable energy source!
If you burn carbon you get carbon dioxide.
C + O2 = CO2
This may be of value as a means of generating Hydrogen. And pure carbon has lots of uses.
If it is cheaper than the alternative methods then this is good. If it isn't cheaper then it need not be used.
The only downside is if it is claimed to be cheaper because of fanciful externality costs of CO2. That would waste resources.
WUWT has a post today about Monckton's FOIA request to the Supreme Court. They turned it down citing costs but gave him some answers anyway. The Q&A is rather verbose so I posted an edited version.in a new BH thread to help you.
I really don't like WUWT's clickbait intro - "Britain’s highest court apologizes for breaking the law but dodges questions"
..em actually they apologise for being late answering the FOIA (thats the lawbreak) ..and they answer about half of his questions
" but does carbon actually burn?"
Yes, it burns by combining with oxygen which produces carbon-dioxide.
It is amazing at a time when there is no physical evidence of harm from CO2 (Antarctic ice growing, 18 years no warming, only fabricated and probably fraudulent surface data showing warming) - when there hasn't been increases in severe weather etc. etc., that on a blog supposedly sceptical in nature anyone is ever considering wasting their time with such a stupid idea.
There is no problem to be solved. CO2 is at worst - a plant food greening the planet. At best it will reduce the number of winter fatalities worldwide AND green the planet. The only people who will suffer as this scam ends - are the scamsters.
There really is no issue whatsoever with CO2.
Courtney
C can be burned to CO2, but this will cost energy and turn something useful (C) into a nuisance (CO2)
But there is an issue with CO2. It's the highly convenient peg the eco-warriors have chosen to hang their opposition to fossil fuels on. And that is all that is the issue here. Any reading of the history of the study of climate shows that until the assorted activists, whether traditional Greens or the Ehrlichs or Tickells or Hansens, reached critical mass in around the mid-80s, nobody was really interested in "doing" anything about climate except as an interesting intellectual exercise.
No serious observer believes either that there is anything that needs to be done or can realistically be done to influence the climate and that as and when it varies we will follow our usual course and adapt to what nature throws at us.
Global warming per se is irrelevant.
Mike Hasele @ 10:15r: +10
A pile of black carbon? You can make an awful lot of pencils.
"..how much energy would be required to turn it into structural materials..."
Carbon from cracking methane would probably be the purist possible. The criterion would therefore be the existence of a market for the expected quantities of carbon of this purity. The focus would be the cost savings from using this form of carbon instead of the next best source of carbon that would have to be purified in some way.
So long as the producers and consumers don't ask for a subsidy, this could be useful technology.
The issue here is simply about thermodynamics and entropy. By stopping the process at the constituent element stage, it has failed to extract all the available chemical energy. Additionally, it is highly likely that a considerable amount of energy is consumed during the cracking process, either externally provided energy or energy won from the cracking feedstock.
As a method of producing pure hydrogen and carbon black as raw materials, it may have great merit. As a means of producing process heat, it is probably on a par with the rest of the loony green energy schemes in terms of efficiency and cost. It would probably waste as much, if not more energy than CO2 reclamation does. So if you are so obsessed with not putting CO2 into the atmosphere, it would probably be better to burn it as methane and introduce the requisite inefficiency into the scheme by removing the CO2 through carbon capture.
Incidentally, it is highly unlikely that the amorphous carbon produced could be used structurally as in the illustration. Carbon fibres are manufactured by carbonising rayon fibres or polymeric plastic fibres such as polyacrilonitrile in an inert atmosphere such that the polymeric chains are retained in order to give high tensile strength and stiffness properties. To convert this amorphous carbon into long chain carbon would require that it be recombined to create a long chain polymer, another process requiring substantial energy. So what is the point of that?
Exactly. And the rest.
A typical green press release - full of hype and well sprinkled with pixie-dust but totally devoid of any useful information that would allow an evaluation.
As usual we are expected to accept what we are told and rejoice that there are such 'scientists' leading the way to --- nowhere.
The diesel engine was originally designed to burn coal dust. Powdered black carbon would seem a very obvious substitute.
Alternatively, I believe conversion to diamonds requires a lot of pressure. Couldn't they pile up the weight of evidence that fails to prove CO2 causes global warming?
Those poor plants.
Wont someone think of the plants!
Gaia will die!
Oh woe is me!
Richard Tol
“C can be burned to CO2, but this will cost energy and turn something useful (C) into a nuisance (CO2)”
Apologise for questioning the knowledge of a great man, but if I mentioned the word “coke,” a man of your age would probably think it to be a completely different product than I know it as. In my early days, coke was manufactured by the destructive distillation of coal to make town gas and coke, an early form of smokeless solid fuel and a constituent fuel of blast furnaces. It is almost pure carbon and has a calorific value of around 30,000 kJ/kg.
So if I may modify your statement, C can be burned to CO2 and this will release energy and turn something very useful (C) into a very valuable nutrient (CO2).
Here's the report on eurekalert.org:
http://www.eurekalert.org/pub_releases/2015-11/kift-cie111915.php
There are lots of different forms of pure carbon, they are called allotropes. Diamond, graphite, fullerenes, glassy carbon. Non of these are useful as an energy source but can be used in manufacturing. Converting methane to Carbon and Hydrogen wastes a lot of the potential energy of the methane. Crude oil is cracked into gasoline efficiently but I don't believe that crude can be cracked into methane efficiently and I don't believe that methane can be cracked into Hydrogen and Carbon efficiently. Water is more stable than Hydrogen and Oxygen so "cracking" it is an endothermic reaction. I suspect that methane is more stable than Hydrogen and Carbon so cracking it is also endothermic. This would only be viable as a CO2 reduction scheme if sunlight or sunlight using plants could do the cracking. Otherwise one would have to burn a whole bunch of oil to generate the energy necessary to crack the methane into Hydrogen and Carbon, very similar to hydrolysis reaction with water.
Nov 20, 2015 at 12:26 PM | Colin Porter
Saved me asking the question.
I think Richard Tol meant that CO2 was a nuisance because it is taxed whether we like it or not. He is on the record as saying that manmade CO2 is demonstrably good for the planet up to a point so cut some slack!
The fact that we have SO2 reduction policy still in place long after acid rain was proven to be vastly overhyped tells me that even if the scientists change tack now, the politicians and lawmakers will keep right on dogmatically ploughing the same furrow. Doing a U-turn is rarely the option taken for politicians regardless of how sensible it may be.
CH4 ΔH is -75 kJ/mol
H2O ΔH is about -240 kJ/mol (basis steam)
So about 200 kJ/mol of H2 is theoretically available if there is no loss en route. 1 kg H2 is 500 mol
UK households pay around €18/GJ for CH4 according to europastat, although wholesale prices are only a quarter of that.
I think the plan is to burn some of the hydrogen produced by the process.
There is indeed a large market for the carbon produced, usually referred to as Carbon Black the main difference between it and existing thermal production methods is that most current producers use heavy fuel oils as the feedstock as its not only cheaper than methane but has a higher yield as there is more carbon in it. This process is claimed to produce a surplus of hydrogen which current plants typically use as fuel for the production process so if it works it will be a worthwhile advance.
The Green Industry (Sollab.eu) tried and failed to build a solar furnace to do this. The last heard from the project was 'send more money'
Heat of combustion:
CH4 +2O2 = CO2 2H20 gives 889 kJ/mol
2H2 +O2 = 2H2O gives 2x286kJ/mol= 572kJ, but you have to give back that ~75kJ to crack the methane, plus process inefficiencies in the engineering.
So you're still losing about 1/2 of your energy if you don't burn the carbon. Then you have all the capital and running costs of the extra plant engineering. It's all based on classically useless green non-economic thinking.
The team from the Karlsruhe Institute for Technology are perfectly well aware of this, of course. I wouldn't insult them by pretending otherwise. But if corrupt green politics says "This is what we'll fund you to do, and not sensible stuff", then someone will step up to plate and take the cash. Especially if the alternative is unemployment.
In principle you could run the H2 through a fuel cell; it would be mad to use it in a combustion engine.
More than twenty years ago I proposed methane cracking on behalf of an industrial company, having done the sums to show that at high enough temperatures the thermodynamics would be favourable. The company's chemistry consultants hit the roof and denied its practicality. They were German academics, oddly enough.
After a bit of research, a follow up on my last post. According to http://physics.weber.edu/schroeder/eee/chapter4.pdf:
1) Burning one kilogram of graphite yields 33 MJ. High-grade coal generally yields a little less energy, roughly 29 MJ per kilogram.
1a) Burning one mole of graphite yields 394 kJ.
2) Burning one kilogram of methane releases 50 MJ.
2a) Burning one mole of Methane yields 802 kJ.
3) Burning a kilogram of hydrogen gas releases 121 million joules.
3a) Burning a mole of hydrogen gas releases 242 kJ.
I was wrong about burning carbon, right about hydrogen having more energy than methane by weight, but not by mole. So to crack a mole of methane (CH4) into hydrogen and carbon would require changing potential energy from 802 kJ of energy in a mole of methane to 2x(242kJ) in 2 moles of molecular hydrogen + 394kJ in one mole of graphite, or 878 kJ total. 878 kJ – 802 kJ = 76 kJ of energy needed per mole to crack methane into molecular hydrogen.
There are 62 moles of methane in a kilo so we’d need 4.7 MJ of energy to crack a kilo of methane. Burning a kilo of methane will release 50 MJ of energy so it will take about 10% of the methane to convert it to hydrogen.
This might actually work. I may also have miscalculated.
Redbone, thermodynamically, it can certainly work. Energetically speaking, the money comes from the oxidation (burning).
So if you can afford to design, build and operate a large plant, to throw away half of your revenue compared to existing technologies before you even start tying to turn a profit, then fine.
IMO, the innovative approach comes in this bit:
That the process produces solid carbon as a by product is probably the worst problem from a chemical engineer's standpoint. They really do like to work with fluids (liquid and gases). Solids are a pain in the butt.
"A pile of black carbon? You can make an awful lot of pencils."
When we used to make engineering drawings with pencils (later, plastic "leads" on Mylar) we were very careful to avoid mistakes because erasing and redrawing was a bitch. Now, anything goes.
They assume there is a need for H2. Hydrogen fuel cells are foolish, especially if H2 is created with electricity.
SO Fuel Cells run directly on methane or hydrogen and produce heat for winter. They are more efficient than diesel, so they produce the least CO2 of any fossil-fuel technology. Yet it's completely ignored by Greens.
Michael Hart,
You beat me to it, I was just doing the same calc. One can actually end up with a slightly worse number depending on the use of high heating value or low heating value in the end use of the hydrogen, especially given the combustion products are now all condensable. For none engineers that's essentially the difference between a condensing versus none condensing boiler with the difference effectively being doubled.
Lets not get into the impracticality of trying to transmit and combust pure hydrogen through existing infrastructure. I for one would want to live no where near those systems. (Lines and fittings that are leak proof for methane are not leak proof for hydrogen. Stable combustion of hydrogen is not a trivial matter.)
Extend the consequences of this stupid idea and we burn through available NG at about twice the rate with exponentially higher system cost.
Based on a similar proposal from a local university prof I calculated an approximate cost of avoided CO2 emission of north of $100 Cdn per tonne at a gas price of about $2.00 Cdn per giga-joule ignoring any capital or operating cost for the additional plant.
This is a similar overall result to both the post combustion carbon capture concepts and oxy-combustion concepts, and all of them are totally irresponsible to future generations, morally bankrupt .
It amuses and scares me at the same time to see proponents of these concepts try to "out do" each other regards the relative merits of the ideas. That these ideas are even given the light of day is a very sad commentary on academia.
I think they should stockpile it in abandoned mines and quarries for recovery to help turn back encroaching ice sheets during the coming solar minimum.
On a related but more pragmatic note Compsite Recycling Ltd http://www.crlltd.com/ proposes whole tyre pyrolysis using molten Zn.
Michael Hart, Redbone
Fine, but they compare their process to gas + CCS. Carbon capture takes energy too.
The article, of course, doesn't give enough details to assess the process. They don't mention catalysis, which is one of the first things I'd look for in a new cracking method. If it's there, the carbon would plug the catalyst bed fairly rapidly.
All one need say is encapsulated here:
http://vps.templar.co.uk/Cartoons%20and%20Politics/117322.strip.gif
Mike Singleton said:
If the process can be industrialised you could crack methane on site supplied by the existing gas network.
I wonder if it would work with coal dust too.
Indeed, Richard. It's a sign of the times we live in that they will do that.
It will never get off the ground without the boondoggle subsidy payments. The next great breakthrough is always driven by need not fantasy, almost never takes place in a University, and will probably arrive with the end of the interglacial when the desperation involved in keeping 2 or 3 billion people who live outside the tropics from freezing to death puts a sense of proportion into our decadent political wasters.
As a P.S. It would seem to me that the next great energy source will originate in the Earths molten core and will be accessed by Engineers and drillers using the future smart drilling technologies, more resilient metals discovered by engineers, and money from forward looking entrepreneurs not Jurassic brained Liberal Throwbacks.
Quote me in a thousand years.