Nanocopper CO2 catalyst û???? 2

[jmw]

From MIT comes news of a new paper claiming that nanocopper catalysts can help convert CO2 to CH4......

This seems a bit like perpetual motion to me. You burn fuel (including CH4) and get CO2 and H2O etc. and then convert the CO2 back into fuel?

But the claim is that it will reduce greenhouse gases.... well not really. Methane is also a greenhouse gas.... that's why all the fuss about cow farts. Except presumably it will get converted straight back into CO2 when used as a fuel again.....

If this were from the usual sources with fancy graphic web sites and a list of directors that outnumber everyone else and calls for investment I'd know where I stood. But MIT and a link patent? And unless the original press release was on the 1st of April and not the 11th.......
Oh my head hurts. I'm off to the pub.

JMW

http://www.ViscoAnalyser.com

 

[JohnRBaker]

But the claim is that it will reduce greenhouse gases....

Perhaps what they had in mind was that since CH4 can be immediately used as a fuel, to generate electricity for example, that this would provide sufficient financial incentive to actually justify setting-up plants to do that on a large enough scale so as to be effective in controlling the amount free CO2 in the atmosphere. After all, if there was something which could justify (more than just the environmental benefit) the removal of CO2 in sufficient quantities to make a difference, I would suspect that it would already be happening. Unfortunately, the world can only use just so much dry-ice at any one moment ;-)

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

UG/NX Museum:

http://www.plmworld.org/p/cm/ld/fid=209

To an Engineer, the glass is twice as big as it needs to be.

 

[jmw]

The trouble is that if this is the path to unlimited energy we are fine so long as we consume all the CO2, convert to Methane, burn it to get CO2, convert to methane ..... and never ever stop the cycle. Once we stop, turn off the machine we'll have a lot more methane than we know what to do with or a lot more CO2 and both will cause global warming and we all die of heat death.

No, hang on, we just redirect the electricity produced to AC.... (and running wind turbines when there is no wind or need for them.... they have to consume outside power to turn over when there is no wind or the crank shafts deform).
Got it.
Perfect solution.
So in theory, I can convert my car to run off a single recyclable cow fart and it will run forever.


JMW

http://www.ViscoAnalyser.com

 

[TheTick]

It also requires applied voltage, so there is energy going into the reaction. A catalyst only reduces the energy required to get a reaction "over the hump". It does not change the net energy difference between reactants and products.

 

[patprimmer]

Tick is right

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

http://eng-tips.com/market.cfm

for site rules

 

[JohnRBaker]

Yes, but all fuel sources require the input of energy to make them available for use. In the case of a petroleum-based cycle you have the cost of drilling the oil, refining it and transporting the refined fuel to where it will be consumed. The same with coal, and while there's no significant 'refining', it does require energy to mine and transport. Even natural gas needs to be extracted from the ground and then transported.

One of the potential advantages of this proposed scheme is that since the 'sky' is accessible from anywhere, one could co-locate the facility which converts the CO2 into CH4 with the generating facility which will convert the CH4 into electricity. Even with the expenditure of energy needed to power the catalytic converters, it's possible that once all the costs are tallied-up, that this might prove to be more efficient than many of the more conventional energy cycle alternatives.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

UG/NX Museum:

http://www.plmworld.org/p/cm/ld/fid=209

To an Engineer, the glass is twice as big as it needs to be.

 

[jmw]

We not only have to allow for energy consumed in the regeneration process but for inefficiencies.

This regeneration process, catalysts or not, isn't going to run on a flash-light battery.
So it might prove that the most energy consuming part of the process is the regeneration.
Say X tons of fuel gives Y energy (and Y is based on whatever the best current efficiency is for gas fired co-generation)
90% of Y goes into regenerating dX fuel. i.e. less fuel back than went into the process.
10% of Y is available as usable energy e.g. to us consumers.

To get the same available energy as simply burning X tones of fuel you now need a plant to burn 10*X tons of fuel and get the equivalent energy of simple burn and release.
The calculations of efficiency are going to be where the fun comes if this isn't to be one of those "Interesting" but so what ideas.




JMW

http://www.ViscoAnalyser.com

 

[patprimmer]

jmw

Is that your way of saying it's just another over unity scheme.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

http://eng-tips.com/market.cfm

for site rules

 

[jmw]

No but I'm highly suspicious of something for nothing ideas. The fact that most of the articles seem to link this to some sort of "green" benefit means to me that the cost and efficiency probably won't matter to the pollies who will happily subsidise it but as a commercial proposition it probably stinks.
Of course, nano technology is all the rage these days. Nano-technology, catalysts, gold doped copper, green - it's a dead cert to win some of Obama's cash.


JMW

http://www.ViscoAnalyser.com

 

[TheTick]

I think most of the issue with the article is bad journalism, lots of conjecture and projection without exploring the details or taking a realistic assessment of the new discovery.

 

[SnTMan]

Of course there is still this: thread730-310979

Regards,

Mike

 

[jmw]

How did I miss that thread?
You mean they want to turn out engineers like media studies students? Oh dear.

JMW

http://www.ViscoAnalyser.com

 

[moltenmetal]

Taking CO2 and H2O back to CH4 and O2 take at least as much energy as you can get from BURNING it. There is no getting around that fact- no catalyst or process can change it. Remember your thermo or phys chem: what you get out of the reaction is the difference between the internal energies of the reactants and products.

Mere over-unity in energy is not enough: any process which takes 1 watt of electricity and produces 1.01 or even 4 watts of chemical energy (i.e. a proxy for heat, NOT work) is not an over-unity machine. Any heat pump does that already. True over-unity machines takes 1 watt of work (or electricity, basically "work on tap") and produce 1.01+ watts of work.

The reason you produce useful energy from burning CH4 is that you can dump CO2 as a low internal energy product. Any process which does anything with that CO2 other than dumping it to the atmosphere is going to sap some of your product energy, making you p*ss through the source of that energy even faster to obtain the same amount of product work.

If you had a limitless source of nonpolluting energy available as electricity, you could run reactions like this to recover CO2 from the atmosphere, I guess. But you would also do something first that makes a hell of a lot more sense: you'd stop burning fossil carbon and dumping the product CO2 into the atmosphere. Once you stop the massive unnatural input, nature can take over and will fix the carbon in the atmosphere as biomass, carbonate etc. using solar-powered devices that have evolved for millions of years to do just that. The only problem at present is, we're dumping so much CO2 into the atmosphere from fossil reserves that these natural "devices" have no hope of keeping up.

 

[jmw]

So I'm not mad after all.
That's a relief.

I have to confess that it is easier these days to accept that even MIT can turn out garbage than formerly once we have seen how journals like Nature and organisations like the Royal Society can be corrupted or so deviate from good science that it brings science back to the days of alchemy and the search for the elixir of youth and transmutation.

This has to be one of those "nice observation and interesting science but of no practical value."

Sure the news is full of buzz words like "nano-technology" "Catalysts" etc but it alos has phrases like "...an energy-efficient means of recycling carbon dioxide emissions in powerplants".
Under no definition that I can think of does it satisfy the criteria for energy efficiency.

But let's not blame the MIT news department. The blame lies with the researchers:

Co-author Kimberly Hamad-Schifferli of MIT says the findings point to a potentially energy-efficient means of reducing carbon dioxide emissions from powerplants.

“You normally have to put a lot of energy into converting carbon dioxide into something useful,” says Hamad-Schifferli, an associate professor of mechanical engineering and biological engineering. “We demonstrated hybrid copper-gold nanoparticles are much more stable, and have the potential to lower the energy you need for the reaction.”

There is no reason to doubt the second part of the statement, that a catlysed reaction will be more efficient than other methods to dispose of CO2. But it requires some leap to believe it will lead to more energy efficient power generation. More than a leap.
It can't.
The main strength of the research seems to be the discovery that gold doping extends the catalyst life and (maybe) leads to improved energy efficiency.
But that's it.





JMW

http://www.ViscoAnalyser.com

 

[moltenmetal]

The people who published this paper should be run out of MIT on a rail.

The authors state that there would be an "energetic cost" to reducing the product CO2 from a power plant electrocatalytically back to methane. They fail to mention that the energetic cost would, necessarily by virtue of the 2nd Law, exceed the energetic output of the plant, i.e. rendering the entire plant totally useless as a power plant.

One of the comments had it right: this thing was probably published April 1st...either that, or it's a sad commentary about what it takes, or doesn't take, to get a PhD and a gig as an MIT researcher these days...

 

[jmw]

The quote isn't from some ambitious post grad student but from a Professor.
Taken alongside the rubbish being spouted by Shakum et al in Nature and you wonder what has happened to science these days.
Then you wonder if something similar isn't taking place across the spectrum of education. (e.g. the thread "Farewell to Engineering Education")
Then you start to worry.
Worry at every high rise, bridge tunnel or any enterprise where you depend on the engineering competence to save you from being killed.

JMW

http://www.ViscoAnalyser.com

 

[cranky108]

There was a process proposed by NASA, when I was in high school, that was proposed for long term space trips. It went something like splitting H2 and O2 from water. Release O2, and use the H2 to convert CO2, with a catalyst, into H2O. The carbon would be scraped off the catalyst, and thrown away.

The energy in this process is in splitting H2 and O2 from water.

Not that I agree with this process, because it only works if you have energy, and need O2.

The thing I don't remember is how to handle fouling of the catalyst, but that was probally never mentioned.

Is this some sort of change of the theory I heard in high school?

 

[moltenmetal]

By the way, there is nothing wrong with seeking feedstock uses for CO2. Where they went wrong wasn't in experimenting with catalysts for the electrochemical reduction of CO2 in the first place. Rather, it was in claiming that this approach, i.e. the reduction of CO2 back to methane, holds out ANY promise as a means to reduce CO2 emissions from power plants.

In the comments section, one of the co-authors states that there is no reason the energy (electricity) used to do the CO2 reduction needs to come from the power plant, i.e he claims that you could use solar panels to provide this etc. But what does he think a power plant exists to provide?! So: this is an energy storage scheme now (with the unlikely choice of CH4 as a storage medium), not a CO2 reduction scheme? And this guy has a PhD?

 

[jmw]

Sad, isn't it.


JMW

http://www.ViscoAnalyser.com

 

[dwallace1971]

This is indicative of the "free-lunch" mentality persistent in modern society. I read a recent article that descibed it as the Second Law of Disney vs. the Second Law of Thermodynamics. In the real world the Second Law of Thermodynamics always wins.

"On the human scale, the laws of Newtonian Physics are non-negotiable"