Monday, November 05, 2007

The Methanol Economy?

The term "Hydrogen Economy" is familiar by now, but there are numerous attendant difficulties which may not be overcome, or not in time to circumvent the energy-crash caused by cheap oil running short, signalled by a massive and inexorable hike in oil prices, as is now well underway. Notwithstanding the economic minefield the "Oil Dearth Era" will set, there are intrinsic technical problems in producing and handing hydrogen per se, if it is to be used on a scale of substitution equivalent to that for oil.

I have written on this subject in previous postings at some length, but the following points are salient. Hydrogen is not a basic fuel as are oil, gas and coal, but it must be produced artificially by liberating it from other elements, such as carbon and oxygen with which it is normally combined in nature, in the form of methane (natural gas) and water. These are, however, all energy intensive processes and almost entirely require the use of fossil fuels or nuclear power to drive them. Most of the world's current 50 million tonnes or so of hydrogen, produced annually to make fertilizers and to crack hydrocarbons, comes from "synthesis gas", a mixture of CO and H2 formed by reacting fossil fuels with steam in a process called "reforming", and so both chemical feedstock and heat depend upon them; hardly a "green" process, since CO2 is incurred both from combustion and by chemical stripping of the carbon component.

The ideal would be to make clean hydrogen by the electrolysis of water using renewable electricity (wind, wave, solar, hydro), but we need to go a very long way before that can be done on a large scale, although some think that enough new nuclear power might be installed to make the necessary electricity. I am skeptical that this can be implemented quickly enough, if at all, in the vast dimension that is demanded.

Even if we can make enough hydrogen, there is the issue of how to store, handle and distribute it. In comparison with liquid hydrocarbon fuels, gaseous hydrogen at normal pressure is highly voluminous, and hence it is necessary to handle it either as an extremely volatile liquid (with a boiling point of -253 degrees C, and only 20 degrees above absolute zero), or under high pressures. Either arrangement would require special technology to maintain it safe over time and to prevent leaks, since hydrogen forms highly explosive mixtures with air over a range of concentrations, and there would in any case need to be built a completely new infrastructure for generation, handling and distribution, once again within 10 years or so, and we haven't started yet.

For onboard storage of hydrogen as a fuel in vehicles, a considerable proportion of the energy actually contained in the hydrogen would be required to liquefy (30 - 40%) or pressurise (20%) the material into a "fuel tank". A fuel/tank weight ratio of 6.5% has been proposed below which the hydrogen strategy is inviable and there are numerous suggestions of porous solids into which hydrogen might be packed to occupy a smaller volume, e.g. zeolites, in some cases allowing an energy density close to that of liquid hydrogen but at significantly higher temperatures then -253 degrees C. Nonetheless, cryogenic cooling is still required. As an alternative, it has been postulated that the hydrogen might be stored chemically in the form of methanol. Indeed, one litre of liquid hydrogen contains 70.8 g of hydrogen at -253 degrees C, while one litre of liquid methanol contains 98.8 g of hydrogen and that is at room temperature.

The "methanol economy" could achieve holy grail status as a CO2 emission remediation strategy, by providing the carbon component of CH3OH, thus both preventing it from being released into the atmosphere and providing a vital source of fuel. Actual carbon-capture from atmospheric air on a degree of real significance is the stuff of the future, but capturing CO2 from power stations is feasible, which could be reacted with H2:

CO2 + 3H2 ---> CH3OH + H2O.

We are still left with the problem of making hydrogen on a vast scale and the infrastructure to do so does not exist at all. It is possible that rather than using preformed H2, it might be produced in situ, in the form of electrons and protons, by electrolysing CO2 in aqueous (water) media, so overall the effect is equivalent:

CO2 + 6H+ + 6e- ---> CH3OH + H2O.

However, the latter is difficult, since the reduction of (electron addition to) CO2 at the cathode (negative electrode) occurs in competition with electron addition to protons (H+) making hydrogen atoms and hence H2, the production of which competes with CH3OH formation. CH3OH is not the only organic product of CO2 reduction (either by electrons or H2), but also formic acid HCO2H and formaldehyde H2CO), although George Olah and his team at the Loker Hydrocarbon Research Institute at USC (University of Southern California) have patented a means to convert the latter to methanol, in an overall reaction where HCOOH provides "hydrogen" to reduce H2CO:

HCOOH + H2CO ---> CH3OH + CO2.

It is thought that the methanol would ultimately be "burned" directly in "direct-methanol-fuel-cells", but these currently depend on scarce supplies of precious metals such as platinum, as indeed do hydrogen fuel cells, and that appears to be a drawback on the technology. However, methanol can be converted to mixtures of hydrocarbons by reacting it over zeolite catalysts, for either purpose of making fuel (methanol to gasoline (MTG) process; invented by Mobil in the '70's) or as a feedstock for e.g. making plastics (methanol to olefin (MTG) process. In principle, many organic chemicals including pharmaceuticals might be made from methanol.

Most methanol is currently produced from natural gas (as is hydrogen) and so feeding the methanol economy by this means would impose further demands on a reserve that is, after all finite, as is oil; hence using CO2 as the carbon source appears perfect. Much of the current state of play in the field is heavily guarded by patents, and so I have not been able to tie-down the best efficiency so far achieved for CO2 reduction and nor do I know whether it is more efficient to do this with pre-prepared H2 or by electrochemical methods. However, my impression is that the latter are quite some way off and the process should be seen as a means for storing H2 made independently.

According to one report, the overall energy efficiency incurred in reducing CO2 with H2 and handling the resulting CH3OH is about 20%, and that is before the "fuel" has actually been used in some way. Therefore, while there would be considerable advantages met in handling liquid methanol at room temperature rather than H2 (either as a cryogenic liquid or a highly compressed gas), in terms of energy efficiency I doubt methanol is better than hydrogen, for which a value of nearer 40 - 50% might be accounted in terms of its manufacture by water electrolysis and the subsequent handling processes. Nor can it be, in the sense that installing a gargantuan new electricity generating capacity of similar capacity is necessary to underpin it.

On safety grounds, convenience of handling, storage and distribution (for which the existing oil infrastructure could be adapted), and that methanol might be converted to the numerous products that we presently get from oil (which is becoming more expensive all the time), as well as providing a clean fuel, the strategy holds much appeal. What it is not though, is a limitless supply of synthetic "oil", since CO2-derived methanol depends on electricity from fossil fuels and uranium, and may prove no more than a means for temporarily extending the illusion that the carbon-driven Western lifestyle is sustainable, which it is not.


Related Reading.
(1) "Beyond Oil and Gas: The Methanol Economy," G.A.Olah, A.Geoppert and G.K.Surya Prakash. Wiley-VCH, 2006.
(2) "Novel CO2 Electrochemical Reduction to Methanol for H2 Storage," T.Kobayashi and H.Takahashi, Energy and Fuels, 2004, 18, 285 - 286.
(3) "Beyond Oil and Gas: The Methanol Economy," G.A.Olah, Angew. Chem. Int. Ed., 2005, 44, 2636 - 2699.
(4) "Renewable hydrogen utilisation for the production of methanol," P.Galindo Cifra and O.Badr. https://aerade.cranfield.ac.uk/bitstream/1826/1449/1/Renewable+Hydrogen-Methanol.pdf

16 comments:

sustain_ability said...

Based on the book "The Dymaxion World of B. Fuller*" (co-authored with Robert Marks), I humbly submit that Fuller's ideas should, if at all possible, be brought to fruition. Some changes may be introduced to account for newer building materials and such.
http://buckminster.info/Index/D/Dymaxion-A-G.htm

Fuller designed, patented and even built working versions of his inventions in shelter, transportation, waste management, energy recycling, etc.

The energy component has increasingly become the centre of attention. A mindboggling discussion is available here:
http://europe.theoildrum.com/node/3090#more

I am increasingly optimistic that we already have the building blocks that, if correctly assembled, will see us through Peak Oil and beyond.
Sustain
*If this book from 1973 is impossible to acquire, I will provide access to it.
Please let me know.

energybalance said...

Buckminster Fuller was an interesting man, and wrote much on the matters you refer to. Some have dismissed him as a "utopian", but his dome and the "dome effect" stand out as seminal.

I would love to get hold of a copy of his book, but all offers (even second hand) from Amazon.co.uk are really very expensive: about $100.

Could you provide access to it for me, as you say, please? I would appreciate that!

Thanks,

Chris.

Drewes E. Hielema said...

I agree that the methanol economy at this moment is still not feasible. But, before we come to produce enough and cheap electricity from sunlight, we could thermally convert our caloric waste into synthesis gas to be the feed for methanol. This conversion should be done with downdraft oxygen blown gasifier systems. It is possible to achieve efficiencies of over 50% instead of butning it now. Theoretically if you should convert all the 70 million tons of waste in the Netherlands, you could produce 35 million tons of methanol.This would be sufficient for fuelling all the ICE in the Netherlands. Everybody happy but not the oil companies.

energybalance said...

Hi Drewes,

that is very interesting! I am coming round to the idea that actions on a local level are what is needed and so, if each village or town in the Netherlands were to produce its own methanol (or other fuel) supply perhaps overall the amount of waste-to-methanol conversion you refer to might be possible.

Thanks for your comment,

Chris.

Bryan Seigneur said...

Nice to see this. I only recently started thinking about methanol. I was thinking about the problems with hydrogen, when I remembered reading about methanol fuel cell car trials in the 90s (actually probably h fuel cells with onboard methanol reformers). (No one thought hydrogen made any sense, until America's first ex-coker president imposed it...hmmmmm.)

What's sad is that as imperfect as methanol is, it's better than other more in-vogue alternatives like hydrogen and ethanol.

I think I have condensed the best points about methanol versus the others in a chart here: http://gnuber.com/pix/fuels.png.

Kurt said...

Britt Borden here, the methanol economy makes a lot more sense than the hydrogen economy because of storage and transportation issues, Britt Borden.

energybalance said...

I agree with you that the main issue is to provide liquid fuels fro transportation and I can envisage that the current system if distribution etc. might be adapted to methanol.

However, I would like some better numbers for methanol vs H2 in terms of energy efficiency but as I allude these are hard to come by. e.g. Professor Olah's reference to "patents".

Regards,

Chris Rhodes.

Kurt said...

I, Dr Britt Borden, agree with the above comment that the Methanol Economy makes much more sense then the Hydrogen Economy. Methanol also makes more sense than Ethanol (it is a much more simple molecule).

Tim Pozza said...

Excellent arguments and well written. Thank you.

Though, having turned methanol over, for me it comes down to heads or tails in the quantity available in the fractioning department. To speak of methanol, to me you're still talking about a comprehensive and successful bio-fuel program which would produce more ethanol than methanol at the start. Methanol is also toxic. Even considering its use in a PEM (or more accurately, a DMFC) product ecology its expected quantity forced micro-DMFC innovation using pre-pressurized canisters. Ethanol, as you're aware, was the energy target for the mobility market. Since the North American ethanol expansion targets have fallen short and as of 2005 government here has breathed a *sigh of relief over liquifaction and fracturing along with new finds of LNG, it is doubtful methanol will move vehicles. I think it is more likely we'll see the same reasoned arguments keeping methanol in micro-devices and small portable appliances.

I think the discussion should come back to bio-fuel development and a renewed excitement in the commercialization of alternatives which can make use of seawater -- not necessarily using electrolysis either. Here I'm thinking of steam reform, and desalinated source water for industrial processing to produce such alternatives as are available in cyano-bacterial, algal, and highly alkaline electrolysis solutions -- any process which produces hydrogen gas directly without C4 or C6 or what have you.

I put it to you that the fossil fuel industry must stay vibrantly alive to effect the change management of its product.

Even more important is electrification.

And, to me, the only way to retain a forward thinking fossil fuel industry which can see its future profits and also achieve electrification, we need to move the fossil fuel industry into base load generating with a fuel type born of seawater. Our continental source water protections will require this as will the distributed processing worldwide of alternatives to oil which are more water intensive. The network would fall apart without desalination to support bio-fuel expansion.

To clarify, electrification is important to me because I see it as the means to facilitate economic renewal through manufacturing; using the refresh of the existing fossil fuel product ecology across all sectors and vertical markets and segments.

For electrification to succeed and the product migration to occur with minimal financial disruption the fossil fuel industry must survive.

It may not be difficult to shoot holes in many of the arguments presented by me here; however, I am grateful for the chance to place them in your forum. I hope there are some elements you find interesting enough to carry on and develop farther than I have done to give them the solidity I believe they deserve. I hope to soon know what you think.

Tim Pozza said...

Excellent arguments and well written. Thank you.

Though, having turned methanol over, for me it comes down to heads or tails in the quantity available in the fractioning department. To speak of methanol, to me you're still talking about a comprehensive and successful bio-fuel program which would produce more ethanol than methanol at the start. Methanol is also toxic. Even considering its use in a PEM (or more accurately, a DMFC) product ecology its expected quantity forced micro-DMFC innovation using pre-pressurized canisters. Ethanol, as you're aware, was the energy target for the mobility market. Since the North American ethanol expansion targets have fallen short and as of 2005 government here has breathed a *sigh of relief over liquifaction and fracturing along with new finds of LNG, it is doubtful methanol will move vehicles. I think it is more likely we'll see the same reasoned arguments keeping methanol in micro-devices and small portable appliances.

I think the discussion should come back to bio-fuel development and a renewed excitement in the commercialization of alternatives which can make use of seawater -- not necessarily using electrolysis either. Here I'm thinking of steam reform, and desalinated source water for industrial processing to produce such alternatives as are available in cyano-bacterial, algal, and highly alkaline electrolysis solutions -- any process which produces hydrogen gas directly without C4 or C6 or what have you.

I put it to you that the fossil fuel industry must stay vibrantly alive to effect the change management of its product.

cont. -->

Tim Pozza said...

Even more important is electrification.

And, to me, the only way to retain a forward thinking fossil fuel industry which can see its future profits and also achieve electrification, we need to move the fossil fuel industry into base load generating with a fuel type born of seawater. Our continental source water protections will require this as will the distributed processing worldwide of alternatives to oil which are more water intensive. The network would fall apart without desalination to support bio-fuel expansion.

To clarify, electrification is important to me because I see it as the means to facilitate economic renewal through manufacturing; using the refresh of the existing fossil fuel product ecology across all sectors and vertical markets and segments.

For electrification to succeed and the product migration to occur with minimal financial disruption the fossil fuel industry must survive.

It may not be difficult to shoot holes in many of the arguments presented by me here; however, I am grateful for the chance to place them in your forum. I hope there are some elements you find interesting enough to carry on and develop farther than I have done to give them the solidity I believe they deserve. I hope to soon know what you think.

energybalance said...

Hi Tim,

I think the overall solution will be the sum of a range of smaller solutions. To cut our dependence on oil, electrification and light railways can bear some of the load. We are then looking toward as far as is feasible localised production (food etc.) and economies.

Having made what savings we can in this way, then there is the issue of what to use by way of the necessary liquid transportation fuel.

Biodiesel will play a part, but there is the vexed issue of limited land for growing crops for food or fuel. Growing microalgae coupled with either transesterification to make biofuels or hydrothermal liquefaction/gasification of the raw biomass (without the need to use a lot of energy to dry it), to turn it into liquid hydrocarbons and methane etc. look more promising but the necessary engineering to do this on the necessary scale is staggering.

To avoid rambling-on, my feeling is that we need to think about how to live as locally as possible and curb the excesses of the global village concept and then provide by biofuels/ethanol, methanol etc. for what is left, so reducing overall our demand for risingly expensive and hard to get oil.

The transition might prove impossible however.

Regards,

Chris Rhodes.

Tim Pozza said...

Hi Chris,

Glad you looked in. Nice to hear from you. Very timely. You must see that I've matured on methane solutions. In fact, while I agree with your latest comment in principal, I'm not sure the base load assumptions are sufficient precepts to the 'proper' and financially scalable smaller solutions.

That the way forward IS the sum of smaller solutions rather ignores those larger generating solutions (primarily traditional nuclear) already in the pike in the U.S. as de facto replacements to coal fired generating. In my view these projects should be deprecated and that methane muxed with carbon capture should take up the core with renewable energy following in the wake.

The generating density of fuel cell solutions, to me, is a primary issue of great importance.

Should General Electric and others eschew nuclear in favor of buying up and amplifying fuel cells to match the LNG/CNG infrastructure developments to come, AND ensure the infrastructure is purposed from the get-go to support primarily methane derived fuels including formic acid then, I believe the right path will have been taken.

Anything less is not a solution, but a band aid for making profit. And this bandaid would leave a lot small people bleeding money and having trouble making ends meet. Do we have that many enemies in the world that domestic social mobility in the English-speaking world must be curbed the cost of both fuel and electricity?

Maybe that's not the right question.

The original article to which I responded is, to me, prescient and close to the target. I'm not sure though that it's the methanol economy so much as it's the methyl hydrate economy. Isobutanol comes up as an early entry competitor extending the ICE in mobility.

What is the right question?

One that comes to mind: Should geologic carbon sequestration be set aside so as to allow capture solutions involving reuse to be implemented?

Please find me on LinkedIn so I can add you as a friend.

Tim Pozza

Chris Rhodes said...

Dear Tim,

you raise several different, but inter-related questions. I think, in a nutshell, the main problem is how to undertake the "Transition" from the world we live in now, to a lower-energy way of living.

I am reading an article entitled: "Can Britain Feed Itself" and the conclusion is that by eating less meat and food production on a more local scale, using organic methods, including permaculture yes it can.

I am not assuming that the lights powered by large scale power stations are going to go-off in one go, but that smaller community energy generation will become increasingly important, e.g. small hydroturbines in rivers and CHP units to supply homes maybe at a dozen at a time.

If I understand you right, you are looking to the use of methane for large-scale power generation - you refer to "methyl hydrate" - do you mean extracting methane from "methane hydrate". You also refer to fuel cells in the same context - do you mean producing electricity by large scale fuel-cells rather than by burning methane as in conventional gas-fired power stations?

Well, I see a future role for nuclear actually, including thorium energy, and if power can be generated on a large scale by nuclear reactors e.g. Integral Fast Reactors, that can consume nuclear waste, that would be all to the good.

What we can't easily do is keep over one billion cars on the roads - let alone expand the number to a projected 2 billion in a decade or so - in the absence of cheap crude oil. So, most immediately we are facing a liquid fuels crisis, and while some degree of electrified transport can be introduced, it is personalized transport that will fall in capacity over the next decades, with all kinds of retarding consequences for a globalised, oil-powered civilization.

So, it is in the light of this, that I am looking toward localism, as without the means to move people, food and goods around the world as we do now, it is the only viable option.

I hope these remarks are useful.

Best regards,

Chris

Tim Pozza said...
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Tim Pozza said...
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