Olah (1994 Nobel laureate carbocation chemistry, director of the Loker Hydrocarbon Research Institute) and his coauthors do an excellent job going over fossil fuel(coal, natural gas, oil) resources, how close we are to running out of each, the vast number of uses for these resources, and the likelihood of climate change due to their burning. It is assumed that in the future we will have abundant energy available from nuclear and alternative sources. Methanol would then be one of the prime carriers of this energy, and an alternate source for all petrochemicals.
They also cover alternative renewable energy sources, compare using hydrogen versus methanol as a carrier of energy from new renewable energy sources and nuclear energy plants. The authors do a thorough job pointing out the enormous use of hydrocarbons throughout the industrial world for a huge array of products. Not only do we need vast new renewable sources of energy we also need to be able to use this energy to change new carbon sources into useful products. The new source of carbon, methanol from CO2 and H2! Olah, et al shows in great detail how methanol can be changed chemically into the precursors for just about anything and at very high efficiencies. We would use energy from nuclear and new renewable energy sources directly where we can, such as powering our factories and homes' electrical systems. We would use some of this new energy to change CO2 from emissions and hydrogen from electrolysis of water, into methanol to run our cars, trucks, etc., and provide feedstock for all the products now produced from petroleum. Note that methanol formed this way adds no new CO2 since CO2 from the surroundings is used to make it. This is very similar to using ethanol produced from corn or other biomass, except it involves more chemistry.
The new process involves using electrochemical or photochemical reduction of CO2, which forms methanol, formic acid and formaldehyde, CO2 + 2H2 -> CH3OH with additional products which are also changed to CH3OH,
HCHO + HCO2H -> CH3OH + CO2
They don't give a lot of details, because they have a patent pending on the process.
In the interim, while we are developing and building alternative renewable energy sources, we can change coal, natural gas, biomass, etc., into methanol. This is already done to a small degree and existing infrastructure for gas and oil can be used with small adjustments. The authors also compare using hydrogen and methanol, as storage and transport media.
It was a surprise to me that there is more hydrogen in a liter of liquid methanol (98.8 g of hydrogen) than in a liter of liquid hydrogen (70.8 g at -253?C), water for comparison has 111g of hydrogen. Methanol would store and transport much more easily than liquid hydrogen.
The first sources of CO2 would be exhaust gas from utilities and big factories, which generate a lot of CO2, hydrogen would come from water being electrolyzed, CO2 + 3H2 -> CH3OH + H2O. Then as our CO2 capture methods get better it would be captured directly from the air. Anyone in the world would with access to energy, would then have a source for a vast array of chemicals! Note that if CO2 becomes a useful commodity people and nations will compete to pull it out of the atmosphere, and prevent it from being released since it has value. This has much greater appeal than other proposals such as sequestering of the CO2. A lot would depend on how efficient the process is. It would be useful if they would give some information on this, but Olah replied to me that `...we have of course extensive patent coverage filed for and in process. For obvious reasons in our book we could not go into any details.
The driving force for the Methanol Economy is new energy from nuclear and alternative renewable energy sources, which we don't have yet, replacing hydrocarbons as fuel. Olah, et al has great confidence that the many problems facing these new energy sources are solvable. The authors are quite negative on the safety of hydrogen, but don't seem to see a major non solvable problem with nuclear. Nuclear as we know certainly has its problems, and most of us are wary of nuclear. Scientific American had an article (December 2005 issue) on the latest nuclear plant design which uses 99% of the fuel rather than 1% in current plants. It would also have proportionally less radioactive waste, with a much shorter halflife. One of the hookers is using two separate liquid Na (at 600?C) loops as a coolant. Not a minor engineering feat. Another recent Scientific American article Sept 2006, instead sings the praises for 3rd generation nukes with improved technology, but with the same problems we currently have.
A fuel cell is being developed which uses methanol directly.
Anode: CH3OH + H2O -> CO2 + 6H+ + 6e-
Cathode: 1.5O2 + 6H+ + 6e- -> 3H2O
Overall: CH3OH + 1.5O2 -> CO2 + 2H2O
It has a theoretical efficiency of 97%, so far 34% has been achieved, while using H2 and O2 in a fuel cell has a theoretical efficiency of 83%. Of course methanol produces CO2 (which would eventually be used as feedstock) as compared to H2 which just produces water, a great advantage.
Anytime we contemplate huge installations for generating energy, whether they are nuclear or renewable we face the problem of transporting the energy to the user. Methanol, since it can use existing infrastructure of pipelines, trucks, gas stations with few changes would appear to be far cheaper than hydrogen. A July 2006 article in Scientific American `A Power Grid for the Hydrogen Economy' pointed out that our nation's electrical grid is experiencing problems and a possible solution would be to create a new national grid which would carry electricity from distant plants-renewable, nuclear, coal fired etc., by a superconductor cooled by liquid hydrogen. You would have the electricity almost resistance free (about 10% is currently lost in transmission) and the hydrogen for chemical uses. The economics of all these proposals is very hazy.
Some further food for thought is a 1998 study that indicates that the unsubsidized price of gasoline was between $6- 15/gal. A number of other studies place it at $3-11. If their methodology is close to correct then the current subsidy is much higher now, and if this subsidy were available to alternative energy sources they would be much more competitive.
