Wednesday, May 5, 2010

After Oil: The Methanol Economy

It's spilling into the Gulf of Mexico at an alarming rate. Our armed forces are in the Middle East fighting for it. We would all be toast without it.

But what will we do when we run out of oil?

Nobel prize winner in Chemistry George Olah has the solution: methanol.

Technology Review: Why methanol?

George Olah: Methanol in its own right is an excellent fuel. You can mix it into gasoline -- it's a much better fuel than ethanol. And we have developed a methanol fuel cell.

Methanol is a very simple chemical that can be made in a very efficient way. It is just one oxygen atom inserted into methane, the basal component of natural gas; but methanol is a liquid material which is easily stored, transported, and used.

TR: What's wrong with hydrogen fuel cells?

GO: Even today you could put a pump dispensing methanol at every gasoline station. You can dispense it very well without any [new] infrastructure. For hydrogen, there is no infrastructure. To establish a hydrogen infrastructure is an enormously costly and questionable thing. Hydrogen is a very volatile gas, and there is no way to store or handle it in any significant amount without going to high pressure.

TR: But methanol is a way of storing energy, not a source of energy like gasoline. Where will the energy come from?

GO: The beauty is we can take any source of energy. Whether it's from burning fossil fuels, from atomic plants, from wind, solar, or whatever. What we are saying is it makes a lot better sense, instead of trying to store and transport energy as very volatile hydrogen gas, to convert it into a convenient liquid. And there's a fringe benefit: you really mitigate carbon dioxide in the atmosphere.

TR: How do you make methanol?

GO: One approach is to produce methanol by converting still-existing huge reserves of natural gas, but in entirely different, new ways. Today, methanol is made exclusively from natural gas. Natural gas is incompletely burned, or converted, to synthesis gas, which can then be put together into methanol. Now we have developed ways to completely eliminate the use of synthesis gas.

The second approach involves carbon dioxide. We were co-inventors of the direct methanol fuel cell. This fuel cell uses methanol and produces CO2 and water. It occurred to us that maybe you could reverse the process. And, indeed, you can take carbon dioxide and water, and if you have electric power, you can chemically reduce it into methanol.

So the second leg of our methanol economy approach is to regenerate or recycle carbon dioxide initially from sources where it is present in high concentrations, like flue gases from a power plant burning natural gas. But eventually, and this won't come overnight, we could just take out carbon dioxide from air.
Dr. Olah makes a persuasive case. We can take energy from anywhere; hydroelectric, nuclear, wind, solar, even coal and gas, and turn it into an easily transportable fuel.

Anyone who has accidently lit a gas can on fire can tell you that gasoline has TONS of energy stored inside. It's what makes it so useful as a fuel. But matching that level of energy without using petroleum is a very difficult problem.

Currently, electric and hybrid vehicles draw energy from heavy and expensive lithium-ion batteries. Despite their large mass, these batteries are still very limited in their storage capacity.

Methanol has the advantage of having enough energy that it can replace gasoline, and we can get it without digging into the ocean floor or dealing with unstable Middle Eastern nations.

It's certainly worth thinking about, as it's the best gas alternative I've come across.

No comments:

Post a Comment