Sunday, September 19, 2010

Welcome to the Methanol Economy

Remember back in aught-three when GW Bush, proposed the Hydrogen Economy in a national speech. I was so proud of him. He even knew what switchgrass was. The hydrogen economy is when hydrogen is generated from electricity, solar energy or biofuels. The energy is stored in the form of hydrogen, and then burned directly or in a fuel cell. Burning hydrogen produces only water as a by-product, and this is even carbon neutral -- although Mr. Bush in 2003 did not care about that.  Bush got a fair amount of criticism for being too fringy green, but he was actually ahead of his time.

From Wikipedia
Sad thing was, this was about the last gasp for hydrogen advocates. Making hydrogen from electricity was not that easy, and then burning it for fuel was wasteful as well. On top of that, hydrogen is a bulky gas, and it was hard to carry enough of it to power an automobile. In the jargon, its energy density is low.

The advantage of methanol is that it is a liquid at room temperature with far higher energy density of 15 MJ/L vs 0.013 MJ/L for low density gas or 5.6 MJ/L at 700 bar. This means you could pump it into a regular gas tank like gas. You would need a larger tank since gasoline is three times more energy dense.

Methanol can be made by bacteria from sugar just as easily as ethanol can. Methanol can also be made from synthesis gas. Naturally BASF, my employer, makes catalysts for that. Synthesis gas can be made from nearly any biomatter like corn stover, switchgrass, or aged biomatter like coal.

What I just learned was the methanol is quite efficient in a fuel cell. Although it produces carbon dioxide, the greenhouse gas. If the methanol is originally made from waste carbon dioxide, the whole process could be carbon neutral though.

See my recent post on the stalling of cellulosic ethanol. For further reading on the methanol economy click here.