Energy: A methane economy


Natural gas has always been the bane of oil production. The processes deep in the earth that create oil over millions of years tend to produce even more volatile gases than liquid oil. These have typically been “flared”, or burned off to get rid of them, since they are difficult to transport or do anything with.

This is one post in a small series on energy in the US, focusing on energy independence and renewables.

The value of this great resource is finally being tapped around the world, and with some new technologies there are processes in place which can make suitable fuels directly from natural gas. These systems need development and refinement, which can only come from implementation. That, and a bit more research in the lab can revolutionize gasoline – and open the market to a vital new source of supply.

Natural gas is primarily methane. It’s not chemically all that different from oil, tar, or even the common plastics that we use. The difference is only “molecular weight”, or the number of carbon atoms strung together in a chain with hydrogen dangling from the side. Gasoline is primarily octane, or 8 carbons, diesel is about 10, and polyethylene plastic several million. Methane is one carbon by itself, not joined to any others.

Crude oil out of the ground is a mix of many different lengths of chain that has to be refined and “cracked” to produce shorter chains that can be pumped and burned easily. The commonly used process for doing this is what made the father of the legendary Koch Brothers rich when he developed it in the late 1940s. Oil refining is nothing more than taking the mixture of big molecules, cutting them apart and separating them.

Going the other direction, building up 8 carbons in a row from one, requires different technology. One method, the Fischer-Tropsch Process, has been around for a long time. It’s not very efficient and requires many expensive steps to implement, but the Nazis were forced to rely on it in WWII when their supplies of oil were cut off. It has never been economical other than to a desperate dictatorship in the process of losing a war.

Research since that time has developed several catalysts for making octane or other chained carbons directly from methane. Several big breakthroughs have taken place in the last 20 years using some intense chemistry. The only by-product is hydrogen gas, which can be used for many things including direct electricity production. Big oil companies have never really been all that interested in these processes, however, because they are in the business of taking oil and running it the other way. They don’t build up carbon chains, they break them down.

Until now, that is. Several processes have been developed that prove this new technology works in the field and is far more economical than the Fischer-Tropsch process. Where the value of gasoline at the refinery is about $3.50 per gallon, the input of natural gas necessary as a raw material costs about $0.90 at current prices. There is a lot of room for the cost of the process.

The reason methane, or natural gas, is so cheap is that it is very hard to capture and use. Methane does not liquefy easily, requiring very high pressure. This makes it hard to transport. Development of a process for making longer chain liquid on a very small scale, perhaps right at the well head, would make it possible to capture a tremendous amount of natural gas that is now being wasted.

Natural gas itself is not without controversy, however. The reason the US is awash in it lately is the development of a technology called “fracking”, or hydraulic fracture. Rocks containing natural gas are literally smashed with pressure, releasing the gas the contained. Many horror stories have been told when methane bubbles up into aquifers, contaminating drinking water, and literally creating flames in people’s kitchen sinks.

New regulations have gone into place requiring, among other things, that all methane be captured directly at the fracking site. That could be very expensive and difficult – unless the methane is made into a transportable liquid.

There is more work to do to develop and refine the process for making methane directly into gasoline. This is an ideal candidate for a government challenge grant written around specific economic goals that specify practical implementation. But the technology is there. It could easily make the US energy independent, given the tremendous amount of methane under our land.

Yet there is much more to it than an alternative source of fuel and strategic national interests. Once we convert from an oil based infrastructure to a methane based one there are more interesting options that open up with natural, renewable sources of methane that can plug right into the same systems started up with natural gas. That’s the topic next time.