Is natural gas green?

Dr. Robert M. Gresham, Contributing Editor | TLT Commentary August 2012

We have another energy opportunity to think through. The answer soon could be motoring up your driveway.
 

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KEY CONCEPTS
• 70% of oil in the U.S. goes to fuel cars, which then generate 30% of our greenhouse gases.
• Natural gas-fueled automobiles are on the horizon, and the technology already is being used for some trucks.
• More technology is needed to make natural gas-fueled cars a reality, but the costs aren’t prohibitive.

WE HAVE A CONUNDRUM TO THINK THROUGH.

First, we are all concerned with being “green.” We are slowly learning to recycle, adding controls to all manner of devices that pollute, burning our consumables (ethanol), eating more so-called organic foods and on and on. Indeed, in the U.S. and a number of other countries, our collective behavior has changed considerably—yet some other countries won’t even consider such changes.

Second, we are quite concerned with energy, since without it our economy and our security will collapse. Yet we want our energy to be clean, cheap, abundant and, of course, green. Here, green means sustainable and relatively non-polluting when consumed. Further, abundant and cheap means we don’t want to be dependent on others for our energy, especially with variable pricing, embargoes, wars, etc.

The result is that we are tilting at wind, solar, biomass and other technologies, most of which are not cheap, at least as of yet, abundant, nor do they have the needed energy density to supply the megaquantities of energy that we currently consume. Legislatively, we have raised the bar on crude oil drilling through limiting drilling permits, taxation and related moves to make other forms of energy more attractive. Socially, we are defining crude oil and coal as bad sources of energy, even though both have a high energy density, relative low cost, are available and, through somewhat extensive engineering controls, manageable emissions. So with this as context, regardless of the merits of all the arguments pro and/or con, we are finding yet another energy opportunity to think through. This opportunity arises from the virtual deluge of low-cost shale gas, natural gas, being discovered.

Natural gas has some really attractive advantages: low-cost, abundance, much lower emissions when burned, and much of it has been found relatively locally. Indeed the Bakken Formation, primarily located far underground (~6,000 feet) in North Dakota and parts of Montana and Saskatchewan, is a good example of its abundance in the U.S.

Further, there is new technology called hydraulic fracturing, which has made its extraction more economic and safer. Hydraulic fracturing, called “Fracing,” (pronounced like fracking), involves drilling down to the prescribed depth and lining the hole with a steel casing seated in concrete. This step is important as the steel concrete lining protects the higher up ground water layer that is drilled through. The hole then is drilled to extend through the desired layer of oil shale horizontally. High pressure water and sand are pumped into the oil shale layer to create cracks, which allow the oil or natural gas to flow back into the well.

Already, we find more electric utilities are turning to natural gas. We will likely see more homes heated by natural gas. Manufacturing operations are beginning to be fueled more by natural gas. But to use the phrase of Tom Fowler in a recent article in the Wall Street Journal, “America, Start Your Natural Gas Engines,” the Holy Grail is transportation.

Mr. Fowler notes that we consume 70% of our oil going from place to place and 30% of our greenhouse gases are generated in so doing. The commercial truck market is already beginning to embrace natural gas for applications like delivery and trash. This is especially true for fleet-managed trucks that operate in a relatively small local area where refueling is done at the end of the day or at least upon return to base. While these opportunities are already going forward, the real opportunity, the Holy Grail opportunity, is passenger cars.


Will consumers view natural gas as a suitable fuel for heating their houses and running their cars and trucks?

The downside to natural gas is its cost to use. There are no public refueling stations. However, I can readily recall when fleet trucks using diesel could only find that fuel available at large truck stops on major highways. Then, as cars and pickup trucks began to use more diesel, most public filling stations added at least one diesel pump. This cost was relatively minor. Natural gas will need special storage tanks and handling equipment, which will be inherently more expensive—yet still doable.

The next problem lies with the cost of the cars themselves. While gasoline or natural gas engines are not that different, according to Mr. Fowler, the big issue is the needed onboard natural gas tanks. Relative to gasoline tanks, these need to store gas under high pressure, thus they will be larger, stronger, heavier and, of course, more expensive. For comparison, the only natural gas car sold in the U.S. is the Honda Civic GX, which costs about $5,200 more than a comparable gasoline model and about $3,600 more than a gasoline/hybrid Civic.

So we need an invention or two. Already, 3M Corp. is working with Chesapeake Energy Corp. to develop fuel tanks from composite materials such as those used in the aerospace industry. The University of Missouri has a project to store natural gas at lower pressures. Chrysler and GM are looking at pickup trucks that run on both gasoline and natural gas. Already, according to Mr. Fowler, the possibility exists for in-home refueling. There is an appliance, called Phill, about the size of a vacuum cleaner, which can be hooked to the natural gas line coming into the house to refuel the car in about six hours or overnight.

Further on the invention front, in a philosophical endrun some years ago I learned from STLE Past President Dr. Selda Gunsel that her company, Shell Global Solutions (US) Inc., has been working on gas-to-liquid technology. This would preclude the need for special tanks and infrastructure. They currently can produce diesel fuel for vehicles and jet fuel for aircraft.

For the lubricants industry, will engine oils need to be reformulated to better accommodate natural gas engines? Probably we will need some modification of the additive package but nothing major.

Eventually, the best of all this research will emerge as a reasonable cost solution to the inherent problems in using natural gas.

Finally, we need to reinvent the consumer. Will consumers view natural gas as a suitable fuel for heating their houses and running their cars and trucks? Will consumers view natural gas as inherently unsafe, like nuclear power? Will natural gas be viewed as a green alternative to crude oil?

Those are the scary questions where there are no obvious answers.


Bob Gresham is STLE’s director of professional development. You can reach him at rgresham@stle.org.