CNG

Here we go again. Is this going to be permanent or is it going to be temporary? Either way it’s going to be painful. The pain of which I speak is that pain in your wallet that you feel when you go to the gas station to fill up. Gas prices are not only high, but they are the highest they have ever been for this time of year, ever. Imagine what is going to happen this summer, which is the time of year when the price of a gallon of gas usually reaches its yearly high. Prices north of $4.00 a gallon are not only a certainty but the highest prices ever seen are very likely.

What are the alternatives to gasoline powered cars? Well, you could ride a bike, or walk… that will never happen. How about buying a hybrid? That might help somewhat but most likely it will mean getting a car that’s smaller than what you are used to, and any savings on fuel that might be realized on fuel purchase, might not be worth the extra cost of purchasing the car. Hybrids still run on gasoline so you can’t completely avoid the petrol station. Ethanol is a joke as a fuel (this is a subject for another article altogether), so it’s not worth discussing here. A purely electric car like the Nissan Leaf might be good but they are very expensive and are only good as a commuter because of a limited range. Most of these technologies are good for one reason or another but most of them are still not at the level where they can really begin to reduce our dependence on good old gasoline. So what else is there?

Compressed natural gas (CNG) is perhaps the best alternative to gasoline, and there are many facts out there that can support such a claim. First of all compressed natural gas is only stored in the compressed form, in order to increase the energy density of the fuel that is stored in a special tank on the vehicle. This helps to increase the range of the CNG powered vehicle. Typical pressure of the CNG fuel tank is between 1000 and 3600 psi.

A CNG tank mounted in the trunk

Let’s look at the pros and cons.

Pros

• CNG is cheaper than gasoline everywhere in the country where it’s available. Prices range between $1.00 gasoline gallon equivalent (GGE), to $2.50 GGE
• Little to no reduction in vehicle performance. Power output with CNG is very similar to what it is when running standard petrol. Fuel economy is also very comparable
• This technology can be fairly easily retrofitted to any gasoline powered vehicle. A vehicle that can run on CNG or gasoline is referred to as being bi-fueled.
• The distribution network for natural gas is already in place in most areas around the country. Nearly every business and residential establishment has natural gas hookups already in place. This would make it possible to refuel at home which would put the cost of refueling somewhere near .50¢ GGE.
• Natural gas pipelines spread across the country from places like Eastern Utah, Southwest Wyoming, Western Colorado, Oklahoma, Texas, North Dakota, and Pennsylvania. This means almost all of the natural gas used in the U.S. comes from the U.S. The reserves in these areas are huge, much bigger than anybody knows.
• Because natural gas is a gas it is shipped in pipelines and rarely shipped over seas. Natural gas has to liquefied in order to be shipped in tankers. This requires cryogenic tanks that keep the gas at about -260° F, and special loading and unloading facilities at the ports where the tankers are loaded. Because of all this natural gas is not globally traded the way crude oil is. This means that instability in the Middle East has less of an impact on price here at home.
• Natural gas is the cleanest of fossil fuels. Emissions from an engine burning natural gas are much lower because atomization of the fuel is not required at the same level that it is for efficient combustion of gasoline. Natural gas has less carbon in it than gasoline so there is less carbon coming out of the tail pipe. This means less carbon monoxide, less hydrocarbons, or other volatile organic compounds, and if you care, less carbon dioxide. Also, there has never been a natural gas spill that contaminated a river or a coastline.
• With less carbon in the fuel there is less carbon buildup in the engine. This means engines last longer and require less maintenance. This also means that additives and detergents, along with octane boosters, are not required. The normal octane rating of natural gas is already very high.
• Natural gas works as a fuel right out of the ground and requires very little processing, and as I mentioned before additives are not required. This means that refining capacity is much less of an issue, such as it is with gasoline.

A CNG vehicle filling up at home

Cons

• While states like Oklahoma, Texas, California, Colorado, Utah, and some others have quite a few CNG stations, many states have very few or none at all.
• Don’t run out of gas if your vehicle is a dedicated CNG vehicle. If you run out of gas you will have to call a tow truck because you can’t just fill a small gas can and transfer it to your tank. If the vehicle is bi-fueled then it will automatically switch over to gasoline on the fly, once the CNG runs out.
• CNG systems store the fuel at 3600 psi. The general public might look at this as a problem because they may fear highly pressure explosive gas. The fact of the matter is gasoline in a non pressurized tank is probably more dangerous than a tank of CNG because it’s doesn’t dissipate easily when it leaks, and the tanks that store gasoline are weak and flimsy compared to those that store CNG.
• CNG tanks have expiration dates which means legally they can’t be used longer than 15 to 20 years depending on the design.
• CNG is still a fossil fuel so there will still be some controversy surrounding its use.

One of the biggest things standing in the way of more bi-fueled and CNG vehicles on the road is the regulation of parts suppliers by the Environmental Protection Agency. If the average person in this country wants to covert their vehicle to run on CNG there are many obstacles, and most of them are very expensive to overcome. In order to make your conversion legal, the parts must be EPA certified. Very few kits are available that are EPA certified because the parts manufacturers have too much red tape to endure through the certification process. While some oversight is warranted, the process could use real streamlining.  

CNG is unbeatable as an alternative fuel. This is not a permanent alternative because there will never be anything that will be permanent about our personal transportation. CNG can be the bridge between the gasoline of today and the batteries of tomorrow. When gasoline prices skyrocket, that’s when we will see some action.