This is good news. Adsorbed natural gas can be one way to use less oil. Since methane can be created by gasifying biomass and we all ready have the transport pipelines, this makes it even more viable.

@ DS -

not sure where you are located, but CNG only accounts for a tiny fraction of the total automotive market. The cost overhead of compressing and storing natural gas at 200-300 atmospheres is substantial.

ANG can make do with the pressure already present in natural gas trunk lines. It also offers much greater flexibility wrt the shape of the tank because the mechanical stresses are much lower. Finally, the adsorption material could perhaps double as soundproofing, reducing the weight penalty associated with running on natural gas.

What's this stuff weigh relative to the weight of the gas being stored, and what's the energy density in terms of total volume?

CNG requires heavy steel tanks because of the high pressure involved, and the energy required to compress the gas is significant. The overall weight of a lighter tank with this stuff inside might be less than that of a steel tank with ordinary CNG, but even if there is not a weight advantage, there's a big advantage if further compression beyond standard natural gas supply pressure is not required.

CNG is somewhat available around here, but the big advantage if further compression is not required is that the vehicle could be simply connected to the standard gas supply in your house.

Very good for city cars, better still if hybridized.
Good also for city buses ".
My understanding is there is a lot of gas around, so we could be in business here - or with some gas adsorption system if this one proves impractical.
Could be important.

I kinda got the sums right but I cant tell you as the conversions from cu ft - M3 back to btu-cuft and us gallons -cuft -litres ! But its somewhere the otherside of Mars.
You dont really want know do you?
How does the energy density compare?
At standard pressure,and temp. At a guess 1 bar. Guess 16.9oC
At 35 atmospheres just over 500psi, stores 230 times the volume (weight) at the same (standard) temp.
Or concentrated 230 times at just over 500psi.

A bit more to go to get accurate.
NG 1000 -1100btu's per ft3 .353357 M3
CNG 32,154 BTU,s per us gallon @3,000 psi 210 atm
LNG 83,000 BTU,s per us gallon @ minus 162oC
1 gall gasoline equivalent to 100ft3

Personally I prefer the metric system

last line should read:
1 us gallon gasoline equivalent 100ft3 NG

Another thing I wonder about is how much of that adsorbed CNG you can easily draw out when you want? I'm guessing that if CNG likes adsorbing onto this high surface area material, that it doesn't want to let go too easily. Also, how is affected by temperature? I left me cell phone (off) in a frozen car overnight on a ski trip and in the morning, the charge indicator said the battery was dead even though it had a full charge. I left it on the heat vent for 2 minutes and suddenly it said it had a full charge again. Anyway, I'm guessing this process is sensitive to the usual -20 to +40 degrees celsius range most cars have to deal with.

@ Brian P -

the paper gives a gravimetric density of 0.871 g/cm^3 for PCN-14, roughly the same as diesel fuel. The upshot is that the tank walls will be much thinner than in a CNG system yet total weight will be the same or more. That's why it would be useful to shape ANG tanks such that they can do double duty as soundproofing.

@ sjc -

CNG = natural gas at 200-300 atmospheres

ANG = adsorbed natural gas at ~35 atmospheres, i.e. backbone pipeline pressure. Filling stations connected directly to the backbone would not need to invest in compressors at all, nor would any additional (electrical) energy be required for the filling process.

There is no such thing as adsorbed CNG.

NG engines are spark-ignition.

@ Mike Z -

the thermodynamic cycle for natural gas is the Otto cycle. A spark plug or other external trigger (e.g. diesel pilot injection, laser ignition) is required to initiate combustion. Except for very large engines, iridium-tipped points are typically used.

However, since most NG engines today are very large stationary gensets or bus engines, they are usually derived from diesel engine designs. Natural gas has a research octane number of 120-130 (depending on impurities), permitting geometric compression ratios as high as ~14. That is less than is possible in a diesel engine but higher than for gasoline designs. The extra mechanical strength afforded by a beefy crankcase, cranktrain and cylinder head is therefore no luxury.

For mobile applications, the distribution networks for NG fuel are still patchy. Passenger car NG engines are therefore almost always derived from gasoline engines and adapted for bivalent operation. In a pinch, they must run on gasoline stored in a small emergency tank. This emergency facility limits the feasible geometric compression ratio of mobile CNG engines to ~12 to avoid engine knock. Even that number is only possible with direct injection and severe retardation of the ignition timing when running on the inferior fuel. The result is poor fuel economy and reduced power in this emergency mode.

@EP: It makes more sense when adequate electric storage is available and biogas is blended with other methane and used to power gas turbines.

Unfortunately, warnings from you and others about peak natural gas go mostly unheeded. The only place where some shift may be occuring is CAFOs (Confined Animal Feed Operations). Perhaps, we shall see more investment in such anaerobic digestion as NG prices rise further.

ANG (Adsorbed Nat. GAs) is one viable solution for petroleum dependency, just like PHEV's, but less expensive due to the fact that an ANG tank would be a lot less expensive than a 10-16 kwh battery, and more durable. Methane is a renewable fuel from various sources like cellulosic biomass, synthesized from renewable H2 or nuclear H2, and from coal also.

NG can be used in diesel engine using the diesel cycle at high compression by using a pilot injection of diesel fuel to ignite the NG. In this way, there is no efficiency penalty at part load for using NG. At full load, efficiencies of Otto cycle and Diesel using NG are comparable.

To avoid the problem of lack of availability of NG at the gas station, the government should mandate all larger gas stations to make NG available to motorists, AND mandating that more and more cars (HEV's) should run on methane exclusively, in order to avoid the efficiency tradeoff and weight and cost of bi-fuel vehicle (gasoline and methane). This is similar to the CARB's ZEV mandate, but much easier to carry out. ANG would make this less expensive since no compression would be required for the gas station.

While I think ANG would make for a much cleaner fuel for a range extender than gasoline. I would be concerned about a wholesale conversion to NG for transportation for the following reasons.

1) NG is still primarily a fossil fuel
1a) Limited global supplies (post peak in NA)
1b) Although much cleaner than gasoline it still creates tailpipe pollution.
1c) Carbon positive

2) I'm not entirely comfortable putting our transportation energy in direct competition with our primary source of home heating. (much like ethanol competes with our food supply). Do we really want all of our eggs in one basket?