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Report: Opportunities for Natural Gas as Transportation Fuel

Price and environmental quality are two of NGVs’s biggest strengths and opportunities. Click to enlarge.

A report prepared for the International Gas Union (IGU) concludes that natural gas has a tremendous opportunity to become a much more widespread global transportation solution, given the constant rise of oil prices, downward trends in oil reserves, and upward trends in gas reserves and supply (partly through the exploitation of hydrates and renewable bio-methane).

Another driving factor is environmental concern over criteria pollutants and carbon dioxide emissions from petroleum-fueled vehicles.

A study group of 30 worked on the report for three years. The report was presented to the World Gas Conference in Amsterdam 5-9 June 2006.

Four generations of CNG systems for light-duty vehicles.

The study includes an overview of existing technologies for light- and heavy-duty vehicles, fueling, fuel production and storage in 23 countries. The report also analyzes adoption trends in those countries.

Successful growth of the natural gas vehicle market will require internationalization, support from governments, and more OEM product, according to the report.

Specific recommendations include:

  1. Support worldwide harmonization efforts for regulations, codes and standards for NGVs (retrofit and OEM) including:

    • ISO standards and UN regulations
    • Fuel connectors and filling
    • Vehicle type approval
    • Regular vehicle inspections
    • Harmonization of fuel measurement units and accuracy
    • Highest level international standards and regulations for retrofits
    • Training
  2. Support strategic approach to regionalization / internationalization of fuelling infrastructure strategy (and vehicle homologation).

  3. Engage all stakeholders.

  4. Lobby for consistency in long-term policies.

  5. Support awareness and growth of other methane options including renewable bio-gas strategies and use of LNG in specific niche markets and specialty applications where: 1) vehicle range is a factor and; 2) where vehicle size is compatible with large fuel storage capacities (i.e. over-the-road haulage, marine and rail applications).

    A follow-on project over the next three years will use the report and the associated databases to look more closely at the national, regional and global potential and markets for NGVs.

    The purpose of the new project is to develop a global strategy for NGV commercialization using different and appropriate technologies, covering on and off the road applications and taking into account CNG, LNG and biomethane. The updated report will be presented at the next World Gas Conference in Argentina in 2009.




    Great. So now we have the gas industry shills telling us that we can all run our cars on natural gas. And wave their hands about where it all comes from.

    allen zheng

    Oil tankers are already a risk that we live with, possibly even more than LNG tankers due to the fact that oil (and oil products) float and linger. They also coat/stick onto objects and can burn down ports. Having LNG tankers just increases that risk. At the very least, the enornous volume of gas liquified can be spilled, releasing large amounts of GHGs. The extreme cold of the dense liquid/gas could also suffocate/kill/ freeze, causing damage to steel structures.
    ____Additionally, while relying on Norway for natural gas may look nice, the reality would be a global market for LNG/LPG. Russia, Qatar, Iran, Saudi Arabia, and Bahrain, look to be the other LNG/LPG titans.
    (sidenote): Steel structures, under dynamic stress due to loads, tend to flex/deflect slightly under normal conditions. When cooled suddenly, and severly, steel becomoes brittle. A steel column that, at its base, has been subjected to conditions above, may break where forces/loads concentrate due to differing ductility/ flexibility of structural member (think Terminator 2, when the liquid metal robot shattered after frozen by liquid nitrogen, and shot). It may be concievable a bridge may be damaged by a passing ladened LNG/LPG tanker that ruptures (accidentally/ intentionally), while traffic passes above. An ensuing fireball may inperil the structural integrity furher.

    allen zheng

    Cross out Bahrain, except as a for point of processing/ liquifacation/shipment for LNG/LPG. It is not a producer of large quantites of NG or PG from indigenous sources for export. On the other hand, add the UAE, Algeria, maybe Venezuela, Nigeria and Iraq as well.

    Rafael Seidl

    Eric -

    CNG vehicles don't make sense everywhere, especially in the US (except for NYC bus fleet). However, there are other countries for whom this is considered a sensible option, either because they have significant domestic resources (e.g. Argentina, Italy, Pakistan, Bolivia, Russia, Iran, Australia, South Africa, the Netherlands) or, because it allows them to diversify their imports (e.g. Japan, China, India). Not all of these countries have embraced CNG vehicles yet. Mobile applications, especially in series production passenger cars, are still fairly new. Even where national gas grids exist, filling stations are usually not connected nor do they have the equipment for on-site compression to 200 (soon 300) bar. Exceptions: Argentina, Italy, Pakistan (, Germany).

    The article mention biogas and hydrates as potential future sources of natural gas. Biogas may be produced from biomass via fermentation, TDP, pyrolysis and other processes. However, the gas produced is often mixed with CO, CO2, N2, H20 and other compounds that reduce the aggregate energy density. It may also be contaminated with sulphur compounds. For these reasons, biogas is generally considered more suitable for stationary gensets. Any fossil NG saved can be used for transportation.

    Hydrates are similar to water ice except that methane molecules are individually trapped in the matrix. The deposits are stable at low temperatures and high pressures; most are found at 500-1000m depth below the continential shelves of all six continents. The total volume of methane is estimated at 1-10x the amount in regular oil & gas fields. However, so far no-one has figured out a way to mine these deposits safely and economically.

    As for LNG in mobile applications, the distribution and on-board storage overheads are daunting: safe storage of the fuel at ~160 Kelvin requires letting a little of it boil off all the time. This would lead to an evaporative emissions issue, plus a safety issue for vehicles parked underground. In the transportation sector, GTL is therefore preferable to LNG. It also has excellent properties as a motor fuel. Large scale diesel GTL plants are operational in Malaysia and Qatar. More are likely to come onstream in the coming years if oil prices stay high enough.

    Note that Fischer-Tropsch synthesis is rather inefficient (~60%) and hence, expensive per gallon of product. At higher process temperatures, FT based on iron catalysts delivers synthetic gasoline instead. The difficulty is securing a high enough octane number. Either way, the CO2 footprint of vehicles running on GTL is higher than for fuels refined from oil. Therefore, GTL should be considered something of a last resort, its cousins CTL (from coal) and OTL (from tar sands and oil shale) even more so. BTL (from biomass) and WTL (from waste) are very expensive but produce no incremental CO2.

    Rafael Seidl

    Allen -

    the concerns you raise regarding LNG transports are valid. That is why the scope of existing LNG operations is limited to marine operations using special ship plying well-defined routes (e.g. Brunei to Japan) between special LNG terminals. There are temporary LNG storage tanks on land at the terminals but basically the fuel is boiled off and fed into the gas grid as soon as is economically possible. There have not been any reports of major accidents in the past two decades, so within this scope, LNG transports may be considered proven technology.


    Here in the UK, over 1300 stations sell LPG (liquefied petroleum gas) which is mainly propane, IIRC. Compare this to approximately zero stations selling E85 or B100... Nobody retails CNG that I am aware of.

    allen zheng

    as possible sources of LNG/LPG.
    ____If LNG/LPG gets off the ground, and becomes a major energy player worldwide like coal, or oil, we could see a large U in energy prices. The high price of natural gas in the west, and a few other places (PRC, India) will come down over the short/medium term as terminals, ships, and production facilities are built. However, there is less than a trillion barrels oil equivalent in reserve. Furthermore, think of the CO2, and leaked methane! An energy hungry world, consuming ever more energy will deplete this within a century. By 2050, we will see a sharp rise in the cost of LNG/LPG.
    ____3 billion people (developing nations) on top of the 1 billion of the developed/ industrialized nations; 3 bilion to join in the next decade. Then you have pop. growth that will swell another 2 billion. Unless we have a catastrophe, plague, or total world war, we will need to conserve, improve efficiency and productivity, and move to renewables that also do not destry the environment.


    It's hopeless as evidenced by the weather, which once again, is setting records in what used to cool, colorful Colorado.

    Max Reid

    CNG is definitely a viable alternative for automobiles and 5 million vehicles worldwide are using this fuel.

    As for the mileage issue, current CNG powered vehicles store the fuel at 350 bar and there are technology to store it at 700 bar which can double the range of vehicles.

    I have read about LNG powered ships, but how will it be used for Land based transport is big question.

    Should the LNG tank be maintained at 160 Kelvin all the time, if so, it will not be viable for cars, but will be good for trains and trucks, since they travel longer distance.

    Any comments.

    Rafael Seidl

    Allen -

    LPG = liquid petroleum gas, mostly propane and butane. It is a by-product of oil refining and can be liquefied at room temperature using moderate pressures. The city bus fleet of Vienna, Austria runs on LPG. The fuel is a good substitute for gasoline but suffers from two disadvantages: LPG vehicles are banned from underground parking structures as the fuel it is heavier than air but normally odorless and invisible; any spill in an enclosed space creates a serious fire hazard. The chemical industry uses LPG as a feedstock, which drives up prices. Hence, LPG is unlikely to increase its currently low share of the motor fuel market.

    LNG = liquefied natural gas, mostly methane with a little ethane and propane. Liquefaction is physical, i.e. via condensation at ~160 Kelvin. This requires substantial refrigeration energy. The liquid must be stored in special and carefully monitored cryotanks. LNG is an expensive but viable alternative to pipelines whereever those cannot be constructed due to physical distance or (more likely) political constraints. The attraction of LNG would be tank size and vehicle range; however, the overheads associated with cryogenics are very high.

    CNG = compressed natural gas, again mostly methane. This is already used as a motor fuel in some countries. The main drawbacks are the lack of distribution infrastructure, high tank weight and short range. The main advantage to the consumer is a low price per mile, due to mild taxation.

    Note that global natural gas reserves (even excluding hydrates) are far greater than the remaining oil reserves. The limiting factor in NG exploration & production may turn out to be global warming rather than availability.

    Roger Pham

    _______Eric, methane can also be synthesized from concentrated solar energy via a process of solid oxide high-temp electrolysis, with input of H2O and CO2, at about 33% efficiency. If only H2O is input, you'll get only H2 as output, but at higher efficiency of up to 50%. In one hour, the earth receives enough solar energy equal to human energy utilization in one year.

    _______Allen, LNG tanker is safer than oil tanker. The stuff will evaporate away very quickly, and be reacted in the upper atmosphere with UV light. How often did we have an oil spill? Pretty rare event, so the potential amount of methane as GHG released in unforseeable accidents will be minuscule. Rafael has pointed out the safety record of LNG tankers in the past two decades.
    Bridges are made from concrete with pretensioned steel re-enforcement inside. The concrete will insulate the steel from extreme coldness. Furthermore, the role of steel re-enforcement is for greatly increase tensile strength only, while the already-brittle concrete carries nearly all of the compression strength. As such the steel will be completely protected from shattering by the thick concrete column.
    Allen, please remember that methane is also a renewable fuel that can be directly synthesized from concentrated solar energy, or from biomass gasification or fermentation. Once these processes are perfected and in place, we will never run out of renewable methane nor hydrogen, and we will have all our energy needs satisfied without requiring lowering of living standard.

    ______Rafael, the methane fraction in biogas can be easily separated from the biogas via the process of liquefaction. It's kinda like reverse distillation for separation of liquids in oil refinery. ICE-electric hybrid vehicles do not require high-purity H2 or methane as would fuel-cell vehicles.
    Re. the venting of methane in LNG (or of H2 in LH2): Do not let it vent to the atmosphere, but combust it in the engine to recharge the hybrid drive train battery, or plug the vehicle into the grid if parked at home. Practically, LNG should only be used when most of the fuel will be burned in one long trip, or for vehicles used continously such as buses or delivery vans. The fuel tank should be able to withstand some pressure, such that the engine can be run for at least ~5 minutes every hour or so while the LNG tank is venting. Hybrid cars has coolant sequestration for coolant insulation, thus preventing poor engine emission during frequent engine start-up during the day. CNG would be more practical for daily commute, but compressed H2 stored in the same CNG tank would be cheaper and more efficient for daily commute in comparison to synthesized methane, albeit at 1/3 the range of CNG.

    I hope that the above will address many concerns regarding our future renewable energy option of using combined methane-hydrogen as energy currency.

    Max Reid

    So all the heavy vehicles like Ships, Trains, Trucks, Buses which drive longer (16-24 hours / day) can be powered by LNG while the private vehicles like cars, SUV's vans can be powered by CNG.

    Any idea about the range between CNG and LNG.
    I guess the compression level of CNG can be increased from 350 bar to 700 bar and even further, so how does these technologies alter the balance between CNG & LNG.


    The rule of thumb for LNG tanks are 3/4 the amount of fuel of the same size diesel tank. Up to this point the standard for the US has been 3600 psi. Canada 3000 psi. For 3000 psi fast fill the storage needs to be 3400 psi. storage for 3600 should be 4500 psi. As you raise the fuel pressuer the maintaince costs go up as well as the cost of storage. Of course Time fill (slow fill) is the most economical.


    Any gas compressed to high pressure is inherently UNSAFE. Any equipment dealing with high pressure gases is EXPENSIVE. Hence CNG engines are confined to niche markets only, like centrally-maintained city buses or refuse trucks.

    Rafael Seidl

    Andrey -

    you are misinformed. In Germany, for example, Opel as a brisk line of business selling passenger cars running on CNG. Range and performance are worse than for the base gasoline models, and they are mre expensive to purchase. However, the fuel is much cheaper and produces less CO2 per kWh of mechanical energy delivered (methane has the highest H/C ratio of any hydrocarbon).

    richard schumacher

    Roger Pham has put his finger right on it. Global warming makes continued use of fossil-derived fuels unacceptable in the middle term, that is even before we run out of economically recoverable fossil oil and gas. In the absence of other feasible power supplies for vehicles, sooner rather than later we must start making hydrocarbon fuels from some mix of biological sources and water and atmospheric CO2, using energy inputs from Solar, wind, and nuclear.



    In Vancouver, where I live, there are plenty of CNG stations and refueling is not a problem. However, consumer’s decision, not distorted by artificially overtaxed gasoline prices, like in Europe, is quite clear here. There are a lot of taxis and delivery vehicles running on CNG, almost all city hall fleet of vehicles is running on CNG, but there are very few privately owned CNG cars.

    Roger Pham

    Thanks, Richard for your support. The most important issue is to get the policy makers world-wide to realize this and to act without further lost of time. This massive transformation will take a lot of time and investment. However, the effect of the transformation toward the renewable fuel economy will cause significant economic growth for decades as employment opportunities for millions.

    ____Andrey, initial consumer's decision should be distorted by artificially overtaxed gasoline prices like in Europe, in order to get people to migrate toward an eventual all renewable fuel economy. That's about the only way that the renewable fuel economy will happen within our lifetime. Synthetic renewable fuel will always be more expensive than fossil fuel removed from the ground. The artificially high prices of petrol now is due to price gouging by OPEC, while it remains very cheap to extract and to refine fossil fuel. If we wait until the final exhaustion of fossil fuel before we move toward renewable, we may never be able to avert environmental catastrophe.



    Wow! You have mixed everything together. Let’s keep things simple. Let’s put aside fossil fuel resources exhaustion and climate change theories. Both NG and liquid fuel could be directly fossil (as it is today)– gasoline, diesel, and NG; or synthetic - produced from coal, NG, biomass; or being directly bioderived - anaerobic digestion biogas, corn or cellulosic ethanol, biodiesel. If you want to push market to renewable fuel by taxation – fine with me, but as of today both types of fuel are fossil and contribute to so-called global warming almost equally.

    The only thing I wanted to point out is that CNG fueled vehicles versus liquid fueled vehicles have distinct advantages and disadvantages, and this mix defines where CNG vehicles are more advantageous: in centrally maintained fleets of heavily used vehicles. Typical examples are city buses, taxis, delivery vehicles, refuse trucks, etc. Economical factors dictate then if we want somehow significantly diversify our fuel sources, we have to convert NG to liquid fuel. Use of CNG as direct automotive fuel is not economically viable on massive scale.

    Now come to equation overtaxing. Wholesale gasoline in US costs about 0.5$ per liter, and at gas pump, including significantly higher then for other goods taxes, it is about 0.8$ per liter (at crude prices around 70$ per barrel).

    Natural gas enjoyes less taxation and is cheaper (where available), but despite this for family sedan with average use CNG option is more expensive to run then liquid fueled one. With prices for gasoline in Europe artificially tripled by overtaxation, and with NG still not, use of more expensive and less convenient CNG vehicle makes totally sound economical sense for individual driver. That’s what I call market distortion by overtaxation.

    Interesting enough, same distortion makes diesel cars and SCR NOX reduction more economical in Europe for individual buyer then gasoline car or regenerative NOX adsorber in US/Canada.

    allen zheng

    Come to NYC and see all the steel bridges. Come to NYC and see we usually have a spill a few times a year. Most are contained by floating booms. What would a cold gas be contaned by? Worldwide, there are alot of harbor bridges that have exposed steel columns and other structural elements.


    Honda sells a natural gas Civic with a compressor you mount on a wall
    which uses the natural gas supplied to your home to fuel that car.

    The range is maybe 150 miles, but the idea of starting every day with a full tank
    and not having to go to a gas station could be some of the desired attributes.


    There is another company coming online now making an all American made vehicle that gets 70 mpg using natural gas. They include the compressor with the vehicle and it is supposed to get 700 miles on a 10 gallon tank. So like SJC said starting the week off in this case with a full tank for less than $15 or so is quite a deal not to mention ZERO Pollution and decreasing our dependcy on oil!!!!


    ship ullage report/causes of loss/gain of cargo quantity

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