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Gas Goes Solid
Roland Piquepaille writes "This innovation from Japanese researchers can potentially revolutionize the energy distribution sector. Instead of transporting liquid gas, they changed gas into a solid material which is easier, safer and cheaper to distribute. Technology Review has the story. "Rather than extracting methane from hydrates, they want to turn methane into hydrates -- essentially, transforming the colorless and odorless gas into small pellets that can be easily stored, transported, and eventually turned back into natural gas. A few months ago Mitsui, in partnership with Osaka University, opened a demonstration plant near Tokyo to promote the concept and show that it works." Check this column for an analysis."
Gas Goes Solid
Japanese researchers may have found the secret to exploiting the world's untapped natural gas reserves.
By David Wolman
April 11, 2003
Nearly 95 percent of the known gas fields in the world are too small to justify the costs required pipe the gas to a plant, turn it into a liquid, and then transport it on specially equipped tankers.
But a handful of researchers have an idea that could make these fields worth mining: rather than figure out cheaper ways to transport this cleaner-burning energy source from point A to point B as a liquid, why not change natural gas into a solid substance that's easier and cheaper to transport?
Japanese researchers Hajime Kanda and Yasuhara Nakajima at Mitsui Engineering and Shipbuilding in Tokyo think they've found a solution with the aid of hydrates, solid crystals in which natural gas--composed chiefly of methane--is caged inside of water molecules.
For decades, researchers have been looking for ways to gather these crystals from their deep-ocean deposits and reap what they expect could be a natural gas harvest. Kanda and Nakajima are taking an opposite approach. Rather than extracting methane from hydrates, they want to turn methane into hydrates--essentially, transforming the colorless and odorless gas into small pellets that can be easily stored, transported, and eventually turned back into natural gas. A few months ago Mitsui, in partnership with Osaka University, opened a demonstration plant near Tokyo to promote the concept and show that it works. If the Mitsui's process proves feasible and economical, many untapped natural gas deposits could become vital energy sources.
Changing natural gas into a hydrate form for cheaper transport gained attention in the early 1990s. Norwegian petroleum engineers first proposed the idea after comparing the transport economics of liquid natural gas to natural gas hydrates, knowing that hydrates could store large amounts of natural gas in a small space. "More than 180 standard cubic feet of gas can be stored in one cubic foot of hydrate," says Rudy Rogers, professor of chemical engineering at Mississippi State University, and an authority on industrial use of gas hydrates.
Another major advantage: "transporting natural gas as hydrates can be done at lower temperature and pressure than liquid natural gas, and the risk of ignition in transport is much lower," explains Hugh Guthrie, who studies natural gas at the U.S. Department of Energy's National Energy Technology Laboratory in Morgantown, WV. Much of the high cost of liquid natural gas comes from temperature and pressure demands on piping, shipping, and storage facilities.
Producing the hydrates requires mixing natural gas with water in a continuously stirred tank reactor. When gas is piped into the water from the bottom, hydrates form on the surface of the gas bubbles. Removing the residual water leaves behind a residue of hydrate powder. Kanda and Nakajima envision a hydrate-pellet production plant close to gas fields in Southeast Asia. From there, a pellet carrier would transport the hydrate load to plants where the pellets would be turned back into gas and piped to market.
The company's demonstration plant produces as much as 600 kilograms of hydrates per day, moving the methane through all the necessary phases: hydrate formation, storage, pelletizing, and "controlled dissociation," or separation of the gas and water. Whereas a liquid natural gas facility requires temperatures of -162 C, Mitsui's plant operates at -10 C, which means huge savings in cooling costs. Kanda says the project, which is co-sponsored by the government's New Energy and Industrial Technology Development Organization, demonstrates that hydrates can be a successful vector for gas transport.
Mitsui's only significant competition in gas hydrate technology comes from another Japanese company, Mitsubishi. Mitsubishi is pursuing its own gas-to-solid technology based on a hydrate-oil slurry, a process whose main drawback is that i
Ugh. First off, they are talking about natural gas, not gasoline.
Secondly, they arent expecting the consumer to recieve these pellets, the pellets are just a intermediary to ship and store the gas easier before it gets to the customer. This should have been EXETREMELY obvious since it specifically states that the pellets are harder to ignite then regular gas, you shouldnt have even had to RTFA for this one.
And thirdly, you wouldnt convert all the cars on the road to a new fuel source, you would just produce new cars, and eventually phase the current ones out.
IAAAE - I am a automotive engineer
The water might not be so unwanted as you suggest.
There are some concepts of internal combustion
engines which use a mixture of fuel and water.
The water will be evaporized during combustion
and the produced steam will provide an added force
to the piston. Think of an additional steam-engine
you get for free.
johnboy
When the temperature of your freezer goes up by even a fraction of a degree (and it need not go anywhere near as high as 0 degrees celsius), some of the ice melts. When the temperature drops again, it re-freezes, but in a slightly different location.
Bzzt. No. But thanks for playing.
Whether a liquid or a solid, water is has a vapor pressure. If a system of ice and air is at the same temperature, there will be water vapor in the the air. The system will be (once there is enought water vapor in the air) in equilibrium - there will be no net movment of water from its ice form to its vapor form. But this is dynamic equilibrium, ice will be moving to vapor at the same rate that vapor is moving to ice. (Both processes - solid to gas and gas to solid - are called sublimation.)
If there is a temperature difference in your freezer, the ice will move from the (even slightly) warmer spot to a colder one. However, the process, for instance, of having all your ice cubes smoothing their edges and attaching themselves to each other would occur even if the contents of the freezer were all at the same temperature. The ice is trying to get itself into its minimum energy configuration, where it would be one big sphere.
If the top of the ice cream container is cooler than the rest of it, water will migrate to the top. The migration just requires a spatial temperature gradient, not a temporal temperature change.
You can thank Slashdot for another useless article summary and title. The process is actually talking about Natural Gas, not Gasoline. The primary goal of this is not to make "fuel pellets" for cars (although that would be cool), rather it's to find an alternative method of transporting Liquified Natural Gas (LNG). LNG tankers have to maintain a very cold environment (-162 C) and high-pressure environment, as do the processing facilities. This new method only requires facilities at -10 C (or 14 F, slightly cooler than your kitchen freezer) so it would be a huge savings in costs. It would also eliminate the need for huge pipelines, since most transportation from the field to the distribution area could be done in pellet form.
Yay ambiguous article headlines.
There is no sig, there is only Zuul.
Yep, I'm thinking that a bit of heat would be all you need. Then some separators to do the bulk water-gas separation and some dryers to get it to pipeline spec. No real technology show stoppers on the other end.
Laugh while you can, monkey boy!
The BBC also have a story including a picture from Geomar showing "burning ice" resulting in water dripping in some brave soles hands. As the Beeb's website says "Don't try this at home!"
wot no sig
Not sure the C1 to C5+ is the exact method, but yes, GTL at room temp = White Crude. (GTL is still term used for condensation as well, we're told to say white crude to differentiate...)
The United States Minerals Management Service (MMS) has done an extensive amount of investigation and research on this topic. Since they regulate federal offshore waters, this has been a topic of interest to them. You can find out what is going on in hydrate research at MMS from these links: http://www.mms.gov/eppd/sciences/esp/hydrates/rese arch.htm
http://www.mms.gov/tarprojects/
Of course Japan would be pushing this technology because they have the largest know reserve of hydrates off their coast. In the U.S. there is a large reserve off the coast of South Carolina. Unfortunately this is in a development restricted area so research opportunities have been slow developing.
Hopefully we will see more new stories about this type of research in the future.
Look for how many hazardous chemical spills we had in the US by trucking or train in the last couple of years...
When you use overland transportation, the variables increase -- thousands of potential collisions, more human error capable (as there are now thousands of drivers instead of a few pipeline controllers), weather variables, road conditions, etc.,etc.
1) Hydrates are not stable at room temperature and pressure - you still have to keep them cold (-10 C). Granted, -10C is better than -100C, but you will still have to have a refrigeration unit or a pressurized tank.
energy conservation: >90%
standard technology (cooling trucks) sufficient.
2) When you break the hydrate down, you have methane and water. You have to do something with the water - dump it on the ground, feed it into the engine to be vaporized, something.
mass water to mass methane: 2:1, ie. breaking hydrates to gain 1 kg methane produces at max 2 kg water.
dispose of in agriculture (sprinklers) or the sewers.
vehicles using this tech could just dump their water, it's not *that* much compared to a decent rainfall.
3) While hydrates may store more methane than storing the methane as a gas, I don't think hydrates store more methane per unit volume than storing the methane as a liquid.
solids have an even tighter packing of molecules than liquids. it may be possible that these can store more energy per cubic meter. after all, you don't need a bulky high pressured tank...
4) You are storing methane and water - you will have more mass per unit methane than storing just methane.
don't need that heavy high pressure container. the saving in steel may be worth the loss for extra water.
Those things said, this could be a good thing, in that anything that allows better storage and transport of methane makes it a more viable fuel source.
it's not even that, it's perfect. imagine it's use for space travel: have methane AND water in a relatively compact form with you. optimal, i think.
Go study hydrates, it is not the same as just transporting methane in liquid form!
Actually it turns out that the methane density in sI (structure I, there are a bunch of different hydrate structures) hydrate is considerably higher than LNG at equal pres/temp. Assuming full occupancy of the "cages" in the hydrate structure. I doubt it is the 180x quoted in the article, but it is higher.
I used to do research on hydrates and the density issue was really non-intuitive but turns out to be true. It has to do with thermodynamic stability inparted by the massive amount of hydrogen bonding in the hydrate form.
Excellent point on the pressure. What the story leaves out is that it takes a considerable amount of pressure to form the hydrates in any significant amounts. The reason being that methane is highly hydrophobic. So the kinetics of the reaction demand high pressure, although they are thermodynamically stable at lower pressure/temp than LNG. The reaction is highly limited by the amount of gas/liquid interface that you can get going in a reactor. Perhaps the japanesse have come up with a new reactor that makes a lot of gas/liquid contact w/o freezing it up in the process.
If you would like to learn more about hydrates, the epicenter of research in the states is here:
http://www.mines.edu/research/chs/
Dendy Sloan has a book in its second or third edition that covers nearly all that is know about the current state of hydrates. Lots of great phase diagrams. Its required reading for anybody who is anybody in the hydrate field....
ODP has been doing research into the area of gas hydrates for a while now. Not only can natural gas be turned into hydrate, but there are vast amounts of gas hydrate "stable" on the sea floor. Gas hydrates are also stable in certains areas of permafrost in the arctic. On an environmental note, it is not known exactly how hydrate. influences global climate change. Methane is 10 times the the global warmer that CO2 is. A large hydrate landslide off the northern coast of norway coincides nicely with an warm period. As sea level falls during an ice age, pressure on hydrates decreases, destabalizing them, and releasing methane into the atmosphere. This could serve as a natural buffer against ice ages. On an interesting side note, Gas hydrates have been proposed as the cause of the dissappearances in the bermuda. triangle. The theory is that a field of gas hydrates destabalizes right below a ship releasing a plume of methane gas. The water density will decrease. The ship sinks.
Opinions were like kittens, I was giving them away.