Posted on 04/15/2011 7:32:28 PM PDT by decimon
LIVERMORE, Calif. -- A new computational study published in the Proceedings of the National Academy of Sciences reveals how hydrocarbons may be formed from methane in deep Earth at extreme pressures and temperatures.
The thermodynamic and kinetic properties of hydrocarbons at high pressures and temperatures are important for understanding carbon reservoirs and fluxes in Earth.
The work provides a basis for understanding experiments that demonstrated polymerization of methane to form high hydrocarbons and earlier methane forming reactions under pressure.
Hydrocarbons (molecules composed of the elements hydrogen and carbon) are the main building block of crude oil and natural gas. Hydrocarbons contribute to the global carbon cycle (one of the most important cycles of the Earth that allows for carbon to be recycled and reused throughout the biosphere and all of its organisms).
The team includes colleagues at UC Davis, Lawrence Livermore National Laboratory and Shell Projects & Technology. One of the researchers, UC Davis Professor Giulia Galli, is the co-chair of the Deep Carbon Observatory's Physics and Chemistry of Deep Carbon Directorate and former LLNL researcher.
Geologists and geochemists believe that nearly all (more than 99 percent) of the hydrocarbons in commercially produced crude oil and natural gas are formed by the decomposition of the remains of living organisms, which were buried under layers of sediments in the Earth's crust, a region approximately 5-10 miles below the Earth's surface.
But hydrocarbons of purely chemical deep crustal or mantle origin (abiogenic) could occur in some geologic settings, such as rifts or subduction zones said Galli, a senior author on the study.
"Our simulation study shows that methane molecules fuse to form larger hydrocarbon molecules when exposed to the very high temperatures and pressures of the Earth's upper mantle," Galli said. "We don't say that higher hydrocarbons actually occur under the realistic 'dirty' Earth mantle conditions, but we say that the pressures and temperatures alone are right for it to happen.
Galli and colleagues used the Mako computer cluster in Berkeley and computers at Lawrence Livermore to simulate the behavior of carbon and hydrogen atoms at the enormous pressures and temperatures found 40 to 95 miles deep inside the Earth. They used sophisticated techniques based on first principles and the computer software system Qbox, developed at UC Davis.
They found that hydrocarbons with multiple carbon atoms can form from methane, (a molecule with only one carbon and four hydrogen atoms) at temperatures greater than 1,500 K (2,240 degrees Fahrenheit) and pressures 50,000 times those at the Earth's surface (conditions found about 70 miles below the surface).
"In the simulation, interactions with metal or carbon surfaces allowed the process to occur faster -- they act as 'catalysts,' " said UC Davis' Leonardo Spanu, the first author of the paper. The research does not address whether hydrocarbons formed deep in the Earth could migrate closer to the surface and contribute to oil or gas deposits. However, the study points to possible microscopic mechanisms of hydrocarbon formation under very high temperatures and pressures. Galli's co-authors on the paper are Spanu; Davide Donadio at the Max Planck Institute in Meinz, Germany; Detlef Hohl at Shell Global Solutions, Houston; and Eric Schwegler of Lawrence Livermore National Laboratory.
Founded in 1952, Lawrence Livermore National Laboratory is a national security laboratory, with a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by Lawrence Livermore National Security, LLC for the U.S. Department of Energy's National Nuclear Security Administration.
Ping
I knew it wasn’t ancient forests.
According to this it was.
So much for “peak oil” and the dinosaur/plants—>oil theory. Jupiter’s moon, Titan, has lakes of methane and it never had dinosaurs and plants millions of years ago.
"Do you smell oil?"
I always wondered how dead dinosaurs and prehistoric plants got two miles down anyway.
I’m not as familiar with oil as I am with coal.
There is a continuum with coal. Peat to lignite to sub-bituminous to bituminous to anthracite.
There are massive areas of peat being formed in the world today, mostly in northern Russia and Canada. When it is eventually buried and compressed, it will begin to change into the higher grades of coal.
I have little knowledge of how the processes that supposedly forms oil and gas may vary.
OMG! There are giant jacks floating in space!!
Funny, the Russians have been telling us this for years, as well as OIL being Abiotic and from compressed minerals NOT FOSSIL Fuel,Ancient Algae.....
That was the comment I was about to make. The eastern block gave up on “fossil” fuel long ago. The refilling oil wells seem to agree with them. It is simply methane or carbon and hydrogen trapped in the earth’s core when the earth was formed.
Hydrogen is the most common element in the universe while carbon is a direct line element formed during chain nuclear fusion... like in a star...
“The Kola borehole penetrated about a third of the way through the Baltic continental crust, estimated to be around 35 kilometres (22 mi) deep, reaching rocks of Archaean age (greater than 2.5 billion years old) at the bottom.[7] The project has been a site of extensive geophysical studies. The stated areas of study were the deep structure of the Baltic Shield; seismic discontinuities and the thermal regime in the Earth’s crust; the physical and chemical composition of the deep crust and the transition from upper to lower crust; lithospheric geophysics; and to create and develop technologies for deep geophysical study.
To scientists, one of the more fascinating findings to emerge from this well is that the change in seismic velocities was not found at a boundary marking Harold Jeffreys’s hypothetical transition from granite to basalt; it was at the bottom of a layer of metamorphic rock that extended from about 5 to 10 kilometers beneath the surface. The rock there had been thoroughly fractured and was saturated with water, which was surprising. This water, unlike surface water, must have come from deep-crust minerals and had been unable to reach the surface because of a layer of impermeable rock.[8]
Another unexpected discovery was the large quantity of hydrogen gas, with the mud flowing out of the hole described as “boiling” with hydrogen.[9]”
http://en.wikipedia.org/wiki/Kola_Superdeep_Borehole
........................... FRegards
Would be interesting to see what some of our ‘tapped out’ oil fields of today look like a few thousand or million years from now. I’d be willing to bet they would be as full as they were before we put a pipe into the ground.
There has never been any reason to beleive the Earth is any different from any other planet in having a large portion of its makeup being primordial methane. There is probably at least as much methane as there is water.
Bump for later.
That is a LOT of methane.
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