Though, there are a few experiments indicating that sono-cracking hydrocarbons can occur at near room temperature. --------
The Chemical Effects of Ultrasound
Intense ultrasonic waves traveling through liquids generate small
cavities that enlarge and implode, creating tremendous heat.
These extreme conditions provide an unusual chemical environment
by Kenneth S. Suslick
http://www.scs.illinois.edu/suslick/doc ... er8980.pdf
The sonochemistry of liquids depends mainly on physical effects of the quick heating and cooling caused by cavity implosion. For instance, when Peter Riesz and his colleagues at the National Cancer Institute irradiated water with ultrasound, they proved that the heat from cavity implosion decomposes water (H20) into extremely reactive hydrogen atoms (W) and hydroxl radicals (OH-). During the quick cooling phase, hydrogen atoms and hydroxl radicals recombine to form hydrogen peroxide (H202) and molecular hydrogen (H2). If other compounds are added to water irradiated with ultrasound, a wide range of secondary reactions can occur. Organic compounds are highly degraded in this environment, and inorganic compounds can be oxidized or reduced.
Other organic liquids also yield interesting reactions when they are irradiated with ultrasound. For' example, alkanes, major components of crude oil, can be "cracked" into smaller, desirable Crude oil is normally cracked by heating the entire mixture to temperatures above 500 degrees C. irradiating alkanes with ultrasound, however, makes cracking possible at room temperature and produces acetylene, which cannot be produced through simple heating. Perhaps the most unusual chemical phenomenon associated with ultrasound is its ability to produce microscopic flames in cold liquids by a process known as sonoluminescence. When an imploding cavity creates a hot spot in various liquids, molecules may be excited into high-energy states. As these molecules return to their ground state, they emit visible light. Edward B. Flint in our laboratory discovered in 1987 that hydrocarbons irradiated with ultrasound provide a most striking result: emitted light similar in color to a flame from a gas stove.
The effects of ultrasound on liquids have also been used to enhance the chemistry of compounds in solution. Compounds that contain metal-carbon bonds, called organometallics, are particularly illustrative. This diverse class of chemicals is important in the formation of plastics, in the production of microelectronics and in the synthesis of pharmaceuticals, herbicides and pesticides. In 1981 Paul F. Schubert and I first investigated the effects of ultrasound on organometallics, in particular iron pentacarbonyl, or Fe(CO)5 The results, when compared with the effects of light and heat on Fe(CO)5 underscore the distinctive chemistry that ultrasound can induce [see illustration on opposite page]. When Fe(CO)5 is exposed to heat, it decomposes into carbon monoxide (CO) and a fine iron powder, which ignites spontaneously in air. When Fe(CO)5 is exposed to ultraviolet light, it first breaks down into Fe(CO)5 and free CO fragments. Fe(CO)5 can then recombine to form Fe2(CO)g. Cavity implosion creates different results. It delivers enough heat to dissociate several CO molecules but cools quickly enough to quench the reaction before decomposition is complete. Thus when Fe(CO)5 is exposed to ultrasound, it yields the unusual cluster compound Fe3(CO)12. The sonochemistry of two immiscible liquids (such as oil and water) stems from the ability of ultrasound to emulsify liquids so that microscopic droplets of one liquid are suspended in the other. Ultrasonic compression and expansion stress liquid surfaces, overcoming the cohesive forces that hold a large droplet together. The droplet bursts into smaller ones, and eventually the liquids are emulsified. Emulsification can accelerate chemical reactions between immiscible liquids by greatly increasing their surface contact. A large contact area enhances crossover of molecules from one liquid to the other, an effect that can make some reactions proceed quickly. Emulsifying mercury with various liquids has particularly interesting chemistry as delineated by the investigations of Albert J. Fry of Wesleyan University. He developed the reactions of mercury with a variety of organobromide compounds as an intermediate in the formation of new carbon-carbon bonds. Such reactions are critical in the synthesis of complex organic compounds. The sonochemistry of solid surfaces in liquids depends on a change in the dynamics of cavity implosion. When cavitation occurs in a liquid near an extended solid surface, the cavity implosion differs substantially from the symmetrical, spherical implosion observed in liquid-only systems. The presence of the surface distorts the pressure from the ultrasound field so that a cavity implosion near a surface is markedly asymmetric. This generates a jet of liquid directed at the surface that moves at . speeds of roughly 400 kilometers per hour. The jet, as well as the shock waves from cavity implosion, erode solid surfaces, remove nonreactive coatings and fragment brittle powders. Reactions are further facilitated by high temperatures and pressures associated with cavity implosion near surfaces. These processes all enhance the chemical reactivity of solid surfaces, which is important in the synthesis of drugs, specialty chemicals and polymers. The sonochemistry of solid surfaces in liquids is best exemplified by reactions of active metals, such as lithium, magnesium, zinc and aluminum. Ultrasonic irradiation of reaction mixtures constituting these metals provides better control at lower temperatures and produces relatively higher yields. Pierre Renaud of the University of Paris first examined such reactions. More recently Jean-Louis Luche of the University of Grenoble and Philip Boudjouk of North Dakota State University have popularized the use of an ultrasonic cleaning bath to accelerate the reactions of active metals. The chemistry of these metals is very difficult to control. Traces of water, oxygen or nitrogen can react at the surface to form protective coatings. Increasing the reactivity of the protected surface by direct heating, however, can result in undesirable explosions. Ultrasound can keep the surface clean and allows the reaction to proceed evenly at reduced ambient temperatures. Excellent yields and improved reliability can be achieved for many reactive metals in large-scale industrial applications.
The extreme conditions generated by cavitation near surfaces can also be utilized to induce reactivity in "unreactive" metals. Robert E. Johnson in our laboratory, for instance, examined reactions between carbon monoxide and molybdenum and tantalum, as well as other comparable metals. Conventional techniques require pressures of from 1 00 to 300 atmospheres and temperatures of from 200 to 300 degrees C. to form metal carbonyls. Using ultrasound, however, formation of metal carbonyls can proceed at room temperature and pressure. The implosion of a cavity, in addition to all the effects described so far, sends shock waves through the liquid. The sonochemistry of solid particles in liquids depends heavily on these shock waves; they drive small particles of a powder into one another at speeds of more than 500 kilometers per hour. My co-workers and I have recently shown that such collisions are so intense in metal powders that localized melting takes place at the point of impact. This melting improves the metal's reactivity, because it removes metallic-oxide coatings. (Such protective oxide coatings are found on most metals and are responsible for the patina on copper gutters and bronze sculpture.)
Since ultrasound improves the reactivity of metal powders, it also makes them better catalysts. Many reactions require a catalyst in order to proceed at useful or even appreciable rates. Catalysts are not consumed by the reaction but instead speed the reaction of other substances. The effects of ultrasound on particle morphology, surface composition and catalyst reactivity have been investigated by Dominick. Casadonte and Stephen. Doktycz in our laboratory. They have discovered that catalysts such as nickel, copper and zinc powders irradiated with ultrasound show dramatic changes in surface morphology. Individual surfaces are smoothed and particles are consolidated into extended aggregates. An experiment to determine the surface composition of nickel revealed that its oxide coating was removed, greatly improving the reactivity of the nickel powder. Ultrasonic irradiation increased the effectiveness of nickel powder as a catalyst more than 1,000,000 times. The nickel powder is as reactive as some special catalysts currently in use, yet it is nonflammable and less expensive.
http://www.scs.illinois.edu/suslick/doc ... er8980.pdf
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New waves of seismic technology yield big oil finds (video)
HOUSTON — For decades, the giants of the oil industry were confounded by salt.
While oil companies for years had shot sound waves into the deep to help create images of undersea geology, salt located far under the floor of the Gulf of Mexico was unpredictable. It muffled reflections, or bounced them away from survey vessels, leaving geophysicists in the dark.
But that was before a series of recent seismic imaging breakthroughs involving supercomputers and the largest moving objects in the ocean. The advancements helped oil companies peek under salt layers located miles below the Gulf and have spurred a number of discoveries and billions of dollars in new investment in offshore oil production.
"It’s like a medical imaging experiment that we’re all familiar with when they take an ultrasound and show us an image of the baby, only it’s done on a planetary scale," said Craig Beasley, chief geophysicist for Schlumberger’s WesternGeco subsidiary.
Making waves
Using the new and evolving methods, oil companies have found ways to shoot sound miles below the surface and capture more echoes of those sound waves than they ever have.
Teams of mathematicians, geophysicists and software engineers use large computer systems to translate those echoes into three-dimensional images of reserves more than six miles below ocean, rock layers and salt, a feat that was little more than a dream a decade ago.
The innovations have helped oil companies tap into some of the largest offshore oil reserves ever discovered and are a big reason why four towering oil platforms were under construction this summer at a single yard in Ingleside near Corpus Christi. The platforms are the culmination of multibillion dollar projects to extract oil from reservoirs that would have been challenging to target prior to seismic imaging advances.
"If the seismic had stayed the same as it was in 1999 and 2000…today we would be effectively drilling in the dark," said John Etgen, BP’s distinguished adviser for seismic imaging.
Beasley said salt previously created havoc in seismic images.
"The easiest way to think about it is the swimming pool where you put your pole in the swimming pool, and it looks like there’s a kink in the pole," he said.
The shape of the pole hasn’t changed, of course, but its image is distorted. Salt in underground layers as thick as 18,000 feet can have the same effect, sending sound waves back at different speeds and angles and leaving gaps in data and distorting images.
Since salt reflects sound in a variety of directions, geophysicists had to find a way to capture more echoes. Covering the ocean surface with sensors isn’t practical, so experts at BP decided to experiment with additional sources of sound, Etgen said.
Capturing sound
Most seismic surveys involve boats towing arrays of cables up to five miles long and half a mile wide, perhaps creating the largest moving bodies in the sea. The cables are equipped with hydrophones, which measure sound in water.
To generate sound waves, oil companies use air guns to create explosive sounds under water in intervals as long as 15 seconds.
Environmentalists say the noise can endanger sea life.
The air guns can produce underwater noise of more than 130 decibels, 10 miles from the source, said Michael Jasny, director of the Natural Resource Defense Council’s marine mammal protection project. That’s as loud as a jackhammer and almost as loud as the sound of a jet engine, which measures 140 decibels.
A settlement earlier this year among environmentalists, regulators and a leading industry group puts some limits on air gun use.
When they are used, each blast sends sound waves deep below the ocean and seafloor. Their echoes return and hit the hydrophones.
BP’s breakthrough
BP in 2004 pioneered the wide azimuth towed streamer method, a new approach to seismic that would change the industry. The process captures more sound waves with the same set of cables by using multiple boats firing air guns, Etgen said.
Each boat sends soundwaves into the ground, delivering reflections to the surface from multiple angles. Powerful computers use mathematical processes called algorithms to combine the echo images, creating a sharper view of what lies beneath the salt, Etgen said.
Video: ‘Augmented reality’ turns animation into oil business tool
The effect is similar to sports broadcasts that use multiple cameras to show the action from different angles. If one angle produces a distorted or incomplete image of the underground rocks, measurements of other reflection angles help fill in the missing parts.
"The more of that thing that I can catch and record, the better chance I have of making an image," Etgen said. The wide azimuth survey produced 16 times as much data as conventional seismic surveys, he said.
The success prompted other experiments.
Beasley said WesternGeco championed an approach involving just one boat with an air gun and streamers attached. The guns fired as the vessel moved in a giant circle, with a radius of up to 5 miles. Then it moved over slightly and made another, overlapping circle. The method allowed a single array to encircle the reflections bouncing up from the subsurface, helping a survey vessel capture more sound waves from each air gun blast, Beasley said.
WesternGeco now is advancing seismic imaging that involves multiple sounds being fired at the same time, cutting out the waiting period needed between air gun shots, Beasley said.
On the ocean floor
Another revolutionary approach places sensor nodes on the ocean floor rather than towing them on the surface, said Roger Keyte, director of marketing and strategy for Sugar Land-based Fairfield Nodal.
It produces the yellow, disk-shaped nodes in its Sugar Land facility, then ships them by the thousands to locations where they’re dropped off boats, sink to the ocean floor and listen for sound.
They can produce the most detailed images possible because they don’t encounter ambient noise from moving through the water and can be placed in position to capture sonic reflections, he said.
The technique, called on-bottom seismic, allows oil explorers to examine plays beneath existing structures like platforms and pipes, which isn’t possible for unwieldy vessels towing strings of hydrophones. BP first used the method in a commercial survey at its Atlantis field in 2005, Etgen said.
Although they produce more data than towed hydrophones, on-bottom seismic surveys can cost as much as four times more, Fairfield Nodal’s Keyte said.
But companies have found on-bottom seismic critical to expanding their drilling efforts.
"I view it as a ground-breaking kind of technology that’s allowing us to see the subsurface like we’ve never seen it before," said John Hollowell, Shell’s executive vice president for deep water in the Americas, in a July interview. "And the success of these projects in many respects is your ability to see the subsurface better than anybody else."
Deep water discoveries
Several of the largest oil fields ever discovered were not produced until many years later, after advances that helped oil companies better plan for the deep obstacles they might face.
BP’s Thunder Horse field, the second largest field discovered in the Gulf with an estimated 1.1 billion barrels of oil equivalent in recoverable reserves, was discovered in 1999, but production didn’t begin until 2008, according to research from energy consulting firm Wood Mackenzie.
Shell’s Mars-Ursa field, which was discovered in 1989, is the largest in the Gulf of Mexico, with 1.3 billion barrels of oil equivalent in recoverable reserves, according to Wood Mackenzie. Production didn’t begin at the Mars field until 1996.
Reserve estimates for both fields, and others, have increased as seismic imaging advancements have helped companies better understand underground rock layers. And a new effort to produce oil from the Mars field is currently underway, following advancements in seismic imaging that helped Shell drill new wells there.
Advancements since then have led to a rush of huge new Gulf discoveries, some that have lifted the profile of smaller oil companies, such as Cobalt International Energy. Cobalt explicitly targets reserves located below salt layers, focusing on its use of advanced seismic imaging to help it find oil, the company says.
Cobalt made one of the largest gulf discoveries in the last decade when it found the North Platte field last year. The field holds 500 million barrels of oil equivalent in recoverable reserves, according to Wood Mackenzie.
Beasley said that further seismic advances are likely to help oil companies find more oil that they couldn’t see before.
"I’m sure there’s a limit somewhere," he said. "We haven’t reached it yet."
http://fuelfix.com/blog/2013/10/28/new- ... nds-video/
