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  • richardmitnick 11:38 am on August 8, 2018 Permalink | Reply
    Tags: , CO2 studies, ,   

    From ESRF The European Synchrotron: “Research gives clues to CO2 trapping underground” 

    ESRF bloc
    From ESRF The European Synchrotron


    Carbon dioxide is a widespread simple molecule in the Universe.

    CO2 is an environmentally important gas that plays a crucial role in climate change. It is a compound that is also present in the depth of the Earth but very little information about it is available. What happens to CO2 in the Earth’s mantle? Could it be eventually hosted underground? A new publication in Nature Communications unveils some key findings.


    In spite of its simplicity, it has a very complex phase diagram, forming both amorphous and crystalline phases above the pressure of 40 GPa. In the depths of the Earth, CO2 does not appear as we know it in everyday life. Instead of being a gas consisting of molecules, it has a polymeric solid form that structurally resembles quartz (a main mineral of sand) due to the pressure it sustains, which is a million times bigger than that at the surface of the Earth.

    Researchers have been long studying what happens to carbonates at high temperature and high pressure, the same conditions as deep inside the Earth. Until now, the majority of experiments had shown that CO2 decomposes, with the formation of diamond and oxygen. These studies were all focused on CO2 at the upper mantle, with a 70 GPa of pressure and 1800-2800 Kelvin of temperature.

    A team of scientists from the European Laboratory for Non-linear Spectroscopy (LENS), the University of Florence, the National Research Council of Italy, the University of Vienna and the ESRF came to the high-pressure beamline ID27 to study, using x-ray diffraction and Raman scattering (the latter performed in the facilities of LENS), what happens to CO2 at the depth of 2000 to 2400 kilometres, i.e. at the boundary between the silicate minerals of the lower mantle and the metallic core.

    “One of the added value of our team is the fact that we all have different backgrounds: from chemists, to mineralogists and the physicists of the ESRF. This means that we complement each other and, together, we try to get a full picture of what happens to CO2 from our different points of view”, explains Dziubek, corresponding author of the study.

    In order to achieve these conditions, they used a diamond anvil cell and submitted the sample to 2400 degrees Celsius (2700K) and 120 GPa of pressure, which is almost double than previous research. “It was a very complex setup, in particular the laser heating with a 10 micron infrared laser at pressures above 100 GPa was very challenging”, explains Mohamed Mezouar, scientist in charge of ID27. Thinking that they would come up with similar results to existing literature, they were in for a surprise: CO2 is, in fact, stable in a crystalline form and does not dissociate like previously believed.

    Mohamed Mezouar, scientist in charge of ID27, on the beamline. Credits: S. Candé.

    “Our results indicate that the crystalline extended form of carbon dioxide is stable in the thermodynamic conditions of the deep lower mantle and therefore could be helpful to understand the distribution and transport of carbon in the depths of our planet. It could even open doors to the possibility of trapping CO2 underground, if it stays there or just in its polymeric form”, explains Kamil Dziubek.

    CO2 sequestration in geological formations is one of the potential solutions for mitigating the climate changes associated with the greenhouse effect. It is important, however, to investigate the fate of carbon dioxide in deep geosphere and to recognize the form in which it can be stored within the host rock. If the neat polymeric CO2 stays stable in the deep mantle, it can represent a long-term storage of carbon.

    Therefore, the next step of the team is to mimic the real conditions not only in the terms of thermodynamics but also geochemistry, and study in detail stability and reactivity of the CO2 in presence of silicates, carbonates and other minerals, which are known to exist in the deepest parts of the Earth’s mantle.

    See the full article here .


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    The ESRF – the European Synchrotron Radiation Facility – is the most intense source of synchrotron-generated light, producing X-rays 100 billion times brighter than the X-rays used in hospitals. These X-rays, endowed with exceptional properties, are produced at the ESRF by the high energy electrons that race around the storage ring, a circular tunnel measuring 844 metres in circumference. Each year, the demand to use these X-ray beams increases and thousands of scientists from around the world come to Grenoble, to access the 43 highly specialised experimental stations, called “beamlines”, each equipped with state-of-the-art instrumentation, operating 24 hours a day, seven days a week.

    Thanks to the brilliance and quality of its X-rays, the ESRF functions like a “super-microscope” which “films” the position and motion of atoms in condensed and living matter, and reveals the structure of matter in all its beauty and complexity. It provides unrivalled opportunities for scientists in the exploration of materials and living matter in a very wide variety of fields: chemistry, material physics, archaeology and cultural heritage, structural biology and medical applications, environmental sciences, information science and nanotechnologies.

    Following on from 20 years of success and excellence, the ESRF has embarked upon an ambitious and innovative modernisation project, the Upgrade Programme, implemented in two phases: Phase I (2009-2015) and the ESRF-EBS (Extremely Brilliant Source) (2015-2022) programmes. With an investment of 330 million euros, the Upgrade Programme is paving the way to a new generation of synchrotron storage rings, that will produce more intense, coherent and stable X-ray beams. By constructing a new synchrotron, deeply rooted in the existing infrastructure, the ESRF will lead the way in pushing back the boundaries of scientific exploration of matter, and contribute to answering the great technological, economic, societal and environmental challenges confronting our society.

  • richardmitnick 2:25 pm on December 13, 2016 Permalink | Reply
    Tags: , , CO2 studies, Critical Step for Carbon-Cycle Science, Eye-Popping View of CO2, NASA OCO-2,   

    From Orbiter.ch: “Eye-Popping View of CO2, Critical Step for Carbon-Cycle Science” 



    NASA – Orbiting Carbon Observatory-2 (OCO-2) logo

    Dec. 13, 2016
    No writer credit

    A new NASA supercomputer project builds on the agency’s satellite measurements of carbon dioxide and combines them with a sophisticated Earth system model to provide one of the most realistic views yet of how this critical greenhouse gas moves through the atmosphere.

    Scientists have tracked the rising concentration of heat-trapping carbon dioxide for decades using ground-based sensors in a few places. A high-resolution visualization of the new combined data product – generated by the Global Modeling and Assimilation Office at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, using data from the agency’s Orbiting Carbon Observatory-2 (OCO-2) satellite build and operated by NASA’s Jet Propulsion Laboratory in Pasadena, California – provides an entirely different perspective.

    The 3-D visualization reveals in startling detail the complex patterns in which carbon dioxide in the atmosphere increases, decreases and moves around the globe over the course of September 2014 to September 2015.

    Video above: Carbon dioxide plays a significant role in trapping heat in Earth’s atmosphere. The gas is released from human activities like burning fossil fuels, and the concentration of carbon dioxide moves and changes through the seasons. Using observations from NASA’s Orbiting Carbon Observatory (OCO-2) satellite, scientists developed a model of the behavior of carbon in the atmosphere from Sept. 1, 2014, to Aug. 31, 2015. Scientists can use models like this one to better understand and predict where concentrations of carbon dioxide could be especially high or low, based on activity on the ground. Video Credits: NASA’s Goddard Space Flight Center/K. Mersmann, M. Radcliff, producers.

    Atmospheric carbon dioxide acts as Earth’s thermostat. Rising concentrations of the greenhouse gas, due primarily to the burning of fossil fuels for energy, have driven Earth’s current long-term warming trend. The visualization highlights the advances scientists are making in understanding the processes that control how much emitted carbon dioxide stays in the atmosphere and how long it stays there – questions which ultimately will determine Earth’s future climate.

    Scientists know that nearly half of all human-caused emissions are absorbed by the land and ocean. The current understanding is that about 50 percent of emissions remain in the atmosphere, about 25 percent are absorbed by vegetation on the land, and about 25 percent are absorbed by the ocean. However, those seemingly simple numbers leave scientists with critical and complex questions: Which ecosystems, especially on land, are absorbing what amounts of carbon dioxide? Perhaps most significantly, as emissions keep rising, will the land and the ocean continue this rate of absorption, or reach a point of saturation?

    The new dataset is a step toward answering those questions, explained Lesley Ott, a carbon cycle scientist at NASA Goddard and a member of the OCO-2 science team. Scientists need to understand the processes driving the “carbon flux” – the exchange of carbon dioxide among the atmosphere, land and ocean, Ott said.

    Orbiting Carbon Observatory-2 (OCO-2) satellite. Image Credit: NASA

    “We can’t measure the flux directly at high resolution across the entire globe,” she said. “We are trying to build the tools needed to provide an accurate picture of what’s happening in the atmosphere and translating that to an accurate picture of what’s going on with the flux. There’s still a long way to go, but this is a really important and necessary step in that chain of discoveries about carbon dioxide.”

    OCO-2, launched in 2014, is NASA’s first satellite designed specifically to measure atmospheric carbon dioxide at regional scales.

    “Since September of 2014, OCO-2 has been returning almost 100,000 carbon dioxide estimates over the globe each day,” said David Crisp, OCO-2 project scientist. “Modeling tools like those being developed by our colleagues in the Global Modeling and Assimilation Office are critical for analyzing and interpreting this high resolution dataset.”

    The Global Modeling and Assimilation Office has previously included carbon dioxide in its GEOS Earth System model, which is used for all manner of atmospheric studies. This new product builds on that work by using the technique of data assimilation to combine the OCO-2 observations with the model. “Data assimilation is the process of blending model simulations with real world measurements with the precision, resolution and coverage needed to reflect our best understanding of the exchange of carbon dioxide between the surface and atmosphere,” explained Brad Weir, a researcher based in the GMAO.

    The visualization showcases information about global carbon dioxide fields that has not been seen before in such detail: The rise and fall of carbon dioxide in the Northern Hemisphere throughout a year; the influence of continents, mountain ranges and ocean currents on weather patterns and therefore carbon dioxide movement; the regional influence of highly active photosynthesis in places like the Corn Belt in the U.S.

    While the finely detailed carbon dioxide fluctuations are eye-catching, they also remind Global Modeling and Assimilation Office chief Steven Pawson of the progress scientists are making with computer models of the Earth system. One future step will be to integrate a more complex biology module into the model to better target the questions of carbon dioxide absorption and release by forests and other land ecosystems.

    The results highlighted here demonstrate the value of NASA’s unique capabilities in observing and modeling Earth. It also emphasizes the collaboration among NASA centers and the value of powerful supercomputing. The assimilation was created using a model called the Goddard Earth Observing System Model-Version 5 (GEOS-5), which was run by the Discover supercomputer cluster at Goddard’s NASA Center for Climate Simulation.

    “It’s taken us many years to pull it all together,” Pawson said. “The level of detail included in this dataset gives us a lot of optimism that our models and observations are beginning to give a coherent view of the carbon cycle.”

    Related Links:

    NASA’s AGU website: http://www.nasa.gov/agu

    NASA’s OCO-2 website: https://www.nasa.gov/mission_pages/oco2/index.html

    See the full article here .

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  • richardmitnick 7:28 am on September 1, 2016 Permalink | Reply
    Tags: , CO2 studies, , Susan Rempe,   

    From Sandia: Women in STEM – “Blowing bubbles to catch carbon dioxide” Susan Rempe 

    Sandia Lab

    September 1, 2016
    Mollie Rappe
    (505) 844-8220

    Sandia, UNM develop bio-inspired liquid membrane that could make clean coal a reality

    Sandia National Laboratories researcher Susan Rempe peers through bubbles. The CO2 Memzyme she helped design captures carbon dioxide from coal-fired power plants and is 10 times thinner than a soap bubble. (Photo by Randy Montoya).

    Sandia National Laboratories and the University of New Mexico (UNM) have created a powerful new way to capture carbon dioxide from coal- and gas-fired electricity plants with a bubble-like membrane that harnesses the power of nature to reduce CO2 emissions efficiently.

    CO2 is a primary greenhouse gas, and about 600 coal-fired power plants emitted more than a quarter of total U.S. CO2 emissions in 2015. When you include emissions from natural gas plants, the figure goes up to almost 40 percent. Current commercial technologies to capture these emissions use vats of expensive, amine-based liquids to absorb CO2. This method consumes about one third of the energy the plant generates and requires large, high-pressure facilities.

    The Department of Energy has set a goal for a second-generation technology that captures 90 percent of CO2 emissions at a cost-effective $40 per ton by 2025. Sandia and UNM’s new CO2 Memzyme is the first CO2 capture technology that could actually meet these national clean energy goals. The researchers received a patent for their innovation earlier this year.

    It’s still early days for the CO2 Memzyme, but based on laboratory-scale performance, “if we applied it to a single coal-fired power plant, then over one year we could avoid CO2 emissions equivalent to planting 63 million trees and letting them grow for 10 years,” said Susan Rempe, a Sandia computational biophysicist and one of the principal developers.

    Membranes usually have either high flow rates without discriminating among molecules or high selectivity for a particular molecule and slow flow rates. Rempe, Ying-Bing Jiang, a chemical engineering research professor at UNM, and their teams joined forces to combine two recent, major technological advances to produce a membrane that is both 100 times faster in passing flue gas than any membrane on the market today and 10-100 times more selective for CO2 over nitrogen, the main component of flue gas.

    Stabilized, bubble-like liquid membrane

    One day Jiang was monitoring the capture of CO2 by a ceramic-based membrane using a soap bubble flow meter when he had a revolutionary thought: What if he could use a thin, watery membrane, like a soap bubble, to separate CO2 from flue gas that contains other molecules such as nitrogen and oxygen?

    Thinner is faster when you’re separating gases. Polymer-based CO2 capture membranes, which can be made of material similar to diapers, are like a row of tollbooths: They slow everything down to ensure only the right molecules get though. Then the molecules must travel long distances through the membrane to reach, say, the next row of tollbooths. A membrane half as thick means the molecules travel half the distance, which speeds up the separation process.

    CO2 moves, or diffuses, from an area with a lot of it, such as flue gas from a plant that can be up to 15 percent CO2, to an area with very little. Diffusion is fastest in air, hence the rapid spread of popcorn aroma, and slowest through solids, which is why helium slowly diffuses through the solid walls of a balloon, causing it to deflate. Thus, diffusion through a liquid membrane would be 100 times faster than diffusion through a conventional solid membrane.

    Soap bubbles are very thin – 200 times thinner than a human hair – but are fragile. Even the lightest touch can make them pop. Jiang and his postdoctoral fellow Yaqin Fu knew they would need to come up with a way to stabilize an ultra-thin membrane.

    Luckily, his colleague Jeff Brinker, another principal developer who is a Sandia fellow and regent’s professor at UNM, studies porous silica. By modifying Brinker’s material, Jiang’s team was able to produce a silica-based membrane support that stabilized a watery layer 10 times thinner than a soap bubble. By combining a relatively thick hydrophobic (water-fearing) layer and a thin hydrophilic (water-loving) layer, they made tiny nanopores that protect the watery membrane so it doesn’t “pop” or leak out.

    Enzyme-saturated water accelerates CO2 absorption

    Enzymes (the –zyme part of Memzyme; the mem– comes from membrane) are biological catalysts that speed up chemical reactions. Even the process of CO2 dissolving in water can be sped up by carbonic anhydrase, an enzyme that combines CO2 with water (H2O) to make super soluble bicarbonate (HCO3-) at an astounding rate of a million reactions per second. This enzyme can be found in our muscles, blood and lungs to help us get rid of CO2.

    Rempe and her former postdoctoral fellow Dian Jiao were studying how CO2 dissolved in water, with and without this enzyme. They thought the enzyme could be combined with something like Jiang’s watery membrane to speed up CO2 capture. An enzyme-loaded membrane is almost like an electronic toll collection system (such as E-ZPass). The enzyme speeds up the dissolving of CO2 into water by a factor of 10 million, without interacting with other gases such as nitrogen or oxygen. In other words, the liquid Memzyme takes up and releases CO2 only, fast enough that diffusion is unimpeded. This innovation makes the Memzyme more than 10 times more selective while maintaining an exceptionally high flow rate, or flux, compared to most competitors that use slower physical processes like diffusion through solids.

    However, the nanopores in the membrane are very small, only a little wider than and a few times as tall as the enzyme itself. “What’s happening to the enzyme under confinement? Does it change shape? Is it stable? Does it attach to the walls? How many enzymes are in there?” Rempe wondered.

    Rempe and her postdoctoral fellow Juan Vanegas designed molecular simulations to model what happens to the enzyme in its little cubby to improve performance. Interestingly, the enzyme actually likes its “crowded” environment, perhaps because it mimics the environment inside our bodies. And more than one enzyme can squeeze into a nanopore, acting like runners in a relay passing off a CO2 baton. Because of the unique structure of the membrane, the enzymes stay dissolved and active at a concentration 50 times higher than competitors who use the enzyme just in water. That’s like having 50 E-ZPass lanes instead of just one. Protected inside the nanopores, the enzyme is still efficient and lasts for months even at 140 degrees Fahrenheit.

    Working toward a greener future

    Having successfully tested the CO2 Memzyme at the laboratory scale, the Sandia-UNM team is looking for partners to help the technology mature. Each part of the membrane fabrication process can be scaled up, but the process needs to be optimized to make membranes for large power plants.

    In addition, the team is looking into more stable alternatives to the common form of the enzyme, such as enzymes from thermophiles that live in Yellowstone National Park hot springs. Or the Memzyme could use different enzymes to purify other gases, such as by turning methane gas into soluble methanol to produce purified methane for use in the natural gas industry.

    The CO2 Memzyme produces 99 percent pure CO2, which can be used in many industries. For example, U.S. oil companies buy 30 million tons of pure CO2 for enhanced oil recovery. The CO2 could be fed to algae in biofuel production, used in the chemical industry or even used to carbonate beverages.

    Initial funding for the research was provided by Sandia’s Laboratory Directed Research and Development office, with additional funding provided by DOE Basic Energy Sciences, Defense Threat Reduction Agency’s Joint Science and Technology Office, and the Air Force Office of Scientific Research. The technology won a Federal Labs Consortium Notable Technology Development Award in 2014, an R&D100 award in Materials and an R&D100 Gold Award for Green Technology in 2015.

    “Partnership between theory and experiment, Sandia and UNM, has proven fruitful here, as it did in our earlier work on water purification membranes. Together we developed a membrane that has both high selectivity and fast flux for CO2. With optimization for industry, the Memzyme could be the solution we’re looking for to make electricity both cheap and green,” said Rempe.

    See the full article here .

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    Sandia Campus
    Sandia National Laboratory

    Sandia National Laboratories is a multiprogram laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major R&D responsibilities in national security, energy and environmental technologies, and economic competitiveness.

  • richardmitnick 8:08 am on June 15, 2016 Permalink | Reply
    Tags: , , CO2 studies,   

    From INVERSE: “CO2 Concentrations Won’t Dip Below the 400 PPM Again”… 



    June 14, 2016
    Jacqueline Ronson

    …Not in your lifetime anyway.

    Until very recently, atmospheric concentrations of carbon dioxide below 400 parts per million were all you had ever known. They were all this planet had known for millions of years. But those days are gone, and they’re not coming back any time soon according to a new study published in Nature Climate Change.

    The benchmark of 400 ppm is arbitrary, but worth noting because it represents a huge increase over what the planet has seen in millions of years. For the past 800,000 years, excluding the past century, the level of carbon dioxide in the atmosphere has varied between 180 and 280 parts per million. Then humans figured out how to burn fossil fuels for energy, and CO2 levels took off from there. Some researchers have suggested that 350 ppm is a “safe” level for the humans, plants, and animals that have adapted to life on this planet as we know it.

    What’s most shocking is how quickly the planet has gone from one where 400 ppm is unheard of, to one where levels below 400 won’t be seen again for the foreseeable future. There were some instances of readings over 400 ppm in 2012 and 2013, but the first time the planet sustained readings over 400 for a full month was barely a year ago, in March 2015.

    Global CO2 concentrations go up and down seasonally, but on average they are increasing at an increasing rate.

    The CO2 concentrations in the atmosphere cycle up and down every year with the seasons, as great northern forests suck up large quantities of carbon in the spring and summer. But the overall upward trend is clear, and the gap between being seasonally above 400 ppm and permanently — almost nonexistent.

    Thanks to a particularly strong El Niño, researchers believe we won’t dip back below 400 ppm for a very, very long time. The problem is, once CO2 gets into the atmosphere, it can stay there for centuries or even millennia. The major way it comes out of the atmosphere is by being dissolved into the oceans, which has its own consequences for the health of the planet. So even though human emissions have flattened out, the carbon dioxide in the atmosphere continues to grow at an increasing rate. Reversing the trend will take dramatic decreases in fossil fuel burning, and probably negative emission technologies like carbon capture and storage, too.

    The consequences of global climate change may be dramatic and irreversible, or they may be incremental. Either way, it’s time to start saying your goodbyes to Planet Earth as you once knew it.

    Maybe say your first goodbye to your cousins the Bramble Cay melomys, a rat-like rodent that is the first confirmed mammal to go extinct because of climate change. This species of melomys lived exclusively on Bramble Cay, a tiny coral island off the northern coast of Australia. Rising sea and storm surges inundated the cay with salty water often enough to kill off the vegetation the little guys depended on for food. The floods may have also drowned the melomys in large numbers. Researchers surveyed the island in 2014, and found no evidence of survivors.

    See the full article here .

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  • richardmitnick 9:53 pm on May 13, 2016 Permalink | Reply
    Tags: , , , CO2 studies,   

    From AGU: “Earth’s Atmosphere Passes Significant Carbon Milestone” 

    AGU bloc

    American Geophysical Union

    May 12, 2016
    Dan Satterfield

    The illustration was created by interpolating 20 profiles measured on February 5 and 8, 2016. The vertical axis has been increased for better visibility. Eric Morgan, Scripps Institution of Oceanography.

    Earth’s atmosphere is crossing a major threshold, as high levels of carbon dioxide (CO2)—the leading driver of recent climate change—are beginning to extend even to the globe’s most remote region. Scientists flying near Antarctica this winter captured the moment with airborne CO2 sensors during a field project to better understand the Southern Ocean’s role in global climate.

    This illustration shows the atmosphere near Antarctica in January, just as air masses over the Southern Ocean began to exceed 400 parts per million of CO2. The 400 ppm level is regarded as a milestone by climate scientists, as the last time concentrations of the heat-trapping gas reached such a point was millions of years ago, when temperatures and sea levels were far higher.

    The field project, led by the National Center for Atmospheric Research (NCAR) and known as ORCAS, found that there is still air present in the Southern Hemisphere that has less than 400 ppm of CO2—but just barely. In the north, the atmosphere had first crossed that threshold in 2013, as shown by observations taken at Mauna Loa, Hawaii, by the National Oceanic and Atmospheric Administration and Scripps Institution of Oceanography.

    Image from NOAA/Climate Central

    Most fossil fuels are burned in the Northern Hemisphere, and these emissions take about a year to spread across the equator. As CO2 increases globally, the concentrations in the Southern Hemisphere lag slightly those further north.

    “Throughout humanity, we have lived in an era with CO2 levels below 400 ppm,” said Ralph Keeling, director of the CO2 Program at the Scripps Institution of Oceanography and a principal investigator on ORCAS. “With these data, we see that era drawing to a close, as the curtain of higher CO2 spreads into the Southern hemisphere from the north. There is no sharp climate threshold at 400 ppm, but this milestone is symbolically and psychologically important.”

    The air found by ORCAS with less than 400 ppm of CO2 was located in a wedge at lower altitudes. At higher altitudes, the air had already exceeded 400 ppm. This pattern is mostly a consequence of the way the air circulates in the region. At these southerly latitudes, the air arrives from the Northern Hemisphere at higher elevations and then mixes downward.

    Emissions of CO2 have been increasing since the 19th century.

    See the full article here .

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    The purpose of the American Geophysical Union is to promote discovery in Earth and space science for the benefit of humanity.

    To achieve this mission, AGU identified the following core values and behaviors.

    Core Principles

    As an organization, AGU holds a set of guiding core values:

    The scientific method
    The generation and dissemination of scientific knowledge
    Open exchange of ideas and information
    Diversity of backgrounds, scientific ideas and approaches
    Benefit of science for a sustainable future
    International and interdisciplinary cooperation
    Equality and inclusiveness
    An active role in educating and nurturing the next generation of scientists
    An engaged membership
    Unselfish cooperation in research
    Excellence and integrity in everything we do

    When we are at our best as an organization, we embody these values in our behavior as follows:

    We advance Earth and space science by catalyzing and supporting the efforts of individual scientists within and outside the membership.
    As a learned society, we serve the public good by fostering quality in the Earth and space science and by publishing the results of research.
    We welcome all in academic, government, industry and other venues who share our interests in understanding the Earth, planets and their space environment, or who seek to apply this knowledge to solving problems facing society.
    Our scientific mission transcends national boundaries.
    Individual scientists worldwide are equals in all AGU activities.
    Cooperative activities with partner societies of all sizes worldwide enhance the resources of all, increase the visibility of Earth and space science, and serve individual scientists, students, and the public.
    We are our members.
    Dedicated volunteers represent an essential ingredient of every program.
    AGU staff work flexibly and responsively in partnership with volunteers to achieve our goals and objectives.

  • richardmitnick 7:13 am on April 21, 2016 Permalink | Reply
    Tags: , , CO2 studies,   

    From SA: “Can Oil Companies Save the World from Global Warming?” 

    Scientific American

    Scientific American

    April 19, 2016
    David Biello

    ENHANCED OIL: Pumping the greenhouse gas carbon dioxide underground can scour more oil out of already tapped reservoirs. Credit: © David Biello

    Kevin Macumber wanted to be a forester. Today he manages about 4,000 acres of longleaf pine in Mississippi—not for the timber, but for what lies far beneath the woods. It’s black gold: oil, deep underground. And the key to getting it out is the same molecule that lets all those trees grow: carbon dioxide.

    “Another day in paradise,” says Macumber as we meet at a Chevron gas station in southeastern Mississippi, about the closest thing to a landmark around here. We’re headed to the old trailer home that’s become the operational headquarters for Tellus Operating Group, a wildcat oil company with some old oil fields in this neck of the woods. I follow his black Chevy pickup down country byways until we finally turn off on a dirt road that winds through forests to the company trailer, where the coffee is fresh and Macumber can banter with a few of his workers on this warm sunny day.

    The secret about old oil reservoirs below the surface is that they still have oil, sometimes a lot, but it no longer comes out easily. Companies can pump large volumes of CO2, piped in from natural deposits belowground, down into the wells, forcing out the oil that would otherwise stay put. Macumber used to work at Occidental, one of the large oil companies that helped pioneer this “enhanced oil recovery” technique in Texas. But now he’s helped found Tellus—named after one of the Roman Earth goddesses—to do the same thing in Mississippi.

    Right now, Tellus gets its CO2 from a deposit called the Jackson Dome in western Mississippi, and other oil companies are using a similar approach at hundreds of old wells around the country. But Tellus is one of two U.S. oil companies that hopes to try something entirely new, any day now. Instead of piping in natural CO2, it will use the greenhouse gas captured at a coal-fired power plant just completed nearly 100 miles north of here and send it down into the reservoir, pushing oil out and leaving the greenhouse gas deep below, safely locked away from the atmosphere, so it does not add to global warming.

    A well in the Raleigh oil field where extra petroleum scoured out of underground deposits flows back to the surface, for sale. © David Biello

    At least three coal-fired power plants are under construction in the U.S. that are designed to have their CO2 emissions captured and sent to an oil field for enhanced oil recovery, including the Kemper County Energy Facility up the road from here. More arrangements like this are being made worldwide. The scheme is vital: The only way nations can meet the targets in the Paris Agreement to combat climate change is to eliminate the burning of fossil fuels or to capture emissions and find a place to store them besides the atmosphere. Sequestering the gas belowground costs money, and the only way to pay for it on a scale large enough to slow global warming is for oil companies worldwide to buy the CO2 for enhanced oil recovery. The coal plants, in return, would make money selling their CO2.

    But there’s a new flaw in this game plan: cheap oil. Oil companies that today pay for CO2 to be delivered from natural deposits are in danger of losing money, because the current price of oil is so low. For now, company’s like Tellus and others have to keep CO2 flowing into their old reservoirs because if they shut down, they lose the underground pressure they spent so much money to create. But if oil prices stay too low for too long, they will no longer be able to afford to keep purchasing CO2. Then the world will lose the one prospective way it currently has for paying to keep CO2 out of the atmosphere.

    Macumber says Tellus loses money on oil produced with CO2 when a barrel of oil sells below $50. Oil is currently selling for around $40 a barrel, thanks to a world awash in petroleum, perhaps because producers are scrambling to pump as much as possible, before economies move away from oil in an attempt to limit climate change. The industry has survived price swings before, but the low price now could be an early sign of a long-term decline.
    One big piping system

    To show me how enhanced oil recovery works in Tellus’s Raleigh oil field, Macumber takes me down the dirt road to the pipeline that makes it all possible. It carries CO2 from Jackson Dome, but the same line will one day carry CO2 captured at the Kemper facility. The only signs of the pipe are a gap in the trees that stretches for kilometers, a tiny yellow marker that says “Warning: Carbon Dioxide Pipeline,” and a little shack that houses the pumps that keep the CO2 moving underground and pressurized.

    Pipelines for CO2 crisscross Mississippi, like this one in Smith County. © David Biello

    The process is not as easy as just getting CO2 and dumping it down a well, however. A kind of mini factory needs to be built—pumps, compressors, generators for electricity, among other kit. The entire old field and wells need to be refitted to cope with CO2 going down and, more importantly, to cope with CO2-laced water (otherwise known as carbonic acid) coming back up, which eats away at machinery and metals that are not properly protected. Then there are the big electric bills that come from running all those pumps and compressors—the single largest expense, which doesn’t include the $1 million or more a mile it costs to lay an electric line through these woods to power the equipment.

    Before the CO2 goes down into a reservoir it has to be pressurized up to as much as 4,500 pounds per square inch. Millions of cubic feet of the gas must be pumped underground each day. All of that costs billions of dollars in initial outlay, plus daily operating expenses. The oil company behind it must be patient, because it can take years to put enough CO2 down the hole to build up sufficient pressure to push up an extra barrel of oil out the other end. Since 1999 the largest enhanced oil recovery (EOR) company operating in Mississippi, Denbury, estimates it has spent more than $5 billion to build and operate oil facilities and pipelines using CO2 in the Magnolia State alone. A 15 percent federal tax credit helps offset some of that cost, as do various state tax exemptions, but it’s still a significant chunk of change.

    Bringing CO2 up to the pressure needed to scour more oil out of underground reservoirs at Tellus’s Raleigh oil field. © David Biello

    Once underground, the tiny greenhouse gas molecule mixes with the bigger molecules that make up the toxic stew known as oil, both helping them flow better and restoring the subterranean pressure that had been reduced by the original tapping of the petroleum. CO2 also acts kind of like dishwashing liquid; it scours out oil lurking between grains of sand. The CO2 goes down, pressure goes up and less viscous oil flows back to the surface, ready to be sold. The oil industry calls the whole operation a recycling facility: burn oil, produce CO2, capture that CO2 and use it to force out more oil to burn. If the CO2 can be captured from a coal-fired power plant, even if it ends up producing a few more barrels of oil, the overall approach can help to reduce emissions, slowing global warming.
    Cheap gas a must

    The trick to EOR is getting the CO2 on the cheap. Nationwide, the oil industry injects roughly 60 million metric tons of CO2 into old oil wells each year. That’s the equivalent of the pollution from 20 coal-fired power plants. Roughly 70 million barrels of oil per year are produced this way. Since 1972 CO2 has been injected into U.S. oil reservoirs continuously, resulting in an extra two billion barrels of oil and a billion metric tons of CO2 stored underground. Today about one quarter of that CO2 comes from industries that happen to be located close to old oil fields and produce lots of CO2 as a by-product, such as fertilizer manufacturing plants or cement kilns. The other three quarters is naturally occurring CO2, which simply transfers the gas from one underground reservoir to another.

    Right now, CO2 can cost less than $10 per metric ton. In Mississippi roughly one ton of CO2 yields almost two barrels of oil, so $5 of CO2 per barrel is significant if oil is selling for less than $40 a barrel—and that’s before adding in all the capital costs for the equipment. The cost of dealing with CO2 can be as much as half the cost of recovering a barrel of oil this way, according to the National Energy Technology Laboratory (pdf).

    Yet the practice is widespread, in part because oil prices have been much higher in recent years and because it is hard to find new multimillion barrel reservoirs these days, especially in the picked over U.S. Denbury, based in Plano, Texas, controls more than 1,000 miles of CO2 pipelines and has published reserves of 17 trillion cubic feet of the greenhouse gas, used to pump more than 70,000 barrels of oil a day. It is using CO2 at roughly 170 wells at the Tinsley oil field here in Mississippi. Everywhere the trees try to grow in around the wells, sequestering CO2 the biological way. “Grappling with the jungle is part of the business out here,” says Greg Schnacke, executive director of governmental relations for Denbury, on a tour of Tinsley.

    Pumping petroleum from the Tinsley oil field in the Mississippi forest in Yazoo County. © David Biello

    All told, there are maybe 5,000 miles of CO2 pipeline in the U.S. Despite what sounds like big numbers, “it’s not a big industry,” Schnacke notes. “It’s roughly 3 percent of U.S. [oil] production.”
    Designing coal for carbon capture

    If the Jackson Dome did not exist underground in Mississippi, the Kemper County Power Facility to burn coal and capture the CO2 would not exist either. In fact, geology dictates everything about this particular power plant and oil scheme: There are billions of metric tons of the dirtiest form of coal—lignite—literally underneath where Kemper was built by Mississippi Power and its corporate parent Southern Co. The lignite was laid down by an old iteration of the Gulf Coast millennia ago. Similarly, the ancient coast left lots of oil deposits, salt domes and the like.

    The dirtiest kind of coal—lignite—mined from right next door to the Kemper County Energy Facility. © David Biello

    The Kemper facility is the world’s first full-scale coal-fired power plant designed for carbon capture. The costly plant will clean the dirtiest form of coal by first turning it into a gas, then stripping off the various pollutants—acid rain–causing sulfur, smog-forming nitrogen and globe-warming carbon—before any burning. To pay for this expensive proposition, each of the pollutants gets turned into a product: sulfur into sulfuric acid for the pulp and paper industry, nitrogen into ammonia for agriculture and carbon into pure CO2 for oil companies, traveling down a new specially built pipeline 60 miles to interconnect with the existing network.

    For the CO2 captured at Kemper to work for enhanced oil recovery, oil prices need to go up. Whether they do depends as much on geopolitics as geology—the vagaries of market speculation on future oil prices and how much economic pain private oil companies can take compared with their national oil company counterparts, like Saudi Arabia’s Aramco. As it stands, long-term futures contracts suggest that oil is headed to more than $40 per barrel in 2018. The world may be awash in oil at present, making it cheap, but such gluts have not lasted forever in the past—and the oil industry is gambling that it will not last forever this time either. Cheap oil usually boosts demand, which then consumes available supply, driving prices back up over time—or so it has been over the course of the 20th and early decades of the 21st centuries.

    Driving back from Tinsley, Schnacke and I pass a coal train. “That’s our competition,” he observes, meaning the coal is destined for a different power plant.

    “That’s your future CO2 source,” I counter. For a system of enhanced oil recovery fed by coal plants designed for carbon capture to pay off, Denbury, Tellus and every other oil company must survive current low oil prices.

    The last time oil prices stayed low for a very long time was the 1980s and 1990s. But this is not the same oil industry. Now the only big finds are offshore or, perhaps, in the Arctic. These are places that require not just substantial planning but also a huge amount of money invested before the first barrel of oil appears, not unlike EOR with CO2, only with a much less certain payoff. In fact, Denbury might use the low oil prices to acquire more reservoirs on the cheap. “A lot of oil fields are capable of accepting CO2,” Schnacke notes. “It requires capital investment and time.”
    Does carbon capture pay?

    At the nearby Oil Field Café, everybody I ask chuckles when I observe that the fight against climate change seems to rely on burying CO2 to bring up more oil—which then gets burned to create more CO2. Yet, putting CO2 capture on coal-fired power plants and other big industrial polluters seems less a question of whether and more a question of when. The real question is: Who will pay for it?

    Dumping CO2 in the sky is free, but capturing it—and even more so, storing it underground—costs money. This gap between market realities and action to combat climate change is where the government comes in, in theory. Indeed, the Clean Power Plan proposed by the Obama administration to clean up CO2 emissions from power plants relies on capture and storage to allow coal-fired power plants to continue to produce electricity, but with less climate-changing pollution. In the long run even power plants that burn natural gas will need to capture CO2.

    Companies that do this get a federal tax credit of $10 for every ton up to 75 million tons, but that does not defray the massive initial expense. Kemper has cost more than $6 billion to build. “EOR is the best choice,” says Rich Esposito, a geologist turned chemist at electric utility Southern Co.

    Kemper will capture roughly three million metric tons of CO2 each year. Tellus and Denbury need so much CO2 that they’ve contracted with Kemper to purchase all of it.

    Injecting CO2 underground to get out more oil at Denbury’s Tinsley oil field. © David Biello

    For the climate to benefit, however, enough of that CO2 has to remain sequestered underground after it’s done scouring out more oil, a complex calculation that also depends on how many barrels of oil—and of what quality—are ultimately produced. “All of this is for naught if we don’t get the CO2 certified as permanently sequestered,” Esposito says. Industry practice and academic research suggest that one third of the CO2 pumped underground stays there—trapped in the same microscopic holes in the rock that once held the oil—and two thirds comes back up with the petroleum. That two thirds is then topped up with fresh CO2 from the pipeline and sent back underground to scour out more oil. Few such EOR operations have come to the end of their useful lives, which means few have closed in a well that used CO2. So a full accounting of how much CO2 really gets stored is postponed for some future reckoning.

    Still, CO2 for oil recovery can hardly be worse than simply dumping the greenhouse gas directly into the atmosphere, where it has already accumulated in sufficient quantity to stave off the next ice age for millennia. “We frankly believe that probably 99-plus percent of what we purchase and put into EOR remains behind,” says Dan Cole, Denbury’s vice president of commercial development. That remains to be proved.

    Drilling cores show the rock beneath Mississippi, including sandstone that can store CO2. © David Biello

    Ordinary folks fear the CO2 will simply leak upward, worrying about CO2 mingling with water to form carbonic acid that leaches heavy metals and other contaminants out of the deep. Or about it escaping directly to the surface and settling in a smothering cloud on a home or town, as happened in 1986 when Lake Nyos in Cameroon burped out a pure, invisible cloud of natural CO2 that killed more than 1,700 people. The storage benefit is obviated if there’s even a small leak that provides a path back to the atmosphere. Old wells that connect underground to newer ones could prove a problem, some of which were plugged with nothing better than a tree stump or have simply been forgotten and lost.

    And in the end there is only so much CO2 the oil industry can use. Even all the oil reservoirs in the world could not handle the more than 13 billion metric tons of CO2 that come from burning coal each year, even if pipelines and the rest could be built. “We can only take a certain amount of CO2 that could potentially be captured in the future,” Cole says. “EOR can’t be the end-all answer for CO2 capture.”

    The U.S. has the most oil recovered with CO2 but it is really China that needs the technology. China is the world’s largest source of CO2 pollution yet it is less capable of affording the technology to clean up its coal-burning habit. Getting more oil out of the ground, in the Jilin or Shengli petroleum reservoirs for example, could help defray the cost.

    One can imagine an underground network of CO2 pipelines for EOR—and ultimately underground storage of the greenhouse gas—that grows to the size of the underground and aboveground network of oil and gas pipelines that currently exists, one that covers most continents and even extends offshore to where CO2 can most safely be buried under the seafloor. But it is also easy to imagine how many trillions of dollars it would take to build such a vast, sprawling industrial infrastructure to clean up the vast, sprawling industrial infrastructure that already exists to burn fossil fuels. And, besides EOR, there is no current way to make money from that infrastructure.

    The start of a vast infrastructure for CO2 in the middle of Mississippi? © David Biello

    Perhaps low oil prices are a practice run for life under climate change, when fossil fuels have to be forsaken, driving down their prices and driving companies to produce cleaner forms of energy. A carbon tax could make the dirtiest fossil fuels unprofitable. Low oil prices may render impossible petroleum found in difficult environments like the Arctic or far offshore in the oceans or found in difficult forms like tar sands. Even flooding old oil reservoirs with CO2 could prove too expensive to sustain in a world where oil costs $30 a barrel rather than the $120 a barrel of a few years back.

    Economics is one rubric that works to keep fossil fuels in the ground. Another is the government and regulations like the Clean Power Plan. The Paris Agreement may also help. But the U.S. is in the vanguard of the effort to have coal and burn it, too. As it stands, oil fields like Tinsley or Macumber’s Raleigh will make or break prospects for cleaning the dirtiest power plants.

    Fracking and CO2 are the best available routes to more oil here in the U.S., Macumber and others argue. “This is our golden child in the future,” the oil industry veteran says of his Mississippi assets. CO2 “is a fairly inexpensive commodity for what it does,” he adds. “It’s hard to beat.”

    See the full article here .

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  • richardmitnick 12:10 pm on January 26, 2016 Permalink | Reply
    Tags: , , CO2 studies, ,   

    From Eos: “Scientists Discover a New Source of Atmospheric Carbon Dioxide” 

    Eos news bloc


    JoAnna Wendel

    Rift zone faults cut across the East African rift
    Faults cut across the East African Rift zone, where the slow motion of the Nubian and Somalian plates of Earth’s crust pulls the continent apart. Scientists have found that faults in this zone contribute significant amounts of carbon dioxide to the atmosphere every year. To give a sense of scale, the vegetated (green) valley floor at the lower right is 17 kilometers long. Credit: ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center

    Researchers have discovered a previously unknown source of carbon dioxide leaking into the atmosphere. The gas emerges from faults where the slow separation of plates of the planet’s continental crust is cracking and deforming the Earth.

    Techtonic plates
    The tectonic plates of the world were mapped in the second half of the 20th century.

    Faults in the East African Rift zone release about 71 megatons of carbon dioxide (CO2) into the atmosphere every year—a value comparable to CO2 leaking from volcanic chains that stitch across the sea beds of many of Earth’s oceans and mark where new oceanic crust is forming—according to a new study published last week in Nature Geoscience.

    Although researchers have long investigated the East African Rift, none of them have explored if “the Rift could release CO2 along the faults,” said Hyunwoo Lee, lead author on the paper and a doctoral student at the University of New Mexico.

    The discovery of a new significant source of CO2 gives scientists a more complete picture of natural sources of atmosphere-warming CO2, said James Muirhead, a doctoral student at the University of Idaho, Moscow, and a coauthor on the study. In addition to the East African Rift zone, a handful of other continental rift zones dot the planet, such as the Basin and Range in the southwestern United States and the Eger Rift in central Europe.

    “This relevant result highlights how diffuse degassing along continental rifts is a main source of carbon dioxide to the atmosphere, not considered until now, which in the past, such as in the Cretaceous during widespread continental rifting, could have dramatically modified the climate of the Earth,” said Giovanni Chiodini, a researcher at the National Institute of Geophysics and Volcanology in Naples, Italy, who was not involved in the research. “Despite [CO2’s] major role in modulating Earth’s climate, we remain largely unaware of the processes governing the natural fluxes of carbon between Earth reservoirs and the atmosphere.”

    However, the new source doesn’t play as major a role in influencing climate as human-driven emissions of greenhouse gases, Muirhead noted. “Even though this is a large amount, it’s still on the order of 500 times smaller than human outputs” of CO2, which exceeded 36 gigatons in 2013.

    Deep Magma Bodies

    Previous research found CO2 seeping from faults in Italy, which inspired Lee and his colleagues to look at the East African Rift zone (EAR). Because the EAR is so large—stretching thousands of kilometers across northeastern Africa—it offers many more faults to study.

    A lot of magma can build up beneath such an extensive rift zone, “so you have the potential to produce a lot more CO2 coming into the atmosphere,” said Muirhead.

    The researchers collected CO2 samples from fault zones around the Natron-Magadi region of the rift valley, at the border between Kenya and Tanzania, to assess “diffuse degassing”—seepage of small amounts of CO2 over a large area. They then analyzed the samples to determine their origins. Carbon dioxide from magma sources generally contains a higher ratio of the heavier carbon isotope, carbon-13 (13C), compared to the lighter isotope, carbon-12 (12C). Conversely, more 12C compared to 13C indicates biogenic origins. In this case, the researchers found more of the heavier isotope, which means the CO2 was originating from magma deep below the Earth’s surface.

    Simultaneously, the researchers tracked seismic activity in the region, Lee said. Using an already established network of seismic instruments, the researchers observed constant earthquakes occurring deep below the crust—sometimes as deep as 30 kilometers, Muirhead said, indicating that CO2 seepage from the rift valley comes from deeper within the Earth than the CO2 spewed by active volcanoes, which are powered by magma closer to the surface. The researchers suspect that the magma bodies supplying the CO2 lie in the lower portion of the Earth’s crust or even in the upper mantle.

    The researchers found that the Natron-Magadi region of the EAR releases about 4 megatons of CO2 every year. If that’s typical of the entire rift valley, then the system is releasing 71 megatons per year, the team calculated.

    Mid-ocean ridges across the globe pump out about 53–97 megatons of carbon dioxide per year, but most of it dissolves into the ocean or recycles back into the Earth’s crust through subduction, Muirhead said. On land, CO2 degassing from continental rifting has no such buffer and enters the atmosphere directly.

    According to Lee and his colleagues, that the EAR rivals the output of all mid-ocean ridges means that continental rifting could be a significant player in long-term shifts of Earth’s climate and that active volcanoes aren’t the only places where CO2 emerges naturally.

    Citation: Wendel, J. (2016), Scientists discover a new source of atmospheric carbon dioxide, Eos, 97, doi:10.1029/2016EO044671. Published on 26 January 2016.

    See the full article here .

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  • richardmitnick 3:41 pm on September 27, 2014 Permalink | Reply
    Tags: , CO2 studies, ,   

    From LBL: “Pore models track reactions in underground carbon capture” 

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    Berkeley Lab

    September 25, 2014

    Using tailor-made software running on top-tier supercomputers, a Lawrence Berkeley National Laboratory team is creating microscopic pore-scale simulations that complement or push beyond laboratory findings.

    Computed pH on calcite grains at 1 micron resolution. The iridescent grains mimic crushed material geoscientists extract from saline aquifers deep underground to study with microscopes. Researchers want to model what happens to the crystals’ geochemistry when the greenhouse gas carbon dioxide is injected underground for sequestration. Image courtesy of David Trebotich, Lawrence Berkeley National Laboratory.

    The models of microscopic underground pores could help scientists evaluate ways to store carbon dioxide produced by power plants, keeping it from contributing to global climate change.

    The models could be a first, says David Trebotich, the project’s principal investigator. “I’m not aware of any other group that can do this, not at the scale at which we are doing it, both in size and computational resources, as well as the geochemistry.” His evidence is a colorful portrayal of jumbled calcite crystals derived solely from mathematical equations.

    The iridescent menagerie is intended to act just like the real thing: minerals geoscientists extract from saline aquifers deep underground. The goal is to learn what will happen when fluids pass through the material should power plants inject carbon dioxide underground.

    Lab experiments can only measure what enters and exits the model system. Now modelers would like to identify more of what happens within the tiny pores that exist in underground materials, as chemicals are dissolved in some places but precipitate in others, potentially resulting in preferential flow paths or even clogs.

    Geoscientists give Trebotich’s group of modelers microscopic computerized tomography (CT, similar to the scans done in hospitals) images of their field samples. That lets both camps probe an anomaly: reactions in the tiny pores happen much more slowly in real aquifers than they do in laboratories.

    Going deep

    Deep saline aquifers are underground formations of salty water found in sedimentary basins all over the planet. Scientists think they’re the best deep geological feature to store carbon dioxide from power plants.

    But experts need to know whether the greenhouse gas will stay bottled up as more and more of it is injected, spreading a fluid plume and building up pressure. “If it’s not going to stay there (geoscientists) will want to know where it is going to go and how long that is going to take,” says Trebotich, who is a computational scientist in Berkeley Lab’s Applied Numerical Algorithms Group.

    He hopes their simulation results ultimately will translate to field scale, where “you’re going to be able to model a CO2 plume over a hundred years’ time and kilometers in distance.” But for now his group’s focus is at the microscale, with attention toward the even smaller nanoscale.

    At such tiny dimensions, flow, chemical transport, mineral dissolution and mineral precipitation occur within the pores where individual grains and fluids commingle, says a 2013 paper Trebotich coauthored with geoscientists Carl Steefel (also of Berkeley Lab) and Sergi Molins in the journal Reviews in Mineralogy and Geochemistry.

    These dynamics, the paper added, create uneven conditions that can produce new structures and self-organized materials – nonlinear behavior that can be hard to describe mathematically.

    Modeling at 1 micron resolution, his group has achieved “the largest pore-scale reactive flow simulation ever attempted” as well as “the first-ever large-scale simulation of pore-scale reactive transport processes on real-pore-space geometry as obtained from experimental data,” says the 2012 annual report of the lab’s National Energy Research Scientific Computing Center (NERSC).

    The simulation required about 20 million processor hours using 49,152 of the 153,216 computing cores in Hopper, a Cray XE6 that at the time was NERSC’s flagship supercomputer.

    cray hopper
    Cray Hopper at NERSC

    “As CO2 is pumped underground, it can react chemically with underground minerals and brine in various ways, sometimes resulting in mineral dissolution and precipitation, which can change the porous structure of the aquifer,” the NERSC report says. “But predicting these changes is difficult because these processes take place at the pore scale and cannot be calculated using macroscopic models.

    “The dissolution rates of many minerals have been found to be slower in the field than those measured in the laboratory. Understanding this discrepancy requires modeling the pore-scale interactions between reaction and transport processes, then scaling them up to reservoir dimensions. The new high-resolution model demonstrated that the mineral dissolution rate depends on the pore structure of the aquifer.”

    Trebotich says “it was the hardest problem that we could do for the first run.” But the group redid the simulation about 2½ times faster in an early trial of Edison, a Cray XC-30 that succeeded Hopper. Edison, Trebotich says, has larger memory bandwidth.

    cray edison
    Cray Edison at NERSC

    Rapid changes

    Generating 1-terabyte data sets for each microsecond time step, the Edison run demonstrated how quickly conditions can change inside each pore. It also provided a good workout for the combination of interrelated software packages the Trebotich team uses.

    The first, Chombo, takes its name from a Swahili word meaning “toolbox” or “container” and was developed by a different Applied Numerical Algorithms Group team. Chombo is a supercomputer-friendly platform that’s scalable: “You can run it on multiple processor cores, and scale it up to do high-resolution, large-scale simulations,” he says.

    Trebotich modified Chombo to add flow and reactive transport solvers. The group also incorporated the geochemistry components of CrunchFlow, a package Steefel developed, to create Chombo-Crunch, the code used for their modeling work. The simulations produce resolutions “very close to imaging experiments,” the NERSC report said, combining simulation and experiment to achieve a key goal of the Department of Energy’s Energy Frontier Research Center for Nanoscale Control of Geologic CO2

    Now Trebotich’s team has three huge allocations on DOE supercomputers to make their simulations even more detailed. The Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program is providing 80 million processor hours on Mira, an IBM Blue Gene/Q at Argonne National Laboratory. Through the Advanced Scientific Computing Research Leadership Computing Challenge (ALCC), the group has another 50 million hours on NERSC computers and 50 million on Titan, a Cray XK78 at Oak Ridge National Laboratory’s Leadership Computing Center. The team also held an ALCC award last year for 80 million hours at Argonne and 25 million at NERSC.

    MIRA at Argonne

    TITAN at Oak Ridge

    With the computer time, the group wants to refine their image resolutions to half a micron (half of a millionth of a meter). “This is what’s known as the mesoscale: an intermediate scale that could make it possible to incorporate atomistic-scale processes involving mineral growth at precipitation sites into the pore scale flow and transport dynamics,” Trebotich says.

    Meanwhile, he thinks their micron-scale simulations already are good enough to provide “ground-truthing” in themselves for the lab experiments geoscientists do.

    See the full article here.

    A U.S. Department of Energy National Laboratory Operated by the University of California

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