Sustainability

This story appears in the 2014-15 issue of Mines' research magazine, "Energy & the Earth."

 

Water and oil don’t mix. With oil and gas production and water, it’s quite the opposite.

Getting at the unconventional oil and gas reserves at the heart of America’s energy boom can take millions of gallons of water per well before the first hydrocarbons emerge.[1] One estimate puts the hydrologic demands of the 80,000 wells in 17 states drilled since 2005 at more than 250 billion gallons.[2] That’s three times the volume of Denver Water’s Dillon Reservoir.

Yet in the western United States and elsewhere, geologic “accident” has placed some of the most promising unconventional oil and gas reserves below parched landscapes.

Mines researchers are at the forefront of enhancing our still-nascent understanding of this modern story of oil and water, and more broadly in the development of new ways to boost freshwater resources in an era of rising demand and growing scarcity.

ConocoPhillips’ recent $3 million gift to establish the new Center for a Sustainable WE2ST (Water-Energy Education, Science and Technology) is the latest testament to Mines’ strengths in water.

The idea is to focus on a single formation such as the Niobrara, taking a comprehensive look at the complex technical and social interdependencies of oil and gas development and limited water resources. Professor John McCray, head of Mines’ Civil and Environmental Engineering Department, describes a wide-ranging effort, involving remote sensing and hydrological models to map out water sources and the tools of geochemistry, hydrology, microbiology and environmental engineering to develop ways to clean up the water that emerges from the depths during oil and gas operations. The work also will involve a strong social-sciences component led by Mines anthropologist Professor Jessica Rolston, McCray said, to help define ways to communicate the actual risks of unconventional energy development and get energy companies, regulators and the public on the same factual page.

“It’s a partnership with ConocoPhillips that can break new ground, and one that doesn’t exist outside of this center,” McCray said. “We want to come out and be the honest broker.”

Education is a key component of the ConocoPhillips center, said Associate Professor Terri Hogue, who is directing the new center. A big part of the budget will go to fellowships for 15 to 20 masters and PhD students, she said, in addition to 10 undergraduate fellowships each year. The center will attract top-notch talent all focusing on the nexus of water resources and energy development.

Professor Tzahi Cath is among those at Mines already at work at that confluence. Cath directs Mines’ Advanced Water Technology Center (AQWATEC), which is developing a range of water-treatment technologies. This spring, the masters students in Cath’s Environmental Engineering Pilot Lab course were studying if adding an inky slurry of activated charcoal to the city of Golden’s water treatment process might help remove the organics that have spiked in reservoirs along Colorado’s Front Range after the 2013 flood. A green garden hose snaked from a tank in the bed of the AQWATEC pickup parked on the sidewalk outside Coolbaugh Hall. It fed a bench-scale model of Golden’s water treatment plant, its upper tanks full of fluid like curdling apple cider. If it worked here, they would test the activated charcoal in a Mines pilot plant housed in the treatment facility itself and, assuming the city adopts the approach, would help with the transition to the full-scale plant.

“Usually, the city adopts our recommendations,” Cath said.

A bit downhill, in AQWATEC’s space in Mines’ General Research Laboratory, PhD student Bryan Coday was working near several hip-high plastic drums, some encrusted with salt (they’re for a project testing new ways to extract valuable potassium sulfate from the Great Salt Lake).

Others contained produced water from hydraulic fracturing operations, and Coday was working on a system to cleanse it using low-pressure osmosis and flat-sheet polymeric membranes. To the touch, the membranes felt like high-end wrapping paper, but in practice is a very sophisticated material. The system uses salt water to attract clean water from the deep-brown produced water across the membrane, which retains contaminants.

“Produced water is difficult to treat because of the hydrocarbons and complex organic compounds, plus high salinity,” Cath said. Mines environmental chemist Professor Christopher Higgins is working with Cath to identify just what chemicals from the different samples of produced water cross the membranes, and how they can improve the process to produce even drinking-quality water from produced water.

A test system had performed well enough that Coday and research assistant Mike Veres were now in the midst of building a pilot-scale system. “Harnessing the natural chemical energy of brine as the driving force for wastewater treatment has its advantages,” Cath said. “Such systems are mechanically simpler, take less energy, and are easier to clean because the grime hasn’t been rammed into filter pores as happens with high-pressure systems.”

If some combination of low-pressure filtration and microbial treatment (another AQWATEC project being tested across the lab in columns of activated carbon next to the AQWATEC aluminum boat) can economically bring produced water to the high standards of municipal wastewater treatment, the benefits are hard to miss. Water locked up two miles below could be released into streams in drought-prone regions, actually boosting the water budget. And oil and gas operations could reuse some portion of this new resource in their hydraulic fracturing operations. Coday is enthusiastic.

 “It’s a great opportunity to work on a project where industry is moving at such a quick pace on the energy side, on the water side and on the regulatory side,” he said.

Another major project has a similarly sweeping purview, but pertains to urban water use. Since 2011, Mines has teamed with Stanford University, the University of California at Berkeley and New Mexico State University on a 10-year, $40 million effort that aims to transform how cities in the arid West use and reuse water. The program, called Re-Inventing the Nation’s Urban Water Infrastructure (ReNUWIt), is the first National Science Foundation-funded Engineering Research Center to focus on water issues.

McCray, who leads the Mines effort, said a dozen Mines faculty are leading or working on some 20 ReNUWIt projects. Hogue is spearheading an effort involving several Mines colleagues to determine the potential impact of August 2013’s 257,000-acre Sierra Nevada Rim Fire on water supplies to San Francisco and surrounding counties. Cath’s team is refining a portable, commercial-scale sequence batch membrane bioreactor that has proven its mettle with the wastewater from the apartments at Mines Park – capable of producing drinking water from domestic wastewater. Mines professors Tissa Illangasekare and Kate Smits lead a project that is developing technology to allow underground aquifers to treat and store water and then re-use it rather than letting it escape downstream. They are researching the use of sensors that provide real-time feedback on system performance, so decisions can be made to improve operation efficiency. Mines Associate Professor Linda Figueroa is working with the Plum Creek Wastewater Authority south of Denver on a pilot-scale system using anaerobic wastewater treatment. The system has been in operation for 1.5 years and has reduced more than 40 percent of the influent organic matter without the expense of oxygen (unlike traditional aerobic methods) and, as a bonus, produces energy while it cleans wastewater.

As with the ConocoPhillips center, ReNUWIt involves a heavy social science component. That’s because, for all the technological capabilities on display at Mines, the biggest challenges facing smarter water systems may reside between our ears. People just don’t like the idea of drinking reclaimed water (in Singapore they call it NeWater), McCray said, even though that’s what the South Platte River really is. Collectively, such apprehensions coalesce into powerful social and political barriers.

 “They’re by far the biggest hurdles to clear if we’re going to have any change in the way we develop our infrastructure,” McCray said.

 

This story appears in the 2014-15 issue of Mines' research magazine, "Energy & the Earth."

For those of us residing on the planet’s surface, the term “shale” evokes visions of flaking layers of rock you can all but peel away by hand. Oil and gas shale is nothing like this. Pick up a cylindrical core brought up from a reservoir two miles below – from the Bakken in North Dakota, the Niobrara in Colorado, the Vaca Muerte in Argentina, it doesn’t matter – and it’s heavy and solid like a hunk of marble. The hydrocarbons are locked inside, perhaps 100,000 times more tightly than would be the case were it merely mixed into concrete.

This is the stuff, though, of the American – and, increasingly, global – boom in unconventional oil and gas. You can’t just drop a well bore into rock like this and watch hydrocarbons gush out. You muse use advanced horizontal drilling and hydraulic fracturing technologies to release the oil and gas. Roughly one-third of the U.S. natural gas production heating our homes and fueling our factories is won this way. Two-thirds of all rigs are drilling horizontal wells. Unconventional energy, at least as applies to shale oil and gas, has become conventional.

Hydraulic fracturing has been around for decades, but we’re still learning about it. What are the true environmental impacts? How can we increase yields to bring more output per well and so have fewer wells, lower costs, cut trade imbalances and lessen the impact on the planet? Can these same techniques be applied to renewable geothermal technologies? Researchers at Colorado School of Mines are working to answer these and other questions via a broad set of disciplines and several noteworthy vehicles. Among them include the Marathon Center of Excellence for Reservoir Studies (MCERS); the new ConocoPhillips Center for a Sustainable We2st (Water-Energy Education, Science and Technology); and a new National Science Foundation (NSF)-sponsored program to understand the risks of natural gas development to the Rocky Mountain Region’s air and water.

As Mines Professor Dag Nummedal, who directs the Colorado Energy Research Institute, put it, “We really focus on making fossil energy more sustainable. That means reducing CO2 emissions, reducing methane emissions, and doing energy development in ways that allow the fossil energy industry to coexist with clean water, agriculture, breathable air and optimal temperatures.”

As part of a five-year, multi-institution NSF project, Mines researchers will focus on quantifying what those risks actually are, said Professor Will Fleckenstein. In the public arena in particular, assertions about the environmental and public health impacts of hydraulic fracturing have not infrequently outstripped their scientific basis, he added.

The projects include a study of the stresses in the cement sheaths and well casings for a better sense of what they can actually handle, he said. Fleckenstein is at the forefront of such work, having invented a technology, now ready for market, that uses a pressure test to ensure a sound hydraulic seal at depths of 300 to 2,000 feet, the zone of freshwater aquifers. The team will also examine databases relating to hydrocarbon migration for a better sense of if, how, and how often it happens.

Elsewhere at Mines, researchers will use a wind tunnel filling what used to be the Volk Gymnasium pool to better grasp how methane from natural gas production migrates through surface soils. Ground and aircraft-based sensors are sometimes finding methane hot spots with no obvious methane sources. That ground-based and air-based sensors tend to disagree on the volume of methane leaking has made the work all the more urgent, said Kathleen Smits an assistant professor. PhD student Ariel Esposito was at work on a small-scale version of the experiment at the pool’s edge. She would feed methane into the bottom of a tank of fine gravel, sand and water and detect it through sensors on top at a rate of 500 samples per second.

“It’s a really important field because there’s a lot of uncertainty about the amount of gas that’s leaking,” Esposito said. “We’re trying to lend some insights into the underlying processes.”

Meanwhile, Mines is applying its renowned strengths in reservoir characterization to boost the production of hydraulically fractured wells, which makes both economic and environmental sense. There’s a big potential upside, said Professor Hossein Kazemi, who co-directs MCERS: current production techniques only yield about 10 percent of unconventional oil, compared to 30 to 40 percent for conventional reservoirs. The work ranges from major field studies of the Bakken, Niobrara and Vaca Muerte led by Professor Steve Sonnenberg to lab experiments focusing on the nanoscale properties of reservoir rock.

As with much of the work at Mines, the research involves both experimentation and computer modeling. In one of Kazemi’s Marquez Hall labs, Mines PhD student Younki Cho has spent two years building a core flooding experiment to measure shale permeability at the nanoscale. The experiment can also inject surfactants or carbon dioxide to simulate enhanced oil recovery, he said. The stainless-steel setup was forcing pressurized brine into a 1.5-inch by 2-inch cylindrical rock core at confining stress of 2,625.7 pounds per square inch (psi) and pressure differential of 2,100 psi, producing a flow of 0.003 cubic centimeter (cc) per minute.

“It’s a very slow rate because permeability is so small,” Cho said. “You have to be very patient.”

Downstairs, PhD student Somayeh Karimi was spinning cores in an ultracentrifuge humming at 13,000 rpm. It was 420 hours into a cycle.

“Right now we have not seen any published data on direct measurement of capillary pressure with reservoir fluids in tight shale rocks,” she said. The results will feed into modeling of how much oil and gas might be recoverable, how fast, and how long that recovery might take, Karimi added.

Over in Professor Marte Gutierrez’s Brown Hall lab, PhD student Luke Frash was fracturing rocks of his own, but larger ones of about a cubic foot. Using a black-steel cell of his own design, Frash applies heat and pressure in three dimensions, and then drills into and hydraulically fractures cubes of shale, high-strength cement and granite, testing for strain, temperature, pressure, sound, even micro-earthquakes. The idea is to understand the rock-mechanical behavior of underground formations, Gutierrez said.

“It’s a scale model of what’s going on in the field,” Gutierrez said.

The granite cubes in Frash’s lab are for studies of hydraulic fracturing for renewable geothermal applications, an active field of study at Mines, said Associate Professor Bill Eustes. He and Fleckenstein are working on a project with the National Renewable Energy Laboratory to see if multi-stage hydraulic fracturing technology used in unconventional shale can be applied to geothermal energy. There are many challenges, Eustes said – among them, thicker geothermal well bores and much more heat.

These and other efforts, including work to characterize possible reservoirs for carbon sequestration and storage, illustrate how the definitions of conventional, unconventional and renewable energy are starting to blur. It’s a fascinating time to be in the energy business, Nummedal said.

“The push for sustainability is driving technology at a faster rate of change than ever before,” he said.

 

 

Researchers at Colorado School of Mines took delivery of the world’s first Geothermic Fuel Cell (GFC) on Aug. 5, 2013. 

Designed and built by Delphi, headquartered in Rochester, NY, for IEP Technology, of Parker, Colo., the GFC will efficiently generate 4.5 kW of electricity from natural gas fuel. 

Its real value lies in the heat that it liberates while generating this electricity -- scientists and engineers seek to harness this heat to recover unconventional oil. This electricity comes as a useful and valuable byproduct of the oil-recovery process. 

In partnership with IEP Technology and Delphi, students, engineers, and faculty will characterize the thermal and electrical performance of the geothermic fuel cell at the Colorado Fuel Cell Center laboratory on the Mines campus. 

The solid-oxide fuel cells packaged within the GFC operate at high temperature (nearly 750 ºC) to convert natural gas into electricity and heat. When implemented, clusters of GFCs will be placed into the earth within oil shale formations for oil recovery. GFCs present a potentially transformative technology for accessing the world’s vast oil-shale reserves, which are estimated at 4.8 trillion barrels worldwide, in an environmentally responsible manner.

“This privately funded research and development project leverages the past investments in infrastructure made by Colorado School of Mines and federal agencies in the Colorado Fuel Cell Center. Such university-industrial partnerships are common at Mines, and create unique learning experiences for both our students and faculty, while answering important questions facing our industrial partners in bringing such technologies to market,” said Dr. Neal Sullivan, Mines associate professor of mechanical engineering.

To learn more about geothermic fuel cells, visit the IEP Technologies website: http://www.iepm.com/

Learn more about the Colorado Fuel Cell Center at www.coloradofuelcellcenter.org.

 

By Todd Neff

Forests across the Mountain West have gone orange and faded to gray. Since about the turn of the millennium, the mountain pine beetle’s appetite for lodgepole has killed off some four million acres of trees in Colorado and Wyoming alone. That the larvae of an insect the size of a grain of rice can bring such destruction is in itself a wonder of nature.

The changes go far beyond appearance, and while questions about the effects of so many dead trees on forest fires may be the most obvious, some of the beetles’ biggest impacts lie downstream. Pine beetles are shrinking the snowpack, hastening runoff and parching summer soil. The bugs have affected everything from the molecular habits of soil metals to the makeup of soil microbes. They have changed the chemistry of forest earth and increased the loads of carcinogens flowing through water treatment plants.

It’s more than a provincial concern of cabin dwellers and ski condo owners. Mountain runoff into the Colorado and Platte rivers alone sustains 30 million people and 1.8 million acres of irrigated farmland. With a warming climate, the deep freezes that once killed off pine beetles will be fewer, threatening more frequent, longer lasting epidemics affecting the region in ways science is only beginning to grasp. But science will soon catch up. A Mines-led team of hydrologists, microbiologists, geochemists, numerical modelers and social scientists is sharpening the picture of pine beetle impacts below a given dead tree and connecting how those changes trickle out to watersheds and the people who depend on them.

A five-year, $3 million National Science Foundation grant and $375,000 in Colorado state matching funds are fueling the effort. Mines Associate Professor Reed Maxwell, who specializes in hydrological modeling, serves as principal investigator. His Mines office is big and sparse. Its notable features include a high-end road bike outfitted with commuter lights, a wall clock whose arms at noon point to the cube root of 1728, and a 28-square-foot whiteboard, mostly empty on this day.

“The water quality in, say, Lake Granby has a lot to do with a watershed area that’s heavily beetle impacted,” Maxwell said. “We want to move from tree to plot to hillslope to watershed scale. That’s one of the big tasks in our grant, and we’re developing the models from scratch. They aren’t really out there.”

There are plenty of hypotheses, supported — but also contradicted — by a growing number of studies. Combined, the story goes something like this: Pine beetles kill trees, which drop their needles and load the soil with carbon as they break down. Their denuded branches let more snow into the ground, but they also stop less sunlight and block less wind, accelerating melting and runoff. The water moves through the hillslope and watershed faster. That influences how fast it reacts chemically, which in turn affects carbon balance, metal absorption and microbial makeup. At larger scales, the flow paths and speeds of rivulets, creeks and rivers change, too. The sum of the impacts shifts water quality, quantity and timing to new equilibriums, Maxwell said.

But no one knows for sure, which is why the team of eight faculty, eight graduate students and two postdoctoral researchers from Mines and Colorado State University has much to do.

If recent studies are any indication, the pine beetle plot will have many twists. Mines hydrological engineering PhD student Kristin Mikkelson spent three summers doing field work in Pennsylvania Gulch near Breckenridge and Keystone Gulch, focused on testing surface waters for copper and zinc. Dissolved organic carbon, more abundant with all the fallen pine needles, latches onto metals and keeps them mobile, boosting their soil concentrations and, one would think, the volume of metals flowing in surface waters. But while soil concentrations of metals have indeed been higher, Mikkelson said, “We’re not seeing it in the surface water.”

Another curiosity relates to municipal water quality. In a separate Mikkelson-led study, published in Nature Climate Change in October 2012, she and Mines colleagues reported that higher concentrations of organic carbon from pine needle pulses react with chlorine-based disinfectants in water treatment plants and produce more carcinogenic disinfectant byproducts. The study compared water treatment plants in five pine-beetle-impacted watersheds with four controls and linked increases in disinfectant byproducts with the degree of pine beetle infestation. The surprise, Mikkelson said, was that one class of disinfectant byproducts, known as trihalomethanes, spiked while others, haloacetic acids, didn’t.

“When we saw the jump in only the one, it was clear that the pine beetle epidemic is not only changing the amount of organic carbon, but also its composition,” she said.

Mikkelson is following up with experiments in which she percolates artificial rainwater presoaked with brown pine needles through columns of soil. “We’re measuring how that organic carbon is changing as it goes through the columns — what parts are partitioning and sorbing into the soil and which metals they’re grabbing.”

That effort complements Mines hydrology PhD student Lindsay Bearup’s work. In a Berthoud Hall lab, Bearup pulled a one-gallon Ziploc® bag from a refrigerator. Its dirt would find its way into jars, and then vials.

“I have jars and jars of dirt – really exciting!” she joked.

Bearup had collected it from a site north of Bear Lake in Rocky Mountain National Park. After hiking the eight miles in, she had filled bags of dirt beneath trees in various states of beetle impact – some green and untouched, some orange, some gray. In the lab, she had put single grams of soil into 50 milliliter falcon tubes and added chemicals to determine how organic fractions differed and what metals were present. This information, combined with water captured in a rain gauge (to determine precipitation volume and stable isotopes) and other data, may help explain the surface water metal mystery, among other things.

“I’m looking at where metals are associated with soils,” she said. “It’s interesting because organic matter is changing as trees die.”

Those changes probably affect the microbial communities in forest soils, added Jonathan Sharp, a Mines assistant professor who focuses on the intersection of microbiology, geology and hydrology. With the pine beetle work, Sharp is guiding graduate students as they work to determine microbial makeup in soil based on DNA analysis. The theory is that, as trees die, microbial ecosystems face a pulse of needles and lifeless root systems and will evolve accordingly. That, in turn, could ultimately affect the transport of metals and water quality.

“We’re trying to look from the millimeter scale all the way up to the watershed,” Sharp said.

Maxwell’s modeling work will incorporate the team’s fieldwork, as well as data from partners at the U.S. Geological Survey and the University of Colorado, to bridge these scales. One aim is to put new information in the hands of water managers and policymakers. Part of the project, Maxwell said, will involve partnering with water municipalities in Colorado and southern Nevada to help them understand how pine beetles may be affecting the quality of their inflows and how they might adjust their water treatment regimes.

“We’re seeing real water quality changes,” Maxwell said. “At best, this is going to mean an increase in water bills.”

John McCray, a co-investigator and head of Mines' Department of Civil and Environmental Engineering, says the project’s combination of field work, chemical and DNA analysis, and computer modeling could help answer questions well beyond those posed by the pine beetle.

“The processes we’re looking at really have to do with any sort of change in mountain and forest hydrology,” McCray said. “Those could be changes due to fire, development or climate change.”

It’s good that the work’s happening now, he added. “Pine beetles appear to have significant effects on hydrology and water quality, and we’ve only had a limited window in which to study this.” 

 

This article appears in the 2013-14 edition of Mines' research magazine, "Energy and the Earth."

As it’s often said, the real world can be the best classroom. That’s precisely the idea behind an assignment students in Teaching Professor Chuck Stone’s ENGY 320 Renewable Energy course received: to individually design their own field trips to companies or organizations involved in renewable energy or sustainability and come back with a report.

“It was wide open,” said Stone as students showed off their posters and reports during the Forum on Renewable Energy at Colorado School of Mines, Dec. 6. “If I had told them what to do we wouldn’t have this depth and breadth of projects here. I was incredibly impressed with the variety and creativity.”

The field trips took students from solar companies to train stations and even elementary schools.

Senior Katherine Bony contacted engineers at Wheat Ridge based Major Geothermal learning how engineers at the company access heat energy from below the earth’s surface.

“I learned all about the different types of geothermal [systems]. I originally thought there was only vertical, but there’s horizontal, there are slinky loops. It all depends on the thermal conductivity of the ground,” said Bony.

Bony’s experience also led to an internship opportunity with the company.

Senior Kristen Heiden reported on her experience working with civil engineers working on the LEED certification for the Union Station redevelopment project in Denver.

“What I think is really neat is Union Station has a big waste management system,” said Heiden. “They use waste material to help in the construction, but they also recycle a lot of it.”

Heiden also learned how engineers are making the building greener by installing skylights, improving indoor air quality with large fans and planting gardens outside the station.

“It’s a great look at what we can look forward to as engineers when we’re actually designing things,” said Heiden.

Other projects showcased included a bike that measures electrical energy produced from pedaling. The project could be taken to middle and elementary schools as an interactive lesson about energy.

Stone’s ENGY 320 Renewable Energy class is part of the energy minor at Colorado School of Mines. For more information, click here.

Take a look at a solar panel on a sunny Colorado day and, if you’re like most people, you won’t see much more than a blinding glare. Mark Lusk sees wasted opportunity.

“I see that glare and feel how hot the panels on my roof get and say, ‘What a waste! We’re losing energy!’” says Lusk, a Mines physics professor and solar energy researcher, who admits to checking out his panels and their energy output more than most. On a clear day, he explains, only a fraction of the photons hitting the photovoltaic cells on his roof are converted into electricity—the rest bounce off as light or are lost as heat. On a cloudy day, or as dusk approaches, the long-wavelength, low-energy particles of light are scarcely enough to produce any juice at all. On average, just 20 percent of the sun’s rays actually get converted to energy in a contemporary solar cell.

“In terms of efficiency, there is a lot of room for improvement up there,” he says.

Fueled by a six-year, $12 million grant from the National Science Foundation, Lusk and his colleagues at the Renewable Energy Materials Research Science and Engineering Center (REMRSEC) have spent the last four years working to improve that efficiency via a complex merging of nanotechnology, quantum physics and computational wizardry known as “exciton engineering.”

The nascent and controversial field hinges on the manipulation of “excitons”—the combination of an excited electron and the hole from which it is dislodged by an incoming photon. In conventional photovoltaic cells, the exchange is generally one-for-one; upon impact, a photon creates an exciton, which sends a highly energized electron racing into an electrical circuit.

Continue reading in Mines Magazine...

 

Learn more about Mines research in renewable energy here.

A group of Mines students and faculty are collaborating with area teachers, college professors and school administrators on a project aimed at enhancing education in STEM (science, technology, engineering and math) fields, particularly as they relate to sustainability and energy.

Initiated in 2010 by members of the Red Rocks Foundation board, which includes former Mines president John Trefny, and funded by a three-year grant from the Community First Foundation, the Red Rocks Institute for Sustainability in Education (RISE) includes partners at Red Rocks Community College, Colorado School of Mines and Jeffco Public Schools.

... read more at minesmagazine.com.

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