From developing more water-efficient ways to extract oil and gas to creating technology that holistically examines a building's energy use, faculty and students at the Cockrell School of Engineering are leading comprehensive and interdisciplinary research on the world’s two most crucial and strained natural resources: water and energy.
The two resources have traditionally been viewed independent of each other – they're governed by separate agencies and regulatory authorities. But thinking about the two has shifted in recent years as constraints on water have triggered constraints on energy, and vice versa.
"Energy production requires large amounts of water, and transporting water requires large amounts of energy," said Danny Reible, the faculty lead on UT's water-energy nexus research and a professor in the Civil, Architectural and Environmental Engineering Department. "Moreover, many of our most sustainable energy choices, such as biofuels, seemingly have unsustainable demands for water. By ensuring our water future, we will reduce the number of limitations on our energy choices."
Universities across the nation are focusing research on the two resources, whose mutually-dependent relationship is referred to as the water-energy nexus. But what distinguishes the Cockrell School's research from others is an unmatched track-record in oil and shale gas extraction, development of ahead-of-the-curve technology to produce fuel from algae and the unique opportunity for faculty and students to test their research applications on a 700-acre test-bed known as the Pecan Street Project. Other areas of water-energy nexus research will be explored in future Cockrell School feature stories.
The following are just a few highlights of research being conducted by Cockrell School faculty and students, and each of them could forever change how we use water and energy.
Water efficient oil and gas recovery
For every barrel of extra-heavy oil in the U.S. and Canada, it takes four to five barrels of water to produce it.
But thanks to research by faculty and students at the Cockrell School, the process for oil and natural gas recovery is becoming increasingly less water-intensive and, in some cases, water may not be needed at all. The goal of the research is to secure viable domestic energy resources while reducing negative impacts on the environment.
"In our method [of heavy oil extraction] there’s a conscious effort to reduce the carbon footprint," said Sanjay Srinivasan, a professor in the Petroleum and Geosystems Engineering Department, who's leading research on water-efficient heavy oil extraction. "I have graduate and undergraduate students involved in this who are passionate about working on this problem. They think this work is very important and something of consequence."
Srinivasan and engineering faculty have developed technology that makes it easier and less water-intensive to extract ultra-heavy oil, a type of crude oil that is widely available in places like Canada, Utah and Venezuela, but that does not flow freely and is difficult to extract.
The researchers inject a concoction of chemicals together with steam to cause it to flow more freely, so that the recovery process requires less water. To minimize the carbon footprint, they are studying ways to generate steam in the subsurface. They also are developing a brand new technology to capture flue gas (a combination of carbon dioxide, nitrogen, water and other materials that is a major contributor to greenhouse gasses) and inject it together with the steam used during the recovery process. The flue gas is slightly less efficient than the chemicals at causing the oil to flow, but the method recycles the greenhouse gas and prevents it from entering the Earth’s atmosphere.
Shale gas extraction
Natural gas from shale requires significantly less water than oil to produce, and large amounts of it are available domestically – so much so that it and two other forms of unconventional gas have increased the nation’s domestic energy production by 30-40 percent.
"They've added the equivalent of about 3 million barrels of oil production per day to the U.S. To give context, we only produce about 7 million barrels of oil per day here," said Mukul Sharma, a professor in the Petroleum and Geosystems Engineering Department. "You can't think of any technology that has done that in the last 50 years or more, it's a pure revolution."
But a number of factors are hindering the broad-scale use of natural gas, namely environmental concerns about groundwater contamination and how water used to get the gas is handled after the extraction process, known as hydraulic fracturing or "fracking."
Gas, salt and sand stick to water during this process, making the water difficult to recycle and resulting in 90 percent of it being treated and put back into the ground instead of reused, Sharma said.
Hoping to reverse this trend, chemical engineering Professor Benny Freeman and a doctoral student created technology that binds to water membranes so that they are more resistant to sticking, and, therefore, easier to reuse.
Sharma and engineering faculty have also built software that allows users to design simulated fractures in which gas and oil are extracted by injecting CO2, nitrogen, liquid foam, or others types of fluids into fracture wells, instead of water.
"It's the only simulator of its kind in the world. Nobody else has this capability," Sharma said.
If successful, the two technologies could make the extraction process for one of our largest natural resources not only less water intensive, but more environmentally-friendly.
Algae from fuel
In laboratories at the Center for Electromechanics (CEM) at the Pickle Research Campus, large tanks store what could be one of the most promising forms of biofuel: algae.
The plant-like organisms contain a high percentage of oil, don't require fresh water and consume more greenhouse gas carbon dioxide than is released when algae-based fuel is burned. Among the hang-ups to algae's wide-scale commercialization, however, is the amount of water required to grow it and the need for an easy, cost-effective extraction process.
Faculty and students at the Cockrell School are leading a multidisciplinary research and development program that addresses both challenges.
Mechanical Engineering Professor Halil Berberoglu has developed a technology that reduces the energy and water demand during the algae cultivation process by a factor of 60. Berberoglu's technology is now being used by faculty like Bob Hebner, CEM director, who helped develop a way to easily extract oil from algae by zapping the organism with electric pulses. The extraction process, known as lysing, has been patented and CEM is currently scaling up its algae growing efforts.
Smart grid
Cockrell School faculty and students are working with members of Pecan Street Project, a smart grid research and development organization headquartered at the University of Texas. Members of the project include Pecan Street Project Executive Director Brewster McCracken and, (l-r), UT professors Suzanne Barber, Ross Baldick, Arumugam "Ram" Manthiram and Thomas Edgar.
Imagine a power grid that allows residents to monitor their home's energy use from cell phones and schedule appliances, like a dryer or battery charger for an electric vehicle, to run during times of day when power is in least demand and therefore less expensive.
And what if residents could find out how much water they are using in real-time? Such a system would allow them to better manage water use and to see where water is wasted in their homes.
Engineering faculty and students are working to make this scenario a reality, and their research is leading to more integrated and intelligent uses of water and energy.
Working in collaboration with the City of Austin, Austin Energy utility and private companies, the groups are transforming a 700-acre test-bed of homes and businesses in east Austin into a green community whose smart grid could reinvent the way communities across the U.S. generate, distribute, store and consume energy.
Research on the project, known as the Pecan Street Project, will allow power generation and distribution to react in real-time to consumer demands and the intermittency of solar/wind energy production.
Approximately 150 homes in the project will also be installed with technology to collect data on how and when homes use water. As far as UT researchers know, such data does not yet exist.
The "smart water" research could eventually enable a water utility to remotely read water meters and turn off water connections so that the resource is more intelligently managed, said Joshua Rhodes, an architectural engineering graduate student whose leading water/energy research at UT. That way if a homeowner was away on vacation and a pipe burst, the utility could turn off their water. Rhodes said that real-time water use data will also allow homeowners to find small leaks that they would not notice on an aggregated monthly water bill, but could end up costing tens of thousands in foundation/home repairs, including costly mold damage.
"Water meters are generally buried underground underneath metal panels, and so it's hard for water users to get real-time information about their usage," said Michael Webber, Rhodes's faculty advisor and an assistant professor in the Mechanical Engineering Department. "However, with smart meters, they can get much more information—minute-by-minute if they want it—about water use and its costs."
Atila Novoselac, an assistant professor in the Department of Civil, Architectural and Environmental Engineering, is developing technology that can determine where energy is used and wasted in a building or home. The computer modeling software works on existing and future structures and allows users to input a range of variables – like different types of lighting and window or roofing material – to see which lead to optimal energy savings and also ensure good indoor air quality.
Because more than 40 percent of energy in the U.S. goes to powering buildings, Novoselac said improving their energy efficiency could go a long way toward reducing carbon emissions.
"They're the most neglected but the largest contributors," Novoselac said.
Danny Reible holds the Bettie Margaret Smith Chair in Environmental Health Engineering.
Mukul Sharma holds the W. A. "Tex" Moncrief, Jr. Centennial Chair in Petroleum Engineering.
Benny Freeman holds the Paul D. and Betty Robertson Meek and American Petrofina Foundation Centennial Professorship in Chemical Engineering and the Kenneth A. Kobe Professorship in Chemical Engineering.
Suzanne Barber holds the AT&T Foundation Endowed Professorship in Engineering.
Arumugam Manthiram holds the Joe C. Walter, Jr. Chair in Engineering.
Thomas Edgar holds the George T. and Gladys H. Abell Endowed Chair of Engineering.
