TAGS: Sustainability / Natural Coatings
The U.S. Department of Energy (DOE) announces $19 million in funding over four years for a new research center focused on exploring the chemical and mechanical properties of cement composites and other materials used in enhanced geothermal systems (EGS).
The ‘Center for Coupled Chemo-Mechanics of Cementitious Composites for EGS (C4M), one of 11 Energy Earthshot Research Centers (EERCs) just announced by DOE as part of its Energy Earthshots™ Initiative, will be located in the Interdisciplinary Science Department at DOE’s Brookhaven National Laboratory.
Designing Earth-friendly Coatings
Research there and at partner institutions will inform the design of earth-friendly varieties of cement composites, coatings and other barriers designed to protect geothermal wells. The ultimate goal is to expand the use of this abundant, sustainable form of energy.
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Our Energy Earthshots are game-changing endeavors to unleash the technologies of the clean energy transition and make them accessible, affordable and abundant,” said Jennifer M. Granholm, U.S. secretary of Energy. “
The Energy Earthshot Research Centers and the related work happening on college campuses around the country will be instrumental in developing the clean energy and decarbonization solutions we need to establish a 100% clean grid and beat climate change.”
Brookhaven Lab materials scientist Tatiana Pyatina, who leads the geothermal materials research effort at Brookhaven Lab and will direct the new C4M EERC said, “
Geothermal energy has the potential to transform abundant heat trapped deep underground into gigawatts of electricity for powering millions of American homes. It is renewable, has a small geographical footprint and, unlike other green energies (like wind and solar), is available around-the-clock.”
But there are a few sticking points. The materials used to construct the wells, including cement composites that support and insulate the pipelike metal casings that carry Earth-heated fluids from subterranean depths to the surface, must withstand extreme temperatures and corrosive conditions and last for many years.
Enhanced geothermal systems, which force more fluid than is naturally present through hot underground rocks to increase the extraction of heat, experience even greater thermo-mechanical stresses. Such stringent materials requirements can drive up construction costs.
In addition, the cement currently used in well-supporting composites is an extreme carbon dioxide (CO
2) emitter. Almost a pound of the heat-trapping gas is released for every pound of cement produced through cement-making chemical reactions and the use of fossil fuels to power the process.
Developing Cost-effective Materials with Net-zero CO2 Footprint
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To realize geothermal energy’s potential, it is therefore essential to rationally design cost-effective, sustainable well-construction materials with a net-zero CO2 footprint. Our hope is that this research will achieve our goal of developing net-zero CO2 materials that will cut the cost of enhanced geothermal systems by 90% by 2035,” continued Pyatina.
To achieve that goal, the C4M team will conduct extensive studies of the chemical and mechanical properties of new forms of cementitious composite materials. Their goals are to understand the chemical changes that take place in these materials under high temperature and pressure so they can design reliable and durable composites for use in the extremely challenging underground environments.
By quantifying the effects of these chemical changes on materials’ performance, they will learn to control the solidification and transformations of these materials so they can be deployed successfully and economically in well construction and operation.
Use of Inorganic Coatings
To ensure well durability, the team will be seeking to identify materials with geologically stable mineral phases. They will also investigate the use of inorganic coatings that make the pipe-like well casings more resistant to high temperatures and aggressive environments. Some coatings may protect the metal casings so well that cement would no longer be needed.
The team will use both laboratory experiments and computational modeling to elucidate and predict the performance of these new cements and composite materials from the atomic to the macroscopic scale and for a time span ranging from seconds to years.
They expect to use information identified through these studies and the use of artificial intelligence and high-performance computing to design advanced materials with long durability for geothermal applications.
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Through this Center, an incredibly talented team has been assembled to develop the fundamental understanding of the materials needed to push back the pressure and temperature boundaries of geothermal power production,” said Thomas Butcher, a research engineer who leads the energy conversion group in Brookhaven Lab’s Interdisciplinary Science Department.
Source: Brookhaven National Laboratory