New Applications for Beneficial Reuse of Coal Combustion Ash

New Applications for Beneficial Reuse of Coal Combustion Ash Authors Ms. Anne Oberlink - United States - University of Kentucky Center for Applied Energy Research Dr. Bob Jewell - United States - University of Kentucky Center for Applied Energy Research Dr. Thomas Robl - United States - University of Kentucky Center for Applied Energy Research Mr. Curtis Wilie - United States - Commonwealth Energy Technologies Mr. Jim Crenshaw - United States - Commonwealth Energy Technologies Mr. Scott Hoskins - United States - Commonwealth Energy Technologies Ms. Hailey Mattingly - United States - Office of Energy Policy, Commonwealth of Kentucky Abstract The University of Kentucky Center for Applied Energy Research, along with its industrial partner, Commonwealth Energy Technologies, Inc., with the support of the Office of Energy Policy, has initiated a project to explore and develop new uses for both current production and ponded coal combustion fly ash. This research will characterize and modify the fly ash for enhanced oil & gas recovery and provide materials for improved efficiency and safety of plugging and abandonment of wells in Kentucky. This effort is partly based on new fly ash technology for recovering and enhancing production from pre-existing oil and/or gaswells. In some cases, the rejuvenated wells have surpassed their original production levels. This technology has been successfully pilot-tested in heritage oil and gas fields in Eastern Texas and the Texas panhandle and is currently well into implementation. Ash fracking is a patented technology that uses a micro-proppantproduced from coal combustion fly ash to open and maintain micro-fractures in shale and sandstone. This approach reduces the energy needed for the operation by as much as 95%, improving efficiency and reducing greenhouse gas emissions. This green technology is conducted with simple pumping equipment, creating a small operational footprint, a crucial factor in Eastern Kentucky’s topography. Because using fly ash eliminates the need for viscosity modifiers, it results in a simpler post-fracking cleanup. It also uses less water and can reuse well water, eliminating environmental contamination. This approach also provides theultimate disposal solution for fly ash, storing it thousands of feet below the earth’s surface

Swell compression testing on Kaolinite Gypsum Systems

Swell compression testing on Kaolinite Gypsum Systems Authors Mr. Kelden Andrews - United States - University of Kentucky Center for Applied Energy Research Dr. Thomas Robl - United States - University of Kentucky Center for Applied Energy Research Dr. Tristana Duvallet - United States - University of Kentucky Center for Applied Energy Research Dr. Bob Jewell - United States - University of Kentucky Center for Applied Energy Research Mr. Ewen Floch - France - Polytech Dijon Abstract The understanding of soil swell mechanics and mechanisms is critical to both the treatment of soils for stability as well as site selection for structures in areas where soil swell may be a problem. Soils rich in kaolin clay are of concern for their potential to swell. Its principal mineral, kaolinite (Al2Si2O5(OH)4, is alumina rich and, with the right surrounding environment or because of treatment, may be exposed to calcium, and sulfates, and may become unstable and expansive. To investigate this, kaolinite clay with various doses of gypsum and small amounts of calcium hydroxide (.3 - .7wt%) was placed into a swell compression test (ASTM D4546, Test C) to measure the rate of expansion and how additional loading on the soil would slow or collapse that expansion. Lower doses of Kaolinite (1 and 2.5%wt) had unpredictable swell with an initially high expansion followed by collapse as the loads increased. The collapse began at about 3/4 tsf (US tons per square foot). The higher doses had a gradual swell and significantly enhanced load-bearing capabilities, marking them a greater concern for building. After testing, samples were removed and examined using SEM to see morphological changes to identify ettringite and/or thaumasite crystals. None were found in the examined samples, even in the samples with 20 % wt. gypsum and calcium hydroxide additions. This combined with the relatively low pH of the sample’s expansion solution (about 8) suggests an Alkali sulfate attack was present but other mechanisms were likely at work as well, other options are discussed to try and explain the phenomena

Rapidly Deployable Shotcrete System for the Structural Stailization of Shock Damaged Structures

The University of Kentucky Center for Applied Energy Research, along with Minova USA Inc., and the University of Dundee, developed a rapid strength, high bonding shotcrete system for infrastructure repair and stabilization, at the request of a mandate from the U.S. Department of Homeland Security. This mandate called for development of a material that gains structural strengths very rapidly, as well as the development of a corresponding deployment system to stabilize and repair shock damaged structures to avoid catastrophic failure. Tekcrete Fast® is a material that was developed for this process, and is a specially designed, rapid-setting, and high performance dry-mix shotcrete. This system will stabilize structures like airport runways, tunnels, bridges, and dams that have been shocked and damaged by explosives, or seismic activity, etc. before they fail, by reaching compressive strengths of 41.4 MPa in 3 hours, and 75.8 MPa in 28 days. Additionally, in November 2014, a civil engineering demonstration of Tekcrete Fast® took place in Disaster City, Texas to show that Tekcrete Fast® can help first responders to stabilize building structures