Jefferson William Tester

Jefferson W. Tester

David Croll Sesquicentennial Fellow and Professor
Smith School of Chemical and Biomolecular Engineering
2160 Snee Hall


Dr. Tester is a professor of sustainable energy systems in the Smith School of Chemical and Biomolecular Engineering at Cornell University. He also serves as principal scientist for Cornell’s Earth Source Heat project. Dr. Tester is a Croll Energy Fellow and a Fellow in the Atkinson Center for a Sustainable Future. Prior to his appointment at Cornell in 2009, Dr. Tester was the H.P. Meissner Professor of Chemical Engineering at the Massachusetts Institute of Technology where he served as Director of MIT's Energy Laboratory (1989-2001) and Director of MIT's School of Chemical Engineering Practice (1980-1989). His research on geothermal and biomass energy extraction and conversion and environmental control technologies has resulted in over 280 scientific publications and 12 co-authored books. Dr. Tester is a fellow of the Royal Society of Chemistry and was a member of the IPCC's Working Group on Renewable Energy Sources, and advisory boards of the National Renewable Energy Laboratory, the American Council of Renewable Energy, and Idaho National Laboratory.

Research Interests

Energy/Resource Related Problems – Thermal-hydraulic processes for geothermal energy extraction in subsurface rock reservoirs - Geothermal reservoir engineering (tracer transport and rock–water interactions in fractured geothermal reservoirs) - Geothermal heat pumps for integrated cooling and heating applications - Deep drilling in hard rock using chemical-assisted hydrothermal jets - Recovery of critical energy materials using supercritical fluid extraction - Thermochemical liquefaction and gasification processing of waste biomass feedstocks – Integrated energy systems analysis of renewable biomass and geothermal including life cycle and technoeconomic assessment

Applied Thermodynamics and Kinetics – Chemical kinetics in supercritical fluids - Molecular simulations of condensed matter - Properties of aqueous organic and electrolyte mixtures for thermal energy storage and power cycle applications - Rock-water interactions in hydrothermal environments - Salt crystallization/dissolution phenomena in supercritical water

Research Group Members

Teaching Interests

Energy systems analysis methods, renewable energy and fossil energy technologies, emphasis on applying quantitative methods using thermodynamic, kinetic and transport fundamentals in the context of scalable practical energy processes operating under environmental and economic constraints.

Selected Publications

  • Hawkins, A.J., D.B. Fox, M.W. Becker, and J.W. Tester, “Measurement and simulation of heat exchange in fractured bedrock using inert and thermally degrading tracers,” Water Resources Research 53, 1210-1230 (Feb. 2017)

  • Ishmael, M.P.E., L.B Stutzman, M.Z. Lukawski, F.A. Escobedo, and J.W. Tester, “Heat capacities of supercritical fluid mixtures: Comparing experimental measurements with Monte Carlo molecular simulations for carbon dioxide-methanol mixtures,” J. Supercritical Fluids 123, 40-49 (May 2017)

  • Posmanik R., R.A. Labatut, A.H. Kim, J.G. Usack, J.W. Tester, and L.T. Angenent,  “Coupling hydrothermal liquefaction and anaerobic digestion for energy valorization from model biomass feedstocks,” Bioresource Technology 233, 134-143 (June 2017)

  • Sinclair, L.K., J.W. Tester, J.F.H. Thompson, and R.V. Fox, “The role of water in extraction and separation of rare earth elements in supercritical carbon dioxide,” J. Supercritical Fluids 136, 180-188 (2018)

  • Angenent, L.T., J.G Usack, J. Xu, D. Hafenbradl, R. Posmanik, and J.W. Tester, “Integrating electrochemical, biological, physical, and thermochemical process units to expand the applicability of anaerobic digestion,” Bioresource Technology 247, 1085-1094 (Jan. 2018)

Selected Awards and Honors

  • Excellence in Teaching Award (College of Engineering) 2013

  • Special Achievement Award (Geothermal Resources Council (GRC)) 2011

  • Fellow of the Royal Society of Chemistry 2010

  • Outstanding Faculty Member Award (Massachusetts Institute of Technology) 2004

  • Outstanding Faculty Member Award (Massachusetts Institute of Technology) 2001


B.S. (Chemical Engineering), Cornell University, 1966

M.S. (Chemical Engineering), Cornell University, 1967

Ph.D. (Chemical Engineering), Massachusetts Institute of Technology, 1971


Research Group Members

Graduate Students

  • Venktesh Vidyadhar Katkar
    Smith School of Chemical and Biomolecular Engineering
  • Hanifrahmawan Sudibyo
    Smith School of Chemical and Biomolecular Engineering

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