Dissertation title: Fluid-rock interaction and H2S and CO2 mineralization in geothermal systems: experiments and geochemical modeling
Opponents: Dr. Alasdair Skelton, Professor at the Stockholm University, Sweden.
Dr. Orlando Vaselli, Associate Professor at the University of Florence, Italy.
Advisor: Dr. Andri Stefánsson, Professor at the Faculty of Earth Sciences at the University of Iceland.
Doctoral committee: Dr. Sigurður R. Gíslason, Research Scientist at the Institute of Earth Sciences at the University of Iceland.
Dr. Bergur Sigfússon, Manager for environment and value streams at the Department of R&D of Reykjavík Energy
Chair of Ceremony: Dr. Magnús Tumi Guðmundsson, Professor and the Head of the Faculty of Earth Sciences at the University of Iceland.
Fluid-rock interaction is an important process in nature, and in many industrial fields. Fluid-rock interaction can be utilized to sequester industrial gases like CO2 and H2S in porous rocks of geothermal systems. In order to study these factors of fluid-rock interaction and mineralization of CO2 and H2S under geothermal conditions, a number of laboratory experiments and reaction calculations were conducted.
Three scenarios were studied: (1) dissolution of primary minerals and glasses under flow-through conditions using solution chemistry and solid imaging; (2) incongruent alteration of mafic minerals in CO2-rich solutions using solution chemistry, mineralogy and isotopes; (3) mineralization of CO2 and H2S under flow-through conditions using solution chemistry and mineralogy.
The results of the study demonstrate that sequestration of CO2 and H2S into geothermal systems is geochemically feasible. Based on the measured sequestration rates, ~0.2-0.3 t of CO2 and 0.1-0,2 t of H2S are sequestered annually per cubic meter. This suggests that the re-injection of CO2 and H2S into geothermal reservoirs is a potential solution for making geothermal energy production close to zero greenhouse gas emission.
About the doctoral candidate
Jan Prikryl was born in Czech Republic in 1987. He received his BS degree in 2010 and MS degree in 2012 both in geology from Masaryk University, Brno, Czech Republic. Jan is married to Margrét Rán Kjærnested.