Assessment of the Possibility of the CO2 Use Obtained from Biomass Burning as a Working Medium in Enhanced Geothermal Systems

Abstract

The article describes the possibility of the use of CO2 as a working fluid in an enhanced geothermal system. The consideration is focused on the choice of the appropriate closed geological structures in Poland. In typical HDR and EGS geothermal systems, injected water is the heat carrier. In the proposed system, CO2 is extracted from exhaust gases coming from a biomass-based power or heating plant. The exhaust gases undergoes a process of CO2 purification and separation. Carbon dioxide after receiving energy from the rock matrix can be used as an energy carrier for its direct or indirect use. According to the nomenclature used in geothermal energy, direct use means obtaining energy for heating purposes, while indirect use means transforming geothermal energy into electricity. In order to determine the effects of the proposed solution, mathematical and numerical modelling of heat and mass transfer will be used. Due to the preliminary nature of this work, chemical processes in the reservoir were not taken into account. Therefore, the results of mathematical modeling are preliminary.