Özet:
The modern world depends on the fossil fuel consumption as a primary energy source,
and this is especially obvious in all industrialized countries. Due to the resource depletion
and non-sustainable resources, fossil fuels are not capable of compensating the growing
energy needs. In addition, the easily extractable fossil fuels are facing an increase in their
prices. It is worth mentioning that greenhouse gases (mainly CO2) have been accumulated
in the atmosphere by burning fossil fuels. Therefore, recently scientific research and
academic studies as well as energy policies have been focused to find a permanent
solution for the environmental issues by utilizing from the non-polluting resources such
as renewable energy and hydrogen. Furthermore, one other way to reduce the greenhouse
gases emissions is to design the energy systems in a more effective manner by producing
multiple useful commodities from the system. Therefore, one of the main goals of the
thesis is to design three different types of renewable based energy systems which provide
higher energy and exergy efficiencies by producing electricity, heating, cooling, hot
domestic water and hydrogen outputs, as useful outputs.
One of the most important enviromental issues related to the using geothermal operating
fluids to generate electricity is non-condensable gases (NCG) emissions. Hydrogen
sulfide (H2S), which is one of these gases, has many adverse effects on the environment
and human body. Therefore, another objective of the present study is to reduce the
hydrogen sulfide emissions in the geothermal power plants. For this purpose, an AMIS
(AMIS® - acronym for “Abatement of Mercury and Hydrogen Sulfide” in Italian
language) unit and an electrolyzer system are integrated to the presently developed
systems. In this way, not only the negative effects of hydrogen sulfide are reduced, but
also hydrogen is generated as a clean fuel which has a vast potential to replace fossil fuels.To accomplish the specific objectives and evaluate the newly developed systems and their
performance both energetically and exergetically, a detailed thermodynamic analysis is
performed by using Engineering Equation Solver (EES) software. The results show that
overall energy and exergy efficiencies for the studied systems becomes 67.95% and
60.94%, respectively. In addition, hydrogen sulfide emissions are reduced by 738.8 g/s,
while the inlet mass flow rate of geothermal fluid is 60 kg/s. Also 6.234 MW additional
power can be produced through hydrogen fuel from the geothermal power plants.