Sharif Digital Repository

Geothermal energy is a type of renewable energy with high availability and independence from climatic and atmospheric conditions. It has been shown that geothermal energy is technically, economically and environmentally more suitable for hydrogen production than other renewable sources. Hydrogen has wide applications in many fields including cooling, oil, gas, petrochemical, nuclear, and energy industries. Afghanistan has significant potential in geothermal power generation and also several hydrogen-consuming industries that provide opportunities for geothermal-based hydrogen production. This study attempted to find suitable locations for the construction of geothermal power plant for... 

Hybridization of biogas and geothermal energies for power plants can present a promising way to resolve drawbacks of each individual heat source from economic viewpoint, especially when low-temperature geothermal heat source is posited. Concerning this aspect of hybrid renewable heat sources, a novel hybrid biogas-geothermal multigeneration system was proposed in the first part of our study, which was modeled under privilege of thermodynamic laws. In continuation of our previous study, the current study is performed to investigate economic, environmental, and enviroeconomical aspects of the introduced system. Furthermore, single and multi-criteria optimizations of this integrated system are... 

Among different types of geothermal processing used in the energy conversion systems, flash-binary geothermal can be the best scenario for high-temperature geothermal sources. Reviewing the available literature it can be found that the flash-binary geothermal power plants have a great potential to be extended to trigeneration systems, nonetheless they have received less attention. In this regard, a new trigeneration system for freshwater, power, and cooling production is devised using a flash-binary geothermal heat source at 170°C. In this devised trigeneration system, a humidification-dehumidification (HDH) unit is used as a binary cycle. Another merit of the devised trigeneration system is... 

In this study, the performance of a system consisting of an organic Rankine cycle (ORC) for generating power and an electrolyzer for producing hydrogen with a zeotropic mixture as working fluid to recover waste heat in a geothermal flash-binary cycle is investigated from energy and exergy point of view. The study also investigates the effect of using zeotropic mixtures with different compositions as the ORC's working fluid rather than pure fluids. Using the particle swarm optimization (PSO) algorithm, the optimization is performed to maximize the power production of the entire system. The results show that using the combination of pentane with other pure fluids as working fluid led to...