Sustainable hydrogen production process development using reducible oxides

2020
Çalışan, Atalay
The energy demand is driven by increasing world population and living standards. Sustaining this demand with available and renewable energy sources is a major challenge. The options such as solar and wind power, are unreliable for a steady energy production due to their intermittent nature. Therefore, the storage of renewable energy, such as hydrogen, gains importance. In the scope of this thesis, a sustainability barrier in front of solar integrated hydrogen production processes was addressed in terms of material development and energy utilization perspectives for the two step thermochemical cycles and methane reforming processes. From the material development perspective, thermodynamic analysis was performed for investigating the driving force towards metal oxygen bond breaking and bond formation. The effect of reaction control mechanisms on the processes is studied through temperature programmed experiments etc. Conducted experiments revealed that hydrogen yield (maximum 52.5 mL/g MO¬¬x) was limited by heat and mass transfer resistances as well as a severe thermodynamic barrier in front of metal oxygen bond breaking. The studied red/ox couples were also investigated in conventional methane reforming process. Thereafter, solar energy integration to methane reforming process was studied for sustaining reaction energy from solar. Simulations performed by ASPEN Plus revealed that the solar energy losses observed in a daily basis is overcame with an integrated combustion zone to solar reformer, so a unique hybrid process was proposed for uninterruptable hydrogen production. The demonstration of this proposed process under real environment was left as a future subject.

Suggestions

Green energy for the battlefield
Aslan, Murat; Isik, Halil (2017-01-01)
Population of the world is growing with increasing rate and it seems that existing fossil fuel energy sources will not be able to meet energy demand in the near future. Energy is not only crucial for civil sector but also it is one of the most important assets in defense sector. Energy for military operations is mostly provided from fossil fuel as it is the case in other sectors; however, fossil fuels have hazardous effects to the environment and cause global environment concerns. These drawbacks of fossil ...
Hydrogen adsorption on CU (I)-exchanged zeolites
Altıparmak, İsmihan; İpek Torun, Bahar; Üner, Deniz; Department of Chemical Engineering (2019)
The growing population of the world increases the energy demand exponentially; necessitating utilization of a clean and renewable energy source. In this manner, H2 is a prominent candidate to be the future fuel by having gravimetrically high energy density, provided that a new lightweight, safe and economical onboard hydrogen storage system is developed for H2 fueled fuel cell vehicles. In this thesis, Cu(I)exchanged micro- and meso-porous zeolites (Cu(I)-[B]-ZSM-5, Cu(I)-[Al]-ZSM-5, mesoporous Cu(I)-[B]-ZS...
Phototrophic hydrogen production by agar-immobilized Rhodobacter capsulatus
Elkahlout, Kamal E. M.; Yücel, Ayşe Meral; Eroğlu, İnci; Department of Biotechnology (2011)
photosynthetic bacteria is attractive field as production is fueled by solar energy. Hydrogen production potential of two photosynthetic bacteria R.capsulatus (DSM1710 wild type and R.capsulatus YO3 Hup- uptake hydrogenase deleted mutant strain) were examined in agar immobilized systems. In the present work agar and glutamate concentrations were optimized for immobilization of bacteria while feeding bacteria with 40/2-4 mM acetate/ glutamate. Immobilized bacteria produced hydrogen for 420-1428 hours coverin...
Preliminary Study on Site Selection For Floating Hybrid Wind And Solar Energy Systems In Turkey
Yerlikaya, Nevzat Can; Çakan, Çağatay; Başara, Ilgın; Caceoğlu, Eray; Huvaj Sarıhan, Nejan (2021-09-08)
It is well-known that even though fossil fuels are the main energy resource in Turkey, use of sustainable energy resources such as wind and solar energy has been increasing in the past years and expected to continue on this trend in the next years to come. The suitable land for land-based wind turbines and photovoltaic (PV) systems could also be convenient for various other purposes, such as agriculture. This study aims to investigate the suitable sites for a combined floating wind and solar systems in the ...
A Density functional theory investigation for solid state hydrogen storage materials
Gencer, Ayşenur; Toffoli, Hande; Department of Physics (2018)
The world’s energy demand is increasing with the population growth and technology development. In addition, the electronic devices are an essential part of the daily life that require portable energy sources. Therefore, energy storage is necessary in order to store energy from the renewable energy sources and also provide portable energy sources for electronic devices. Hydrogen being the most abundant element in the world, is a good energy carrier with high energy density. Also, hydrogen does not release gr...
Citation Formats
A. Çalışan, “Sustainable hydrogen production process development using reducible oxides,” Thesis (Ph.D.) -- Graduate School of Natural and Applied Sciences. Chemical Engineering., Middle East Technical University, 2020.