Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Design of Ni-Metal Organic Framework (ni-Mof(74)) for Efficient Co2 Adsorption(01. Izmir Institute of Technology, 2024) Gürsel Karpuz, Hande; Özkan, Seher Fehime Çakıcıoğlu; 01. Izmir Institute of TechnologyThe urgency the address high CO2 concentrations in the Earth's atmosphere increases each day prompting collaborative efforts between industry and the science community to develop various solutions. Among these, carbon capture utilization and storage (CCUS) technologies are proven to be integral. Rooted in CO2 adsorption, carbon capture forms the cornerstone of CCUS technologies. Consequently, developing effective CO2 capture materials and designing systems capable of integrating these materials into real-world practical applications play a crucial role. In this study, one of the most promising materials for future CO2 capture technologies, Ni-MOF-74, is synthesized, characterized, and tested for CO2 adsorption capacity. Following the synthesis process Ni-MOF-74 is immobilized on acrylonitrile fabric in order to achieve a flexible and versatile structure with high CO2 capacity that can be integrated in various applications. The highest surface area and CO2 adsorption capacity achieved by the synthesized Ni-MOF-74 powder are 180 m2/g and 1.98 mmol/g, respectively. Synthesized Ni-MOF-74 powder was successfully immobilized on an acrylic fabric substrate through the drip casting method. The resulting composite showed a decrease in CO2 adsorption capacity only by 8% which is promising for practical applications and a fair compromise considering that the flexible structure offers an opportunity to be utilized in a wide range of scenarios.Master Thesis Renewable natural gas production via Sabatier reaction(01. Izmir Institute of Technology, 2021) Çamlık, Cansu; Şeker, Erol; Şeker, Erol; 01. Izmir Institute of Technology; 03.02. Department of Chemical Engineering; 03. Faculty of EngineeringThis study attempts to understand the effect of support basicity on Sabatier reaction and improve the performance of Ni based catalysts by introducing calcium which is known for its basicity. In accordance with this purpose, Ni-Al2O3-CaO catalysts were synthesized with modified sol-gel method. Effect of Ni loading, calcination temperature and calcium content were investigated. Al2O3-CaO supports were synthesized at three ratios as follows; 70-30 wt.%, 40-60 wt.%, 10-90 wt.% wherein Ni/Al2O3 catalyst was used as reference catalyst. Based on thermodynamic analysis, reaction was conducted at 400oC and 1 atm with inlet composition of CO2/H2=1/4 and total volumetric flow rate of 100 ml/min. Reference catalyst calcined at 700oC was found to be inactive at used reaction conditions due to the presence of inactive NiAl2O4 phase. Increasing Ni loading from 1 wt.% to 10 wt.% increased both CO2 conversion and methane selectivity. Over the catalysts calcined at the temperature of 900oC, maximum methane yield was obtained over 10Ni-70Al-30Ca-900 as 8%. The influence of Ni loading was more pronounced for catalysts calcined at 700oC. In 10Ni-70Al-30Ca-700 catalyst, NiO particles were smaller than 5 nm. Therefore, it is conceivable that the alumina-calcium mixed oxide support could disperse higher loadings of Ni, which could result in higher CO2 conversion. Ca modification was found to have a prominent impact on both methane selectivity and yield. With 10Ni-10Al-90Ca-700, being best performing catalyst, CO2 conversion obtained as 76% and methane yield was 60%. The promotion of catalytic performance might arise from intensifying the CO2 chemisorption supported by XRD and TGA results.Master Thesis Electrolyte-Based Simulations of a Laboratory Scale Carbon Dioxide Capture Process(01. Izmir Institute of Technology, 2020) Özdamar, Ateş Batıkan; Uzunlar, Erdal; Özdamar, Ateş Batıkan; Uzunlar, Erdal; 01. Izmir Institute of Technology; 03.02. Department of Chemical Engineering; 03. Faculty of EngineeringThe aim of this thesis is to design and simulate a laboratory-scale CO2 capture system on Aspen Plus. The studied CO2 capture process is a post-combustion CO2 capture process. The commonly employed monoethanolamine (MEA) sorbent is compared with the piperazine (PZ) sorbent in terms of reaction kinetics and energy consumption throughout the study. Three main simulation studies were performed in order to compare MEA and PZ sorbents. First, an absorption column, then an open loop (single pass) process and finally a closed loop (recycle) process were designed and simulated on Aspen Plus. The simulations were carried out at various inlet gas pressures. After designing an absorber column, CO2 loading, temperature, pressure, mole flow, packing details, column height and diameter constraints were determined. As a result of open loop and closed loop processes, the column operations in absorber and stripper columns regarding CO2 reactions and energy consumption were investigated. The results showed that PZ absorbs and releases more CO2, has a faster kinetics, and is more energy efficient compared to MEA in CO2 capture processes.