Chemical and Biological Engineering MS Thesis Defense by Burak Koyutürk

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KOÇ UNIVERSITY

GRADUATE SCHOOL OF SCIENCES & ENGINEERING

CHEMICAL AND BIOLOGICAL ENGINEERING

MS THESIS DEFENSE BY BURAK KOYUTÜRK

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Title: [BMIM][BF₄] Incorporation into ZIF-8: Gas Storage and Separation Performance

Speaker: Burak Koyutürk

Time: July 25, 2017, 10:00

Place: ENG-208

Koç University

Rumeli Feneri Yolu

Sariyer, Istanbul

Thesis Committee Members:

Assoc. Prof. Seda Keskin Avcı (Advisor, Koç University)

Asst. Prof. Alper Uzun (Advisor, Koç University)

Assoc. Prof. Uğur Ünal (Koç University)

Prof. Levent Demirel (Koç University)

Prof. Ramazan Yıldırım (Boğaziçi University)

Abstract:

Gas storage and separation processes have been playing a significant role to overcome energy shortage. Both CH₄ and CO₂ exist in the natural gas; CH₄ is considered as a clean energy source, while CO₂ is an impurity which causes to corrosion in the pipelines and decreases the energy content of the natural gas. In the storage and separation processes of these gases, Metal organic frameworks (MOFs) are nominated as promising materials due to their high surface area and large porosities. Modification of MOFs to reach higher gas storage capacities and better separation performances has been recently started. In the first part of this thesis, incorporation of ionic liquids (ILs) into the pores of MOFs with different loadings (wt%) was investigated. [BMIM][BF₄]/ZIF-8 samples were characterized using different techniques including X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Brunauer–Emmett–Teller (BET) Surface Area, Fourier Transform Infrared (FT-IR) and Scanning electron microscope (SEM). Gas uptakes of the samples prepared were measured using volumetric analysis and gas separation performances were found calculating ideal selectivities. For each sample, different gas storage and separation performances were obtained as a result of the distinct IL-MOF interactions. Results showed that 30 wt% IL-loaded MOF samples are promising materials for especially CO₂/CH₄ and CO₂/N₂ separation applications where the corresponding selectivities increased from 2.2 to 4 and 6.5 to 13.3 at 0.1 bar, respectively. 20 wt% loading can be used for storage purposes as CO₂ uptake increased by 9% at 0.1 bar. In the second part of this thesis, we extended the IL-MOF pairs and studied several combinations. Same characterization techniques were used for different IL incorporations into ZIF-8 and the relationship between IL-MOF interactions and performances of composite materials was examined. ZIF-8 was modified with annealing process to investigate the CH₄, CO₂ and N₂ static adsorption capacities and separation performances. IL incorporation into MOF offers opportunity for improvement in gas storage and separation applications. Results showed that these composite materials can be used in purification of natural gas and flue gas to overcome energy shortage.