Metan kuru reform reaksiyonunun kinetiğinin incelenmesi

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Thesis Type: Postgraduate

Institution Of The Thesis: Gazi University, Fen Bilimleri Enstitüsü, -, Turkey

Approval Date: 2009

Thesis Language: Turkish

Student: SELEN ÖZKOÇER

Co-Supervisor: SENA YAŞYERLİ, NAİL YAŞYERLİ

Open Archive Collection: AVESIS Open Access Collection

Abstract:

Methane dry reforming process is being considered as a promising reaction system for conversion of greenhouse gases to valuable raw materials and alternative fuels. In this work, development of catalysts for long term use with high activity and H2 selectivity was aimed. To this end, Ni-MCM-41 catalysts were synthesized by hydrothermal method, and noble metal (Ru) and promoter (Mg) were added to Ni-MCM-41 catalysts to improve catalytic activity. MCM-41 with high surface area and thermal stability was used as a support for the catalysts. Ni-MCM-41 (Ni/Si:0,2 molar) catalysts were prepared by hydrothermal synthesis method. In order to increase the catalytic activity, Ru@Ni-MCM-41 catalysts were prepared by impregnation Ru into Ni-MCM-41 materials with the different Ru/Si molar ratios (Ru/Si molar ratios: 0,004, 0,011 ve 0,036). XRD, BET surface area, N2 adsorption, EDS and TGA analyses were performed to determine structural and physical properties of the prepared catalysts. It was observed that pore volume and surface area of the catalyst had decreased by increasing Ru/Si ratios in Ni-MCM-41 catalyst. Reaction tests using different ruthenium containing Ni-MCM-41 catalysts were performed in a packed bed reactor system with online GC analysis. After performing at the same catalytic reaction conditions, 1,0Ru@Ni-MCM-41 catalyst showed highest activity in the prepared catalysts. Dry reforming reaction experiments using 1,0Ru@Ni-MCM-41 (Ru/Si: 0,011) were repeated in a temperature interval of 500-600oC and feed ratio of CH4/CO2: 0,5-2. In the last part of the study, magnesium containing 1,0Ru@Ni-MCM-41 catalysts were prepared by the impregnation. Catalytic reaction tests were repeated using magnesium containing 1,0Ru@Ni-MCM-41 catalysts (1 and 5 % (w/w)). Significant enhancement in H2 selectivity was observed when the 1,0Ru@Ni-MCM-41 catalysts were modified by addition of magnesium as a promoter into catalyst structure.