Keramische Wabenkatalysatoren zur chemischen Methanisierung von CO2

Translated title of the contribution: Ceramic honeycomb catalysts for methanation of CO2

Philipp Biegger

Research output: ThesisDoctoral Thesis

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Abstract

Global warming necessitates a significant reduction of CO2 emissions within the next decades. This can either be achieved by cyclization and utilization of CO2 or by substitution of fossil fuels, just to name a few possibilities. However, an implementation of such processes is inherently linked to several challenging problems, such as decentralization of power generation, increasing energy storage demand, extension of the power grid and integration of processes for carbon utilization. With these aspects in mind, Power-to-Gas (PtG) is a promising technique, since it is suitable for energy conversion and storage as well as for reuse of CO2. However, PtG is a comparably young technology and its process steps were originally developed for other applications. The variety of possible applications leads to high requirements regarding operational flexibility, which cannot be provided with todays state of the art techniques. Therefore, a substantial research demand for improvements is still necessary. Within the scope of this work an innovative methanation process as part of the PtG technology is introduced. A ceramic honeycomb catalyst is used instead of common spherical bulk catalysts. The suitability of these catalysts is investigated in comprehensive experiment series. Operating conditions pressure and space velocity were varied in a range of 1-15 bar and 1400-6000 h-1. Best results were achieved at 10 bar and ≤3000 h-1. The monolithic catalyst consists of a ceramic honeycomb made of cordierite, which is coated with an metal oxid like γ-Al2O3 or yttrium stabilized t-ZrO2 (TZP, 3 mol-% Y2O3). Another washcoat of Ni(NO3)2 is deposited onto the oxide coating, which gives the catalytically active Ni coating upon reduction in H2 atmosphere. Furthermore, the impact of catalyst geometry on CO2 conversion rate was investigated. For this purpose honeycombs with different length (100, 142 and 145,5 mm) and cell densities (82 and 300 cpsi) were used in up to three reactor stages. To evaluate the catalyst performance, benchmark experiments with a commercially available spherical catalyst were conducted. It was found that the honeycomb and spherical catalysts performed similarly. However, the CH4 content of the product gas reached higher concentrations with the commercial catalyst, which is likely caused by its advanced state of development. Additionally, two process chains consisting of methanation and gas purification as well as fermentation, methanation and gas purification were investigated. Test plants of different Austrian research groups were combined to realize these proof-of-concept studies. Since the product gas could possibly be fed into the existing gas grid, the aim of the experiments was to reach CH4 concentration of ≥96 Vol-%. As a result it was proven, that the target concentration could be reached with both process chains. This work provides a solid base for further steps in process development and was directly applied to design a pilot plant.
Translated title of the contributionCeramic honeycomb catalysts for methanation of CO2
Original languageGerman
QualificationDr.mont.
Awarding Institution
  • Montanuniversität
Supervisors/Advisors
  • Lehner, Markus, Assessor A (internal)
  • Kienberger, Thomas, Assessor B (internal)
Publication statusPublished - 2017

Bibliographical note

embargoed until null

Keywords

  • Power-to-Gas
  • power to gas
  • methanation
  • CCU
  • carbon capture and utilization
  • CO2
  • carbon dioxide
  • SNG
  • energy storage
  • honeycomb catalyst

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