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Effect of pore characteristics on hydrogen reduction kinetics based on a novel analysis approach combined model-fitting and iso-conversion
- Source :
- International Journal of Hydrogen Energy. 46:23164-23173
- Publication Year :
- 2021
- Publisher :
- Elsevier BV, 2021.
-
Abstract
- Carbon reductant used in metallurgy industry is a considerable source of carbon dioxide emissions. Growing concerns over greenhouse effect have urgently prompted research in the application of hydrogen energy as an alternative. However, some basic kinetic problems in the hydrogen reduction process have not been clarified and resolved yet, such as the activation energy fluctuations caused by neglect of pore characteristics, along with the overly subjective division of the whole reaction process to analyze rate limiting mechanisms. In this study, a novel approach for acquiring instantaneous activation energy is proposed that is able to identify the activation energy at every reaction moment and thereby provide a quantitative basis for kinetics segmentation and rate-limiting mechanism determination. Moreover, due to the space requirements, the activation energy for the reaction stage controlled by nucleation and nuclei growth has a strong correlation with specific surface area. Whereas the restriction mechanisms of chemical reaction and diffusion are closely related to the average pore size. These results reveal that the different pore characteristics and changes in value have a direct influence on the corresponding rate limiting mechanisms and restriction degrees.
- Subjects :
- Materials science
Hydrogen
Renewable Energy, Sustainability and the Environment
Kinetics
Nucleation
Energy Engineering and Power Technology
chemistry.chemical_element
02 engineering and technology
Activation energy
010402 general chemistry
021001 nanoscience & nanotechnology
Condensed Matter Physics
Kinetic energy
01 natural sciences
Chemical reaction
0104 chemical sciences
Fuel Technology
chemistry
Chemical physics
Hydrogen fuel
Diffusion (business)
0210 nano-technology
Subjects
Details
- ISSN :
- 03603199
- Volume :
- 46
- Database :
- OpenAIRE
- Journal :
- International Journal of Hydrogen Energy
- Accession number :
- edsair.doi...........b7a4d51f435c7a03fe6d80db74c01ced