Experimental and modelling study for the production of hydrogen via a novel intensified sorption enhanced chemical looping methane reforming process.


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Semantic enrichment/homogenization by EKT

2015 (EN)
Experimental and modelling study for the production of hydrogen via a novel intensified sorption enhanced chemical looping methane reforming process. (EN)

Giannakou, Aikaterini (EN)

School of Science and Technology, MSc in Energy Systems (EL)
Giannakidis, Georgios (EN)
Anastaselos, Dimitrios (EN)
Herakleous, Eleni (EN)

H2 is considered as the energy vector of the future due to its clean combustion, resulting in almost no impact on the environment. However H2 is a secondary energy carrier produced mainly through reforming of natural gas, which although a mature process re- mains very energy intensive. Sorption enhanced-chemical looping steam reforming is a novel process for efficient production of pure hydrogen, combining chemical looping steam reforming with in-situ CO 2 capture. In this process, the reformer contains, i n addition to the sorbent, an oxygen transfer material (OTM). In the first step of this cyclic process, the oxide is reduced by CH 4 and serves as the reforming catalyst. The reaction proceeds under near autothermal conditions due to t he heat released by the strongly exo- thermic carbonation reaction of the sorbent. In a second step, the saturated sorbent is regenerated with energy provided by the exothermic OTM re-oxidation. This dissertation was written as a part of my MSc i n Energy Systems at the International Hellenic University. The objective was to evaluate the effect of different operating conditions (temperature, steam/carbon ratio and OTM/sorbent ratio) on the performance of a previously developed optimized NiO-based OTM/catalyst (NiO/ZrO 2 ) and a CaO- based CO 2 sorbent (CaO/CaZrO 3 ) in the novel sorption enhanced steam methane re- forming process combined with chemical looping concept. The experiments were carried out in a bench scale unit in Aristotle University of Thessaloniki, while a thermodynamic analysis of the process was performed using Aspen Plus ® software. Evaluation of the two solids indicated their suitability for the proposed process, with very stable performance under cyclic operation. The combined experiment demonstrated the feasibility and high potential of the novel process. Product concentrations in the outlet of the reformer closely followed the equilibrium at the different studied parameters. During the reforming stage, a very high H 2 concentration was achieved (>95%). During the regeneration stage, the highly exothermic Ni oxidation generates enough heat to increase the reactor’s temperature from 650 to 800°C and supplies up to 45% of the heat required for the regeneration of the sorbent, for a NiO/CaO molar ratio of 0.8. (en) (EN)


Διεθνές Πανεπιστήμιο της Ελλάδος (EL)
International Hellenic University (EN)



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