Advances and trends in two-zone fluidized-bed reactors

Herguido, J.; Menéndez, M.

doi:10.1016/j.coche.2017.05.002

Cited by 16 publications

(10 citation statements)

References 50 publications

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“…Our group has found that the use of a two-zone fluidized bed reactor can counteract the catalyst deactivation, by (1) CH 4 + CO 2 ↔ 2H 2 + 2CO providing simultaneous reaction and regeneration in a single vessel [10]. In order to simulate this reactor and to search for the optimal operation conditions, a good knowledge of the process kinetics is needed, including also the catalyst deactivation kinetics.…”

Section: Introductionmentioning

confidence: 99%

Kinetic Study of Dry Reforming of Methane Over Ni–Ce/Al2O3 Catalyst with Deactivation

et al. 2019

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A kinetic study for dry reforming of methane over Ni-Ce/Al 2 O 3 catalyst was performed, taking into account both the main reactions and the catalyst deactivation. The catalyst was prepared by a sequential wet impregnation process, with loadings of 5 wt.% Ni and 10 wt.% Ce. Experimental tests were carried out in a fixed bed reactor between 475 and 550 °C and several spatial times, using nitrogen as diluent. Several kinetic equations were compared. The best fit of experimental data was achieved using a Langmuir-Hinshelwood mechanism which takes into account the presence of two active sites. Preexponential factor and activation energy were calculated. the kinetics of deactivation was also determined. The relationship between catalyst activity and coke concentration was also studied. Several deactivation equations were considered in order to choose the best fit with experimental data.

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Section: Introductionmentioning

confidence: 99%

Kinetic Study of Dry Reforming of Methane Over Ni–Ce/Al2O3 Catalyst with Deactivation

et al. 2019

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“…To cope with all these disadvantages (i to iii), a two-zone fluidized bed reactor (TZFBR) has been proposed to carry out the MDR, allowing in this way the simultaneous catalyst regeneration in a single unit. In the non-conventional TZFBR reacting system [16,17], due to its design, both processes can be carried out simultaneously: the catalytic dry reforming reaction in the upper zone of the bed, and the regeneration of the catalyst in the lower zone. The formation of two zones is achieved by feeding the The TZFBR+MB configuration, thanks to the simultaneous regeneration, may provide a steady state operation in conditions where a conventional fluidized bed membrane reactor would usually suffer deactivation by coking (e.g., , [18,19]).…”

Section: Introductionmentioning

confidence: 99%

Pure hydrogen from biogas: Intensified methane dry reforming in a two-zone fluidized bed reactor using permselective membranes

Durán

Sanz-Martínez

Soler

et al. 2019

Chemical Engineering Journal

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Methane dry reforming of biogas can be a sustainable source of hydrogen but the development of this technology is hindered by limitations such as endothermicity and catalyst deactivation by coke. A two zone fluidized bed reactor coupling permselective Pd/Ag membranes counteracts them and allows to intensify the process obtaining a stable pure hydrogen production. Here we report the effect of operation variables (i.e., temperature, total bed height, nature and partial pressure of regenerative agent, relative height of the regeneration and reaction zones, and use of an activation period) on the yield to hydrogen and stability of the process. Hydrogen over-yields, compared with the conventional fluidized bed reactor, in the range of +200% to +100% were obtained for the entire interval of temperatures 475-575°C whilst maintaining stable operation by continuous catalyst regeneration. Around 70% of it was pure hydrogen coming from the permeate side of the membranes. The proposed reactor configuration greatly increases both methane conversion and selectivity to hydrogen (expressed as H 2 /CO ratio), not only in relation to our own conventional reactor findings but also regarding other published results.

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“…The Two Zone Fluidized Bed Reactor (TZFBR) is an effective way to counteract the effects of catalyst deactivation, as several previous studies have proved in a variety of reactions (Herguido et al, 2005;Herguido and Menéndez, 2017). In this type of reactor, two zones are created in a fluidized bed by the simple procedure of feeding into the hydrocarbon stream at an intermediate point of the bed and placing an oxidizing stream at the bottom of the reactor.…”

Section: Introductionmentioning

confidence: 99%

Methane Aromatization in a Fluidized Bed Reactor: Parametric Study

Lasobras¹,

Soler²,

Herguido³

et al. 2019

Front. Energy Res.

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Methane aromatization is a promising technology for the transformation of natural gas into liquid products, but suffers from the problem of catalyst deactivation by coke. A two-zone fluidized bed reactor has been proposed as a tool to counteract the catalyst deactivation, by providing continuous catalyst regeneration in the same vessel where the main reaction is carried out. This work shows the effect of the main operating conditions (carburization temperature, reaction temperature, carburization time, nature of regenerating agent and feed flow and height of the hydrocarbon entry point). Optimal reduction time and temperature were 1 h and 350 • C. Best conversion and selectivity were achieved at 700 • C without catalyst deactivation in the TZFBR.

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Advances and trends in two-zone fluidized-bed reactors

Cited by 16 publications

References 50 publications

Kinetic Study of Dry Reforming of Methane Over Ni–Ce/Al2O3 Catalyst with Deactivation

Kinetic Study of Dry Reforming of Methane Over Ni–Ce/Al2O3 Catalyst with Deactivation

Pure hydrogen from biogas: Intensified methane dry reforming in a two-zone fluidized bed reactor using permselective membranes

Methane Aromatization in a Fluidized Bed Reactor: Parametric Study

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