scholarly journals Temperature profile in a reverse flow reactor for catalytic partial oxidation of methane by fast IR imaging

AIChE Journal ◽  
2008 ◽  
Vol 54 (10) ◽  
pp. 2689-2698 ◽  
Author(s):  
M. Simeone ◽  
L. Salemme ◽  
C. Allouis ◽  
G. Volpicelli
Keyword(s):  
Temperature Profile ◽  
Partial Oxidation ◽  
Flow Reactor ◽  
Reverse Flow ◽  
Partial Oxidation Of Methane ◽  
Catalytic Partial Oxidation ◽  
Oxidation Of Methane ◽  
Ir Imaging ◽  
Reverse Flow Reactor

scholarly journals Modelling of a Reverse Flow Catalytic Membrane Reactor for the Partial Oxidation of Methane

2003 ◽  
Vol 1 (1) ◽  
Author(s):  
J. Smit ◽  
M. van Sint Annaland ◽  
J.A.M. Kuipers
Keyword(s):  
Heat Exchange ◽  
Temperature Profile ◽  
Partial Oxidation ◽  
Membrane Reactor ◽  
Reverse Flow ◽  
Air Separation ◽  
Partial Oxidation Of Methane ◽  
Catalytic Membrane ◽  
Fischer Tropsch ◽  
Oxidation Of Methane

Gas-To-Liquid (GTL) processes have great potential as alternative to conventional oil and coal processing for the production of liquid fuels. In GTL-processes the partial oxidation of methane (POM) is combined with the Fischer-Tropsch reaction. An important part of the investment costs of a conventional GTL-plant is related to cryogenic air separation. These costs could be substantially reduced by separating air with recently developed oxygen perm-selective perovskite membranes, which operate at similar temperatures as a POM reactor. Integration of these membranes in the POM reactor seems very attractive because oxygen reacts at the membrane surface resulting in a high driving force over the membrane increasing the oxygen permeation.Because the POM-reaction is only slightly exothermic, the natural gas and air feed have to be preheated to high operating temperatures to obtain high syngas yields and because the Fischer-Tropsch reactor operates at much lower temperatures, recuperative heat exchange is essential for an air-based POM process. External heat transfer at elevated temperatures is expensive and therefore recuperative heat exchange is preferably carried out inside the reactor, which can be achieved with the reverse flow concept. To combine the POM reaction, air separation and recuperative heat exchange in a single apparatus a novel, multi-functional reactor is proposed, called the Reverse Flow Catalytic Membrane Reactor (RFCMR). In this reactor a relatively uniform temperature profile should be established at the membrane section and the temperature fronts should be located in the inert in- and outlet sections.To study the RFCMR concept, reactor models have been developed assuming a shell-and-tube geometry, based on models that are commonly used to describe conventional reverse flow reactors. Simulations of the novel reactor concept revealed that a small amount of methane has to combusted on the air side to create the reverse flow behaviour. Also a small amount of steam has to be injected distributively along the perovskite membrane section to maintain the centre of the reactor at nearly isothermal conditions. With these modifications it was found that the desired temperature profile could indeed be created in the RFCMR and that high overall syngas yields can be achieved.

scholarly journals Oscillatory Behaviour of Ni Supported on ZrO2 in the Catalytic Partial Oxidation of Methane as Determined by Activation Procedure

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2495
Author(s):  
Daniela Pietrogiacomi ◽  
Maria Cristina Campa ◽  
Ida Pettiti ◽  
Simonetta Tuti ◽  
Giulia Luccisano ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Partial Oxidation ◽  
Active Sites ◽  
Direct Reduction ◽  
Partial Oxidation Of Methane ◽  
Catalytic Partial Oxidation ◽  
Oxidation Of Methane ◽  
Short Contact Time ◽  
Oxidation Reduction ◽  
Ni Species

Ni/ZrO2 catalysts, active and selective for the catalytic partial oxidation of methane to syngas (CH4-CPO), were prepared by the dry impregnation of zirconium oxyhydroxide (Zhy) or monoclinic ZrO2 (Zm), calcination at 1173 K and activation by different procedures: oxidation-reduction (ox-red) or direct reduction (red). The characterization included XRD, FESEM, in situ FTIR and Raman spectroscopies, TPR, and specific surface area measurements. Catalytic activity experiments were carried out in a flow apparatus with a mixture of CH4:O2 = 2:1 in a short contact time. Compared to Zm, Zhy favoured the formation of smaller NiO particles, implying a higher number of Ni sites strongly interacting with the support. In all the activated Ni/ZrO2 catalysts, the Ni–ZrO2 interaction was strong enough to limit Ni aggregation during the catalytic runs. The catalytic activity depended on the activation procedures; the ox-red treatment yielded very active and stable catalysts, whereas the red treatment yielded catalysts with oscillating activity, ascribed to the formation of Niδ+ carbide-like species. The results suggested that Ni dispersion was not the main factor affecting the activity, and that active sites for CH4-CPO could be Ni species at the boundary of the metal particles in a specific configuration and nuclearity.

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