Catalytic mixed conducting ceramic membrane reactors for methane conversion

2020 ◽  
Vol 5 (10) ◽  
pp. 1868-1891 ◽  
Author(s):  
Zhigang Wang ◽  
Tianjia Chen ◽  
Nikita Dewangan ◽  
Ziwei Li ◽  
Sonali Das ◽  
...  

Schematic of catalytic mixed conducting ceramic membrane reactors for various reactions: (a) O2 permeable ceramic membrane reactor; (b) H2 permeable ceramic membrane reactor; (c) CO2 permeable ceramic membrane reactor.

2022 ◽  
Vol 9 ◽  
Author(s):  
Sichao Cheng ◽  
Su Cheun Oh ◽  
Mann Sakbodin ◽  
Limei Qiu ◽  
Yuxia Diao ◽  
...  

Direct non-oxidative methane conversion (DNMC) converts methane (CH4) in one step to olefin and aromatic hydrocarbons and hydrogen (H2) co-product. Membrane reactors comprising methane activation catalysts and H2-permeable membranes can enhance methane conversion by in situ H2 removal via Le Chatelier's principle. Rigorous description of H2 kinetic effects on both membrane and catalyst materials in the membrane reactor, however, has been rarely studied. In this work, we report the impact of hydrogen activation by hydrogen-permeable SrCe0.8Zr0.2O3−δ (SCZO) perovskite oxide material on DNMC over an iron/silica catalyst. The SCZO oxide has mixed ionic and electronic conductivity and is capable of H2 activation into protons and electrons for H2 permeation. In the fixed-bed reactor packed with a mixture of SCZO oxide and iron/silica catalyst, stable and high methane conversion and low coke selectivity in DNMC was achieved by co-feeding of H2 in methane stream. The characterizations show that SCZO activates H2 to favor “soft coke” formation on the catalyst. The SCZO could absorb H2in situ to lower its local concentration to mitigate the reverse reaction of DNMC in the tested conditions. The co-existence of H2 co-feed, SCZO oxide, and DNMC catalyst in the present study mimics the conditions of DNMC in the H2-permeable SCZO membrane reactor. The findings in this work offer the mechanistic understanding of and guidance for the design of H2-permeable membrane reactors for DNMC and other alkane dehydrogenation reactions.


2014 ◽  
Vol 2 (1) ◽  
pp. 1-9 ◽  
Author(s):  
E.V. Shelepova ◽  
A.A. Vedyagin ◽  
I.V. Mishakov ◽  
A.S. Noskov

AbstractThe modeling of ethylbenzene dehydrogenation in a catalytic membrane reactor has been carried out for porous membrane by means of two-dimensional, non-isothermal stationary mathematical model. A mathematical model of the catalytic membrane reactor was applied, in order to study the effects of transport properties of the porous membrane on process performance. The performed modeling of the heat and mass transfer processes within the porous membrane, allowed us to estimate the efficiency of its use in membrane reactors, in comparison with a dense membrane (with additional oxidation of the hydrogen in shell side). The use of a porous ceramic membrane was found to cause an increase of the ethylbenzene conversion at 600°C, up to 93 %, while the conversion in the case of conventional reactor was 67%. In this work, we defined the key parameter values of porous membrane (pore diameter and thickness) for ethylbenzene dehydrogenation in catalytic membrane reactor, at which the highest conversion of ethylbenzene and styrene selectivity can be reached.


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