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Communication Dans Un Congrès Année : 2015

development of a water permselective sod zeolite membrane with a modified pore-plugging technique

Francis Bougie
  • Fonction : Orateur
  • PersonId : 993698
F. Larachi
  • Fonction : Auteur
M. Iliuta
  • Fonction : Auteur
P. Fongarland

Résumé

In the last years, water separation by hydrophilic membranes has gained huge importance in the scientific and industrial community. Hydrophilic membranes can be used for selective water pervaporation from liquid mixtures or dehydration of organic compounds and these processes can positively replace distillation due to lower energy requirement. Moreover, water is produced in various chemical reactions as a by-product; its separation by hydrophilic membranes from the reaction media can displace the equilibrium and overcome thermodynamic limitations. As example, the selective removal of H2O during dimethyl ether (DME) synthesis (carbon dioxide hydrogenation into methanol followed by its dehydration to produce DME) by means of a membrane separation process would displace the equilibriums to enhance CO2 conversion into methanol, improve DME productivity and also prevent catalyst deactivation. To develop this process, the main latch is undoubtedly the production of a membrane able to selectively separate water at high temperature and pressure from a gaseous mixture of H2O, H2, CO, CO2, CH3OH and DME. Zeolite membranes appear to offer great potential for this application in reason of their molecular sieving properties, uniform pore size distribution and wide range of hydrophilic behavior depending on their Si/Al ratio. Furthermore, it is known that they have higher thermal resistance and mechanical strength than polymeric membranes and provide higher separation factors than ceramic ones. Highly hydrophilic sodalite (SOD, Si/Al ratio of 1) membranes were produced in this work based on a new mechanical pore-plugging technique. This process involved the insertion of specific sized seeds within the pores of an asymmetric host support followed by their growth by hydrothermal synthesis steps. To obtain membranes with high water selectivity and flux, several parameters were investigated, including composition of the precursor solutions (nature and ratio of the reactants to get clear solutions, without the use of structure directing agents), hydrothermal synthesis conditions, mean pore size and nature of the support top-layer (0.1-0.5 um for TiO2 or a-Al2O3 on stainless steel) and membrane post-treatments. Zeolite seeds and/or synthesized membranes were characterized by X-ray diffraction (XRD), thermal gravimetric analysis (TGA), scanning electron microscopies (SEM), gas permeation and permporosimetry where hydrogen permeance was evaluated as a function of water P/Po up to 250°C. Results revealed that membranes obtained under optimized synthesis conditions have good H2O/H2 selectivity at high temperatures even for low water P/Po indicating their high potential to improve DME productivity industrially.
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Dates et versions

hal-01207712 , version 1 (01-10-2015)

Identifiants

  • HAL Id : hal-01207712 , version 1

Citer

Francis Bougie, F. Larachi, M. Iliuta, N. Guilhaume, P. Fongarland. development of a water permselective sod zeolite membrane with a modified pore-plugging technique. CHEMICAL ENGINEERING AND BIOCHEMICAL ENGINEERING FOR A NEW SUSTAINABLE PROCESS INDUSTRY IN EUROPE, Sep 2015, Nice, France. ⟨hal-01207712⟩
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