Permeation performance

Ismail, A.F., Kusworo, T.D., and Mustafa, A. (2008) Enhanced gas permeation performance of polye-thersulfone mixed matrix hollow fiber membranes using novel Dynasylan Ameo silane agent. /. Memhr. Sci.,... 

The reliability of separation/permeation performance is coupled with (a) fouling problems and (b) the stability of the micro(pore) structure of the membrane system. Fouling is a problem in almost all liquid separation applications. Strategies have been developed to cope with this problem, usually in a satisfactory way. 

Cellulosic Membranes. The first asymmetric membrane for gas separation appeared in 1970 (Table II), and It was not surprising that this membrane was a modified CA membrane of the Loeb-Sourirajan type (17). Gelled CA membranes for water desalination must be stored wet In order to maintain their permeation performance. However, In gas permeation, wet, plasticized membranes tend to lose their properties with time due to plastic creep of the soft material under pressure and due to slow drying during which the microporous sublayer may collapse and thus increase the thickness of the dense skin-layer. Gantzel and Merten (17) dried CA membranes with an acetyl-content of 39.4% by quick-freezing and vacuum sublimation at... 

Catalytic nickelsilicate membranes were synthesized by in-situ techniques on pretreated a- and 7- alumina supports. The resulting films and bulk materials have been characterized by XRD, Nz adsorption-desorption, SEM, TEM and FTIR spectroscopy. Their permeation performances of gases and liquids and catalytic activity in the selective oxidation of styrene with HzOz have been evaluated. The formation, morphology, permeation and catalytic properties of the membranes have been correlated with nature of alumina supports, their surface pretreatment and conditions of the hydrothermal synthesis. The results show a strong effect of 7-alumina surface on the morphology and properties of the membranes. 

New materials placed In new service conditions always raise the question of lifetime performance. In this case, permeation performance, stress-crack resistance, and long-term mechanical Integrity are particularly relevant in situations where the plastic containers are expected to be reused. In the case where hazardous materials are transported In plastic containers, regulatory decisions (Including the ruling on requests for exemptions) on these containers may be facilitated by using data on the material properties of the polymer. 

Our approach is then to define, to design and to develop an architecture and a microstructure for the reactor in order to optimize L and k parameters with respect to permeation performances, as well as thermo-mechanical and chemical integrity of the reactor. 

H.-J. Lee, M. Yoshimune, H. Suda, and K. Haraya. Effects of oxidation curing on the permeation performances of polyphenylene oxide-derived carbon membranes. Desalination, 193(l-3) 51-57, May 2006. 

Deng L, Hagg MB. Swelhng behaviour and gas permeation performance of PVAm/PVA blend FSC membrane. J Membr Sd 2010 363(l-2) 295-301. 

A pressure of 10 bars and a steam-to-carbon ratio of 4 seem to be a good compromise for reaction and permeation performance. 

Obviously, membrane reactor performance is strongly dependent on selective membrane behavior in terms of permeability, selectivity, and stability. Chapter 2 reports several data about hydrogen permeation performance of different metal-based and particularly of Pd-based membranes. 

Table 4.1 Comparison of oxygen permeation performance of BSCF5582 membranes in different geometries with other most studied A Sr, ByCo 0 i based perovskite membranes. All flux values and sweep gas flow rates are quoted at standard temperature and pressure (STP) s C) ... 

Oxy Fuel Combustion Power Production Using High Temperature O2 Membranes 99 Table 4.2 Comparison of oxygen permeation performance of C02 tolerant MIEC materials... 

L. Deng, M.-B. Hagg, Swelling behavior and gas permeation performance of PVAm/ PVA blend ESC membrane. Journal of Membrane Science 363 (2010) 295-301. 

It must be pointed out that a typical issue concerning PVRs with esterification reactions is the time stability of the membrane in the harsh reaction environment. The utilization of add resins as a soUd catalyst in the reactor instead of dissolved homogeneous acid catalysts reduces the severity of the problem, but it does not completely solve it. So, the challenge is the development of membrane materials showing satisfactory chemical and thermal resistance accompanied by good permeation performance at a reasonable cost. 

In order to verify long-term material stability, the effect of discontinuous electrolysis on permeation performance and methods for Pd-Ag electrode reactivation were also analysed. Structural changes to the Pd-Ag alloy, induced by electrolytic hydrogen adsorption, have been studied in detail... 

The permeation performance of perovskite membranes is strongly conditioned by the bulk diffusion and surface exchange properties at the feed/ membrane and permeate/membrane surfaces. The knowledge of such properties is crucial to facilitate the design of membrane modules for CO2 capture applications. 

Influence of CO2 in the oxygen permeation performance and the microstructure of perovskite-type Bao.5Sro.5Coo.8Feo,203 a membranes. 

The permeation performance of dense membranes is often characterized in terms of a transmembrane flux, ji, at a given temperature and pressure gradient. Alternatively, a specific flux, /, can be defined as a normalized membrane flux based on the thicloiess and logarithm of the partial pressure gradient as a reminiscence of the Wagner equation. The specific flux can be related to the membrane permeability as follows ... 

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