Membrane reactors processes

Chemically functional membranes afford yet another intriguing platform upon which process-intensified chemistry can be performed. For example, an enzyme membrane reactor process is used to produce a... 

Damle, A.S., J. Schwartz, and P. Apte, Palladium-alloy based Membrane Reactor Process for Hydrogen Generation, Proceedings of2005 Fuel Cell Seminar, Palm Springs, CA, November 2005. 

There are certainly quite significant advantages that membrane reactor processes provide as compared to conventional reaction processes. The reactor can be divided by the membrane into two individual compartments. The bulk phases of the various components or process streams are separated. This is of importance for partial oxidation or oxidative dehydrogenation reactions, where undesirable consecutive gas phase reactions leading to total oxidation occur very often. By separating the process stream and the oxidant. 

Microporous membranes (pore radius less than 10 A) are ideal materials to be used as separators in membrane reactor processes. Microporous membranes also combine the high selectivities to certain components with high permeation rates. The high selectivities mean that maximum conversions (and thus equilibria shifts) higher than those achieved by porous membranes can be attained, while the high permeation rates allow for high reaction rates... 

W. Leuchtenberger M. Karrenbauer, and U. Ploecker, Scale-up of an enzyme membrane reactor process for the manufacture of L-enantiomeric compounds, Ann. N. Y. Acad. Sci. USA 1984, 434, 78-86. 

Lante A, Crapisi A, Krastanov A et al (2000) Biodegradation of phenols by laccase immobilised in a membrane reactor. Process Biochem 36 51-58... 

Silica membranes have received extensive attention in recent years because of their excellent chemical and thermal stability, especially in the application of gas separation and catalytic membrane reactor processes. And the separation of high purity H2 from the mixed gas, is very important to convert the chemical energy to the electric energy, such as fuel cells. The final objective of this study is to understand the adsorption and separation mechanism in the MTES templating composite silica membrane, which can get hi purity H2 from CO2 and CH4 mixture. 

Thus, expectedly no rigorous mathematical models are available that can accurately describe the detailed flow behavior of the fluid streams in a membrane separation process or membrane reactor process. Recent advances in computational fluid dynamics (CFD), however, have made this type of problem amenable to detailed simulation studies which will assist in efficient design of optimal membrane filtration equipment and membrane reactors. 

Two process flow diagrams have been developed for a ceramic membrane reactor process ... 

In the present concept of styrene dehydrogenation implementation of inorganic membranes is not feasible. Application of Knudsen diffusion membranes with a low permselectivity to hydrogen leads to a considerable permeation of ethylbenzene and thus, to lower yields. Microporous and palladium membranes give better results, but worse than a conventional case, because the conversion is limited by reaction kinetics. The ratio of permeation rate to reaction rate is very important in selecting membranes in a membrane reactor process in which equilibrium shift is foreseen. 

An overview of the variables in the membrane reactor process is given in Fig. 12, and those equations, which are most relevant from an engineering point of view, are summarized in Box 1. The significance of most of the variables should appear from Fig. 13 and Box 1 immediately, - for a full explanation, the reader is referred to the appendix. 

The results given above indicate that there is no obvious advantage of substituting the existing batch process for production of ISSPH by a membrane reactor process. However, this does not in general mean that continuous protein hydrolysis in a membrane reactor will be uneconomical. For example if the substrate is more completely degradable than soy protein (casein might be such a substrate), it is expected that in a small scale plant (where the capital costs would favour the membrane reactor) the membrane reactor process could be very attractive. The production of protein hydrolysates for dietetic and medical use, could well be considered in this context. 

Leuchtenberger,W. Karrenbauer,M. Picker,U. "Scale up of an Enzyme Membrane Reactor Process for the Manufacture of L-enantiomeric Compounds" Report from De-gussa AG, D-6450 Hanau I, FDR. 

Membrane-based reactive separation processes (also known as membrane reactor processes) are attracting attention in catalytic reactor applications. In these reactor systems the membrane separation process is coupled with a catalytic reaction. When the separation and reaction processes are combined into a single unit the membrane, besides providing... 

A interesting new process for the removal of metallic (Cu(II)) compounds in the treatment of industrial waste waters has been proposed by Flores and Cabassud [2.447, 2.448]. It consists of a membrane reactor with a moving-bed of porous ion-exchange resin particles. These authors have carried out laboratory experiments with this novel membrane reactor process. Prior to the initiation of the experiments a number of cationic resins were screened, and IRP 69, a resin whith a small particle diameter and high exchange rate, was chosen for the study. For these resin particles, the influence of stirring velocity and tern-... 

Economic and Technical Feasibility Issues of Membrane Reactor Processes... 

At various places throughout the first five chapters in the book we have, when it appeared relevant to the discussion, referenced studies which addressed issues pertaining to the economic/technical feasibility of membrane reactor processes. In this chapter we specifically focus our attention on these issues. In the discussion in this chapter we have, by necessity, drawn our information from published studies and reports. Several proprietary studies reportedly exist, carried out by a number of industrial companies, particularly during the last decade, which have evaluated the potential of membrane reactors for application in large-scale catalytic processes. By all accounts the conclusions reached in these proprietary reports mirror those found in the published literature. In the discussion which follows, we will first discuss catalytic and electrochemical reactors. We will then conclude with a discussion on membrane bioreactors. 

Membrane-based reactive separation (otherwise also known as membrane reactor) processes, which constitute the subject matter of this book, are a special class of the broader field of membrane-based separation processes. In this introduction we will first provide a general and recent overview on membranes and membrane-based separation processes. The goal is to familiarize those of our readers, who are novice in the membrane field, with some of the basic concepts and definitions. A more complete description on this topic, including various aspects of membrane synthesis can be obtained from a number of comprehensive books and reviews that have already been published in this area [1.1, 1.2, 1.3,... 

With respect to catalytic membrane reactors, processes can be divided in homogeneously and heterogeneously catalyzed reactions (see Fig. 5.2). In homogeneously catalyzed processes, the membrane modules can be used in loop reactors. For heterogeneously catalyzed reactions several configurations are possible ... 

I. A. Abba, J. R. Grace and H. T. Bi, Application of the generic fluidized-bed reactor model to the fluidized-bed membrane reactor process for steam methane reforming with oxygen input, Ind. Eng. Chem. Res., 2003, 42, 2736-2745. 

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