Membrane contactors performance

In Section 38.4, studies and results obtained by applying membrane contactors to processes of industrial interest are reported and discussed. In particular, the research efforts made to improve membrane contactors performance are furnished for... 

Not much work has been reported in the literature on the combination of both absorption and desorption processes for CO2 removal. This is appropriate as the real application consists of both processes running at the same time. Thus, future studies should use the real conditions of gas mixtures, operating pressure, and temperature in order to compare membrane contactor performance with that of conventional methods. 

Generally, a distinction can be made between membrane bioreactors based on cells performing a desired conversion and processes based on enzymes. In ceU-based processes, bacteria, plant and mammalian cells are used for the production of (fine) chemicals, pharmaceuticals and food additives or for the treatment of waste streams. Enzyme-based membrane bioreactors are typically used for the degradation of natural polymeric materials Hke starch, cellulose or proteins or for the resolution of optically active components in the pharmaceutical, agrochemical, food and chemical industry [50, 51]. In general, only ultrafiltration (UF) or microfiltration (MF)-based processes have been reported and little is known on the application of reverse osmosis (RO) or nanofiltration (NF) in membrane bioreactors. Additionally, membrane contactor systems have been developed, based on micro-porous polyolefin or teflon membranes [52-55]. 

Table 20.1 Main effects of some membrane properties on the performance of membrane contactors".

The variety of unit operations that can be performed by membrane contactors has led during last years to many research studies in which membrane contactors are applied to different fields. 

Membrane contactors can be effectively used also for disinfection purposes (e.g., water ozonation) [28] or for the oxidation of species present into water, for example, arsenic. Although the content of arsenic in seawater is today within the accepted limits, it is foreseen that in the future its concentration could increase, due to the increase of pollution of rivers and groundwaters. Usually, arsenic is contained in water as As(III) and As(V) forms, in different amounts. All arsenic-removal technologies have a better performance when arsenic is present in the pentavalent... 

Membranes are polymeric microporous materials in hollow-fiber or flat-sheet configurations. The membrane properties control the contactor and the membrane contactor system performance and economy. The most important membrane properties are ... 

Feron PHM and Jansen AE. CO2 separation with polyolefin membrane contactors and dedicated absorption liquids Performances and prospects. Sep. Purif. Technol. 2002 27 231-242. 

This chapter presents an overview of different membrane processes and a description of all of the chapters presented in this edition. Chapter 2 focuses on updated information of utility to UF and NF membrane research and development, particularly in the preparation of new types of UF/NF membranes with improved performances. Chapter 3 presents a comprehensive review on RO membrane, the latest developments in the field, important installations demonstrating this technology, and future scope of RO processes. Chapter 4 presents the potential of membrane contactors, especially hollow fiber contactors in the field of chemical and nuclear industry along with their applications, performance, and current challenges faced by indnstry. This chapter also gives an introduction to membrane contactors, their principles of operation and associated mechanisms (where chemical reactions are involved), and fntnre scope of these contactors. 

Molinari R., Lavorato C., Poerio T. 2012. Performance of vanadium based catalyst in a membrane contactor for the benzene hydroxylation to phenol. Applied Catalysis A General 417--H8 87-92. 

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