Search results for "Membrane reactors"

Position paper - progress towards standards in integrated (aerobic) MBR modelling.

2020

Membrane bioreactor (MBR) models are useful tools for both design and management. The system complexity is high due to the involved number of processes which can be clustered in biological and physical ones. Literature studies are present and need to be harmonized in order to gain insights from the different studies and allow system optimization by applying a control. This position paper aims at defining the current state of the art of the main integrated MBR models reported in the literature. On the basis of a modelling review, a standardized terminology is proposed to facilitate the further development and comparison of integrated membrane fouling models for aerobic MBRs. ispartof: WATER …

Photocatalytic processes in membrane reactors

2017

Photocatalytic membrane reactors (PMRs) represent an interesting alternative technology useful both in the field of water and air purification and in organic syntheses. The necessity to develop chemical products and industrial processes that reduce or eliminate the use and the generation of toxic substances along with the risk for human health and for environment constitutes the aim of the research efforts based on the principles of green chemistry. Heterogeneous photocatalysis is a technology extensively studied for about three decades, since Fujishima and Honda1 discovered the photocatalytic splitting of water on TiO2 electrodes in 1972, which includes a large range of reactions. When a s…

A Dialysis Photocatalytic Reactor for the Green Production of Vanillin

2020

In the present work, dialysis was used to recover vanillin while being produced by partial photocatalytic oxidation of ferulic acid in an aqueous solution at ambient temperature. The relatively high value of the permeate flux through a dense polyether-block amide membrane allowed continuously extracting vanillin from the reacting solution, thus avoiding its successive oxidation. The rate of vanillin formation was improved, compared to other reactor configurations, because intermediate compounds permeated from the reacting solution and did not hinder the reaction, while ferulic acid permeated in the opposite direction to partially replenish the reactor with the substrate. The photocatalytic …

Photocatalytic membrane reactors: configurations, performance and applications in water treatment and chemical production

2013

Abstract: The configurations and performance of photocatalytic membrane reactors (PMRs) assembled with membranes (also photocatalytic type) and/or suspended photocatalyst are described. Examples of the application of PMRs in water/wastewater treatment as well as in photocatalytic synthesis are shown. An outline of the modeling of PMRs is presented with a brief economic analysis; future trends in PMRs are also discussed.

Pervaporation membrane reactors (Chapter 3)

2013

Photocatalytic membrane reactors: fundamentals, membrane materials and operational issues

2013

Abstract: This chapter reports the properties of semiconductor materials used in heterogeneous photocatalysis together with a comparison of heterogeneous photocatalytic systems and a brief description of the types of membranes that can be used. Some aspects of membrane operations, such as fouling, separation of a photocatalyst and effectiveness of photodegradation on permeate quality are discussed.

Photocatalytic Membrane Reactors: Case Studies and Perspectives

2009

Photocatalysis by polycrystalline semiconductor oxides is being successfully applied to the abatement of organic and inorganic pollutants both in gas and in liquid phase. In order to increase the efficiency of this method, the coupling of this technology with the membrane separation process has been the object of sound investigation. In this combination, the membrane may act in different ways: to confine the photocatalytic powder in the reacting suspension, to selectively separate the photoreaction products, or to be the support of photocatalyst. This article reports recent studies in which different types of membranes (such as distillation, dialysis, nanofiltration, pervaporation and osmos…

PMRs Utilizing Non–Pressure-Driven Membrane Techniques

2018

In the present chapter it is shown how photocatalytic membrane reactors utilizing membrane processes, which are not pressure driven, can exploit various mechanisms to obtain a substantial improvement of the process. The fundamentals of this particular type of membrane reactors are reviewed including the effects of the most important parameters and the methods and rules of coupling photocatalysis and membrane separation. The survey of the studies on photocatalytic membrane reactors (PMRs) utilizing pervaporation, dialysis, membrane contactors and membrane distillation offers the opportunity of discussing the advantages with respect to PMRs adopting pressure driven membrane processes. Indeed,…