De nos jours, les limites du réacteur batch, outil conventionnel de l'industrie de la chimie fine, en termes de transfert thermique et de transfert de matière, conduisent à envisager le passage en continu de réactions dont les problématiques d'exothermie et de rapidité rendent leur industrialisation difficile. Les réacteurs-échangeurs compacts sont un exemple de technologies intensifiées continues alliant les performances d'un échangeur de chaleur couplées à un bon mélange ainsi qu'à un comportement de type piston offert par le design spécifique de leurs canaux. L'objectif de ces travaux est de démontrer la faisabilité de la transposition en continu d'une réaction fondamentale de la chimie des silicones, recensée comme l'une des plus exothermiques, dans un réacteur-échangeur intensifié conçu dans un matériau innovant : le Carbure de Silicium. La démarche a consisté à étudier les différentes phases de la réaction à plusieurs échelles afin de construire un modèle cinétique. L'exploitation de ce modèle a permis de définir les conditions optimales de la réaction permettant de répondre aux contraintes industrielles en termes de conversion, de consommation de catalyseur et de production industrielle. Enfin, une démarche d'optimisation et d'extrapolation du réacteur a été mise en place pour le pilotage industriel de la réaction étudiée. / Nowadays in the field of fine chemistry, limitations of conventional batch reactors in term of heat and mass transfer lead to increase the interest in the transposition of reactions from batch to continuous mode. It is particularly the case of fast and highly exothermic reactions as they raise safety issues in batch reactor. Compact heat-exchanger reactors (HEX reactor) are an example of continuous intensified technologies as they offer the heat transfer performances of heat exchangers coupled with high mixing and plug-flow behaviour, thanks to specific designs of channels. The aim of this work is to demonstrate the feasibility of the transposition of a fast and highly exothermic hydrosilylation reaction, a fundamental method for the industrial synthesis of organosilicon compounds, into a continuous heat-exchanger reactor made of a very innovative material: the silicone carbide. The methodology adopted consists in investigating hydrosilylation kinetics studies at different residence time scales. Then kinetics modelling and optimisation allow defining the features for process industrialization. Industrials objectives in terms of conversion and catalyst reduction are reached with a shorter time. Moreover the outstanding heat transfer performances of the HEX reactor, which entirely absorb the high exothermicity, successfully demonstrate the feasibility of the transposition into continuous

L'objectif de cette thèse est de proposer un réacteur continu et intensifié pour la transformation d’huiles végétales de récupération en produits ou intermédiaires qui seront ensuite utilisés ou formulés en applications destinées au BTP. Ce travail s’inscrit dans le cadre du FUI AGRIBTP, projet de recherche collaboratif qui a pour finalité la création d'un outil industriel de valorisation des sous-produits de l'agro-industrie. Le réacteur se veut pluri-réactionnel, c’est-à-dire adapté et efficace pour réaliser les réactions de transestérification ou d’estérification par le méthanol ou par le glycérol, pour une consigne de production fixée à 100 kg/h. Pour parvenir à cet objectif, une revue de la littérature a permis de dégager une liste de technologies de réacteurs adaptés à ces réactions. L’analyse comparative de ces systèmes a conduit à sélectionner trois types de réacteurs intensifiés existant dans le commerce et qui ont été ensuite testés expérimentalement: les réacteurs microstructurés (type Corning®), les réacteurs micro-ondes et les réacteurs pulsés à chicanes (type NiTech®). De bonnes conversions sont obtenues pour les réactions de transestérification et d’estérification par le méthanol, montrant une meilleure efficacité de ces réacteurs intensifiés par rapport aux réacteurs conventionnels; en revanche les résultats sont encore insuffisants pour l’estérification avec le glycérol en raison de limitations en température. Concernant le réacteur micro-ondes, les excellents résultats rapportés dans la littérature sont à modérer en raison d’une imprécision de mesure de la température. La technologie de réacteurs pulsés à chicanes a finalement été retenue : leur flexibilité, l’indépendance entre le débit et le mélange généré, et enfin leur diamètre suffisamment étendu pour ne pas générer de blocage éventuel dû à l’encrassement du réacteur par la matière entrante sont les principaux arguments qui ont guidé ce choix. Le système disponible construit en verre a tout de même montré ses limites en montée en température et en pression et il a donc été envisagé d’étoffer nos investigations dans des gammes de fonctionnement plus larges. Ainsi une collaboration avec le laboratoire TNO de Delft, aux Pays-Bas a permis d’avoir accès à un réacteur pulsé à chicanes en acier inoxydable. Les résultats obtenus pour la réaction d’estérification par le glycérol - qui n’offrait pas jusqu’à présent des données concluantes - sont satisfaisants, et même de qualité supérieure comparés à ceux obtenus avec un réacteur tubulaire hélicoïdal lui aussi pulsé. Parallèlement à ces études, des simulations numériques des écoulements dans le réacteur ont permis de proposer des améliorations de la forme des chicanes, celle-ci étant déterminante pour la bonne capacité de dispersion liquide-liquide des réactifs immiscibles et la qualité du mélange. Ces simulations ont été comparées à des mesures de vitesses obtenues sur un pilote expérimental conçu pour permettre la visualisation par technique laser des écoulements dans un élément du réacteur à chicanes. Pour terminer, l’extrapolation des résultats obtenus sur les pilotes étudiés à une échelle de production de 100 kg/h a été initiée, aboutissant à la proposition d’un procédé permettant la production sélective de monoglycérides via l’estérification par le glycérol, mais également la fabrication de biodiesel par la transestérification, incluant un réacteur intensifié pulsé dont la géométrie de chicanes a été optimisée, et ce afin de répondre à l’objectif initial de la thèse. / The objective of this thesis is to propose a continuous and intensified reactor to transform waste cooking oil into products that will be used in applications in the building and public works sector. This work is part of the FUI AGRIBTP, a collaborative research project whose finality is to the creation of an industrial tool for the reuse of co-products from agroindustries. The reactor must be able to handle transesterification and esterification (with methanol or with glycerol) reactions efficiently with a total flow rate of 100 kg/h. To achieve this objective, a literature review has identified a list of suitable reactor technologies for these reactions. The comparative analysis of these different technologies has led to the selection of three types of intensified reactors microstructured reactors (Corning® type), microwave reactors and oscillatory baffled reactors (NiTech® type). The performance of these reactors for transesterification and esterification reactions has then been investigated experimentally. High conversions have been obtained for transesterification and esterification with methanol reactions, thereby showing the improved performance of these intensified reactors compared with conventional reactors; however results obtained with esterification with glycerol reaction are still rather low due to limitations in operating temperature. Concerning the microwave reactor, the excellent results previously reported in the literature should be taken with care because of the inaccuracy of temperature measurements, as proven in this work. The oscillatory baffled reactor technology has been selected has the most industrially viable equipment for the considered reactions. The flexibility of this reactor, the independency of the flow rate and mixing, as well as the diameter ,which is large enough to avoid fouling caused by the quality of the feed line, are the main reasons for this choice. The commercial available system, built in glass, has nevertheless shown limitations in terms of operating temperature and pressure. As a result, further work has focused on reactor operation in a wider range of operating conditions. To do this, a collaboration with the TNO laboratory in Delft, Netherlands, was set up in order to investigate reaction performance an oscillatory baffled reactor made of stainless steel. The reaction performance obtained for esterification with glycerol is more than satisfactory, being significantly greater that that obtained in the glass Nitech reactor and even of higher quality compared to that obtained with a oscillatory helicoidal tubular reactor. In parallel to these studies, CFD simulations of flow in the reactor have enable the investigation of new baffle designs, which play a major role in the capacity to generation liquid-liquid dispersions of the immiscible reactants and in the quality of the mixing. These simulations have been compared with velocity measurements and flow patterns obtained in a transparent experimental rig using Particle Image Velocimetry. Finally, the results obtained on the pilot-scale rigs have been used to size a the oscillatory flow reactor for a total flow rate of 100 kg/h, which would be dedicated to the selective production of monoglycerides by esterification with glycerol reaction and also biodiesel production by transesterification reaction.

Dans un contexte de croissance des diagnostics préventifs, la demande en produits de contraste augmente, tandis que leur prix de revient industriel doit être revu à la baisse pour des raisons de compétitivité. La voie de synthèse d’un produit de contraste à rayons X, molécule iodée aux branchements hydrophiles, comporte plusieurs réactions : certaines sont limitées par le transfert de matière (milieu réactionnel polyphasique) ou par le transfert de chaleur (réaction exothermique) tandis que d’autres sont limitées cinétiquement. Les performances des équipements continus intensifiés permettent de favoriser les phénomènes de transfert de matière et de chaleur, tout en garantissant une bonne sélectivité et reproductibilité. La chaine de synthèse globale est repensée en vue d’un passage en mode continu intensifié et les réactions à étudier en intensification locale sont classées par ordre de priorité selon leur potentiel d’intensification. A partir d’une approche combinée alliant résultats expérimentaux et simulation, des modèles réactionnels peuvent être construits pour orienter les essais, afin de converger rapidement vers des conditions opératoires menant aux performances souhaitées. La nouvelle voie de synthèse proposée mettra ainsi en jeu une alternance entre étapes continues et discontinues, ce qui induit des difficultés en termes de gestion de procédé. Une voie de synthèse entièrement soluble permettrait de contourner les limitations d’intensification dues à la présence de solides et d’envisager la chaine de synthèse globale en continu / Preventing diagnostics are increasing and so is the demand for contrast media while its industrial cost needs to be decreased for competitiveness reasons. The synthesis route for a contrast media used in X-ray medical imaging, an iodinated molecule with hydrophilic functional groups, is made of several reactions: some of them are limited by heat transfer (exothermic reactions) or/and mass transfer (multiple-phase media) while others are kinetically limited. The use of continuous intensified equipment leads to enhanced heat and mass transfer performances while keeping good selectivity and reproducibility. The synthesis route is globally modified in the first place in order to shift from batch to continuous intensified and the reactions are classified for local intensification studies. A combined approach based on experimental measurements and simulation enables the building of reaction models which can be used as a guideline for the experiments towards finding the operating conditions that lead to the desired performances at laboratory scale. The new synthesis route production is based on an alternation between continuous and discontinuous steps, which leads to difficult production management. New prospects are created with a new hydrophilic synthesis route, where the limitations for shifting from batch to continuous due to the presence of solids are solved and the whole synthesis route can be transferred from batch to continuous mode

L’étude traite la réalisation et la validation d’un microréacteur destiné à l’électrosynthèse organique. Le système électrochimique modèle est l’oxydation du 4-méthylanisole en 4-méthoxy-benzaldéhyde-diméthylacétal. La simulation du comportement théorique d’un réacteur électrochimique travaillant à haute conversion pour l’oxydation du 4-méthylanisole a permis de déterminer les conditions pour lesquelles le réacteur apporte un meilleur rendement. Les essais expérimentaux effectués sur un microréacteur travaillant en continu et à haute conversion ont montré l’influence de la concentration de l’électrolyte support KF sur le rendement de la réaction. Pour un débit optimal de 0,2 ml min-1, une concentration initiale en réactif de 0,1 M et en appliquant un courant égal à 85% du courant théorique nécessaire à convertir totalement le réactif en une seule passe dans la cellule, la sélectivité atteint 86% (pour une conversion de 95%), alors qu’elle n’est que de 68% dans le procédé BASF. / This work concerns the realization and the validation of a microstructured reactor for organic electrosynthesis. The electrochemical reaction is the oxidation of 4-methylanisole to 4-methoxy-benzaldehyde-dimethylacetal. Theoretical behaviour simulations of high conversion thin-gap flow cell of the 4-methylanisole show conditions for which the reactor has best productivity. The experimental tests carried out on high conversion thin-gap flow reactor showed the influence of the supporting electrolyte (KF) concentration on the reaction yield. For an optimal flow rate of 0.2 ml min-1, an initial reagent concentration of 0.1 M and a current equal to 85% of the theoretical current necessary to convert all reagent, it is possible to reach selectivity of 86% with single pass high conversion (95%) , whereas selectivity on BASF process doesn’t exceed 68%.

I rapporten framgår det en termodynamisk analys för reverse water gas shift med att sammanmata etanol för att undvika det långsammaste steget i reaktionen för att producera högre alkoholer. Ifrån ett termodynamiskt perspektiv, verkar det möjligt att utgå ifrån reverse water gas shift för att producera högre alkoholer vid 100 bar med en temperatur på 300C . Reaktionen är exotermisk, vilket gynnas av det låga temperaturer och det rekommenderas höga tryck p.g.a. en mol kontraktion. Jämviktshalterna var låga, det föreslås att ta bort vatten ifrån jämvikten.  I den matematiska modellen utgick det ifrån en kedja-reaktion för att producera högre alkoholer med reverse water gas shift i processförhållanden på 10–200 bar. I modellen utfördes en senstivty-analysis för jämvikten på tryck och vattenborttagning. Genom att ta bort vatten ifrån jämvikten låg CO2 utbytet kring 95% vid 200 bar även vid låga tryck som 10 bar. Inom CO2 hydrering till högre alkoholer är det begränsat med data och reaktionsmekanismen bakom reaktionen är inte riktigt förstådd. Experimentella försök krävs för att få en mer ökad förståelse. I modellen beskrevs CO2 hydrering och resterande reaktioner som en funktion av en sigmoid. Inom litteraturstudien kom det fram till att det fanns ingen kommersiell tillgänglig membran förtillfället för att ta bort vatten inom krävande process förhållanden. Tekniken ser dock lovande ut. / In this work, a thermodynamic analysis for CO2 hydrogenation by co-feeding ethanol to higher alcohols was performed with the HSC software package. The results suggested a high pressure and a low temperature for the reaction. However, it yielded low equilibrium compositions for the higher alcohols even at a high pressure of 100 bar at 300C . Increasing the equilibrium compositions for the higher alcohols can be done by removing water.  A mathematical model was used to analyse the rate-limiting step in a process for the production of higher alcohols from CO2.  In this process, reverse water gas shift (RWGS) reaction was used to convert CO2 to CO, subsequently, the obtained CO reacts with ethanol and hydrogen to produce higher alcohols directly. The mathematical model was developed in MATLAB to simulate how the reaction could behave by feeding CO2, H2 and ethanol at different pressures ranging from 10-200 bars. The water removal effect on the equilibrium is measured in terms of CO2   conversion by achieving 95% for removing water.  The results indicated that the process can be used to convert CO2 to higher alcohols and at a lower pressure. The limiting factor for CO2 hydrogenation is the reaction mechanism, it’s an urgent problem for the development of the catalysts. In this model it was assumed to be a logistic function. The conversion of CO2 into higher alcohols is an important problem that is required to be addressed by more experimental verifications to understand the mechanism. The literature review shows that there is no available membrane for removal of water for the process currently, due to the harsh process conditions, mainly because of the membrane stability. However, membrane technology is a promising method for separation of water/organic mixtures that can be studied further in the future.

The production of methanol by use of water electrolysis and hydrogenation of carbon dioxide (Power-to-Methanol) is a promising pathway to reduce greenhouse gas emissions. The concept of process intensification and the associated utilization of an in-situ coupling of methanol synthesis with proton-conducting Solid Oxide Electrolysis Cells (H+-SOEC) is a possible way to increase the energy efficiency of this process. Based on an extensive literature research, a novel Power-to-Methanol reactor concept for a concentric in-situ-integration of a tubular H+-SOEC has been designed, manufactured and operated at the Chair of Hydrogen and Nuclear Energy at the Technische Universität Dresden. The conducted experiments served as reference points for the process simulations performed in the second part of this thesis. Here, the Power-to-Methanol process has been modelled and simulated by means of process systems engineering methods to evaluate the in-situ-process in comparison to an conventional uncoupled set-up based on planar H+-SOECs. For this task, a novel and firm H+-SOEC process model was developed and implemented. In addition, the heat integration potential and profitability of the two Power-to-Methanol concepts have been investigated by Pinch Point and Techno-Economic Analysis. On the experimental side, a proof-of-concept of the novel reactor design was demonstrated, but limitations regarding the optimal thermal profile and operational flexibility of each process were identified. Furthermore, the methanol production rate showed potential for further improvement. The simulation results have helped to understand the process characteristics and to locate optimal operation points regarding current density, temperature and pressure. In an optimised operation scenario, high energy efficiencies for both tubular in-situ and planar set-ups have been achieved, by means of harnessing the heat integration potential through exothermic H+-SOEC operation. Notwithstanding the above, planar set-ups have demonstrated to be substantially more profitable than tubular systems. This has been the first investigation on Power-to-Methanol processes based on H+-SOEC. The present work helps to identify remaining development objectives for the use of H+-SOEC and Power-to-Methanol processes in general. The results from experiments and simulations indicate the challenging utilization of tubular electrolysis cells, but also revealed new research priorities that should be addressed in the future.

Due to the remote and dispersed nature of Alberta’s oil wells, it is not economical for the energy industry to capture all of the solution gas produced and as a result, the gas is being flared and vented in significant amounts. The objective of this research is to aid in the conversion of solution gas into dimethyl ether (DME) in a remote location by designing a distillation column that purifies DME and its reaction by-products, carbon dioxide, methanol and water. In order to develop an implementable solution, the distillation equipment must fit inside of a 40-foot shipping container to be transported to remote locations. Given the size constraint of the system, process intensification is the best strategy to efficiently separate the mixture. Several process intensification distillation techniques are explored, including semicontinuous distillation, the dividing wall column (DWC) and a novel semicontinuous dividing wall column (S-DWC). The traditional semicontinuous distillation column purifies DME to fuel grade purity, however the other components are not separated to a high enough grade given the height constrain of the system. The DWC and S-DWC both purify DME to its desired purity along with producing high purity waste streams. The S-DWC purifies the reaction intermediate methanol to a grade slightly higher than the DWC and is pure enough to recycle back to the reactor. An economic comparison is made between the three systems. While the DWC is a cheaper method of producing DME, the trade-off is the purity of the methanol produced. Overall, this research shows that it is possible to purify DME and its reaction by-products in a 40-foot distillation column at a cost that is competitive with Diesel. / Thesis / Master of Applied Science (MASc)

Process industries are cornerstones in today’s industrialized society. They contribute significantly in the manufacturing of various goods and products that are used in our day-to-day life. Our society’s paradigm of consumerism accompanied by a rise in global population drives an ever increasing demand for goods. One of many strategies developed to satisfy these demands and at the same time improve production capabilities is known as process intensification. As an example, this can be accomplished by implementation of devices using the principle of hydrodynamic and acoustic cavitation. High-intensity cavitation in the ultrasonic range can change the physical and chemical properties of a wide range of substances and hence, improve the production rate or quality. Despite the generally accepted benefits of hydrodynamic and acoustic cavitation, applications in the process industry are yet limited. The reasons are that the method requires extensive optimization, which depends on multiple process parameters and encounters problem in the implementation on a larger scale. Scalable cavitation reactor concepts for industrial applications need to meet challenges like stability and robustness, energy efficiency and high flow rates. This thesis focuses on the methodology for the design and optimization of a flow through cavitation reactor. An ultrasound reactor concept has been developed and tested for two different applications: i) Fibrillation processes typical for paper and pulp industry; ii) Metal leaching of mineral concentrates. Simulations were carried out using a commercially available software for multiphysics modeling which combines acoustics, structural dynamics, fluid dynamics and piezoelectrics. However, the optimization procedure requires extensive experimental work in parallel with multi-physical simulations. In general, the application leads to hydrodynamic initiation of small gas bubbles in the fluid to be excited and collapsed by high-intensity ultrasound. This transient collapse of the cavitation bubbles provides both mechanical and chemical effect on materials. The developed reactor has a power conversion efficiency of 36% in batch mode and is well suited for a scale-up. In flow-through mode, the cavitation effect improves extensively and provides stable results. Energy efficiency requires hydrodynamic initiation of cavitation bubbles, high acoustic cavitation intensity by multiple excitation frequencies adapted to the optimized reactor geometry, as well as optimal process pressure and temperature with respect to the materials to be treated. The impact of flow conditions and hydrodynamic cavitation is significant and almost doubles the yield at the same ultrasonic power input. In the case of fibrillation of cellulose fibers, results obtained indicate that generated cavitation intensity changes the mechanical properties of the fiber wall. In the case of leaching, experiments show that six hours of exposure gave a 57% recovery of tungsten from the scheelite concentrate at 80°C and atmospheric pressure. Future research will focus on different types of excitation signals, extended reactor volume, increased flow rates and use of a higher process temperature.

Il est démontré que dans de nombreux procédés de transformation de la matière, les dégradations entropiques (et les consommations énergétiques qui en découlent) peuvent être minimisées en répartissant les flux d’énergies dans le volume plutôt qu’aux bornes du système (exemple de la distillation diabatique). Cependant la réalisation et la gestion de profils thermiques contrôlés (tels que des gradients thermiques et des étagements de température maîtrisés) dans les appareils compactes ne sont pas très souvent réalisées parce que souvent complexes et coûteuses (batterie d’échangeurs, gestion des fluides). Cette difficulté technologique affecte non seulement les performances énergétiques et les efficacités de transformation des appareils classiques de grandes tailles, mais aussi les réacteurs microstructurés dont les faibles dimensions internes associées à la grande conductivité thermique du matériau constituant les parois du contacteur entraînent souvent l’homogénéité thermique de l’appareil au détriment de la gestion des gradients thermiques. Par ailleurs, les garnissages utilisés dans les séparateurs sont de formes très complexes dans lesquels il est difficile de faire à la fois de la structuration thermique et hydrodynamique. Les systèmes microstructurés basés sur des géométries à plaques semblent offrir une possibilité intéressante de structuration thermique (contrôle et modulation de flux énergétiques pour l’obtention d’un profil thermique spécifique) et hydrodynamique (contrôle des transferts de matière, des temps de séjour, des pertes de charges etc.). Dans cette thèse, les réflexions menées sur ces verrous technologiques ont conduit à la conception d’un microcontacteur à film tombant. Ce microprocédé a été caractérisé d’un point de vue thermique et hydrodynamique. Une étude de faisabilité sur le potentiel de ce microcontacteur à séparer un mélange binaire d’alcools (ethanol/n-propanol) a été menée, ses performances ont été expérimentalement évaluées d’un point de vue qualitatif (pureté du distillat et du soutirat) et quantitatif (rapports des débits entrant et sortant), mais aussi en intégrant la notion d’exergie compositionnelle, également appelée puissance de séparation / In many processes of mass transformation, entropic degradations (and energy consumptions which results from) can be minimized by distributing heat flows in all process volume rather than boundaries (example: diabatic distillation). However it is difficult to control and impose thermal gradients on small scales because of their complexity and high costs (exchangers, fluids). This technological difficulty affects not only the performances and energy efficiencies of conventional devices (macro scales) but also small devices (e.g. microstructured reactors). Indeed, compact equipments with small dimensions generate some difficulties. First, the driving force inducing liquid flow by gravity is very small. Second, small size and high thermal conductivity of the material induce thermal homogeneity instead of managing temperature gradients in the system. In many separators, the used packing material has complex forms that make difficult thermal and hydrodynamic structurations. Microstructured devices, based on microchannel plate technologies, offer an interesting possibility of thermal structuration (control and modulation of energy fluxes) and hydrodynamics control (e.g. mass transfer, residence times, pressure drop etc). In this thesis, many discussions on these technological barriers led to the design of a new microstructured falling film contactor. The aim of the present work is to study heat transfer phenomena and liquid hydrodynamics in this device and, investigates the separation feasibility of a binary mixture of ethanol and n-propanol. Microcontactor performances were experimentally evaluated in terms of quality (bottom and top concentrations) and quantity (bottom and top flow rate ratios). To fully characterize contactor performances, the separation power concept (also called compositional exergy) was integrated

The exploitation of lignocellulosic materials with the aim of producing high value-added products will potentially counteract concerns related to the depletion of fossil resources or exponential population growth. Bioethanol produced from lignocellulosic agriculture residue exhibits promising alternative to the petroleum-based fossil fuel which reduces net emission of greenhouse gases (GHG). But, due to certain technological barriers, the large scale production of lignocellulosic bioethanol has not been successfully commercialized. In this thesis, membrane filtration as an energy efficient separation process with low environmental impact was chosen with a possibility of improvement. Interconnected multi-staged microfiltration submerged membrane bioreactors (MBRs) set-up has been applied in order to separate suspended solids, obtain high concentration of yeast inside the bioreactor, and recover particle-free ethanol stream in a continuous high productivity process. The MBRs were effectively optimized comparing to different constant permeate fluxes of 21.9 LMH, 36.4 LMH, and 51 LMH. Moreover, membrane bioreactor performed effectively at low flux 21.9 LMH up to 262 h comparing to other applied fluxes. During continuous hydrolysis, membrane showed the capability of lignin recovery nearly 70% of medium SS content in all applied flux. Although the conversion rate of total sugars by concentrated cells were similar, yeast cells proved the capability of inhibitor tolerance, and to co-utilize 100% of glucose and up to 89% of xylose, resulted in bioethanol volumetric productivity of 0.78 g ethanol/l per hour 1.3 g ethanol/l per hour and 1.8 g ethanol/l per hour for 21.9 LMH, 36.4 LMH, and 51 LMH respectively. Moreover, the effect of different factors such as filtration flux, medium quality and backwashing on fouling and cake-layer formation in submerged MBRs during continuous filtration was thoroughly studied.