Dynamic modeling of fouling over multiple biofuel production cycles in a membrane reactor

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Thien An Huynh ◽  
Edwin Zondervan
Keyword(s):  
Membrane Fouling ◽  
Membrane Reactor ◽  
Membrane Filtration ◽  
Reaction System ◽  
Operating Conditions ◽  
Biodiesel Production ◽  
Biofuel Production ◽  
Cyclic Behavior ◽  
Permeate Flux ◽  
Production Cycles

Abstract In this paper, a novel mathematical model that combines a membrane filtration model, component balances and reaction kinetics models for an intensified separation-reaction process in membrane reactor producing biofuels was developed. A unique feature is that the proposed model can capture the dynamics of membrane fouling as function of both reversible and irreversible fouling; which leads to cyclic behavior. Fouling leads to the decline of the reactor productivity. With an appropriate fouling-model, the operational strategy can be optimized. In the case study of biodiesel production, the developed model was validated with experimental data. The model was in good agreement with the data, where R-squared are 0.96 for the permeate flux and 0.95 for the biodiesel yield. From a further analysis, the efficiency of membrane reaction system in term of productivity can be significantly improved by changing the backwashing frequency under specific operating conditions. As the backwashing frequency increased eight times, the biodiesel yield increased to more than two to three times before the permeate flux dropped under a predetermined limit due to the increase of irreversible membrane fouling.

scholarly journals Direct Membrane Filtration for Wastewater Treatment Using an Intermittent Rotating Hollow Fiber Module

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1836
Author(s):  
Ignacio Ruigómez ◽  
Enrique González ◽  
Luis Rodríguez-Gómez ◽  
Luisa Vera
Keyword(s):  
Hollow Fiber ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Colloidal Particles ◽  
Rotation Speed ◽  
Operating Conditions ◽  
Permeate Flux ◽  
Cake Filtration ◽  
Fouling Control ◽  
Continuous Rotation

Direct membrane filtration of municipal wastewater has attracted a considerable interest in recent years. Preventing severe membrane fouling is a crucial issue in the process development. This paper aims to assess the effectiveness of a rotating hollow fiber module in enhancing fouling control. The effect of rotation speed, intermittence and permeate flux was studied in short-term tests at lab-scale. A combined filtration model considering residual fouling, intermediate pore blocking and cake filtration was used to analyze the effect of the shear induced by rotation. Results showed a significant flux improvement by increasing rotation shear stress and showed a nearly linear correlation between the threshold flux (ranged between 12 and 32 L·h−1·m−2) and the rotation speed. A proper rotation intermittence (10/15 on/off) was found, which may maintain a fouling control comparable to that achieved for continuous rotation. For a given energy demand, the optimal operating conditions involve high speeds (≥180 rev·min−1) with low to moderate intermittences. Analyzing the relative contribution of the different feedwater fractions on membrane fouling, colloidal particles and macromolecules were found to be the main contributors.

scholarly journals Membrane Fouling Controlled by Adjustment of Biological Treatment Parameters in Step-Aerating MBR

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 553
Author(s):  
Dimitra C. Banti ◽  
Manassis Mitrakas ◽  
Petros Samaras
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Municipal Wastewater ◽  
Operating Conditions ◽  
Transmembrane Pressure ◽  
Aeration Tank ◽  
Filamentous Bacteria ◽  
Membrane Performance ◽  
Low Concentrations ◽  
Fouling Reduction

A promising solution for membrane fouling reduction in membrane bioreactors (MBRs) could be the adjustment of operating parameters of the MBR, such as hydraulic retention time (HRT), food/microorganisms (F/M) loading and dissolved oxygen (DO) concentration, aiming to modify the sludge morphology to the direction of improvement of the membrane filtration. In this work, these parameters were investigated in a step-aerating pilot MBR that treated municipal wastewater, in order to control the filamentous population. When F/M loading in the first aeration tank (AT1) was ≤0.65 ± 0.2 g COD/g MLSS/d at 20 ± 3 °C, DO = 2.5 ± 0.1 mg/L and HRT = 1.6 h, the filamentous bacteria were controlled effectively at a moderate filament index of 1.5–3. The moderate population of filamentous bacteria improved the membrane performance, leading to low transmembrane pressure (TMP) at values ≤2 kPa for a great period, while at the control MBR the TMP gradually increased reaching 14 kPa. Soluble microbial products (SMP), were also maintained at low concentrations, contributing additionally to the reduction of ΤΜP. Finally, the step-aerating MBR process and the selected imposed operating conditions of HRT, F/M and DO improved the MBR performance in terms of fouling control, facilitating its future wider application.

scholarly journals Effects of tannic acid on membrane fouling and membrane cleaning in forward osmosis

2017 ◽  
Vol 76 (11) ◽  
pp. 3160-3170 ◽  
Author(s):  
Wanzhu Zhang ◽  
Lin Wang ◽  
Bingzhi Dong
Keyword(s):  
Tannic Acid ◽  
Calcium Ions ◽  
Membrane Fouling ◽  
Driving Forces ◽  
Forward Osmosis ◽  
Operating Conditions ◽  
Permeate Flux ◽  
Membrane Cleaning ◽  
Draw Solution ◽  
Cleaning Methods

Abstract The fouling behavior during forward osmosis (FO) was investigated. Tannic acid was used as a model organic foulant for natural organic matter analysis since the main characteristics are similar, and calcium ions were added at different concentrations to explore the anti-pollution capability of FO membranes. The initial permeate flux and calcium ions strength were varied in different operating conditions to describe membrane fouling with membrane cleaning methods. The observed flux decline in FO changed dramatically with the type of foulant and the type of draw solution used to provide the osmotic driving force. Calcium ions aggravated membrane fouling and decreased transmembrane flux. Membrane cleaning methods included physical and physicochemical approaches, and there was no obvious difference among the typical cleaning methods (i.e., membrane flushing with different types of cleaning fluids at various crossflow velocities and backwashing with varying osmotic driving forces) with respect to flux recovery. Ultrasonic cleaning damaged the membrane structure and decreased permeate flux, and reverse diffusion of salt from the draw solution to the feed side accelerated after cleaning.

scholarly journals Performance of a novel recycling magnetic flocculation membrane filtration process for tetracycline-polluted surface water treatment

2017 ◽  
Vol 76 (2) ◽  
pp. 490-500 ◽  
Author(s):  
Yufei Wang ◽  
Hui Jia ◽  
Hongwei Zhang ◽  
Jie Wang ◽  
Wenjin Liu
Keyword(s):  
Surface Water ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Average Particle Size ◽  
Quality Parameters ◽  
Average Particle ◽  
Permeate Flux ◽  
Personal Care Product ◽  
Surface Water Treatment ◽  
Scale Experiment

A recycling magnetic flocculation membrane filtration (RMFMF) process integrating circulating coagulation, magnetic enhanced flocculation and membrane filtration was investigated for the treatment of surface water micro-polluted by tetracycline, a typical pharmaceutical and personal care product. A bench-scale experiment was conducted and several water quality parameters including turbidity, ultraviolet absorbance at 254 nm (UV254), total organic carbon and tetracycline concentration were evaluated, taking coagulation membrane filtration and magnetic flocculation membrane filtration processes as reference treatments. The experimental results showed that at the optimum doses of 20 mg·L−1 ferric chloride (FeCl3), 4 mg·L−1 magnetite (Fe3O4) and 6 mg·L−1 reclaimed magnetic flocs in RMFMF processes, removal efficiencies of above evaluated parameters ranged from 55.8% to 92.9%, which performed best. Simultaneously, the largest average particle size of 484.71 μm and the highest fractal dimension of 1.37 of flocs were achieved, which did not only present the best coagulation effect helpful in enhancing the performance of removing multiple contaminants, but also lead to the generation of loose and porous cake layers favouring reduced permeate flux decline and membrane fouling.

scholarly journals In-Situ Ultrasound-Assisted Control of Polymeric Membrane Fouling

2021 ◽  
Author(s):  
Westphalen Dornelas Camara Heloisa
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Separation ◽  
Feed Solution ◽  
Solution Concentration ◽  
Polymeric Membrane ◽  
Permeate Flux ◽  
Latex Paint ◽  
Water And Wastewater Treatment ◽  
Maximum Increase

Membrane separation processes have been more widely applied to industrial activities, especially in water and wastewater treatment. However, there are still challenges associated to the use of membranes. Concentration polarization and fouling can cause significant permeate flux decay during the filtration process, hindering its efficiency and increasing cost. Among many strategies, the combination of membrane filtration with ultrasound (US) application has shown promising results in reducing membrane fouling. The main goal of this research was to identify the effect of US frequency, US power intensity and feed solution concentration on permeate flux during ultrafiltration of simulated latex paint effluent. Maximum increase in permeate flux of 19.7% was obtained by applying 20 kHz and 0.29 W.cm-2 to feed solution with 0.075 wt.% of solid concentration. The effect of feed flow rate was analyzed showing that an increase in feed flowrate is not beneficial to the fouling minimization process. Overall, the application of US improves permeate flux by reducing fouling of ultrafiltration polymeric membrane.

scholarly journals Application of Coagulation–Membrane Rotation to Improve Ultrafiltration Performance in Drinking Water Treatment

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 643
Author(s):  
Hongjian Yu ◽  
Weipeng Huang ◽  
Huachen Liu ◽  
Tian Li ◽  
Nianping Chi ◽  
...  
Keyword(s):  
Shear Stress ◽  
Drinking Water ◽  
Water Treatment ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Drinking Water Treatment ◽  
Permeate Flux ◽  
Organic Removal ◽  
Cake Layer ◽  
The Impact

The combination of conventional and advanced water treatment is now widely used in drinking water treatment. However, membrane fouling is still the main obstacle to extend its application. In this study, the impact of the combination of coagulation and ultrafiltration (UF) membrane rotation on both fouling control and organic removal of macro (sodium alginate, SA) and micro organic matters (tannic acid, TA) was studied comprehensively to evaluate its applicability in drinking water treatment. The results indicated that membrane rotation could generate shear stress and vortex, thus effectively reducing membrane fouling of both SA and TA solutions, especially for macro SA organics. With additional coagulation, the membrane fouling could be further reduced through the aggregation of mediate and macro organic substances into flocs and elimination by membrane retention. For example, with the membrane rotation speed of 60 r/min, the permeate flux increased by 90% and the organic removal by 35% in SA solution, with 40 mg/L coagulant dosage, with an additional 70% increase of flux and 5% increment of organic removal to 80% obtained. However, too much shear stress could intensify the potential of fiber breakage at the potting, destroying the flocs and resulting in the reduction of permeate flux and deterioration of effluent quality. Finally, the combination of coagulation and membrane rotation would lead to the shaking of the cake layer, which is beneficial for fouling mitigation and prolongation of membrane filtration lifetime. This study provides useful information on applying the combined process of conventional coagulation and the hydrodynamic shear force for drinking water treatment, which can be further explored in the future.

scholarly journals Challenges of Membrane Technology in Biorefineries

2020 ◽  
Vol 24 (3) ◽  
Author(s):  
Lukka Thuyavan Yogarathinam ◽  
Ahmad Fauzi Ismail ◽  
Pei Sean Goh ◽  
Arthanareeswaran Gangasalam
Keyword(s):  
Membrane Fouling ◽  
Membrane Separation ◽  
Membrane Technology ◽  
Membrane Reactors ◽  
Biodiesel Production ◽  
Biofuel Production ◽  
Polymeric Membrane ◽  
Separation Processes ◽  
Significant Control ◽  
Membrane Engineering

Membrane separation processes have been deployed for downstream applications in biorefineries. This article discusses the challenges of membrane technology in purification of biofuels such as bioethanol, biodiesel and biogas. The significance of membrane technology are discussed towards the fractionation of lignocellulosic biomass for biofuel production.  The membrane reactors for biodiesel production were also studied. Limitation with respect to each individual processes on biofuel purification were also reported. The major limitation in membrane separation are membrane fouling and concentration polarization. Membrane engineering and process optimization are the viable tools to enhance the performance of membrane. Recently, inorganic nanofillers has significant control in alteration of polymeric membrane characteristics for the improvement of permeability and selectivity. This article would be an insight for researchers to understand the challenges of biorefinery membrane separation.

scholarly journals Assessing Enzyme Immobilization on Reverse Asymmetric Membranes and Biocatalytic Reactor Performance

2021 ◽  
Author(s):  
Amirah Syakirah Zahirulain ◽  
Fauziah Marpani ◽  
Syazana Mohamad Pauzi ◽  
'Azzah Nazihah Che Abd Rahim ◽  
Hang Thi Thuy Cao ◽  
...  
Keyword(s):  
Enzyme Immobilization ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Separation ◽  
Permeate Flux ◽  
Reactor Performance ◽  
Membrane Performance ◽  
Reverse Mode ◽  
Substrate Conversion ◽  
Product Separation

Abstract Integration of membrane filtration and biocatalysis has appealing benefits in terms of simultaneous substrate conversion and product separation in one reactor. Nevertheless, the interaction between enzymes and membrane is complex and the mechanism of enzyme docking on membrane is similar to membrane fouling. In this study, focus is given on the assessment of enzyme immobilization mechanism on reverse asymmetric polymer membrane based on the permeate flux data during the procedure. Evaluation of membrane performance in terms of its permeability, fouling mechanisms, enzyme loading, enzyme reusability and biocatalytic productivity were also conducted. Alcohol Dehydrogenase (EC 1.1.1.1), able to catalyze formaldehyde to methanol with subsequent oxidation of NADH to NAD was selected as the model enzyme. Two commercial, asymmetric, flat sheet polymer membranes (PES and PVDF) were immobilized with the enzyme in the reverse mode. Combination of concentration polarization phenomenon and pressure driven filtration successfully immobilized almost 100% of the enzymes in the feed solutions. The biocatalytic membrane reactor recorded more than 90% conversion, stable permeate flux with no enzyme leaching even after 5 cycles. The technique showing promising results to be expanded to continuous membrane separation setup for repeated use of enzymes.

Influence of extracellular polysaccharides (EPS) produced by two different green unicellular algae on membrane filtration in an algae-based biofuel production process

2014 ◽  
Vol 69 (9) ◽  
pp. 1919-1925 ◽  
Author(s):  
Takaki Matsumoto ◽  
Hiroshi Yamamura ◽  
Jyunpei Hayakawa ◽  
Yoshimasa Watanabe ◽  
Shigeaki Harayama
Keyword(s):  
Green Algae ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Specific Growth ◽  
Biofuel Production ◽  
Extracellular Polysaccharides ◽  
Transmembrane Pressure ◽  
Unicellular Algae

In the present study, two strains of green algae named S1 and S2, categorized as the same species of Pseudo-coccomyxa ellipsoidea but showing 99% homology, were cultivated under the same conditions and filtrated with a microfiltration membrane. On the basis of the results of the extracellular polysaccharides (EPS) characteristics of these two green algae and the degree of fouling, the influence of these characteristics on the performance of membrane filtration was investigated. There was no difference in the specific growth rate between the S1 and S2 strains; however, large differences were seen in the amount and quality of EPS between S1 and S2. When the S1 and S2 strains were filtered with a membrane, the trend in the increase in transmembrane pressure (TMP) was quite different. The filtration of the S1 strain showed a rapid increase in TMP, whereas the TMP of the filtration of the S2 strain did not increase at all during the operation. This clearly demonstrated that the characteristics of each strain affect the development of membrane fouling. On the basis of the detailed characterization of solved-EPS (s-EPS) and bound-EPS (b-EPS), it was clarified that s-EPS mainly contributed to irreversible fouling for both operations and the biopolymer-like organic matter contained in b-EPS mainly contributed to reversible fouling.

scholarly journals Separation and Concentration of Health Compounds by Membrane Filtration

2006 ◽  
Vol 2 (3) ◽  
Author(s):  
Zaid S Saleh ◽  
Roger Stanley ◽  
Reginald Wibisono
Keyword(s):  
Phenolic Compounds ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Apple Juice ◽  
Feed Solution ◽  
Operating Conditions ◽  
Sugar Concentration ◽  
Process Efficiency ◽  
Phenolic Fraction ◽  
Quercetin Derivatives

The performance of nano-filtration (NF) for separating phenolic compounds from sugar in apple juice was studied using 1 and 0.25 kDa molecular weight cut-off (MWCO) spiral wound membranes. If these phenolic compounds could be recovered, they could stabilize the juice from haze formation or be added as antioxidants to foods and beverages in order to increase their health properties. Batch experiments were conducted on a pilot scale rig using a diluted clear apple juice concentrate. For the 1 kDa MWCO membrane, the research determined the effect of operating conditions on process efficiency and membrane fouling. The concentration of polyphenolics on the retentate side increased by a factor of up to 4 and the sugar concentration increased by 1.5 times under optimum conditions of lower temperature (30oC), acidic pH (2), lower trans-membrane pressure (5 Bar) and higher initial sugar concentration (20 oBrix). Despite the increase in polyphenolics in the retentate, there was little difference in the phenolic composition between retentate and permeate solutions. As the molecular mass of the rejected phenolics was smaller than the membrane cut-off, this indicated that the rejection was related to the formation of a secondary membrane formed as a result of fouling. A mass balance of polyphenolics in the final retentate and permeate compared with the initial feed solution indicated that up to 4.3 gm of polyphenolics were bound per m2 of membrane. The permeate solutions collected from the 1 kDa MWCO membrane were then filtered using a 0.25 kDa MWCO membrane. Most phenolic compounds were retained by the membrane and the concentration increased by a factor of up to 2. Catechin, rutin, phloridzin and quercetin derivatives were concentrated on the retentate side. However, around 20 - 40% of chlorogenic acid and epicatechin was observed on the permeate side. It is concluded that membrane separation represents a potentially efficient and cost-effective technology to separate the phenolic fraction of fruit juice in a form suitable for use as a functional ingredient.

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