Cross-flow Membrane Research Articles

Multi-phenomenal macroscopic investigation of cross-flow membrane flux in microfiltration of oil-in-water emulsion, experimental & computational

The primary reasons for reduction of permeate flux in membrane separation processes are cake layer formation and concentration polarization phenomenon. Although pore blocking affects cross membrane flux, but its influence has been neglected in the previous numerical studies. In present study, macroscopic 2D CFD modeling and experimental survey in treatment of oil-in-water emulsion with cellulose acetate (CA) membrane in a cross-flow microfiltration are presented. In order to investigate the simultaneous effects of both phenomena of cake formation and pore blocking, an oil droplet size distribution based on experimental measurements is considered in the modeling. The pore blocking is simulated macroscopically in the microfiltration process. As a main result, by considering membrane governing equations into a 2D domain, i.e. pore blocking phenomenon, the simulation prediction can improve about 15%. Effects of various operational conditions such as trans-membrane pressure (TMP), cross-flow velocity (CFV) and feed oil concentration on permeate flux and process performance are also evaluated. By increasing feed oil concentration from 1000 to 10000 mg/L, the maximum value of oil concentration on membrane surface increases 9.68 times and by increasing CFV from 0.5 to 1.1 m/s, the maximum thickness of concentration polarization (CP) layer decreases 14%. Comparison of model predictions against experimental data for permeate flux indicates acceptable accuracies with a maximum error of 4.62%.

Preparation of highly monodispersed emulsions by swirl flow membrane emulsification using Shirasu porous glass (SPG) membranes – A comparative study with cross-flow membrane emulsification

Highly monodispersed oil-in-water (O/W) emulsions with narrow droplet size distribution (span) were prepared using swirl flow membrane emulsification at high dispersed phase fluxes (up to 15.6 m3/m2h) greater than the droplet dripping mode of droplet formation and at very low concentrations of sodium dodecyl sulphate (SDS) surfactant (as low as 0.01 wt.%). The swirl flow membrane emulsification method involved the generation of a centrifugal kind of flow in the continuous phase. This exerted higher radial shear stresses on the membrane wall which overcame the higher kinetic energy of the dispersed phase emerging from membrane pores when high dispersed phase fluxes were applied. The emulsions droplet size (d50) was in the narrow range of 30.2 to 35 and span of 0.239 to 0.34 for swirl flow ME as compared to the highly polydispersed emulsions with d50 in the range of 38.8–43.5 μm and span in range of 0.65–2.32 for the cross-flow ME method, for the 9.6 μm SPG membrane.

Layered organization of anisometric cellulose nanocrystals and beidellite clay particles accumulated near the membrane surface during cross-flow ultrafiltration: In situ SAXS and ex situ SEM/WAXD characterization

The structural organization of the concentration polarization layer (CPL) during the cross-flow membrane separation process of anisometric aqueous suspensions of colloidal cellulose nanocrystals and beidellite clay particles has been characterized by in situ time-resolved small-angle X-ray scattering (SAXS). Dedicated cross-flow filtration cells were implemented on the ID02 TRUSAXS beamline at the European Synchrotron Radiation Facility (Grenoble, France). From the analysis of the scattered intensities and structure factors of particles in the CPL, both the concentration profiles ɸ(Δz,Δt) and anisotropic structural organization have been characterized as a function of filtration time (Δt) and distance from the membrane surface (Δz). Remarkably, a coupling between concentration and anisotropy was revealed and modeled using either a simple or stretched exponential trend for rod- or disk-like systems, respectively. Using a simple filtration model, the time evolution of the deposit thickness, membrane resistance and specific resistance of the deposit, deduced from an analysis of the normalized concentration profiles, allowed directly predicting the rapid decay of permeate flux associated to the exponential growth of concentration and anisotropic organization inside the CPL. Ex situ scanning electron microscopy (SEM) observations and wide-angle X-ray diffraction (WAXD) analyses performed on dried deposits parallel and perpendicular to the membrane surface revealed well-defined layered structures from nanometer to micrometer length scales.

Use of a membrane module for semi-direct air evaporative cooling

This study discusses the use of a membrane module for semi-direct evaporative air cooling. A cross-flow membrane module was used to carry out this air treatment process. For such a flow, it was proposed to describe and solve the heat and mass transfer model as a one-dimensional problem. The mathematical model was used to determine the moisture content and air temperature at the outlet from the module and the temperature of the circulating water. Results obtained using the proposed model are in good agreement with the experimental data. The relative error for the air temperature at the module outlet did not exceed 0.5%. For the moisture content, the relative error did not exceed 4%. For the circulating water temperature, the relative error did not exceed 0.6%. This paper also discusses the heating efficiency of the evaporative cooling process. Methods for determining the unit cooling indicator and the energy efficiency ratio are also proposed.

Manganese oxide integrated catalytic ceramic membrane for degradation of organic pollutants using sulfate radicals

Membrane separation and advanced oxidation processes (AOPs) have been respectively demonstrated to be effective for a variety of water and/or wastewater treatments. Innovative integration of membrane with catalytic oxidation is thus expected to be more competing for more versatile applications. In this study, ceramic membranes (CMs) integrated with manganese oxide (MnO2) were designed and fabricated via a simple one-step ball-milling method with a high temperature sintering. Functional membranes with different loadings of MnO2 (1.67%, 3.33% and 6.67% of the total membrane mass) were then fabricated. The micro-structures and compositions of the catalytic membranes were investigated by a number of advanced characterisations. It was found that the MnO2 nanocatalysts (10–20 nm) were distributed uniformly around the Al2O3 particles (500 nm) of the membrane basal material, and can provide a large amount of active sites for the peroxymonosulfate (PMS) activation which can be facilitated within the pores of the catalytic membrane. The catalytic degradation of 4-hydroxylbenzoic acid (HBA), which is induced by the sulfate radicals via PMS activation, was investigated in a cross-flow membrane unit. The degradation efficiency slightly increased with a higher MnO2 loading. Moreover, even with the lowest loading of MnO2 (1.67%), the effectiveness of HBA degradation was still prominent, shown by that a 98.9% HBA degradation was achieved at the permeated side within 30 min when the initial HBA concentration was 80 ppm. The stability and leaching tests revealed a good stability of the catalytic membrane even after the 6th run. Electron paramagnetic resonance (EPR) and quenching tests were used to investigate the mechanism of PMS activation and HBA degradation. Both sulfate radicals (SO4•−) and hydroxyl radicals (•OH) were generated in the catalytic membrane process. Moreover, the contribution from non-radical process was also observed. This study provides a novel strategy for preparing a ceramic membrane with the function of catalytic degradation of organic pollutants, as well as outlining into future integration of separation and AOPs.

Development of an axisymmetric parallel solution algorithm for membrane separation process

A novel parallel technique that couples the lattice–Boltzmann method and a finite volume scheme for the prediction of concentration polarisation and pore blocking in axisymmetric cross-flow membrane separation process is presented. The model uses the Lattice–Boltzmann method to solve the incompressible Navier–Stokes equations for hydrodynamics and the finite volume method to solve the convection–diffusion equation for solute particles.Concentration polarisation is modelled for micro–particles by having the diffusion coefficient defined as a function of particle concentration and shear rate. The model considers the effect of an incompressible cake formation. Pore blocking phenomenon is predicted for filtration membrane fouling by using the rate of particles arriving at the membrane surface.The simulation code is parallelised in two ways. Compute Unified Device Architecture (CUDA) is used for a cluster of graphical processing units (GPUs) and Message Passing Interface (MPI) is utilised for a cluster of central processing units (CPUs), with various parallelisation techniques to optimise memory usage for higher performance. The proposed model is validated by comparing to analytical solutions and experimental result.

Purifying surface water contaminated with industrial failure using direct contact membrane distillation

Events of acute pollution – as the break of dams, once reached water bodies can difficult or even impair the standard surface water treatments, provoking water shortage. As a mean to guarantee water during these emergency situations, the establishment of decentralized and advanced water treatment routes is a feasible alternative. Membrane distillation (MD) is a technology reported by the literature as a robust process that presents better results for arsenic rejection than RO. Hence, this work aimed to assess aspects as the effect of feed turbidity, temperature and cross-flow velocity, fouling characteristics, chemical cleaning, and membrane ageing for the treatment of surface water contaminated with iron industrial failure. To this, direct contact membrane distillation was used, aiming to produce potable water. Results indicated that at 70 °C and 0.18 m/s the system presented its best energy efficiency without compromising the permeate quality. The maximum flux decline was 30%, caused mainly by the formation of a layer composed of silica, alumina and hematite. Physical cleaning was effective on removing the fouling layer given its low adherence to the membrane surface. In addition, similar results were found after 210 of continuous exposure to the solution. In this case, a decrease in both membrane permeability and retention was reverted by cleaning with DI water, which indicates a very low chemical interaction between metals oxide and the membrane surface. Seeing the results, it can be inferred that MD is an attractive alternative to water treatment after the break of mining dams, and could also be easily applied to other emergency scenarios.

Transient performance of coupled heat and mass transfer in cross-flow hollow fiber membrane module for air dehumidification

Membrane-based liquid desiccant dehumidification has great advantages over traditional method, particularly in avoiding liquid droplets moving into the process air. This paper proposes a simple model to predict the transient performance of the hollow fiber membrane-based dehumidification module. To simplify the fiber-to-fiber influence, the modeled membrane module is assumed to be a parallel-plates heat mass exchanger. The model has been calibrated and validated with a transient experiment reasonably well. Impacts of various parameters on the transient performance were studied by using the proposed model. The results show that the variation of air temperature is more significant than air humidity. The absorption heat of water vapor is the main resistance of heat and mass transfer. It initially restricts the growth of the cooling effectiveness, and then limits the driving potential for moisture transfer. Therefore, it brings the dehumidification effectiveness down. It is found that reducing the heat capacity rate ratio can reduce the equilibrium time, and increase the cooling and dehumidification effectiveness. The high packing density increases the dehumidification effectiveness with a negligible effect of somewhat drop in cooling effectiveness. By contrast, the geometry of the fiber packing arrangement has little influence on dynamic performance of the module formed by numerous fibers. The membrane module can fit the change of weather conditions by varying solution temperature on the inlet of the dehumidifier with the help of this dynamic model. The cooling and dehumidification effectiveness also increase to improve heat and mass transfer performance of the dehumidifier under the adjustment.

Three-dimensional multiphase flow modeling of membrane humidifier for PEM fuel cell application

Purpose In this paper, a single module of cross-flow membrane humidifier is evaluated as a three-dimensional multiphase model. The purpose of this paper is to analyze the effect of volume flow rate, dry temperature, dew point wet temperature and porosity of gas diffusion layer on the humidifier performance.Design/methodology/approach In this study, one set of coupled equations are continuity, momentum, species and energy conservation is considered. The numerical code is benchmarked by the comparison of numerical results with experimental data of Hwang et al.Findings The results reveal that the transfer rate of water vapor and dew point approach temperature (DPAT) increase by increasing the volume flow rate. Also, it is found that the water recovery ratio (WRR) and relative humidity (RH) decrease with increasing volume flow rate. In addition, all mixed results decrease with increasing dry side temperature especially at high volume flow rates and this trend in high volume flow rates is more sensible. Although the transfer rate of water vapor and DPAT increases with increasing the wet inlet temperature, WRR and RH reduce. Increasing dew point temperature effect is more sensible at the wet side is compared with the dry side. The humidification performance will be enhanced with increasing diffusion layer porosity by increasing the wet inlet dew point temperature, but has no meaningful effect on other operating parameters. The pressure drop along humidifier gas channels increases with rising flow rate, consequently, the required power of membrane humidifier will enhance.Originality/value According to previous studies, the three-dimensional numerical multiphase model of cross-flow membrane humidifier has not been developed.

Control pairings of a deoiling membrane crossflow filtration process based on theoretical and experimental results

Despite membrane filtration being extensively used in many industries, it is not widely used for offshore produced water treatment because of the large installation footprint required. Commonly, PID-controllers are deployed to maintain the operating conditions that minimize fouling, but the design of the controllers is rarely highlighted. The interaction between the deployed controllers can cause undesired performance and even instability. In this study, the relative gain array method was used to find the set of control pairings that minimized the interaction between the control loops. Experimental results showed that by accounting for cross couplings in the design phase of the control system, the controllers performance in terms of reference tracking can be improved significantly. By improving the reference tracking and disturbance rejection capabilities of the filtration system, the selected operating point which minimizes fouling growth, can be maintained consistently subject to disturbances in terms of varying feed flow rate. Better tracking of the operating point can reduce membrane resistance, and consequently reducing the operating cost.

Fabrication of silver nanoparticles decorated polysulfone composite membranes for sulfate rejection

The tactic of embedding functional nanomaterials into ultrafiltration (UF) membranes has been investigated in order to augment the integrated properties of the hybrid membranes. Mixing of hydrophilic inorganic nanoparticles or nanofillers into the polymeric membranes to form organic-inorganic nanocomposite membranes were found to be quite effective in improving membrane hydrophilicity. In the present study, polysulfone (PSf) membrane of three different compositions (9, 12, 18 wt%) in-situ immobilized with silver nanoparticles were fabricated using phase-inversion technique. The surface morphology of the membranes were studied by field emission scanning electron microscope (FESEM). The uniformity of the distributed nanoparticles and the elemental compositions were proved by energy dispersive x-ray Spectroscope (EDS). BET (Brunauer-Emmett-Teller), nitrogen adsorption measurement has revealed the increase in surface area from 10.15 to 18.85 m2/g for polysulfone membrane and 12.31 to 20.62 m2/g for silver-polysulfone (Ag-PSf) membrane. The surface charges of the fabricated membranes were studied using zeta potential measurements. Furthermore, water flux and sulfate rejection measurements were also carried out using a cross-flow membrane unit. Among the three different compositions, 12 wt% PSf-Ag membranes had significantly higher rejection rate than that of the other membranes.

Preparation of poly (vinyl alcohol)/palygorskite-poly (ionic liquids) hybrid catalytic membranes to facilitate esterification

Poly (vinyl alcohol) (PVA) hybrid catalytic membranes were prepared for esterification via blending PVA with solid catalyst (PAL-PILs), which was synthesized by grafting polymerization of acid ionic liquids (PILs) (1-butysulfonate-3-vinylimidazole hydrogen sulfate) onto natural nanofiber-like palygorskite (PAL). The embedding of PAL-PILs can enhance the thermal stability, mechanical strength and hydrophilicity of membranes. The cross-linked poly (vinyl alcohol) (CPVA) hybrid catalytic membranes (CPVA/PAL-PILs) was preferable to water removal under mild conditions. Moreover, the hybrid membrane exhibited an obvious catalytic performance for the esterification of oleic with methanol under mild reaction conditions. When running in a cross-flow catalytic membrane reactor (CMR), the yield values reached about 8.7%. Importantly, the yield can be improved by increasing packing density of CPVA/PAL-PILs membranes. Meanwhile, the CMR technology does not require separation of catalysts. The results offer a great potentiality for these catalytic membranes in the CMR for further research.

Dynamic behavior of unsteady-state membrane gas separation: Modelling of a closed-mode operation for a membrane module

Membrane gas separations under unsteady conditions provide various opportunities for enhancement of separation performance, particularly in niche applications. An original model describing the dynamics of a closed-mode operation in a cross-flow membrane module is developed for optimization of a pulsed-retentate separation technique. The closed-mode operation is a key step of a pulsed retentate process providing an improvement of separation performance compared to a conventional steady-state separation without productivity losses. The closed-mode operation results in the evolution of a composition profile in a membrane module over time under a constant transmembrane pressure while the feed is being continuously admitted, and a permeate is being evacuated with no retentate withdrawal. During this step the highest possible concentration gradient is realized inside the module between the feed inlet and retentate outlet. The developed model reflects the dynamics of establishing the composition profile under closed-mode operation, linking concentrations, coordinates, and time, which is essential for the optimization of the unsteady membrane separation, as well as for the initial period after either the start of the process or the change of conditions. An axial mixing effect is considered taking into account the deviations from a plug flow present in a real process. The mathematical model is verified through a dedicated experimental study of two binary mixtures separation (CO2/N2, and CO2/CH4) employing experimental techniques based on periodic sampling for gas chromatography analysis and in-situ monitoring by mass spectrometry. The case of a more permeable impurity removal from a less permeable main component is considered. An analytical solution is provided for the membrane module with zero retentate flow.

Membrane fouling in a hybrid process of enhanced coagulation at high coagulant dosage and cross-flow ultrafiltration for deinking wastewater tertiary treatment

A hybrid process of enhanced coagulation at a high dosage of polyaluminum chloride and flat-sheet cross-flow ultrafiltration was used for the advanced treatment of the effluent from a biological treatment process of deinking wastewater in a paper mill. The experimental results obtained by a small-scale continuous laboratory experimental device showed that the absorption resistance was significantly lower than the membrane intrinsic resistance, the concentration polarization resistance, the pore blocking resistance, and the cake layer resistance and so it can be ignored. With increasing polyaluminum chloride dosage from 0 to 2,000 mgL-1, the total membrane filtration resistance decreased and the membrane flux increased, but the concentration polarization resistance increased. With the increase in cross flow velocity, the total membrane filtration resistance, the pore blocking resistance, the layer resistance, and the concentration polarization resistance all decreased, and consequently, the membrane flux increased. With regard to the concentration polarization resistance, the cross flow velocity had a more significant effect than the trans-membrane pressure. But the trans-membrane pressure had a more significant effect on the layer resistance, the pore blocking resistance, and the total membrane filtration resistance than the cross flow velocity. The filtration resistance at the polyaluminium chloride dosage of <1,000 mgL-1 could be ranked as follows: the membrane intrinsic resistance > the pore blocking resistance > the layer resistance > the concentration polarization resistance> the absorption resistance. But it was the membrane intrinsic resistance > the concentration polarization resistance > the pore blocking resistance > the layer resistance > the absorption resistance at the dosage of ≥1,000 mgL-1. The results are helpful for the membrane fouling control and can promote the application of flat-sheet cross-flow membrane process, resultantly improving the reclaim and reuse of deinking wastewater, and reducing the emission of contaminants in deinking wastewater.

On the in-depth scaling and dimensional analysis of a cross-flow membrane liquid desiccant dehumidifier

Membrane liquid desiccant dehumidification is deemed as an advanced alternative to air dehumidification, as its operation can be sustained using low-grade waste heat. Many of the existing studies focused on the development and investigation of the dehumidifiers with different flow patterns and geometries, however, the key factors that dominate the dehumidification process are not clear. Therefore, in this paper, an in-depth scaling and dimensional analysis is carried out to investigate the basic physical process in the membrane liquid desiccant dehumidifier. A cross-flow flat-plate membrane liquid desiccant dehumidifier has been developed and tested. Concurrently, a 2-D computational fluid dynamics (CFD) model has been proposed. The model was converted into a dimensionless form so that the governing dimensionless numbers/groups were identified. The relative importance of these dimensionless numbers was determined. A key finding emerged from this study revealed that the relevant dimensionless numbers that dictate performance in the dehumidifier are Rea,Rel,HL,δH,DvmDva andβ. In addition, the heat and mass transfer process is controlled by heat and mass convection, as well as transverse heat conduction and mass diffusion. Finally, a correlation has been judiciously formulated for the dehumidified air temperature and humidity which demonstrated good predictive accuracy within ±3.5% and can potentially evolve to become an invaluable tool to predict and optimize the dehumidifier’s performance.

Investigation on electrical tuneable separation properties for phase inversion polyaniline membranes doped in various acids

Electrically tuneable polyaniline (PANI) membranes were fabricated via phase inversion and were doped primarily in various acids namely anthraquinone sulfonic acid (ASA), dodecylbenzene sulfonic acid (DBSA), maleic acid (MA) and poly(methyl vinyl ether-alt-maleic acid) (PMVEA) in comparison with secondarily HCl-doped PANI membrane as the pristine ones. It was found that the addition of different dopants in the PANI matrix changed the thickness of the membrane skin structure. From the dynamic contact angle (DCA) analysis, the PANI-ASA and pristine PANI membranes had the greatest permeation tuneability with a faster permeation rate under electric potential. For the effect of tuneable filtration, by using a modified cross-flow membrane filtration system, ASA showed the highest flux tuneability with a tuneable MWCO in the low UF range at an applied voltage of 7 V rather than at 0 V. Accordingly, the electrical tuneability assessment of the membranes has successfully demonstrated the proof of concept that the fabricated PANI membranes doped at various acids could have a different tuneable MWCO, selectivity and/or flux in a pressure filtration system.

Open-source industrial-scale module simulation: Paving the way towards the right configuration choice for membrane distillation

Understanding the impact of configuration selection of industrial-scale membrane distillation (MD) is critical for a productive and energy-efficient operation of this emerging process for desalination. However, it is rarely considered even as new high flux membranes and wider applications are developed. In this context, three open-source simulators were developed on the Matlab GUI platform for the performance prediction of industrial-size direct contact membrane distillation (DCMD), submerged vacuum membrane distillation (S-VMD), and cross-flow vacuum membrane distillation (X-VMD). Using laboratory-scale experimental results as simulation inputs, the developed simulators were able to predict large-scale MD performance. Furthermore, design considerations on appropriate module scale-up for all three configurations were demonstrated. More importantly, the configuration that shows the optimal mass and heat transfer behaviour was revealed through the performance comparisons across different full-size MD configurations. In addition, these simulators are open-source allowing researchers to use these tools for the development of specific scale-up strategies of their own MD membranes — a critical step towards commercialisation.

Effect of crossflow regime on the deposit and cohesive strength of membrane surface fouling layers

Acquiring knowledge of the properties of membrane fouling layers is crucial to mitigating fouling and developing cleaning strategies. The cohesive strength of these fouling layers, which determines the cleaning requirement of the membrane, is nevertheless rarely investigated. Here we introduced fluid dynamic gauging (FDG) to the crossflow microfiltration of a wood material, namely microcrystalline cellulose (MCC, nominal particle size 20 μm, 95% (in volume) of the particles are bigger than 5.4 μm and smaller than 56.4 μm), to study in situ the cohesive strength of the membrane surface fouling formed under different crossflow regimes. Using regenerated cellulose membrane with a nominal pore size of 0.2 μm, filtration experiments with FDG measurement show that the crossflow regime can lead to the formation of surface fouling layers with distinct cohesive strength. Fouling formed in turbulent/transitional crossflow (Reynolds number, Reduct = 4170) was stronger and its removal required more liquid shear stress compared to the layers formed in laminar crossflow (Reduct = 1560). The fouling layers that can withstand the minimum shear of 35 Pa from the FDG sensor with turbulent/transitional crossflow were, on average 294 ± 10 μm thick, in contrast to those formed in laminar crossflow, which were significantly thinner (144 ± 73 μm at 35 Pa shear stress, p < 0.05). On the other hand, turbulent/transitional crossflow reduced material deposition significantly (p < 0.05). After 1000 s filtration, 0.117 ± 0.003 kg m−2 MCC were found on the turbulent/transitional crossflow membranes, compare to 0.134 ± 0.005 kg m−2 in the laminar crossflow situation. Moreover, a similar permeate flux was observed in all experiments. Therefore, this work also highlights the necessity of developing membrane cleaning protocols based on the fouling layer properties, rather than on the permeate flux decline.

Simple Theoretical Results on Reversible Fouling in Cross-Flow Membrane Filtration.

In cross-flow membrane filtration, fouling results from material deposit which clogs the membrane inner surface. This hinders filtration, which experiences the so-called limiting flux. Among the models proposed by the literature, we retain a simple one: a steady-state reversible fouling is modelled with the use of a single additional parameter, i.e., , the ratio of the critical concentration for deposition to the feed concentration at inlet. To focus on fouling, viscous pressure drop and osmotic (counter-)pressure have been chosen low. It results in a minimal model of fouling. Solved thoroughly with the numerical means appropriate to enforce the nonlinear coupling between permeation and concentration polarization, the model delivers novel information. It first shows that permeation is utterly governed by solute transfer, the relevant non-dimensional quantities being hence limited to and , the transverse Péclet number. Furthermore, when the role played by and moderate (say ) is investigated, all results can be interpreted with the use of a single non-dimensional parameter, , the so-called fouling number, which simply reads . Now rendered possible, the overall fit of the numerical data allows us to put forward analytical final expressions, which involve all the physical parameters and allow us to retrieve the experimental trends.

Alternative Process Routes to Manufacture Porous Ceramics-Opportunities and Challenges.

Porous ceramics can be realized by different methods and are used for various applications such as cross-flow membranes or wall-flow filters, porous burners, solar receivers, structural design elements, or catalytic supports. Within this paper, three different alternative process routes are presented, which can be used to manufacture porous ceramic components with different properties or even graded porosity. The first process route is based on additive manufacturing (AM) of macro porous ceramic components. The second route is based on AM of a polymeric template, which is used to realize porous ceramic components via replica technique. The third process route is based on an AM technology, which allows the manufacturing of multimaterial or multiproperty ceramic components, like components with dense and porous volumes in one complex-shaped component.