Showing papers on "Packed bed published in 2014"
TL;DR: In this paper, a green and effective absorbent for the treatment of hazardous wastewater containing heavy metal ions was first synthesized, and the adsorption capacities for Pb(II, Cd(II), Cu(II) and Pb (II) reached 47.1 µg, 49.9 µg and 41.5 µg per gram of Ca(II)-CS microsphere within 30min, respectively.
189 citations
TL;DR: In this paper, a transient two-dimensional dispersion-concentric (D-C) model is modified to account for the phase change process within capsules so as to determine the temperature distribution and phase change front within each capsule.
148 citations
TL;DR: The results show that 3D printing is a feasible method for producing precisely controlled porous media and are expected to revolutionize not only fundamental studies of flow in porous media but methods of chromatography column production.
144 citations
TL;DR: In this paper, a heat storage system using spherical capsules filled with three kinds of phase change material (PCM) was presented and numerically studied, and the capsules were placed in series based on the melting temperature of PCM.
139 citations
TL;DR: In this article, the behavior of a packed bed latent heat thermal energy storage system with phase change material (PCM) capsules as filler is analyzed using enthalpy method, and the results indicated that decreasing the size of capsule and fluid inlet velocity, or increasing the storage height, results in an increase in the charge efficiency.
127 citations
TL;DR: In this article, a pilot-scale oil/rock thermocline thermal energy storage (TES) system, consisting of a packed bed of two characteristic sizes rocks as storage material and thermal oil as heat transfer fluid, is experimentally studied.
124 citations
TL;DR: In this article, the effects of size ratio and volume fraction on the fluid flow and quantify the drag forces on binary mixtures of particles are studied by a parallel lattice Boltzmann model.
118 citations
TL;DR: In this paper, a set of submodels taken from literature is proposed for simulating the combustion of solid biomass in packed beds, which can help in the realistic estimation of the processes involved in packed be combustion of biomass and point to particle shrinkage and bed mechanics as an important process to be considered.
115 citations
TL;DR: In this article, a parametric analysis was carried out using the validated enthalpy based numerical model that considers the thermal gradient inside the phase change material (PCM) container, and the results of simulation analysis showed that the size of the PCM ball, fluid inlet temperature and the mass flow rate of the heat transfer fluid (HTF) influenced respectively heat transfer area in the packed bed, temperature difference between the HTF and PCM and the surface convective heat transfer coefficient between the HP fluid.
102 citations
TL;DR: In this paper, a model is presented to predict the fluid and solid temperatures in a packed bed thermal energy storage vessel using compressed gas as heat transfer fluid (HTF), compared to data from an experimental vessel that is 10′ tall with a 2.25″ storage diameter filled with 6mm diameter alpha-alumina beads, using air as the HTF.
100 citations
TL;DR: In this paper, the appropriateness of different contact point modification approaches for forced convective heat transfer analysis in structured packed beds of spheres was investigated, and the effects caused by the bridge size for the bridges treatment were discussed, and numerical results were compared with available experiments in literature.
TL;DR: In this paper, a transient 3D model for two main zones, namely the fuel bed and the freeboard, of biomass packed bed combustion systems was developed, which integrates the models for the biomass conversion sub-processes and solves the governing equations for the gas and solid phase and their interactions.
TL;DR: The steady state CP removal efficiency of more than 91% was observed up to the inlet load of 300mgL(-1)d(-1).
TL;DR: A rotating packed bed (RPB), a novel reactor with high mass transfer efficiency and small dimension, is employed in this study to remove H2S and a mathematical model for liquid flow in the packing is established to quantify the length of the end-effect zone.
Abstract: The existence of H2S in a system could lead to catalyst deactivation, pipeline corrosion, and environmental pollution. A rotating packed bed (RPB), a novel reactor with high mass transfer efficiency and small dimension, is employed in this study to remove H2S. For RPB, the most significant section for mass transfer is the end-effect zone of packing. A mathematical model for liquid flow in the packing is established to quantify the length of the end-effect zone. A simple and effective visual experimental method is then proposed to investigate the end-effect zone in the RPB. A gas–liquid mass transfer experiment is finally employed to confirm the validity of the proposed mathematical model. With the aid of this model, the length of packing of a RPB used for pilot-scale H2S removal is optimized. The optimized RPB removes 99.8% of H2S (15 vol % to 0.03 vol %) from the system. The proposed model can help optimize the design of a RPB reactor.
TL;DR: In this paper, the reaction kinetics of carbon dioxide (CO 2 ) capture by the accelerated carbonation of basic oxygen furnace slag (BOFS) in a rotating packed bed (RPB) was evaluated using the surface coverage model.
TL;DR: In this paper, a hybrid plasma catalytic system consisting of a dielectric barrier discharge (DBD) reactor and relaxor ferroelectrics is investigated for syngas generation via the carbon dioxide reforming of methane.
Abstract: A hybrid plasma catalytic system consisting of a dielectric barrier discharge (DBD) reactor and relaxor ferroelectrics is investigated for syngas generation via the carbon dioxide reforming of methane. The study tests three kinds of packing materials, including two relaxor ferroelectrics BaZr0.75T0.25O3 (BZT; er = 149), BaFe0.5Nb0.5O3 (BFN; er = 2025), and glass beads (er = 3–5). The BFN and BZT packed-bed DBD reactors achieve higher CO2 and CH4 conversions and better energy efficiencies for syngas production than the DBD. On the contrary, the DBD packed with glass beads achieves lower conversions and energy efficiencies than the DBD. In terms of packings filled in a DBD reactor, there is a trade-off between an enhancement of the electric field strength and a reduction of the gas retention time. It is interesting that the conversions are increased with the increase of the dielectric constant of the packings tested in the study. Overall, a relaxor ferroelectric with a high dielectric constant is a good can...
TL;DR: In this article, the influence of the reactor selection on the overall process efficiency has been estimated, assuming the fuel conversion at chemical equilibrium, leading to some unconverted CO and H2 in the reaction products.
TL;DR: In this article, a packed-bed dielectric barrier discharge (DBD) was developed for acetone removal, and the effects of packing materials were investigated in terms of discharge characteristics, removal efficiency and byproducts formation.
TL;DR: In this article, the authors apply the Extended Discrete Element Method (XDEM) as a numerical simulation framework to prediction of drying within a packed bed reactor, which resolves the particulate phase by the classical discrete element method, however, extends it by the thermodynamic state e.g. temperature distribution and evaporation of water content of each particle in conjunction with heat and mass transfer to the surrounding gas phase.
TL;DR: In this article, the feasibility of an ammonia-based CO2 capture process using hollow fiber membrane contactors is investigated, and the potentialities of dense skin membrane contactor, particularly based on fluorinated polymers, are discussed with regard to both increased CO2 mass transfer performances and mitigation of ammonia volatilization compared to conventional gas/liquid contactors.
TL;DR: In this paper, the regeneration heat duty of CO 2 desorption from CO 2 rich diethylenetriamine (DETA) solutions was experimentally evaluated in a bench-scale stripper column packed with Dixon ring random packing.
TL;DR: In this paper, a structured concrete thermocline thermal energy storage (TES) system is proposed as an alternative to currently-used TES systems, which avoids the issues of material settlement and thermal ratcheting found in packed bed thermocliners.
TL;DR: In this article, an agglomerated Zr-SBA-15/bentonite catalyst with particle sizes of 1.5mm was used in the continuous production of biodiesel from waste cooking oil on a packed bed reactor.
Abstract: Zr-SBA-15 material has been agglomerated with bentonite clay to form a macroscopic structured catalyst with particle sizes of 1.5 mm with the purpose of being used in the continuous production of biodiesel from waste cooking oil on a packed bed reactor. The influence of different reaction parameters was assessed including methanol to oil molar ratio, residence time and temperature. The pellet-type Zr-SBA-15/bentonite catalyst was highly active in the continuous flow process leading to a steady molar FAME yield of ca. 96% at 210 °C and 70 bar with a methanol to oil molar ratio of 50:1 and a residence time of 30 min. Long-time on stream experiments revealed an outstanding stability of the Zr-SBA-15 particulate material, since this provided a sustained FAME yield of 96% for over 260 h, being negligible the deactivation of the catalyst during this period. Bentonite clay partially contributed to the methanolysis reaction of triglycerides during the early stages of the reaction, but after a short period (1 h) its influence on the reaction became very low. In this way, the outstanding catalytic performance of the agglomerated catalyst must be attributed mainly to the presence of active acid sites in the Zr-SBA-15 material. The leaching of metal species (Na, K, Ca and Mg) coming from bentonite binder was low in the outlet effluent. Catalyst did not suffer any significant changes in physicochemical properties after the long-time on stream experiment, preserving zirconium content and acid capacity.
TL;DR: In this paper, the authors present the results of a numerical investigation on the transient behavior of a packed bed thermal storage unit using different fluids: oil, molten salt and air, where the storage material consists of loosely spherical particles of alumina packed in a reservoir wherein the heat transport fluid flows from the top to the bottom in the charging phase, and in the opposite way in the discharging phase.
TL;DR: In this article, the pyrolysis of high density polyethylene (HDPE) waste products was investigated using both thermal and catalytic cracking techniques, where different reactor bed materials, including sand, cement and white clay were used to enhance the thermal cracking of HDPE.
TL;DR: Results showed a maximum removal efficiency with the addition of 2-4% oxygen into a nitrogen plasma, and it is thought that oxygen concentrations in excess of 4% decreased the decomposition of chlorinated VOCs as a result of ozone and nitrogen oxide formation.
Abstract: This work describes the application of a non-thermal plasma generated in a dielectric barrier packed-bed plasma reactor for the remediation of dichloromethane (CH2Cl2, DCM). The overall aim of this investigation is to identify the role of key process parameters and chemical mechanisms on the removal efficiency of DCM in plasma. The influence of process parameters, such as oxygen concentration, concentration of initial volatile organic compounds (VOCs), energy density, plasma residence time, and background gas, on the removal efficiency of 500 ppm DCM was investigated. Results showed a maximum removal efficiency with the addition of 2–4% oxygen into a nitrogen plasma. It is thought that oxygen concentrations in excess of 4% decreased the decomposition of chlorinated VOCs as a result of ozone and nitrogen oxide formation. Increasing the residence time and the energy density resulted in increasing the removal efficiency of chlorinated VOCs in plasma. A chemical kinetic model has been developed on the basis o...
TL;DR: The intent of this work was to use high‐throughput strategies as a general guide for scaling and assessing operating space rather than as a precise model to exactly predict performance.
Abstract: The emergence of monoclonal antibody (mAb) therapies has created a need for faster and more efficient bioprocess development strategies in order to meet timeline and material demands In this work, a high-throughput process development (HTPD) strategy implementing several high-throughput chromatography purification techniques is described Namely, batch incubations are used to scout feasible operating conditions, miniature columns are then used to determine separation of impurities, and, finally, a limited number of lab scale columns are tested to confirm the conditions identified using high-throughput techniques and to provide a path toward large scale processing This multistep approach builds upon previous HTPD work by combining, in a unique sequential fashion, the flexibility and throughput of batch incubations with the increased separation characteristics for the packed bed format of miniature columns Additionally, in order to assess the applicability of using miniature columns in this workflow, transport considerations were compared with traditional lab scale columns, and performances were mapped for the two techniques The high-throughput strategy was utilized to determine optimal operating conditions with two different types of resins for a difficult separation of a mAb monomer from aggregates Other more detailed prediction models are cited, but the intent of this work was to use high-throughput strategies as a general guide for scaling and assessing operating space rather than as a precise model to exactly predict performance
TL;DR: Expanded graphite (EG) was used to enhance the thermal conductivity in the packed bed reactors of MgO-H2O chemical heat pumps (CHP) as mentioned in this paper.
TL;DR: In this paper, an analytical and response surface methodology combined approach has been applied to investigate the thermal and thermohydraulic performances of a novel type double pass packed bed solar air heater under external recycle with wire mesh screen as a packed bed material.
TL;DR: In this paper, the performance of the oxygen carrier in a packed bed with periodic switching between oxidizing and reducing conditions was investigated, while also studying the (possible) carbon deposition and the effect of sulphur impurities on the stability of the carrier.