Showing papers on "Packed bed published in 2021"
TL;DR: In this article, the authors proposed a membrane-based membrane reactor with high potential to efficiently recover the hydrogen (H2) stored in ammonia (NH3), which has been recently proposed as an alternative for H2 storage.
57 citations
TL;DR: In this paper, a smoothed volume distribution model (SVDM) is developed to simulate the migration of fine powders in suspension flow through a solid packed bed, where the porosity of coarse solids is calculated by a smooth particle volume distribution.
47 citations
33 citations
TL;DR: In this article, a 1D phenomenological reactor model is developed to evaluate and optimize the performance of a membrane reactor for direct hydrogenation of CO2 to dimethyl ether (DME) is a promising technology for CO2 valorisation.
33 citations
TL;DR: In this article, the reduction of iron-manganese oxide particles in a high-temperature packed-bed solar thermochemical reactor is investigated using an advanced transient three-dimensional heat and mass transfer model.
32 citations
TL;DR: In this paper, a comprehensive x-ray tomography study was performed investigating and correlating the void structure of packed beds made of smooth, mono-sized spheres in cylindrical confining walls.
30 citations
TL;DR: In this article, the authors proposed a novel switch-based packed bed system for continuous capture of desublimation-based CO2 capture from natural gas, which was proved through dynamic simulation and experimental study on CO2 separation from multi-component NG.
29 citations
TL;DR: In this article, a thermal energy storage filled with a packed bed of macro-encapsulated latent heat storage elements is studied, and a model describing the charging and discharging processes of the heat storage is developed based on a new approach for the treatment of non-spherical capsules.
27 citations
TL;DR: A continuous ozonation system based on a micro-packed bed reactor (μPBR) was used to improve the dissolution rate of ozone and achieved a rapid and efficient degradation of refractory organic pollutants.
27 citations
TL;DR: In this article, a linear and non-linear regression analysis for packed bed column adsorption of phenol onto corn cob activated carbon was investigated, and the effect of the process parameters on the dynamic adsorment process was investigated at flow rates (9-18 mg/min), initial phenol concentration (100-300 mg/L), bed height (5-10 cm), and particle size (300-800 µm).
27 citations
TL;DR: In this paper, a model for simulating the direct synthesis of dimethyl ether (DME) in a packed bed membrane reactor (PBMR) has been validated, using a LTA zeolite hydrophilic membrane in a lab-scale reaction equipment.
TL;DR: In this article, the effect of packing material on plasma characteristic from the viewpoint of charge transfer process was investigated by measuring voltage and current waveforms and taking ICCD images, which indicated that the discharge behavior has been changed from the view of charge transferring process once the gas gap was packed with pellets.
Abstract: This paper is aimed to investigate the effect of packing material on plasma characteristic from the viewpoint of charge transfer process. Both the charge accumulation and release processes in the dielectric barrier discharge reactor and packed-bed reactor were investigated by measuring voltage and current waveforms and taking ICCD images. The packing material was ZrO2 pellets and the reactors were driven by a parameterized nanosecond pulse source. The quantity of transferred charges in the dielectric barrier discharge reactor was enhanced when decreasing pulse rise time or increasing pulse width (within 150 ns), but reduced when the gas gap was packed with pellets. The quantity of accumulated charges in the primary discharge was larger than the quantity of released charges in the secondary discharges in the dielectric barrier discharge reactor, but they were almost equal in the packed-bed reactor. It indicates that the discharge behavior has been changed from the view of charge transfer process once the gas gap was packed with pellets, and the ICCD images confirmed it.
TL;DR: In this paper, the effect of 3 ¼wt% PdO on Co3O4 coated on three different OCFs (alumina, silicon carbide and zirconia) was investigated toward the reaction of CH4 combustion in lean conditions.
TL;DR: In this article, an actual-arrangement-based three-dimensional packed bed LHS model was built to consider the radial porosity oscillation, which led to a non-uniform distribution of heat transfer fluid (HTF) velocity.
TL;DR: In this paper, various NiMo-promoted catalysts were prepared, tested, and compared with pristine zeolites for the purpose of the gas phase hydrocracking, hydrogenation, and isomerization in a packed bed reactor at 370 °C under atmospheric relative pressure.
Abstract: In this experimental study, various NiMo-promoted (as follows: H-beta, H-mordenite, H-USY, H-Y, and H-ZSM-5) catalysts were prepared, tested, and compared with pristine zeolites for the purpose of the gas phase hydrocracking, hydrogenation, and isomerization in a packed bed reactor at 370 °C under atmospheric relative pressure. 5 wt.% naphthalene/95 wt.% 1-methylnaphthalene were selected as biomass tar model molecule compounds, based on real chemical compositions. A series of material characterization techniques were applied to determine the physical structural, morphological, textural, redox, and acidic properties of synthesized catalysts. An outstanding catalytic activity and stability were found over the 2.5 wt.% Ni–2.5 wt.% Mo/ZSM-5 with high carbon deposition resistance, 2-methylnaphthalene selectivity (96.0 mol.%) in the liquid with the products with a yielded total conversion of 96.3 mol.% after an 18 h time on stream, where ethylene/propane were main (94.2 wt.%). The latter can be attributed to the presence of mesopore volume/surface area, existing boundary interface, the amount of medium/strong acid sites, and the synergetic interaction phenomena between metal atom species/supports. Attention should be paid to particle size dimensions, diameters and acidity, which facilitated poly-aromatic hydrocarbon removal. Considering particular obtained distributions, intermediates reaction pathway was proposed. Cracking, synthetic ring opening, alkylation, condensation and disproportionation were additionally involved. Results were consistent with the occurrence of two competing mechanisms, a monomolecular, as well as a bimolecular one.
TL;DR: Based on the porous morphological characteristics of the packed ice bed produced by suspension freeze concentration (FC), the authors describes the introduction of a full-bed centrifugal filtration step to separate concentrated apple juice from the ice bed.
TL;DR: In this article, a methodology to account for the thermal effect of a coating layer applied over the pebbles of a packed bed was presented, and the results showed that low emissivity coatings could reduce the effective thermal conductivity of a rock-based packed bed of about 58% with respect to a similar uncoated solution, already at 800°C.
TL;DR: In this article, double-layer burners were built by filling the downstream with the hollow cylinders of different sizes and pore numbers due to the high porosity of hollow-structure units compared with the common packed bed of pellets.
TL;DR: In this article, the effect of quasi-dynamic boundary conditions on thermal energy storage performance was evaluated and the levelized cost of storage (LCoS) was applied to thermal storage design.
Abstract: High temperature thermal energy storages are becoming more and more important as a key component in concentrating solar power plants. Packed bed storages represent an economically viable large scale energy storage solution. The present work deals with the analysis and optimization of a packed bed thermal energy storage. The influence of quasi-dynamic boundary conditions on the storage thermodynamic performance is evaluated. The Levelized Cost of Storage is innovatively applied to thermal energy storage design. A complete methodology to design packed bed thermal energy storage is proposed. In doing so, a comprehensive multi-objective optimization of an industrial scale packed bed is performed. The results show that quasi-dynamic boundary conditions lead to a reduction of around 5% of the storage thermal efficiency. Contrarily, the effect of the investigated design variables over the TES LCoS optimization is only slightly influenced by quasi-dynamic boundary conditions. Aspect ratio between 0.75 and 0.9 would maximize the storage thermal efficiency, while low preliminary efficiency around 0.47 would minimize the Levelized Cost of Storage. This work testifies that quasi-dynamic boundary conditions should be taken into considerations when optimizing thermal energy storage. The Levelized Cost of Storage could be also considered as a more reliable performance indicator for packed bed thermal energy storage, as it is less dependent on variable boundary conditions.
Abstract: The integrated gasification combined cycle (IGCC) has been applied as an alternative technology for power plant due to the higher thermal efficiency than that of conventional pulverized coal-fired ...
TL;DR: In this paper, the effects of discharge power, feed flow rate, packing length, circulating water temperature and particle size on discharge characteristics and CO2 conversion were investigated to have a better understanding of the performance of the packing material.
Abstract: Dielectric barrier discharge (DBD) plasma in packed bed reactors are widely used in the environment and energy (such as CO2 conversion). Packing material is a key factor in the reaction of splitting CO2 into CO and O2 by dielectric barrier discharge plasma. To get higher CO2 conversion, grinding balls made of a mixture of ZrO2 and CeO2 in a certain proportion was employed as packing material in this work. The effects of discharge power, feed flow rate, packing length, circulating water temperature and particle size on discharge characteristics and CO2 conversion were investigated to have a better understanding of the performance of the packing material. The reactor discharge behavior was observed by determining the product gas composition and plasma power consumption to determine CO2 conversion and energy efficiency. The packing of the catalyst in the reactor makes the discharge mode from the initial filament discharge to the combination of filament discharge and surface discharge. Compared with oxides composed of a single substance, the two oxides of the composite catalyst can interact, possibly achieving a synergistic effect. Typical results showed that this mixed material had a better property than the reported materials like BaTiO3, Al2O3, ZrO2 and so on which consist of a single substance. The maximum CO2 conversion reached 64.38 % and the maximum energy efficiency reached 8.76 %, which is currently the highest in the known literature. The higher circulating water temperature and larger particle size lead to the decrease of CO2 conversion and energy efficiency. The best performance of the mixture catalyst may be attributed to the oxygen vacancies, which stabilizes the atomic oxygen produced in the reaction and thus facilitates the conversion of CO2.
TL;DR: In this paper, a high-gravity rotating packed bed (RPB) was used for heterogeneous catalytic ozonation of nitrobenzene (NB) in a high gravity rotating bed.
Abstract: In this study, Cu–MnOX/γ-Al2O3 catalyst was first used for heterogeneous catalytic ozonation of nitrobenzene (NB) in a high-gravity rotating packed bed (RPB), as RPB could significantly improve the...
TL;DR: In this article, a void space and micro-baffle were formed in the packed layer and in the blow-through channel, respectively, to enhance convective heat and mass transfer, and resultant reaction efficiency.
TL;DR: In this article, a predictive statistical model was built to investigate the influence of process variables, involving absorption temperature (30−45 °C), inlet gas flow rate (4−6 L/min), and initial solvent concentration of glycerol (5−15 wt %), on the CO2 removal efficiency (ef), and the volumetric overall gas-phase mass transfer coefficient (KGaV) in a CO2+MEA+ Glycerol system.
TL;DR: In this article, a transient two-dimensional dispersion-concentric model is developed to analyze the phase transition of phase change materials and the heat transfer characteristics between air and phase change material capsules in four different packed bed systems.
TL;DR: In this paper, the authors investigated a packed bed thermal energy storage system for small-scale concentrated solar power plants (1-5 MWe) using magnetite ore as heat storage media and a thermal oil, Delcoterm Solar E15, as heat transfer fluid.
TL;DR: In this paper, the authors derived the kinetic rates for the two steam methane reforming (SMR) and water gas shift reactions were derived for 12 commonly used reforming catalysts based on conversion data obtained from the literature.
TL;DR: In this paper, the authors compared the hydrogen productivity of Rhodopseudomonas palustris under planktonic, and immobilized cell conditions, with the reactor operating either as a packed bed or a fluidized bed.