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Computational Fluid Dynamics (CFD) is a worthwhile method for studying complex flows in packed bed reactors. The paper debates different CFD modeling approaches of incompressible laminar flow through packed beds with a particle to column diameter ratio of 2. Using COMSOL Multiphysics 5.6, five different cases have been simulated and compared in term of pressure drop. Excellent agreement was found between the proposed hypothetical and the resolved-particle (3D) models, mainly for the lower Inlet particle Reynolds numbers, with relative deviation of 3% and 7% at inlet Reynolds numbers of 27 and 55, respectively. Concerning the pseudo homogeneous cases, three different drag laws have been exercised and it has been found that applying the semiempirical correlation, which takes into account the wall effects, in the flow equations showed the best agreement to the 3D model, with relative deviation being in the range 5%-25%. Considering these, one can recommend to use the proposed less computationally intensive approach or to apply the chosen drag law model in the momentum balance when designing a packed bed with aspect ratio of 2. [ABSTRACT FROM AUTHOR]

Thermal energy storage (TES) is an enabling system that provides uninterrupted energy from concentrated solar power (CSP) plants. Packed‐bed TES systems have great opportunity to significantly enhance the cost‐effectiveness, efficiency, and sustainability of CSP plants by employing an affordable and sustainable packing material. The objective of this study is to design a demolition waste‐based packed bed TES system with a maximum storage capacity of 40 kWh, specifically tailored to store heat within the temperature range of 290°C to 565°C using solar salt as heat transfer fluid (HTF), thereby making it suitable for integration into CSP plants. Performance and thermal behavior of demolition waste‐based packed‐bed TES system was assessed through numerical analysis. The results demonstrate that a high discharging efficiency of 76.0% was achieved when the HTF flow rate was set at 100 kgh−1. However, it is important to note that at lower HTF flow rate, heat loss increases, leading to a decrease in discharging efficiency to 70%. The experiment also revealed a uniform thermal gradient within the packed‐bed TES system, up to a fluid flow rate of 300 kgh−1. It is worth mentioning that lower flow rates can further improve the stratification effect; however, they may also result in increased heat loss and reduced storage capacity. Based on these findings, an optimal flow rate range of 100 to 200 kgh−1 is recommended to achieve the best performance for the packed‐bed TES system. [ABSTRACT FROM AUTHOR]

Small scale gasification combined heat and power (CHP) systems offer an alternative to diesel fuelled generators for power generation in remote communities and industrial sites. Tar and particulates in the producer‐gas can damage the internal combustion engine generator and increase operation and maintenance costs. In this work, we present a novel trickle‐bed scrubber using filtered waste cooking oil as a cost effective and easy‐to‐operate gas clean‐up method for a small CHP system. The performance of the trickle‐bed scrubber was compared against a packed‐bed filter utilizing woodchips in a 20 kWth downdraft gasifier. Used‐cooking oil was selected as the solvent and woodchips as the bed‐material as these are readily available, inexpensive, and can be recycled in the gasifier as fuel. A woodchip packed‐bed filter reduced the tar and particulate matter (PM) in the producer gas from gasification of spruce chips (11% moisture) from 1.6 to 1.4 g/Nm3 and from 0.16 to 0.087 g/Nm3 respectively. The trickle‐bed scrubber was able to reduce the tar and PM in the producer gas from gasification of pinewood (8% moisture) from 1.38 to 0.28 g/Nm3, and 0.209 to 0.082 g/Nm3, respectively. Tar and PM removal efficiency improved by 60% and 29% respectively. Components such as benzene, toluene, naphthalene, and biphenylene were the major tar components. After passing the trickle‐bed, most tar was removed, with a preference for removal of multi‐ringed aromatics and gravimetric tars. Parameters such as the tar and particulate concentration, feedstock moisture content, and feedstock source affect the performance of the gas clean‐up system. [ABSTRACT FROM AUTHOR]

In order to analyze the packed-bed tank failure and molten salt leakage problems induced by the high temperature creep and alternative stress in the solar power station, a coupled thermal-mechanical method for analyzing the creep and mechanical performances of the commercial tank with 347H material was developed by taking into account the real structure and stress loads, and the corresponding dynamic characteristics in different charging-discharging time were further numerically studied. The results show that the temperature change rate of the tank wall is obviously lower than that of the packed-bed region, and the creep phenomenon occurs at first on the wallboards 1-4 (4.2

A packed-bed anaerobic-aerobic reactor (PBAOR) with two anaerobic and two aerobic compartments was constructed to treat manure-free piggery wastewater which was characterized by high ammonium (NH4+-N) and low ratio of chemical oxygen demand (COD) to total nitrogen (TN). Performed for 60 days at the normal atmospheric temperature of 25 °C with a constant hydraulic retention time of 32 h and reflux ratio of 2.0, a stable state in pollutants removal was obtained in the PBAOR. Within the next routine operation process, the removal of COD, NH4+-N and TN was above 85.7%, 98.2% and 85.8%, with a residual less than 81.7, 7.2 and 39.9 mg L−1 in effluent, respectively. Twelve veterinary antibiotics classified into tetracyclines (TCs), sulphonamides (SAs) and fluoroquinolones (FQs) were detected from the piggery wastewater. The PBAOR was effective in removing TCs and SAs with an average removal of 74.8% and 93.3%, respectively, but presented a negative removal for FQs. Most COD in the piggery wastewater was mainly removed in the first two anaerobic compartments along with an obvious removal of TCs and SAs, while the TN were mainly removed in the last two aerobic compartments with the negative removal of FQs. [ABSTRACT FROM AUTHOR]

The objective of this study is to assess the viability of implementing the methodology proposed in the SFERA-III project for the assessment of key performance indicators (KPIs) of thermal storage prototypes in a specific packed-bed device. SFERA-III project is an EU funded project aiming, among others, to upgrade the infrastructures and services related to Concentrating Solar Thermal technologies. In order to improve the quality of services in relation to the testing of thermal energy storage prototypes, a protocol and KPIs were defined and validated with different types of devices, though none of them was a packed-bed. This study elucidates the challenges encountered in the implementation of the protocol on a packed-bed prototype, alongside the proposed alternative solutions and their influence on the resulting KPIs. The analysis demonstrates that the SFERA-III Key Performance Indicators are an appropriate means of evaluating packed bed thermal energy storage prototypes. Consequently, the use of these KPIs as a standard is supported. • ● Analyse standardization activities related to thermal energy storage prototypes • ● Testing of sensible and latent thermal energy storage prototypes • ● Key performance indicators applied to a packed-bed prototype [ABSTRACT FROM AUTHOR]

Decarbonising the industrial sector is a key part of climate change mitigation targets, and Solar Heat for Industrial Process (SHIP) is a promising technology to achieve this. However, one of the drawbacks of SHIP systems is that they rely on an intermittent energy source. Therefore, sensible energy storage has emerged as a potential solution. In addition, solid byproducts have been proposed as a low-cost but effective material for thermal energy storage (TES). This work presents a SHIP system model coupled with a copper slag-packed-bed TES (PBTES) model using air as heat transfer fluid. The TES has been implemented to preheat the makeup water of the tank where steam is generated. A system design was carried out using a parametric analysis to find a solar field size and a corresponding TES volume. The resulting system was simulated, and the operating variables were analysed in detail. The results show that it is possible to generate 20% more energy due to the storage system. Additionally, a techno-economic analysis indicates that the SHIP with PBTES system results in a payback period of 14 years and a savings of C O 2 emissions of 30 t C O 2. • Integration of a SHIP system with copper slag packed-bed TES • Dynamic simulation and analysis of the system's main variables • System performance assessment and control improvement • Techno-economic analysis of the entire system and carbon savings • SHIP system with TES presents a payback of 14 years and annual savings of 30 tCO2 [ABSTRACT FROM AUTHOR]

Concentrated Solar Power (CSP) is a critical technology for the renewable energy transition, offering high power output at elevated temperatures. However, further integration of CSP plants requires a reduction in investment costs. This study investigates the use of cost-effective, sustainable, waste-based TES materials—such as Electric Arc Furnace Black Slag (BS) and Tundish (TN) from the steel industry, as well as Demolition Waste (DW) from urban regeneration projects—as packing materials in TES systems to reduce the capital expenditure of CSP plants. A One-Dimensional Continuous Solid Phase (1D-2P) model was employed to evaluate and compare the performance of DW, TN, and BS. The results revealed that all materials demonstrated comparable properties, with TN exhibiting the highest energy storage capacity (44.7 kWh) and energy storage density (296 kWh/m³). With high utilization rates of 73–75 %, waste-based TES systems show strong potential for application in CSP plants. The TES systems were scaled for a 110 MW CSP plant, which currently operates with a 2-tank molten salt TES system providing 4648.4 MWh of storage capacity. TN required the smallest storage volume of 22,273 m³ for the 110 MW CSP plant. The reduction of molten salt usage by up to 31,000 tons in the waste-based packed-bed TES system could significantly enhance the economic feasibility of CSP plants. [Display omitted] • Packed beds can reduce amount of molten salt required by 77 % in TES for CSP. • Using waste-based packing provides both economic and environmental benefits. • Efficiency of waste based packed-bed TES is in the range of 79%–82 %. • Tundish waste, with the highest heat capacity, requires the least storage volume. [ABSTRACT FROM AUTHOR]

In this paper, the thermal and mechanical dynamic performances of molten salt packed-bed thermal energy storage (TES) system are investigated by coupling Finite Volume Method (FVM) and Finite Element Method (FEM). Firstly, an integration model coupling FVM and FEM in packed-bed tank is developed. Particularly, the pore water static pressure caused by the liquid level of molten salt is applied in the coupled method. Based on this model, the dynamic characteristics of thermal and stress distributions are simulated. Finally, the effects of porosity, inlet temperature and velocity on the thermal and stress performances are analyzed. The results indicate that the temperature and stress of the wall increase during the discharging process, and the peak stress occurs at the tank bottom connecting with the ground foundation. The method of increasing porosity is helpful to improve the discharging power, but the plastic failure on the wall would probably occur due to the higher stress level. Increasing inlet temperature has negative influence on the thermal and safety performances, because lower discharging power and higher stress would be produced adversely. Although the lower stress can be achieved when the higher inlet velocity is adopted, the effective discharge time would be decreased significantly. [ABSTRACT FROM AUTHOR]

The main objective of this study was to assess hardness reduction of natural water by using variable load substrates from two oxidic lithological materials (OLM), namely “C Material” and “L Material,” that were collected from natural deposits in Venezuela. Adsorption tests were performed with natural substrates that were activated with NaOH. The results revealed the presence of amphoteric iron, silicon, and aluminium oxides in their structures. Column experiments show a retention capacity of 12.51 and 11.02 mgCaCO3/kg for Materials L and C, respectively. Activation increased 2.5 times the yield of the process, 29.28 mgCa2+/kg for Material L and 26.94 mgCa2+ /kg for Material C, due to increases in the density of surface negative charges. The adsorption was non-specific and the data conformed to the Freundlich model. It is concluded that the materials examined are excellent options for treating water hardness. [ABSTRACT FROM AUTHOR]

The real-time change of solar radiation intensity leads to the instability of the outlet temperature of the collector, which has an important influence on the thermal performance of the thermal energy storage system. Therefore, the dynamic thermal performance of a packed-bed latent heat storage system integrated with a solar parabolic trough collector is studied in this paper. Moreover, the effects of different mass flow rates on the total charging capacity, total exergy input, total exergy storage and exergy efficiency of the system are investigated. The result indicates that the steady-state and unstable-state inlet boundary conditions show significant differences in thermal performance. Under the unstable-state boundary conditions, when the mass flow rate increases from 0.1 to 0.2 kg/s and 0.1–0.4 kg/s, the maximum temperature difference between the PCM capsules and the air decreases to 24.11% and 47.39%, respectively. The larger the mass flow rates, the smaller the temperature difference, which is the opposite of the steady-state situation. Under steady-state inlet temperature conditions, the exergy efficiency gradually decreases with the increase of mass flow rate. Under unstable-state inlet temperature conditions, the mass flow rate has little effect on the exergy efficiency, and which is about 41.00%. • The packed-bed latent heat storage system integrated with the solar parabolic trough collector is modeled. • The thermal performance under the steady-state and unstable-state inlet boundary conditions is compared. • The instantaneous energy efficiency decreases as the mass flow rates increases. • The exergy efficiency is about 41.00% under unstable-state inlet temperature conditions. [ABSTRACT FROM AUTHOR]

Summary: This paper concerns the ongoing studies on a Concentrated Solar Power (CSP) plant in operation in Ottana (Italy), comprising a 629 kW organic Rankine cycle (ORC) unit fed by a linear Fresnel solar field. Hexamethyldisiloxane (MM) and "Therminol SP‐I" are used respectively as ORC working fluid and heat transfer fluid in the solar receivers. A two‐tank direct Thermal Energy Storage (TES) system is currently integrated in the CSP plant, serving as a direct interface between solar field and ORC. With the view of improving the solar facility, two alternative TES configurations were proposed in this study: a one‐tank packed‐bed TES system using silica as solid storage media and another similar one including encapsulated phase‐change material (molten salt). Comprehensive mathematical models were developed for simulating daily behaviour as well as for assessing yearly performance of the various TES technologies. Furthermore, a preliminary economic analysis was carried out. Results showed poorer response of the one‐tank TES system to large fluctuations in the ORC inlet fluid temperature, leading to reduction in the mean ORC efficiency (18.2% as against 19.7% obtained with the two‐tank TES). Conversely, higher energy storage density and lower thermal losses were obtained adopting the one‐tank TES, resulting in about 5% more annual solar energy yield. Invariably, equivalent annual ORC energy production of 0.92 GWh/year was obtained for the three TES configurations. Additionally, adopting a one‐tank TES system meant that the purchase costs of a second tank and its storage medium (thermal oil) could be saved, resulting in investment costs about 45% lower and, ultimately, levelized cost of storage about 48% lower than what obtains in the two‐tank TES system. [ABSTRACT FROM AUTHOR]

The current paper investigates the radial gradient arrangement of phase change material capsules effect on the thermal behavior of a packed-bed latent thermal energy storage system. A transient two-dimensional dispersion-concentric model is developed to analyze the phase transition of phase change materials. Moreover, the heat transfer characteristics between air and phase change material capsules in four different packed bed systems are discussed in detailed. The results indicate that the use of radial gradient arrangement in the phase change material capsules significantly enhances the heat transfer performance of the system. The system pressure drop is apparently decreased when the radial gradient arrangement is taken into consideration. From case 1 to case 4, the overall energy efficiency is 84.16%, 80.43%, 83.55%, and 82.46%, respectively. The capacity ratio of case 1 is higher than all studied cases by 5.03%, 1.11%, and 3.74%, respectively. The utilization ratio of case 1 is higher than all studied cases by 5.15%, 1.45%, and 3.43%, respectively. Furthermore, considering the loss of pressure drop, it is found that case 3 is the most viable option of all the studied cases. This study provides a numerical basis for the thermal stability output and the structure optimization of packed bed system. • A new packed-bed LTES system with radial gradient arrangement is suggested to improve the thermal performance. • The thermal performance of four different layouts is compared. • The radial gradient arrangement is proposed to reduce the pressure drop. • The use of radial gradient arrangement significantly enhances heat transfer performance of the system. [ABSTRACT FROM AUTHOR]

The viscosity η m of dense fluid mixtures of carbon dioxide and ethanol was determined from the pressure drop between the inlet and outlet of a packed bed using the Ergun equation at temperatures from 313.2 K to 343.2 K and pressures from 15 MPa to 30 MPa over the entire range of ethanol composition. The η m values for the fluid mixtures decreased with increasing temperature and increased with increasing pressure under isocratic conditions. In addition, the values measured η m with Ergun eq. were correlated with the equation combining the Eyring theory and the perturbed chain statistical associating fluid theory equation of state (PC-SAFT EoS) and with that based on the rough hard-sphere (RHS) model proposed by Dymond and Assael. The accuracies of the Eyring + PC-SAFT EoS and the RHS model were 8.7% and 12%, respectively, in terms of average relative deviation for 80 conditions over the entire range of ethanol composition. [Display omitted] • Ergun equation described pressure drop of dense CO 2 +ethanol flowing in packed bed. • Constants in Ergun equation were modified as functions of temperature and pressure. • Viscosity of dense mixture was determined in packed bed by Ergun equation. • Combined method of Eyring theory+PC-SAFT EoS well expressed CO 2 +ethanol viscosity. [ABSTRACT FROM AUTHOR]

Based on the local thermal non-equilibrium theory, a modified transient two-dimensional numerical model is developed to investigate the simultaneous charging and discharging performance of a molten-salt packed-bed thermocline tank employed in concentrated solar power plants. Two different types of operation including that of stable and periodic charging with steady discharging are analyzed. Three different solid fillers are utilized, including quartzite rock, slag pebbles, and alumina ceramics. The effects of charging/discharging flow rate ratio and non-charging periods on thermocline thickness and energy storage power have been investigated. The results show significant influences of the charging/discharging flow rate ratio. When charging is steady, the discharge performance of a packed-bed tank is better than that of a pure molten-salt tank at lower flow rate ratios. The thermocline thickness of the packed-bed tank is higher than that of a pure molten-salt tank for different solid materials. Compared with quartzite rock and slag pebbles, alumina ceramics achieves a higher thermal gradient. In periodic charging mode, as the cycle's number of charging periods increases, thermocline thickness increases linearly. Operating at higher charging rates and shorter non-charging periods, the discharge outlet temperature of molten-salt becomes more stable for the steam generation process and hence, the discharge performance is improved. [Display omitted] • Simultaneous operation of molten-salt energy storage in porous packed-bed tank presented. • Local non-equilibrium thermal model for simultaneous operation adopted. • Periodic and stable charging with simultaneous discharging process of molten-salt tank investigated. • Influences of flow rate mixing ratio, non-charging period and charging flow rate revealed. [ABSTRACT FROM AUTHOR]

The primary objective of the present research study was to characterize the process of water hardness adsorption in rocks from the Tungurahua and Reventador volcanoes (Ecuador) by using fixed beds. The study was performed on natural material and chemically treated substrates in an alkaline medium to generate negative surface sites. The chemical composition, surface area, porosity, and pH of igneous materials were determined. From the adsorption tests, the results show that the hardness retention capacity depends on the total contents of amphoteric oxides of iron, aluminum, and titanium. The Tungurahua volcano bed showed a higher yield (65.5%) than the Reventador bed (41.6%). It is concluded that the adsorption system examined here is an innovative, simple, economic, and sustainable alternative for treating hard water that can be applied to improve water quality for domestic and agricultural use in low-income communities. [ABSTRACT FROM AUTHOR]

• Laboratory scale packed bed TES was developed to store heat at medium temperatures. • The new STESM developed from demolition wastes was used as packing material. • Demolition waste as STESM was more efficient and cheaper than alternatives. • The results from lab-scale packed-bed with new STESM will be valuable for scaling up. Thermal energy storage (TES) is essential for cost-effective use of solar energy in industries. The most energy intensive processes in industry operate below 200 °C. This study tested a new sustainable and low-cost sensible thermal energy storage material (STESM) based on demolition wastes in a lab-scale packed bed TES system, specifically built to analyze its performance in industrial solar applications below 200 °C. This system was investigated both experimentally and numerically under different operating conditions. One-dimensional continuous phase model used verified that experimental results were in good agreement with numerical ones during charging and discharging steps. Performance of demolition waste STESM was compared with Therminol 66 synthetic oil as a liquid heat storage media. The maximum system energy efficiency of the packed-bed filled with demolition waste STESM was 67% at charging temperature of 150 °C and superficial fluid velocity of 0.95 mm s−1, while it was 63% for Therminol 66. Packed bed TES system with demolition waste STESM showed good performance up to 180 °C in fully laminar flow regime (Re p < 10) and Bi number < 0.1. The material cost of demolition waste STESM is at least tenfold cheaper than the alternative natural rock based packing materials. Packed bed TES systems using demolition wastes can be recommended for low cost and sustainable solar applications in industry. [ABSTRACT FROM AUTHOR]

The paper aims to study the impact of Thermal Energy Storage (TES) technology on the dynamic characteristics of Concentrated Solar Power (CSP). An integrated dynamic model of a CSP plant is firstly established, which combines the concentrating system, the TES system, and S–CO 2 Brayton power cycle system. Three TES alternatives are considered: two-tank molten salt TES (TT-TES), packed-bed TES with solid fillers (PBS-TES), packed-bed TES with phase change materials (PBP-TES). Using this integrated dynamic model, the thermal performance and economic feasibility of different TES technologies applied to CSP are compared and analyzed. The results indicate that utilization of packed-bed TES primarily impacts the optical efficiency of the heliostat field and the thermal efficiency of the power cycle, while having minimal effect on the receiver's thermal efficiency. Furthermore, during the vernal equinox, the daily average system efficiencies of CSP configurations integrating TT-TES, PBS-TES, PBP-TES technologies are 26.0 %, 25.5 %, and 24.5 %, respectively. Meanwhile, the use of packed-bed TES systems significantly reduces the material cost of the TES. In comparison to the TT-TES, the PBP-TES and the PBS-TES can reduce cost by 21.2 % and 42.3 %, respectively, and decrease TES volume by 83.0 % and 63.8 %, respectively. • An integrated dynamic model of a concentrated solar power is established. • The influence of three TES technologies on the dynamic characteristics of CSP is studied. • The TES technologies include two-tank molten salt TES, packed-bed TES with solid fillers, and packed-bed TES with PCMs. • Packed-bed TES affects charging and discharging processes, causing energy loss. • Packed-bed TES reduces cost and volume compared to two-tank molten salt TES. [ABSTRACT FROM AUTHOR]

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has demonstrated the value of pursuing different vaccine strategies. Vaccines based on whole viruses, a widely used vaccine technology, depend on efficient virus production. This study aimed to establish SARS-CoV-2 production in the scalable packed-bed CelCradleTM 500-AP bioreactor. CelCradleTM 500-AP bottles with 0.5 L working volume and 5.5 g BioNOC™ II carriers were seeded with 1.5 × 108 Vero (WHO) cells, approved for vaccine production, in animal component-free medium and infected at a multiplicity of infection of 0.006 at a total cell number of 2.2–2.5 × 109 cells/bottle seven days post cell seeding. Among several tested conditions, two harvests per day and a virus production temperature of 33 °C resulted in the highest virus yield with a peak SARS-CoV-2 infectivity titer of 7.3 log10 50% tissue culture infectious dose (TCID50)/mL at 72 h post-infection. Six harvests had titers of ≥6.5 log10 TCID50/mL, and a total of 10.5 log10 TCID50 were produced in ~5 L. While trypsin was reported to enhance virus spread in cell culture, addition of 0.5% recombinant trypsin after infection did not improve virus yields. Overall, we demonstrated successful animal component-free production of SARS-CoV-2 in well-characterized Vero (WHO) cells in a scalable packed-bed bioreactor.

• Steel making slag pebble as reliable storage medium in central receiver systems. • Metallurgical by-product waste revalorized as a cost-effective storage material. • Comparison between slag pebble and other thermocline filler materials. • Slag pebble used as packed-bed filler in a solar hybrid storage configuration. • The pumping tanks allow to increase the maximum thermocline tanks storage capacity. This work focuses on the reliable use of the steel making slag pebble as filler material of thermocline tanks which are combined with conventional molten salt tanks in a hybrid thermal storage configuration. The use of this hybrid configuration not only improves the efficiency and operation of the plant when there is solar radiation fluctuation but also includes pumps in separate molten salt tanks in order to increase the maximum height of the thermocline tanks and its useful storage volume, i.e. its storage capacity. A packed-bed numerical model has been used to study the potential of the slag pebbles in this hybrid storage configuration, comparing it against other well-known potential filler materials for thermocline tanks as the taconite and quartzite rock. The study carried out considers a storage capacity of 9 full load hours for a central receiver system of 110 MWe gross power. The results show that two thermocline tanks of 20 × 20 m, filled with steel making slag pebbles, reaches a capacity of 6.61 full load hours. An economic analysis is included which shows that the hybrid storage solution using slag pebbles represents a cost reduction of 13.7% against the state of the art solution. Additionally, comparing it against other filler materials, the slag hybrid storage solution has a cost reduction of 3.8% and 13% against the quartzite and taconite hybrid storage solution, respectively. [ABSTRACT FROM AUTHOR]

Highlights • High-temperature packed-bed thermal energy storage of volume 175,000 m3 is studied. • One-dimensional, two-phase transient model is developed. • Parametric study is carried out to analyze the dynamic behavior. • Energy and exergy efficiencies exceeded 98% for most of the cases investigated. Abstract The packed-bed thermal energy storage technology has gained a significant market worldwide as it offers a huge potential for high-temperature air based storage with no adverse environmental impact. The present paper numerically investigates a high-temperature 175,000 m3 truncated conical shaped packed-bed thermal energy storage. One-dimensional, two-phase model is developed to simulate the transient behavior of the storage where the energy balance of both phases, the fluid and the solid, are based on modified equations of the Schumann model. The model developed is used to carry out a parametric study where it is subjected to different design and operating parameters such as storage shape, rock diameter, charge-discharge rate and insulation thickness. The storage performance is assessed through energy and exergy efficiencies taking energy stored and recovered into account. The model satisfactorily predicts the dynamic behavior of a large-scale packed-bed storage system within the range of parameters investigated. Results obtained denote that the truncated conical shaped storage with rock diameter of 3 cm, insulation thickness up to 0.6 m and charging-discharging rate of 553 kg/s leads to lower thermal losses estimated under 1% of the energy recovered during discharge. Furthermore, energy and exergy efficiencies of thermal cycles are found to exceed 98% for most of the selected parameters in the study. The model developed can assist in identifying more advance and cost-effective storage design solutions for a large-scale application. [ABSTRACT FROM AUTHOR]

Abstract This work investigates the behavior during freeze-drying of packing structures formed by spray-frozen microparticles. A multi-scale approach is used to study spray freeze-drying, and in particular, mass transfer during primary drying and its duration. The procedure starts with the generation of realistic packings of microparticles using DEM, and CFD simulations are used to determine some relevant characteristics at pore scale, i.e., porosity, tortuosity, the average size of the particle-to-particle voids, and permeability. Finally, these parameters are used to describe mass transfer within the packed-bed. This procedure is used to describe some actual case studies and evaluate drying time and mass transfer resistance within the packing. We also investigated the role of packing structure on freeze-drying by generating packings from monodisperse and Gaussian-polydisperse microparticles, demonstrating that polydispersity increased the mass transfer resistance, and, finally, drying time. Graphical abstract Unlabelled Image Highlights • A multi-scale approach was proposed to investigate freeze-drying of microparticles. • DEM and CFD were used to estimate structural parameters of microparticles in packed-bed. • The procedure was experimentally validated upon data from the literature. • Packing structure had a significant influence on mass transfer resistance and drying time. [ABSTRACT FROM AUTHOR]

Sulfur-packed beds (SPBs) have been increasingly incorporated into constructed wetland systems to overcome limitations in achieving satisfactory nitrate removal efficiency. However, the underlying impact of hydraulic regimes on SPB performance remains understudied. This study investigated the performance of a pilot-scale SPB, encompassing sulfur autotrophic denitrification (SAD) and sulfur disproportionation (SDP) processes, under various horizontal flow (HF) and vertical flow (VF) regimes. The HF regime exhibited superior SAD efficiency, achieving 3.1–4.4 mg-N/L of nitrate removal compared to 0.9–2.8 mg-N/L under VF regimes. However, greater sulfide production of 3.8–5.6 mg/L was observed, in contrast to only 1.5–2.3 mg/L under VF regimes when SDP occurred. Employing current computational fluid dynamics simulations could predict general regimes but lacked precision in detailing sulfur layer dynamics. In contrast, determining the spatial distribution of SAD substrates and SDP products offered a viable solution, revealing stagnate, short-circuit, and back flows. Moreover, the feasibility of an aeration approach to reduce sulfide emissions below 0.5 mg/L in case of accidental SDP occurrence was confirmed. This study offers a method for assessing detailed hydraulic regimes within SPBs. Additionally, it provides guidance on optimizing the packing of sulfur-based materials when implementing SPBs in constructed wetland systems and presents a strategy for mitigating excessive sulfide emissions. [Display omitted] • SAD and SDP processes were alternatively achieved in a pilot-scale SPB. • The detailed hydraulic regimes within the sulfur layer were determined. • Horizontal flow improved SAD efficiency but concurrently elevated SDP risk. • Equipping aeration devices was suggested to address sudden spikes in SDP. [ABSTRACT FROM AUTHOR]

Packed-bed thermal energy storage (PBTES) systems utilizing phase change capsules have found extensive applications in thermal energy harvesting and management to alleviate energy supply-demand imbalances. Nevertheless, the sluggish thermal charging rate of phase change materials (PCMs) capsules remains a significant impediment to the rapid advancement of PBTES. Here, bionic PCMs capsules are proposed by mimicking the internal and external structure of chloroplast-granum. The heat transfer and flow characteristics of the bionic PCMs capsules in the packed-bed are analyzed by experiments and numerical simulations. The results illustrate that the chloroplast-fin type PCMs capsule exhibits significantly faster heat storage compared to the sphere type PCMs capsule. This improvement is attributed to the bionic folded shape and inner membrane structure, which generate multiple local vortices to enhance heat convection, and shorten the heat transfer distance between the capsule wall and center PCMs to facilitate heat conduction. The PCMs capsules are further filled into the packed-bed in a staggered arrangement, resulting in increased heat transfer area and enhanced disturbance flow as compared to an aligned arrangement. Consequently, the melting time of the packed-bed filled with chloroplast-fin type capsules is reduced by 33.2%, meanwhile the average exergy storage rate and exergy efficiency are enhanced by 48.4% and 8.3%, respectively, compared to the packed-bed filled with sphere type capsules. This research offers a novel approach for designing high-performance PBTES system utilizing bionic capsules. • Chloroplast-granum inspired PCMs capsules are proposed for fast thermal charging. • Heat transfer mechanism is revealed for the bionic capsules and the packed-beds. • Chloroplast-fin type PCMs capsules reduce the melting time by 49.9%. • Packed-beds with bionic capsules increase the exergy efficiency by 8.3%. [ABSTRACT FROM AUTHOR]

In a 10-ton capacity pilot plant solar liquid desiccant air conditioner (LDAC) developed, dehumidification of the outside air is achieved through a honeycomb packed-bed heat and mass exchanger, using lithium chloride solution as the desiccant. The dry air obtained from the dehumidification process is evaporative cooled inside a cooling pad and directed into the conditioned space. The dilute solution thus produced is concentrated in a honeycomb packed-bed scavenger air regenerator using hot water from flat plate solar collectors. Carryover of the desiccant particles has been avoided by using eliminators. The air conditioner was installed on a 250 m2 area of the fluid mechanics laboratory of Babol University of Technology, a hot and humid location in the north on the Caspian Sea. The experimental data obtained were compared with the predicted results of a model developed for the air conditioner based on HYSIS and CARRIER energy soft-wares. The comparison reveals that good agreement exists between the experiments and the model predictions. The above tests further reveal that the unit has a satisfactory performance in independently controlling the air temperature and humidity of the conditioned space. The inaccuracies are well within the measuring errors of the temperature, humidity and the air and solution flow rates. An efficient heat recovery within the air conditioner resulted in a thermal COP of about 1.5 and an electrical COP of 7. A commercialization study reveals that the operating cost of an LDAC is significantly lower than its conventional counterpart. The costs would further reduce if a storage system was used to store the concentrated solution of liquid desiccant. A simple payback of five years was determined for the solar components of the liquid desiccant system in this study.

Currently, energy storage systems are considered a key solution when mismatch occurs between energy supply and demand, allowing a more efficient energy deployment and use. The present paper is focused on the study of a latent heat thermal energy storage (LHTES) system based on a packed bed of encapsulated phase change material (PCM) of spherical shape, conceived as an auxiliary component of a micro-grid to be built in a Research Center located in southwestern Sardinia (Italy). The main purpose of this work was to perform numerical simulations for predicting the performance of the TES system, designed to store the surplus thermal energy produced during the weekend by a heat pump fed by a photovoltaic (PV) plant. The stored energy would then be utilized during the weekdays to integrate the air-conditioning system supply. The numerical simulations were based on a one-dimensional (1-D) two-equation transient model, able to return the thermocline profile of the water and the PCM separately. The behavior of the LHTES device during charge and discharge phases was reproduced, as well as during the standby periods. Finally, two characteristic indexes of the PV system were evaluated, to investigate the effect of TES on grid interchanges, self-consumption, and self-sufficiency.

This is a theoretical study about the influence of turbulence on momentum and heat transport in a packed-bed with low tube to particle diameter ratio. The hydrodynamics is given here by the time-averaged Navier-Stokes equations including Darcy and Forchheimer terms, plus a κ-ε two-equation model to describe a 2D pseudo-homogeneous medium. For comparison, an equivalent conventional flow model has also been tested. Both models are coupled to a heat transport equation and they are solved using spatial discretization with orthogonal collocation, while the time derivative is discretized by an implicit Euler scheme. We compared the prediction of radial and axial temperature observations from a packed-bed at particle Reynolds numbers (Rep) of 630, 767, and 1000. The conventional flow model uses effective heat transport parameters: wall heat transfer coefficient (hw) and thermal conductivity (keff), whereas the turbulent flow model includes a turbulent thermal conductivity (kt), estimating hw via least-squares with Levenberg-Marquardt method. Although predictions of axial and radial measured temperature profiles with both models show small differences, the calculated radial profiles of the axial velocity component are very different. We demonstrate that the model that includes turbulence compares well with mass flux measurements at the packed-bed inlet, yielding an error of 0.77 % in mass flux balance at Rep = 630. We suggest that this approach can be used efficiently for the hydrodynamics characterization and design and scale-up of packed beds with low tube to particle diameter ratio in several industrial applications. [ABSTRACT FROM AUTHOR]

Highlights • The valorisation of steel slag as low cost TES material is proposed. • The compatibility between a molten nitrate salt (Solar Salt) and steel slag is investigated. • All corrosion mechanisms occurring between the salt and the slag are not detectable with XRD and SEM. • A deeper analysis of the salt and slag chemical compositions revealed a migration of cations. • The migration mechanism leads to the modification of the thermo-physical properties of the salt. Abstract Thermal energy storage (TES) systems based on packed bed arrangements are proven to be a very promising route to decrease the levelized cost of electricity (LCOE) in concentrated solar power (CSP) plants. However, the compatibility between the TES material and the heat transfer fluid (HTF), which operate in direct contact, is known to be a major limitation for such configuration. In this regard, the compatibility between a molten nitrate salt (Solar salt) and a ceramic by-product from the steel production, the steel slag, is investigated in this work. The obtained results show that the standard criteria used for determining any chemical incompatibility phenomena like the formation of a corrosion layer or the appearance of structural modifications, are not enough to draw a conclusion on the materials compatibility. A deep analysis of the TES material and the HTF chemical compositions revealed a migration of cations from the slag to the salt, and the formation of nitrites in the latter boosted by the presence of the slag. These two mechanisms lead to the modification of the thermo-physical properties of the salt. [ABSTRACT FROM AUTHOR]

Molten-salt packed-bed thermal energy storage using thermocline technology is more cost-competitive than the conventional two-tank thermal energy storage, due to its integrated design and the employment of a low-cost packed-bed. However, such a storage configuration suffers the main drawback of a low capacity factor when applied to concentrating solar power because of the adoption of conservative cut-off temperatures. The present work evaluates the feasibility of taking less conservative cut-off temperatures to improve the utilization of the packed-bed thermal energy storage from the perspectives of a system-level operation and storage economy. The investigations are carried out on two levels. The first-level investigation reveals the effects of both the charging and discharging cut-off temperature on the thermal performance of the packed-bed thermal energy storage under ideal operating conditions. Three typical packed-bed configurations are involved. The results show that the capacity factor of the packed-bed thermal energy storage increases as the charging cut-off temperature increases and the discharging cut-off temperature decreases, especially for the configurations using latent-heat when the adopted cut-off temperatures jump over the phase change points of the encapsulated phase change materials. The second-level investigation discusses the impacts of different levels of deep charges (using high charging cut-off temperatures) on the scale design of the packed-bed thermal energy storage, the daily operation of the low temperature molten-salt pump (LT-pump) and the central receiver of a 100 MW e conventional concentrating solar power tower plant. The results indicate that a deeper charge operation is always accompanied with a smaller required packed-bed size as well as a higher required delivery capacity and higher pressure head of the LT-pump and that it always results in a larger daily pumping consumption, a higher peak inlet temperature ramping rate and a higher receiver pressure drop. The maximum allowable charging cut-off temperature is identified to be 500 °C for each packed-bed configuration, according to the operating limitations on the pump and receiver. Moreover, a cost analysis is carried out to obtain the optimum charging cut-off temperature for each packed-bed configuration. The obtained results show that performing deep charges with the cost-optimized charging cut-off temperatures can effectively improve the cost competitiveness of the molten-salt packed-bed TES integrated into concentrating solar power plants. [ABSTRACT FROM AUTHOR]

Yersiniabactin, a nonribosomal peptide-polyketide complex natural product with a strong affinity for metals, was immobilized to a polymeric XAD16 resin (forming Ybt-XAD) and used as packing for a successive series of columns designed for scaled removal of Cu 2+ , Mg 2+ , and Ni 2+ from industrial wastewater. Ybt-XAD showed regenerative capacity for two cycles in metal removal and a relatively higher degree of selective for copper within the largest column (5 × 50 cm). System pH variation influenced metal removal and the potential for metal recovery (or stripping) from the column setup. The system was also characterized using Thomas and dose response models for the 2.5 × 10 cm column, providing valuable information on the resin capacity of Cu 2+ , Mg 2+ , and Ni 2+ to inform future column designs for enhanced metal removal. [ABSTRACT FROM AUTHOR]

Thermal management of highly exothermic Fischer‐Tropsch synthesis (FTS) has been a challenging bottleneck limiting the radial dimension of the packed‐bed (PB) reactor tube to 1.5 in. ID. A computational demonstration of a novel microfibrous entrapped cobalt catalyst (MFECC) in mitigating hot spot formation has been evaluated. Specifically, a two‐dimensional (2‐D) model was developed in COMSOL®, validated with experimental data and subsequently employed to demonstrate scale‐up of the FTS bed from 0.59 to 4 in. ID. Significant hot spot of 102.39 K in PB was reduced to 9.4 K in MFECC bed under gas phase at 528.15 K and 2 MPa. Improvement in heat transfer within the MFECC bed facilitates higher productivities at low space velocities (≥1000 h−1) corresponding to high CO conversion (≥90%). Additionally, the MFECC reactor provides an eightfold increase in the reactor ID at hot spots ≤ 30 K with CO% conversions ≥ 90%. This model was developed for a typical FTS cobalt‐based catalyst where CO2 production is negligible. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1723–1731, 2018 [ABSTRACT FROM AUTHOR]

In the study, a transient, two-dimensional and axisymmetric model of the packed-bed thermocline tank is developed. Based on the model, the cyclic thermal performance of a traditional Single-Layered and of a novel Multi-Layered Packed-Bed molten salt Thermocline Tank (SLPBTT, MLPBTT) are analyzed. First, the analysis of cyclic thermal performance of SLPBTT shows the performance can be enhanced by reducing the retention thermocline thickness. Second, this is the first time for a detailed investigation of the expanding and the shortening effects on thermocline thickness at the interface between two kinds of filler. In addition, a novel MLPBTT is designed utilizing the above interface effects for improving the performance by controlling thermocline expansion. Finally, the studies on the performance of MLPBTTs adopting three fillers (quartzite rock, cast iron, and high-temperature concrete) with different heights present that the useful energy can be increased while thermal efficiency will be reduced with the increasing cast iron's height. An optimized MLPBTT shows a significant improvement in the useful energy of 10.5% and a small drop in thermal efficiency of 2.1% in discharging process compared with those of SLPBTT using the quartzite rock. The results can be beneficial for the design and optimization of PBTT. [ABSTRACT FROM AUTHOR]

Numerical simulations of chromatography are conventionally performed using reduced-order models that homogenize aspects of flow and transport in the radial and angular dimensions. This enables much faster simulations at the expense of lumping the effects of inhomogeneities into a column dispersion coefficient, which requires calibration via empirical correlations or experimental results. We present a high-definition model with spatially resolved geometry. A stabilized space–time finite element method is used to solve the model on massively parallel high-performance computers. We simulate packings with up to 10,000 particles. The impact of particle size distribution on velocity and concentration profiles as well as breakthrough curves is studied. Our high-definition simulations provide unique insight into the process. The high-definition data can also be used as a source of ground truth to identify and calibrate appropriate reduced-order models that can then be applied for process design and optimization. • Stabilized space–time finite element method used on massively parallel computers. • Packed bed chromatography simulated at unprecedented spatial resolution. • Packings with up to 10.000 particles simulated. • Impact of particle size distribution and wall effects on band broadening quantified. • Calibration data for reduced order models generated. [ABSTRACT FROM AUTHOR]

[Display omitted] • Efficient nitrogen removal was achieved under influent nitrate and temperature variation. • Nitrate removal loading was more sensitive to temperature than other factors. • Nitrogen gas was the prominent inducement to clogging. • Using gas-venting could save 90% time and energy than conventional back-washing. • No functional instability or "treatment short-circuit" occurred in S0AD biofilter. Elemental sulfur autotrophic denitrification (S0AD) is viewed as a promising alternative to conventional heterotrophic denitrification due to lower running costs, zero carbon dioxide emission, and minimum excess sludge production. However, its scale-up capability and robustness in treating real-life wastewater have not been convincedly demonstrated. In this study, a pilot-scale S0AD packed-bed with over 1000 m3/d of actual wastewater treatment capacity was operated for 197 days. The S0AD packed-bed could effectively remove nitrate to below 12 mg-NO 3 −-N/L that is 20% stricter than China's national standard (15 mg-TN/L). The temperature effect coefficient Q 10 was calculated as 1.01, illustrating that denitrification efficiency could be doubled when the temperature increased every 10 °C. Mass balance calculations indicated that 85% of removed nitrate was contributed by S0AD process, and the rest 15% was by heterotrophic and assimilative processes. A total of 2684 kg sulfur was consumed during the course of the experiment which was attributed to 16.1% DO oxidation and 83.9% denitrification. Nitrogen gas produced through denitrification, could be trapped in the S0 packed-bed that was the primary causality of clogging. Daily gas venting instead of conventional back washing, could effectively recover the packed-bed flux and promote denitrification efficiency. In addition, a weekly thorough back washing was deemed necessary to deeply clean the trapped SS and sloughed overgrowing biofilm. The predominant S0AD bacteria belonged to the genus Thiobacillus, was enriched throughout the packed-bed providing robust and stable denitrification. Overall, we provided some guidance to the design and operation of S0AD packed bed in practical engineering. [ABSTRACT FROM AUTHOR]

The sensible heat storage in low-cost secondary fillers using a single tank thermocline system offers a cost-effective storage option for concentrating solar power (CSP) plants. A comprehensive numerical simulation of 125 MWh t thermocline tank is performed by adopting a transient, two-dimensional, two-phase model to investigate the thermal performance of packed-bed thermocline thermal energy storage (PBTC-TES) system. The effect of relevant design and operating parameters on the performance of TES system are examined by analysing the thermocline expansion and local variation of salt and filler temperature. It is observed that the operating temperature difference (ΔT) has ample role on thermal performance of TES system as the efficiency is found to reduce by 12% with increase in ΔT from 50 K to 150 K. Discharging efficiency is estimated to be high at low operating temperature ranges and tend to decrease with increase in ΔT. Also with increase in power output, discharging efficiency tends to reduce slightly since it demands higher flow rates and operating temperature range. In case of inlet salt velocity, discharging efficiency drops by 3.5% when velocity is increased thrice the initial value. Further, a comparative study is performed to figure out the most dominant efficiency determining operating parameter. It is observed that relative to inlet salt velocity, operating temperature range seems to have more influence on the thermal performance of TES system. When the operating range is increased from 50 to 150 K, efficiency drops by about 10% whereas a reduction of only 2.5% is observed when power output is increased from 15 to 35 MW t for similar ΔT values. Hence, operating temperature range is identified as the dominant efficiency determining parameter of PBTC-TES system. [ABSTRACT FROM AUTHOR]

In a recent paper, box-shaped or cuboid packed bed devices have been proposed as alternative to columns for chromatographic separations. We first propose a mathematical model for residence time distribution in such devices. Based on it, we examine factors likely to affect separation performance, and verify the predictions of our mathematical model by conducting tracer experiments. We then compare the performance of two commercial columns with their respective equivalent cuboid packed-bed devices, i.e. containing the same chromatographic media, and having the same bed-height and bed-volume. Parameters compared include the number of theoretical plates, attributes of flow-through and eluted protein peaks, and resolution in model binary protein separations. For each of these metrics examined, the cuboid packed-bed device outperformed its equivalent commercial column. Other potential advantages likely to be gained from using a cuboid packed-bed instead of a column are elucidated. [ABSTRACT FROM AUTHOR]

Chemical looping combustion with methane as fuel in a packed-bed reactor using Ni as oxygen carrier was numerically investigated. To this aim, a mathematical model that takes into account both oxidation and reduction phases was developed. To describe catalyst fouling due to carbon deposition, CH 4 decomposition and carbon regasification by steam and CO 2 (Boudouard reaction) were considered during reduction phase, while carbon combustion was taken into account during oxidation phase. A catalyst deactivation function due to carbon accumulation on oxygen carrier was introduced too. In the paper the effects of fouling on the operability of packed-bed reactor was studied, focusing the attention on the switch strategy adopted. Results show that a detailed description of carbon deposition and consumption phenomena is an essential prerequisite to properly operate a CLC process. Indeed, it was found that working with variable oxidation and reduction time lengths, the power produced is about three times greater than of that obtainable operating with fixed times. Although carbon deposition can be also reduced by increasing the H 2 O:CH 4 feed ratio, it was found that in this case the power produced decreases by about 30% with respect to that obtained operating with variable oxidation and reduction time lengths. [ABSTRACT FROM AUTHOR]

• Unified thermo-economic optimisation framework for compressed-air energy storage. • Comparison of different configurations and materials at different scales. • Packed-bed stores perform better than liquid stores under the studied conditions. • Roundtrip efficiencies of up to 76% can be attained by these systems. • Costs of 140 $/kWh and 970 $/kW can be achieved for 50 MW and 300 MWh systems. Compressed-air energy storage is an attractive option for satisfying the increasing storage demands of electricity grids with high shares of renewable generation. It is a proven technology that can store multiple gigawatt hours of electricity for hours, days and even weeks at a competitive cost and efficiency. However, compressed–air energy storage plants need to be designed carefully to deliver these benefits. In this work, a consistent thermo-economic optimisation framework is applied to assess the performance and costs of different compressed–air energy storage configurations across different scales. Special attention is paid to the thermal energy stores, with both solid packed-bed stores and liquid stores examined as viable options for advanced compressed–air energy storage plants and different storage materials proposed for both options. The comprehensive thermo-economic optimisation, considering different system layouts, thermal energy storage technologies and storage materials, and system scales is a key novelty of the presented work. A configuration with two packed–bed thermal energy stores using Basalt as the storage material is found to perform best, achieving an energy capital cost of 140 $/kWh, a power capital cost of 970 $/kW and a roundtrip efficiency of 76% at a nominal discharge power of 50 MW and a charging / discharging duration of 6 h. The best-performing liquid storage material is solar salt, which is associated with an energy capital cost of 170 $/kWh and a power capital cost of 1,230 $/kW. Systems with liquid thermal energy stores however are found generally to perform worse than systems with packed–bed thermal energy stores both in terms of cost and efficiency across all scales. [ABSTRACT FROM AUTHOR]

The lack of mass-producible, high-performance medium-high temperature phase change materials (PCMs) is one of the core problems restricting the efficient utilization and application of renewable energy. In this paper, a new type of composite phase change materials (CPCMs) based on starch pore-forming porous SiC ceramic skeleton combined with high enthalpy ternary chloride (NaCl–KCl–MgCl 2) is proposed. The preparation process of CPCMs is optimized, and many characterization and experimental studies are carried out. The SiC skeleton with adjustable porosity (48%–75%) and robust structure is obtained by simple starch pore-forming, cold pressing, and high-temperature sintering. After 200 repeated charging-discharging cycles, the structure of the SiC skeleton/paraffin composite (porosity: 60%; thermal conductivity: 19.72 W m−1 K−1) is intact, with no obvious leakage and only a 3.06% decrease in thermal conductivity, which proves its excellent cycle thermal stability. The thermal conductivity of the CPCMs-60% impregnated with ternary chloride under negative pressure is 22.65 W m−1 K−1, and the effective heat storage density is 513.462 kJ kg−1 in the temperature range of 300–500 °C. In addition, a large number of cylindrical CPCMs batteries are fabricated by this process, and a series of systematic experimental studies are carried out in the laboratory. The temperature changes throughout the charge-discharge process and the effects of the flow rates of different heat transfer fluids on the thermal performance of the system are studied in detail. All of them verified the high charge-discharge rate and thermal performance of CPCMs batteries. This work provides a promising strategy for the development and industrial application of high-temperature packed bed heat storage systems for renewable energy integration. [ABSTRACT FROM AUTHOR]

Odor control has gained importance for ensuring a comfortable living environment. In this paper, the authors report the experimental results of a study on the detailed characteristics of a laminated film-electrode and a laminated film-electrode packed-bed nonthermal plasma reactor, which are types of dielectric barrier discharge (DBD) reactor used for odor control. These plasma reactors can be potentially used for the decomposition of volatile organic compounds (VOCs) and reduction of NOx. The reactor is driven by a low-cost 60-Hz neon transformer. Removal efficiencies under various experimental conditions are studied. The complete decomposition of the main odor component, namely, NH3, is achieved in a dry environment. The retention times are investigated for the complete removal of NH3 in the case of the film-electrode plasma reactor and the film-electrode packed-bed plasma reactor. The removal efficiency of the former reactor is lower than that of the latter reactor. Mixing another odor component such as CH3CHO in the gas stream has no significant effect on NH3 removal efficiency.