Bed Porosity Research Articles

An experimental investigation on debris bed formation from fuel coolant interactions of metallic and oxidic melts

During postulated severe accidents in a light water reactor (LWR), the core melt (corium) may relocate to the lower head and fail the reactor pressure vessel (RPV). The corium is expected to undergo fuel coolant interactions (FCI) if the reactor cavity is flooded with water. Both FCI energetics and resulting debris bed coolability are of paramount importance to reactor safety, since the ex-vessel corium poses a threat to the containment integrity if steam explosion occurs or the debris bed is uncoolable, leading to release of radioactive fission products to the environment. The present study is intended to quantify the characteristics of a debris bed resulting from FCI, which are crucial to debris bed coolability. Different from the previous studies with only oxidic materials, various materials, including metallic ones of Sn, Sn-Bi and Zn as well as oxidic one of Bi2O3-WO3, were employed as the simulants of corium (mixture of UO2/ZrO2/Zr/Fe) in the present study to investigate the effects of melt materials, melt superheat and coolant subcooling on debris bed formation in a water pool. High-speed photography was applied to visualize melt jet breakup, droplets fragmentation, as well as fragments sedimentation on the pool floor. Other obtained data are debris bed shape (profile) and porosity, as well as morphology and size distribution of debris particles. The comparative results of various tests provided insights toward filling the knowledge gap on debris bed characteristics under different melt materials and compositions.

Solid-fluid mixing behavior of conical spouted beds with internal devices

The effect of draft tubes and fountain confiner on the gas and solids mixing behavior is studied in conical spouted beds. Accordingly, the bed porosity has been determined in different hydrodynamic regimes of 1.1,1.25 and 1.5u/ums, with beds equipped with draft tubes of 0%,56% and 100% opening ratio. These devices significantly affect the gas residence time and particle cycle time distributions, which are further improved by using a fountain confiner, specially when high inlet gas flow rates are desired. The addition of this device was found to remove stagnant gas pockets over the annular zone, while reducing the particle cycle time by 15% with the OSDT configuration at 1.5u/ums. This reduction heavily depends on the distance between the bed surface and the fountain confiner. By including draft tubes, the expected particle cycle time can be more than doubled due to the reduced annular-spot solids circulation. Therefore, it was found that a combination of internal devices and operating flow rate present a promising strategy to control the gas flow pattern, while keeping the distribution of particles cycle times required for each application.

Demonstration of direct ocean carbon capture using encapsulated solvents

Direct ocean carbon capture (DOC) is an emerging form of negative emissions technology that requires expedited characterization and comparison against more well-established forms of carbon capture. Using microencapsulated solvents for DOC affords large membrane surface areas for carbon dioxide (CO2) in the ocean water to flux across a gas-permeable membrane, and reversible regeneration of the contained solution. The feasibility of using a packed bed of Na2CO3 capsules to extract CO2 from seawater is assessed here through lab-scale experimentation, one-dimensional modeling, and techno-economic assessment (TEA). The experimental flux measurements match the flux predictions of the 1D model, validating the model. Parametric studies with our capsule bed model suggest that for a balance between pressure drop and breakthrough time the optimal capsule diameter is between 400-600μm, the optimal bed porosity is between 0.5-0.7, and the optimal seawater velocity through the bed is 0.10-0.15 m/s. The TEA estimates that the carbon capture cost of a 1 MTonne/year greenfield system using Na2CO3 capsules would be exorbitant: $8,977.14 per tonne of CO2. This work demonstrates the potential of using microencapsulated solvents for direct ocean carbon capture and illustrates a need for further research to reduce system costs.

Numerical and Experimental Investigation of Fluidized Bed Hydrodynamics at Elevated Temperatures

Fluidized bed gasifiers operate at elevated temperatures, and experimental measurements for the hydrodynamic parameters at high temperatures are difficult and time consuming, making computational fluid dynamics simulation useful for such investigation. In this study, Opensource computational fluid dynamics code, OpenFOAM, was used to investigate temperature effect on the fluidized bed hydrodynamics on a 3D fluidized bed model using Eulerian-Eulerian approach. Silica sand of particle sizes of 500, 335 and 233 m was used as the bed materials under temperatures between 25 and 400 °C. To validate the simulation model, a laboratory scale fluidized bed unit was used to conduct experiments for the same range of temperature and sand particle sizes. The results revealed that the temperature of the bed materials greatly affect fluidized bed hydrodynamics. The minimum fluidization velocity increased with the sand particle diameter but decreased with the temperature. On the other hand, the bed porosity at the minimum fluidization point increased marginally with both the temperature and the particle size of the bed materials. Further analysis showed that the expanded bed height increased with the temperature for a specific superficial velocity while the bubbles grew in size with both the air flow rates and the temperature. The numerical model results were compared with the experimental results based on minimum fluidization velocity, bed porosity and pressure drop at the minimum fluidization point. The hydrodynamic results of the numerical model were in good agreement with the experimental results.

Prediction of the bed expansion of a liquid fluidized bed bioreactor applied to wastewater treatment and biogas production

The high potential of water treatment and biogas production systems using liquid fluidization is still underexplored. The design of this equipment is usually done using the simple Richardson-Zaki equation for bed expansion predictions, which is powerful but overlooks the interactions between fluid and particles. In this work, an alternative method based on a force balance on the bed and drag correlations to estimate the bed porosity was proposed. The accuracy of the methods was assessed by comparing bed porosity estimations with experiments carried out in a wide range of regimes (Reynolds numbers between 498 and 18664), using 7 different particles with various diameters (2.66 to 6.37 mm) and densities (1022 to 3585 kg/m3). On average, the fitting between the Richardson-Zaki equation and the experimental results was improved by 60% when the wall effects were considered. The alternative approach using the drag correlations showed promising results, presenting a coefficient of determination higher than 80% for all particles, and better precision in 4 out of the 7 particles compared to Richardson-Zaki. The results show that, in general, both the Richardson-Zaki equation and the drag correlation approach can be used to predict the liquid fluidized bed expansion. However, the proposed approach using drag correlations showed more reliable results, especially when the Rong drag model was applied, with an average coefficient of determination of 0.92. Comparisons with other results in the literature confirm the extent and the scalability of the method. The use of the proposed method to estimate the liquid fluidized bed expansion allows for easier and safer applicability of the technology in areas such as wastewater treatment and biogas production.

Computed X‐ray Tomography Investigation of Porosity and Permeability of the Liujiagou Formation Sandstone Exposed to CO2‐Saturated Brine

AbstractIn order to improve CO2 capture, utilization and storage (CCUS) to solve carbon emission, sandstone from the Triassic Liujiagou Formation (LF) from the Ordos Basin in China was investigated using permeability tests and computed X‐ray tomography (CT) scanning. The presence of reactive minerals within the geological CO2 sequestration target storage formation can allow reaction with injected CO2, which changes the porosity and permeability of the LF beds, affecting storage effectiveness. To investigate the effect of chemical reactions on the pore structure and permeability of sandstone cores representing the LF CO2 storage, tests were conducted to analyze the changes in porosity and permeability of sandstone cores induced by CO2‐saturated brine at different reaction times (28‐day maximum reaction period). Porosity and permeability of the sandstone increased after reaction with CO2‐saturated brine due to mineral dissolution. The sandstone exhibited an increase in porosity and permeability after 15 days of reaction with CO2‐saturated brine. Moreover, there was an increase in the volume of large pores in the sandstone after the 28‐day period. The pore network of the sandstone was established through CT results, and the porosity calculated based on the obtained pore network was close to that measured in the test, demonstrating the feasibility to use CT to study the evolution of the microstructure of sandstone after long‐time exposure to CO2‐saturated brine.

CFD simulation of CO2 methanation through the Sabatier reaction in a shell-and-tube reactor incorporating phase change on the shell side

This paper reports a computational fluid dynamics simulation of carbon dioxide (CO2) methanation via the Sabatier process in a shell-and-tube reactor, incorporating a water phase change simulation on the shell side using the volume of fluid (VOF) method. The essential heat removal factors and their mechanisms, such as the catalyst size, bed porosity, thermal conductivity, coolant flow rate, and coolant boiling, were primarily investigated. The computational code was a newly developed in-house version of ChtMultiRegionFOAM based on OpenFOAM v2006. This code can simulate catalyst-gas heat transfer, which is called the two-temperature model. The code was extended to new methanation and phase-change models based on the VOF method. The computational code was first validated using existing experimental data. After sufficient accuracy was confirmed, several parametric studies were conducted. Catalyst heat conductivity was the most influential factor among the catalyst-related parameters. The flow rate of the oil coolant significantly affected the cooling performance. Finally, the use of boiling water significantly reduced the coolant flow rate. Moreover, the cooling performance remained unchanged until the total heat release rate from the gas exceeded the total latent heat of the water.

Removal of caffeine using agro-industrial residues in fixed-bed columns: Improving the adsorption capacity and efficiency by selecting adequate physical and operational parameters

Developing effective water treatment technologies is indispensable to mitigate the negative impacts that aqueous contaminants can have on the environment. In this work, the potential of agro-industrial residues such as peanut shells, rice husk, coconut fiber and corn cob was investigated for removing caffeine from water using fixed-bed columns. The effects of the following parameters on the adsorptive performance of the columns were studied: particle size of the residues (Ps = 595–710, 710–1400, 1400–2000 μm), bed height (Z = 10, 15, 20 cm), flow rate (Q = 0.5, 1.0, 1.5 mL/min), and caffeine concentration (Co = 5, 10, 15 mg/L). Results demonstrated that the effect of particle size was influenced by the bulk density of the material (ρ) and bed porosity (ԑ). Increasing the bed height and decreasing the flow rate led to longer residence times and higher adsorption capacities. Increasing the caffeine influent concentration, increased the adsorption capacity, but reduced the removal efficiency. Columns packed with coconut fiber, Ps = 710–1400 μm (ρ = 0.102, ԑ = 0.30), Z = 20 cm, Q = 0.5 mL/min, and Co = 15 mg/L resulted in the best adsorption capacity (0.326 mg/g) and removal efficiency (47 %). The Adams-Bohart, Thomas, Yoon-Nelson, and Dose-Response models were used to describe the dynamic adsorption of the columns. Thomas' model predicted adsorption capacities closer to the experimental ones (R2 = 0.996, for 0.326 mg/g). The results obtained also open the possibility of defining criteria for assessing materials for removing aqueous pollutants in continuous processes.

Experimental investigation on debris bed formation from metallic melt coolant interactions

Motivated by risk quantification of severe core meltdown accidents which may occur light water reactors, an extensive DEFOR (DEbris FORmation) test series with various molten oxidic materials was conducted previously at Royal Institute of Technology to investigate the characteristics of debris beds formed from oxidic melt-water interactions, which are important to the coolability of debris beds and thus the retention of core melt. Yet, little attention has been paid to metallic melt which exist in the core melt. The present study is intended to fill in the knowledge gap, i.e., to characterize metallic melt-water interactions when a melt jet falls into a deep water pool. Nine DEFOR-M tests are carried out to clarify the effects of melt jet diameter, free fall height and water pool depth on metallic debris formation characteristics. Molten tin of 20 kg is employed as the simulant of metallic melt. A melt sensor and a mass sensor are installed to detect the discharging period of coherent jet and the mass accumulation of debris bed, respectively. A high-speed camera is applied to record the process of jet breakup, debris fragmentation and solidification, and debris bed formation. The experimental results show that the water pool depth has a significant influence on steam explosion and debris bed formation characteristics. Moreover, the jet breakup length is sensitive to jet diameter and free fall height. Finally, the features of metallic debris beds are compared with those of oxidic ones in respects of debris bed's configuration and porosity, particles' morphology and size distribution.

Thermal analysis of a micro tubular reactor for methanol steam reforming by optimizing the multilayer arrangement of catalyst bed for the catalytic combustion of methanolr

Packed bed tube reactors are commonly used for hydrogen production in proton exchange membrane fuel cells. However, the hydrogen production capacity of methanol steam reforming (MSR) is greatly limited by the poor heat transfer of packed catalyst bed. The hydrogen production capacity of catalyst bed can be effectively improved by optimizing the temperature distribution of reactor. In this study, four types of reactors including concentric circle methanol steam reforming reactor (MSRC), continuous catalytic combustion methanol steam reforming reactor (MSRR), hierarchical catalytic combustion methanol steam reforming reactor (MSRP) and segmented catalytic combustion reactor with fins (MSRF) are designed, modeled, compared and validated by experimental data. It was found that the maximum temperature difference of MSRC, MSRR, MSRP and MSRF reached 72.4 K, 58.6 K, 19.8 K and 11.3 K, respectively. In addition, the surface temperature inhomogeneity Uf and CO concentration of the MSRF decreased by 69.8% and 30.7%, compared with MSRC. At the same reactor volume, MSRF can achieve higher methanol conversion rate, and its effective energy absorption rate is 4.6%, 3.9% and 2.6% higher than that of MSRC, MSRR and MSRP, respectively. The MSRF could effectively avoid the influence of uneven temperature distribution on MSR compared with the other designs. In order to further improve the performance of MSRF, the influences of methanol vapor molar ratio, inlet temperature, flow rate, catalyst particle size and catalyst bed porosity on MSR were also discussed in the optimal reactor structure (MSRF).

Influence of particle size distribution on espresso extraction via packed bed compression

Espresso extraction is a diffusion-convection process involving both intra-granular pores, and the intergranular pores of the packed bed. Bed hydrodynamics and overall end-cup quality are governed by the bulk porosity, set by the dry coffee bed compression before extraction. In this work, the impact of the initial bed compression on the water permeability during espresso extraction is studied. Coarse fractions of the bimodal coffee particle size distributions were characterized by the particle mean size α and the size uniformity β of the distribution. It was found that under the same axial compression lower bed porosities were obtained with decreasing size uniformity β, even at larger mean size α. A model was developed to predict the dry packed bed porosity. Extraction experiments confirmed that low permeability desired during espresso brewing was found not to be exclusive to distributions with low mean particle sizes. Rather, it can also be achieved by tuning compression force, α, and β together. A modified Kozeny-Carman expression was derived to explain and predict the observed permeability results. • Study of bed compression and espresso extraction impacted by particle size distribution. • Compression and extraction experiments in modified espresso machine. • Bed compression model developed as function of size distribution for roasted coffee. • Lower packed bed porosities achieved with lower size uniformity distributions. • Experiment permeabilities were successfully predicted with modified Kozeny-Carman expression.

Minimum fluidization velocity and bed expansion of the inverse fluidized bed

To define the fluid-dynamic properties of inverse fluidized beds, studies of the minimum fluidization velocity and bed expansion were performed in this work. The experiments were performed in an inverse fluidized bed of polypropylene and polystyrene particles in a cylindrical column using water and an aqueous glycerol solution of different concentrations as fluidizing medium. The dependence of the bed porosity on the superficial velocity of the fluid was determined experimentally for all the particles studied and different fluidizing media. The influence of fluidizing medium viscosity and particle density on the expansion of the inverse fluidized bed and on the minimum fluidization velocity was investigated. Comparison of the experimental data for the expansion of the inverse fluidized bed and the values calculated by the Richardson-Zaki correlation for the conventional fluidized bed showed some deviation, but the experimentally determined data were found to follow the shape of the Richardson-Zaki curve. In this paper, a correlation for the expansion of inverse fluidized beds is proposed.

A new solar mid-and-low temperature receiver/reactor with linear Fresnel reflector

The hydrogen production by a mid-and-low temperature solar receiver/reactor traditionally uses a parabolic trough collector, where the circumferential non-uniformity of the concentrated solar flux poses a challenge to the safety of the catalyst bed and absorber tube. To address this challenge, this study proposes a new hydrogen production method that allows for a more uniform distribution of solar flux, temperature, and deformation in the receiver/reactor by combining a linear Fresnel reflector, a compound parabolic concentrator, a mid-and-low temperature receiver/reactor, and methanol steam reforming reaction. The solar light is concentrated on the surface of the receiver/reactor by the linear Fresnel reflector and the compound parabolic concentrator instead of the traditional parabolic trough collector, and then converted into chemical energy by the methanol steam reforming reaction in the receiver/reactor. A three-dimension model is established to study the performance of the mid-and-low temperature receiver/reactor, including solar flux distribution, fluid flow, mass diffusion, heat transfer, chemical reaction, and structural deformation. The influences of key factors are studied, including the inlet temperature, feeding rate of reactants, molar ratio of water to methanol, and porosity of the catalyst bed. A comparative study between linear Fresnel reflector and parabolic trough collector is conducted to discover the influence of the light-concentrating methods on hydrogen production. The results show that the temperature and reaction fields are highly influenced by the circumferential distribution of the solar flux. The linear Fresnel reflector can achieve a more uniform temperature distribution along the cross-section in the flow direction than the parabolic trough collector owing to the more uniform distribution of solar flux. The maximum temperature difference of the absorber tube in the center of the absorber tube is 12.5 % of that in the parabolic trough collector, which effectively alleviates the local overheating of the catalyst and decreases the thermal deformation of the steel tube. This study provides a reference for the mid-and-low temperature hydrogen production in the linear Fresnel reflector.

Thermophysical properties of parchment coffee: New Colombian varieties

AbstractThe thermophysical properties of coffee have a special partaking during the drying process since a material‐depending heat and mass transfer occurs between the bean and the drying air. Conditional to the thermophysical properties of the parchment coffee, the drying can be more or less efficient, affecting the final quality and seed safety. Several coffee varieties have been studied; however, the National Coffee Research Center of Colombia has developed new highly productive coffee varieties resistant to different diseases: Cenicafé 1 and Castillo®. Nevertheless, the thermophysical properties of these specific varieties were not yet investigated; moreover, the availability of information related to these properties of different coffee varieties in the literature is relatively scarce. Thus, this study targeted to determine the parchment coffee thermophysical properties of these new varieties at five different moisture contents % (wb): 53%, 42%, 32%, 22% and 11%, using optimized techniques and methods to ensure high accuracy and exactness. It was found that the new varieties have larger, heavier, and denser beans; it was also seen that the bulk thermal conductivity and the bulk‐specific heat are higher in these varieties than in the older ones. It was also revealed that the length, width, thickness, and surface area did not change as the moisture was removed, whereas the bulk density, kernel density, mass, bulk‐specific heat, and bulk thermal conductivity decreased as the moisture was reduced. Displaying better thermophysical properties will improve the drying and roasting processes; hence, a better final product can be expected from these varieties.Practical applicationsKnowing the thermal and physical properties of these new varieties will allow the growers and coffee processing facilities to predict, simulate and control different post‐harvesting processes such as pulping, fermentation, drying, storing, and roasting. Also, the already developed mathematical models to estimate coffee drying times can be updated, improving the accuracy of the predictions, bed porosities, mass, and heat transfer in order to safeguard the innocuousness of the product.

Model of terminal debris bed formation after a CANDU core collapse

Abstract A CANDU reactor core comprises several hundred horizontal fuel channels spanning a calandria vessel. Loss of sufficient cooling during a severe accident could result in collapse of the core to the bottom of the calandria. A simple computational tool for simulating, in two dimensions, the resulting build-up of a terminal debris bed is described. The tool is used to model a variety of core collapse scenarios. Computed debris beds are generally lower in the middle, ∼10 fuel channels deep, and have higher decay power in their interiors. The initial debris bed porosity is estimated to be 0.65 ± 0.15. High porosity could augment in-vessel hydrogen generation and fission product release during subsequent debris bed heat-up.

Effects of particle shape and packing style on ethylene oxidation reaction using particle-resolved CFD simulation

Gaining in-depth insights into the effects of particle shapes and packing style on ethylene oxidation reaction is of paramount industrial importance. In this work, reactor models of five packing structures with different particle shapes and three packing structures with different packing styles are established by employing software Blender and COMSOL Multiphysics to explore how the reaction-diffusion behaviors affect ethylene oxidation process. The reliabilities of rigid body dynamics model and particle-resolved reactor model are verified by comparing simulated and experimental pressure drops and ethylene conversions. In all the five packing structures with laminar flow conditions, the high bed porosity and low total particle surface area for the trilobe packing structure give rise to the lowest pressure drop of 27.8 Pa/m, while the internal voids cutting mode provides the excellent heat transfer capacity for the Raschig ring packing structure and the highest ethylene conversion and thereby the highest bed temperature rise of 25.1 K for the four-hole cylinder packing structure. Based on these analyses, changing the packing style to the bottom-up Raschig ring - four hole cylinder packing structure would be a good strategy for the effectively lowered reactor temperature rise by 4.8 K together with the slightly reduced ethylene conversion.

Design and operational guidelines of solar-driven catalytic conversion of CO2 and H2 to fuels

Sunlight-powered catalytic conversion of CO2 and (green) H2 into fuels and chemicals via Sabatier and reverse water gas shift (RWGS) processes offers a promising solution to reduce greenhouse gas emissions and increase renewable energy utilization. The success of this approach relies on the development of efficient catalysts and reactors. Prior research on reactor design is based on fixed-bed concepts using conventional transition metal thermocatalysts that typically require high-temperature activation. The utilization of photothermal catalysts yields fast reaction kinetics and enhanced product selectivity at relatively low temperatures, and, therefore, requires new design and operational guidelines. A comprehensive steady-state model is described to assess the performance of solar-driven photothermal catalytic Sabatier and RWGS processes, with an emphasis on the development of a 1D heat and mass transfer model for a plate-shaped transparent flow reactor. The model allows for the prediction of the temperature profile, pressure drop and reaction extent along the reactor channel, CO2 and H2 conversion, total fuel yield, as well as system efficiency for a variety of design and operational choices. The effects of these parameters are strongly coupled, and a low packed bed porosity of 40% combined with high gas inlet pressure at 18–20 bar leads to both, high fuel yield and high system efficiency, for both the Sabatier and RWGS processes. The maximum system efficiency is predicted via simultaneous optimization of relevant variables within meaningful ranges while also respecting the practical temperature constraints of both the glass and catalysts. Compared with the baseline case, the optimized scenario achieves higher efficiencies of 26.3% (vs 6.7%) and 10.1% (vs 5.4%) for the Sabatier and RWGS processes, respectively, at 20 kW/m2 irradiance. The model also identifies optimal reactor conditions under different concentrated solar irradiance, thus offering design and operational guidelines for solar-driven catalytic conversion of CO2 and H2 processes.

Optimization and technical parametric assessment of a novel triple media rapid sand filter: The effect of height of beds and size of particles

Turbidity is critically important in the drinking water treatment process and optimal performance of a sand filter can reduce it significantly. In this research, the optimization of a rapid sand filter was investigated in COMSOL Multiphysics® to decline the output turbidity. The conventional filter changed to a triple-bed filter. For validation of the large-scale model, an experimental model was used. According to 35 experimental data for surface load rate of 120 and 240 m3/m2.day, the average absolute deviation of outlet turbidity was calculated by nearly 7%. Moreover, 243 experiments were considered based on the different height of beds and dimeter of particles. The optimization results showed that the proposed model could remove the turbidity of 10 NTU in the inlet stream to 0.341 NTU in outlet one. Also, when the bed's porosity reaches about 0.2, the bed undergoes a pressure drop, and modeling calculations get slow, which indicates that the bed becomes filled. Therefore, it could be implemented as an index to estimate the filter's valuable working hours or backwash time.

Experimental investigation on ex-vessel debris bed formation using low melting-point melt of binary metals

During severe accidents in a light water reactor, the core melt (corium) may relocate to the lower head and fail the reactor pressure vessel (RPV). The corium will be ejected to the reactor cavity upon the RPV failure and undergo melt coolant interactions (FCI) if the cavity is flooded with water. The FCI process does not only determines the characteristics of the resulting debris bed which are important to coolability, but also induces a steam explosion risk which may threaten containment integrity. The present study is concerned with characterization of debris bed formed from FCI of metal-rich corium failing into a deep water pool in the reactor cavity. Low melting-point metals Tin and Tin–Bismuth (20 kg) were employed as the simulant materials of metal-rich corium melt. Ten tests were carried out on the DEFOR-M test facility at KTH to investigate the effects of various parameters on debris bed formation, such as melt superheat, coolant subcooling, material. The melt jet fragmentation and fragments movement in the water pool as well as debris deposition on the pool floor were recorded by high-speed cameras. Melt sensors and weight sensors were installed to detect the period of melt jet discharge and the mass of forming debris bed. The porosity of debris bed was obtained through the debris bed volume measured by a three-dimensional laser scanner and the pore volume measured by water absorption. The final configuration of debris bed was also reconstructed through the laser scanner data, and the debris particles were sieved for their size distribution. The experimental results revealed the FCI phenomena and debris bed characteristics including configuration and porosity of debris bed as well as morphology and size distribution of debris particles under different melt superheats, coolant subcooling, materials.

Impact of Fine Solids on Hydrotreating of Bitumen-Derived Gas Oil

Bitumen-derived gas oils that enter hydrotreaters contain fine solids such as minerals, heavy metals, and coke. The deposition of these fines will eventually restrict the flow and result in pressure buildup across the hydrotreater, which eventually necessitate the premature shutting down of the reactor system. To determine if certain types of fine particles had a greater detriment to the hydrotreating process, a series of experiments were performed by accelerated fine deposition in a trickle bed catalytic reactor under industrial conditions using bitumen-derived light gas oil. Kaolinite, montmorillonite, pyrite, and petroleum coke fines had no significant impact on the catalyst activity and catalyst deactivation toward hydrodenitrogenation (HDN), hydrodesulfurization (HDS), and hydrodearomatization. Unlike the above fines, iron(III)oxide was found to convert into FeS under hydrotreating conditions, which provided a promoting effect for HDN and HDS reactions. When comparing the trends in pressure drop across the catalyst bed, there was a delayed period during the initial fine deposition where no change in pressure drop was observed, followed by an exponential increase in pressure due to the decrease in bed porosity. The difference found between these fines was the length of this delayed period, with iron(III)oxide and petroleum coke having the longest periods of no pressure growth. From inductively coupled plasma, scanning electron microscopy with energy-dispersive spectroscopy, X-ray diffraction, and Brunauer–Emmett–Teller analysis of the fresh and spent catalysts, it was determined that the deposition of all fines occurred within the packing material in the preheating zone, with only petroleum coke and iron(III)oxide fines being found on the surface of the catalysts.