Wet Particles Research Articles

The physicochemical properties and Pickering emulsifying capacity of acorn starch

In this work, the granule characteristics, functional properties, in-vitro digestibility, antioxidant capacity, and phenolic composition of acorn starch were investigated and compared to those of potato starch and corn starch, and its Pickering emulsifying ability was also evaluated. The results showed that the acorn starch granules were spherical and oval in shape, with a smaller particle size, and the amylose content and crystallinity degree were similar to those of corn starch. However, the acorn starch was difficult to swell, with poor aqueous solubility, though it had a strong gel strength and setback viscosity. Because acorn starch contained more free and bound polyphenols, its resistant starch content after cooking and ABTS and DPPH radical scavenging activities were significantly higher than those of potato starch and corn starch. Acorn starch also exhibited outstanding particle wettability and could stabilize Pickering emulsions. The assessed emulsion showed an outstanding effect for protecting β-carotene against ultraviolet irradiation and was positively correlated with the acorn starch addition amount. The obtained results may serve as a reference for the further development of acorn starch.

A Predictive Model of Capillary Forces and Contact Diameters between Two Plates Based on Artificial Neural Network.

Many efforts have been devoted to the forecasting of the capillary force generated by capillary adsorption between solids, which is fundamental and essential in the fields of micro-object manipulation and particle wetting. In this paper, an artificial neural network (ANN) model optimized by a genetic algorithm (GA-ANN) was proposed to predict the capillary force and contact diameter of the liquid bridge between two plates. The mean square error (MSE) and correlation coefficient (R2) were employed to evaluate the prediction accuracy of the GA-ANN model, theoretical solution method of the Young-Laplace equation and simulation approach based on the minimum energy method. The results showed that the values of MSE of capillary force and contact diameter using GA-ANN were 10.3 and 0.0001, respectively. The values of R2 were 0.9989 and 0.9977 for capillary force and contact diameter in regression analysis, respectively, demonstrating the accuracy of the proposed predictive model. The sensitivity analysis was conducted to investigate the influence of input parameters, including liquid volume and separation distance, on the capillary force and contact diameter. The liquid volume and separation distance played dominant roles in affecting the capillary force and contact diameter.

A new polishing method for complex structural parts: Moist particle electrolyte electrochemical mechanical polishing (MPE-ECMP)

The improvement of the surface quality of complex structural parts is a major challenge. Electrochemical mechanical polishing (ECMP) plays an important role in the polishing of wafers due to its high material removal rate. However, electrochemical mechanical polishing of the surface of complex structures, such as the bevels of turbine blades, has been little investigated. This paper proposes a new method, moist particle electrolyte electrochemical mechanical polishing (MPE-ECMP), for polishing the surfaces of complex structural parts. Using a sulfonated cation exchange resin as a moist particle electrolyte (MPE), polarization curves are measured using linear scanning voltammetry (LSV) and a selected potential of 1.0 V vs. Hg|Hg2SO4 over a 1 h polishing period. The elemental changes on the copper surface are examined by energy dispersive spectroscopy (EDS) and those on the MPE surface are studied using X-ray photoelectron spectrometry (XPS) to explain the material removal mechanism. The results show that the surface roughness of copper is reduced from the initial Sa = 433.48 nm to Sa = 21.83 nm, a reduction of 95.0%, that no copper oxides are generated during the MPE-ECMP process and that the MPE adsorbs released Cu2+. It is demonstrated that MPE-ECMP has good surface finishing properties for beveled surfaces, and provides an effective approach for surface polishing of complex structural parts.

Fabrication of bijels with sub-micron domains via a single-channel flow device

Particle-stabilized bicontinuous emulsions (bijels) are made of two interwoven liquid channel systems. In contrast to emulsion droplets, the liquid-liquid interface of bijels curves both towards the oil and the water phases. Thus, particles with equal wettability for both oil and water are needed to stabilize the interface. In this research paper, we enhance the understanding of nanoparticle functionalization by a surfactant for controlling the particle wettability. To this end, we develop a novel, single-channel, continuous flow method, enabling the rapid synthesis and analysis of bijels formed via solvent transfer induced phase separation (STrIPS). Silica nanoparticles are functionalized with the positively charged surfactant (cetyltrimethylammonium+, CTA+). Zeta-potential and colloidal stability analysis are employed to characterize the CTA+ functionalization. Confocal and electron microscopy are used to visualize the resulting bijel structures. Bijels with nearly uniform, sub-micrometer channels are obtained when the particle functionalization by CTA+ is regulated. To this end, the initial negative zeta-potential of the particles needs to be low enough to prevent excessive CTA+ adsorption. The adsorption is further controlled by adjusting the concentrations of CTA+, salt and glycerol additive. This report shows that the nanoparticle surfactant modification depends on multiple parameters, providing guidance for future bijel synthesis approaches.

Standardization of Particle Size for Floating Particle Wettability Measurement for Carbonate Rocks.

Misrepresentation of the wettability of a reservoir can lead to potentially low ultimate hydrocarbon recovery resulting in substantial economic losses. At the same time, it is impossible to determine the wettability of a reservoir across its length and breadth on a continuous basis using standard procedures. This work presents the development and standardization of a quick, easy, and low-cost wettability measurement method using the adherence tendency of rock particles in the oil or aqueous phase. The most important aspect of this study was establishing the optimum particle size for sustained floatation and balancing the buoyancy and gravity effect. The results show that the particles sink with a larger than optimum particle size because of the gravity effect. Similarly, the particles would float if they are smaller than optimum due to buoyancy and viscosity advantages. A new scale is designed, and the midpoint analysis shows that a 63-90 μm particle size is the ideal size range for the carbonate reservoir's wettability measurements, as the midpoint of the size distribution coincides with the standard Amott-Harvey (A-H) index. However, this size range is found to be wider for oil-wet particles. The floating particle method has several advantages over the established methods once standardized against a reliable process. Not only is the process fast but it can be performed with basic laboratory tools and does not require a high skill set. Most importantly, reliable wettability information can be obtained from drill cuttings and core fragments, enabling the determination of reservoir wettability on a continuum basis and not as a point basis, thus providing a more reliable average value, particularly for heterogeneous and unconsolidated reservoirs.

Role of the Protein Corona in the Colloidal Behavior of Microplastics.

Microparticles of polyethylene and polypropylene are largely found in aquatic environments because they are the most produced and persistent plastic materials. Once in biological media, they are covered by a layer of molecules, the so-called corona, mostly composed of proteins. A yeast protein extract from Saccharomyces cerevisiae was used as a protein system to observe interactions in complex biological media. Proteins, acting as surfactants and providing hydrophilic surfaces, allow the dispersion of highly hydrophobic particles in water and stabilize them. After 24 h, the microplastic quantity was up to 1 × 1011 particles per liter, whereas without protein, no particles remained in solution. Label-free imaging of the protein corona by synchrotron radiation deep UV fluorescence microscopy (SR-DUV) was performed. In situ images of the protein corona were obtained, and the adsorbed protein quantity, the coverage rate, and the corona heterogeneity were determined. The stability kinetics of the microplastic suspensions were measured by light transmission using a Turbiscan analyzer. Together, the microscopic and kinetics results demonstrate that the protein corona can very efficiently stabilize microplastics in solution provided that the protein corona quality is sufficient. Microplastic stability depends on different parameters such as the particle's intrinsic properties (size, density, hydrophobicity) and the protein corona formation that changes the particle wettability, electrostatic charge, and steric hindrance. By controlling these parameters with proteins, it becomes possible to keep microplastics in and out of solution, paving the way for applications in the field of microplastic pollution control and remediation.

The capture of airborne particulates by rain

Rain cleans pollution out of the atmosphere, as droplets collide with airborne particles during free fall. Such particle–droplet collisions have been presumed to be capture events, but the details of such collisions lack thorough investigation. We show that rain droplets and pollution particles interact through multiple collision behaviours, including captures on the droplet surface, cavity-forming droplet entries and ricochets. Rain drop diameter and free fall velocity, in addition to pollution particle density, size, wettability and droplet impact location, determine which capture or escape behaviour occurs. Our findings reveal that rain does not capture all airborne pollutants equally even upon collision, and certain pollutants prove more difficult to remove from the air than others. Consequently, we must account for both rain and pollution characteristics to understand pollution capture mechanisms and pollution fluxes in the environment.

Fabrication and characterization of high internal phase Pickering emulsions based on pH-mediated soy protein-epigallocatechin-3-gallate hydrophobic and hydrophilic nano-stabilizer

This study describes the feasibility of O/W High internal phase Pickering emulsions (HIPPEs) with an oil volume fraction of 0.82 stabilized by using SECNs at pH 3.0, 6.0 and 9.0. Soy protein isolate (SPI) was converted into the molten globule (MG) state at pH 3.0 and 9.0, modified by (−)-epigallocatechin-3-gallate (EGCG), and heated to obtain SPI-EGCG composite nanoparticles (SECNs). Results obtained demonstrated that with the introduction of EGCG in soy protein nanoparticles (SPNs) and increase in pH from 3.0 to 9.0, the particle distribution and tertiary structures of these nanoparticles were altered, along with decrease in surface hydrophobicity (H0), and enhancement of particle wettability and antioxidant activity. The structure of SPNs at different pH showed that there were two kinds of HIPPEs stabilizing mechanisms: nonshared multilayers (at pH 3.0 and 6.0) and mono-/shared layers (at pH 9.0). These findings provide insights into the design of protein-polyphenol nanoparticles stabilized HIPPEs suitable for the formulation of functional foods.

DISJOINING PRESSURE IN THIN SPHERICAL LIQUID FILMS AND VAPOR LAYERS WITH MOLECULAR CORRELATIONS INCLUDED

Based on the expression for a grand thermodynamic potential as a molecular density functional, disjoining pressures in thin liquid films around nanosized wettable spherical particles and in thin vapor layers around nonwettable particles are calculated depending the degree of lyophilicity, film thickness and particle size. A characteristic feature of the approach is the full consideration of hard-sphere molecular correlations according to the fundamental measure theory in the density functional method and finding the complete dependence of the grand thermodynamic potential of the system on stable droplet or bubble size. Although the obtained results show a qualitative agreement between the new calculated disjoining pressure dependences and those obtained by us earlier in the framework of a simpler gradient method of the molecular density functional, the new results differ significantly quantitatively. It is confirmed that the disjoining pressure in the liquid film around nanosized lyophilic particle grows with the particle radius and lyophilicity.

Determination of the average size of preliminary grinded wet feed particles in hammer grinders

In the conditions of farms, it becomes necessary to grind feed that has a different degree of moisture. Therefore, the choice of universal working bodies is the object of research, and the theoretical determination of the average size of pre-crushed feed particles is of great scientific and practical importance and is a problem that needs to be solved. Proceeding from this, a constructive-technological scheme of a grinder with a universal grinding working body is proposed. The grinding apparatus is equipped with a hammer working body which has cutting edges. In this case, hammers with cutting edges crush the wet mass, and also create an air flow and work as flow accelerators at high speed. As a result of theoretical studies, the steps for arranging these working bodies were determined. Analytical expressions are obtained for determining the average length of pre-crushed feed particles depending on the distance between the faces of replaceable knife working bodies, i.e. from the step of arranging them in rows. At the same time, the calculation results showed that with a distance between the faces of replaceable hammers of 20 mm, the value of the average length of the grinded particles was 38.38 mm. The average size of pre-crushed particles from feed raw materials intended for farm animals was 37.64 mm, i. e. the difference between theoretical and actual value is only 2.0 %. This proves the reliability of the obtained analytical expression, which provides the determination of the main parameter of the grinding working body, i. e. spacing of radial knives in rows. The proposed method of determining the average length of crushed particles allows theoretically finding and planning the required particle size

Study on the Dynamic Characteristics of Bit Anchor Cable Drilling in the Gravel Sediments of a Soft Rock Bottom Hole

During the pore-forming stage of floor heave treatment, the phenomenon of gravel sediment accumulation in the bottom hole often occurs, which causes great difficulties in the normal installation of the anchor cable. Based on this observation, a new anchor cable installation method was proposed, which involves installing a drill bit at the front end of the anchor cable to assist its drilling. With the help of an anchor cable drilling test bench, the influence of the bit, motion parameters, and hole environment on the performance of anchor cable drilling was studied. Through the co-simulation of the discrete element method (i.e., multibody dynamics (DEM-MBD)), the drilling process of the bit anchor cable was simulated, and the dynamic characteristics of the bit anchor cable drilling in the bottom hole gravel sediment were analysed. The results show that installing a drill bit in front of the anchor cable can greatly reduce the drilling resistance and hamper torque during anchor cable drilling. When the rotational direction of the bit anchor cable is consistent with the spiral direction of the anchor cable, the bit anchor cable can exhibit better drilling performance. The drilling resistance and hindering torque of the bit anchor cable are the largest when drilling in soaked particles, followed by drilling in dry particles, and the smallest occurs when drilling in moist particles. The research results can provide reference for the parameter setting of anchor cable auxiliary installation equipment.

An Experimental Study on the Dilute Phase Pneumatic Conveying of Fat-Filled Milk Powders: Particle Breakage

Powder breakage during pneumatic conveying negatively affects the properties of dairy products and causes increased dusting, reduced wettability, and decreased product performance. In particular, particle breakage is a serious issue for fat-filled milk powder (FFMP) which, if it breaks, releases fat that causes odours and leads to sticky blocked pipes. In this work, a conveying rig (dilute phase, positive pressure) with 50 mm diameter food grade stainless steel pipes (1.5 m high and 5 m conveying distance with three 90° bends, two in the vertical plane and one in the horizontal plane) was built as the test system. The effects of operating conditions (conveying air velocity and solid loading rate) on the attrition of FFMP in a dilute phase conveying system were experimentally studied. Four quality characteristics were measured before and after conveying: bulk density, particle size distribution, wettability, and solubility, to access the influence of particle breakage. Conveying air speed shows a significant impact on powder breakage. As air speed increased, more breakage occurred, and the volume mean diameter D[4,3] decreased by around 50%, using the largest conveying air speed of 38 m/s. Bulk density increased accordingly whereas wettability decreased with an increase in air speed, resulting from the higher breakage rate. On other hand, improving the solid loading rate can further reduce the breakage level, but the positive effect is not as good as decreasing air speed.

Influence of Surface-Active Substances and Substrates on the Wettability of Individual Aerosol Particles during Condensation by Environmental Scanning Electron Microscopy

The formation of liquid cloud droplets from aerosol particles in the Earth atmosphere is still under debate particularly because of the difficulties to quantify the importance of bulk and surface effects in these processes. Recently, single-particle techniques have been developed to access experimental key parameters at the scale of individual particles. Environmental scanning electron microscopy (ESEM) has the advantage to provide in situ monitoring of the water uptake of individual microscopic particles deposited on solid substrates. In this work, ESEM was used to compare droplet growth on pure ammonium sulfate (NH4)2SO4 and mixed sodium dodecyl sulfate/ammonium sulfate (SDS/(NH4)2SO4) particles and to explore the role of experimental parameters, such as the hydrophobic-hydrophilic character of the substrate, on this growth. With hydrophilic substrates, the growth on pure salt particles was strongly anisotropic, but this anisotropy was suppressed by the presence of SDS. With hydrophobic substrates, it is the wetting behavior of the liquid droplet that is impacted by the presence of SDS. The wetting behavior of the pure (NH4)2SO4 solution on a hydrophobic surface shows a step-by-step mechanism that can be attributed to successive pinning-depinning phenomena at the triple-phase line frontier. Unlike the pure (NH4)2SO4 solution, the mixed SDS/(NH4)2SO4 solution did not show such a mechanism. Therefore, the hydrophobic-hydrophilic character of the substrate plays an important role in the stability and dynamics of the liquid droplets' nucleation by water vapor condensation. In particular, hydrophilic substrates are not suited for the investigation of the hygroscopic properties (deliquescence relative humidity (DRH) and hygroscopic growth factor (GF)) of particles. Using hydrophobic substrates, data show that the DRH of (NH4)2SO4 particles is measured within 3% accuracy on the RH and their GF could indicate a size-dependent effect in the micrometer range. The presence of SDS does not seem to modify the DRH and GF of (NH4)2SO4 particles. This study shows that the water uptake on deposited particles is a complex process but, once carefully taken into account, ESEM is a suitable technique to study them.

Investigation of correlation of oxide layer surface morphology and magnesium degradation using a gas atmosphere dependent nanosecond laser processed model

In biomedical applications, degradation behavior of Magnesium (Mg) and its alloys is crucial for its outcomes. Various methods have been adopted to regulate Mg metals degradation, in which oxide layer generation has been considered to be a reliable strategy. However, correlation of magnesium oxide layer surface morphology and magnesium degradation is difficult to clarify due to interruption of oxide layer thickness and co-effect of other surface characteristics. In this work, Mg samples with two distinctive oxide layer morphology were prepared by nanosecond laser processing under N2 and CO2 atmospheres, coupled with essential surface and cross-section characterizations using SEM, AFM, TEM, XPS, XRD, and contact angle instrument. Furthermore, oxide layer morphology dependent Mg degradation behavior was investigated by electrochemical experimental, hydrogen precipitation, and pH tests. Results indicated that by changing laser treatment processing gas atmosphere, magnesium oxide morphology generated on sample surface could be tailored while maintaining consistency in thickness and composition. Larger particle size, surface roughness and wettability of magnesium oxide can decrease degradation rate.

Hydrate growth and agglomeration in the presence of wax and anti-agglomerant: A morphology study and cohesive force measurement

During deep-sea and ultra-deep-sea oil and gas exploitation, multiphase transmission lines are prone to be clogged by sediments produced by the various components in crude oils under extreme subsea conditions, such as hydrates, wax, resins, and asphaltenes. The pipelines face higher plugging risks when these deposits exist simultaneously. In order to elucidate the effects of wax and anti-agglomerants (AA) on hydrate growth and aggregation, microscopic morphology observation and cohesive force measurement of cyclopentane hydrate particles were conducted through a piece of equipment similar to the micromechanical force (MMF) apparatus. Results showed that in the low concentration of AA (0.05 wt%), hydrate particles experienced an approximately 10 % reduction in the profile area after converting water droplets to hydrate particles. Furthermore, the cohesive force between hydrate particles decreased from 8.57 ± 0.90 mN/m to 3.51 ± 0.43 mN/m as the AA concentration increased from 0.05 to 0.2 wt%. On the other hand, the presence of wax significantly altered the morphologies of hydrate particles. When wax coexisted with AA, the hydrate cohesive force was reduced by wax under low AA concentration (0.05 wt%) but increased under higher AA concentration. For a given concentration of AA, the hydrate cohesive force increased with the increasing wax content (from 0.1 to 0.3 wt%), indicating that wax crystals weakened the efficiency of AA, such as Span 80. Additionally, the effect of surface wetness of waxy hydrate particles on their cohesion was also investigated. The liquid bridge appeared between wet waxy hydrate particles, while the solid–solid contact existed between dry waxy hydrate particles. The cohesive force between dry waxy hydrate particles was smaller. Either liquid bridge or solid–solid contact that dominated hydrate cohesive force was affected by wax.

Residence Time Distribution Analysis of Drip-Irrigated Beds—The Effect of Material and Fluid Properties with Implications for Heap Leaching Practice

The quantitative effect of particle shape, porosity, wettability, particle size, and solution viscosity on the residence time distribution (RTD) profiles of non-reactive, steady-state, drip-irrigated ore beds characteristic of heap leaching systems is presented. Results were obtained using step-up tracer tests and allowed for the analysis of preferential flow behaviour within the systems. The key findings were as follows. Increased particle sphericity enhanced channelling in beds of smaller particles, but not for larger particle sizes. Higher particle wettability caused greater liquid dispersion during both initial wetting studies and at steady-state fluid flux. Higher porosity levels and the inclusion of fines in mixed sized beds resulted in longer average solute residence times, higher liquid hold-up, longer solution and tracer breakthrough times, and increases in drain-down moisture percentages. Increasing the irrigation fluid’s viscosity, reflective of the increase in ionic concentrations in leach solutions, reduced both the solution and tracer breakthrough times and increased dispersion with signs of more discontinuous or isolated fluid volumes at steady-state. These results highlighted the importance of the inclusion of fines in agglomerated beds to improve uniform wetting especially those with low to moderate particle porosities (<2.5 m2/g specific surface area). The viscosity results suggest that there may be changes in preferential flow extent, due to variations in viscosity owing to the increasing sulphate concentration within the liquid phase in heaps and with time.

How to engineer aerosol particle properties and biopharmaceutical performance of propellant inhalers

Given the environmental compulsion to reformulate pressurised metered dose inhalers (pMDI) using new propellants with lower global warming potential, this study investigated how non-volatile excipients can be used to engineer aerosol particle microphysics and drug release. The dynamics of change in particle size, wetting and physical state were measured for single particles (glycerol/ethanol/beclomethasone dipropionate; BDP) in the aerosol phase at different relative humidity (RH) using an electrodynamic balance. BDP dissolution rates were compared for aerosols from pMDI containing different ratios of BDP:glycerol or BDP:isopropyl myristate (IPM). In 45 % RH, ethanol loss was followed by evaporation of condensed water to generate spherical particles with solid inclusions or compact irregular-shaped solid particles, according to the presence or absence of glycerol. In RH > 95 %, condensed water did not evaporate and BDP formed solid inclusions in water/glycerol or water droplets. Varying the non-volatile component, 0–50 % w/w, in pMDI resulted in a concentration-dependent 4–8-fold reduction in BDP dissolution rate. These findings demonstrate that non-volatile excipients provide a means of engineering aerosol properties and, modifying the rate of drug release from aerosol medicines. We also demonstrated differences between particles formed in vitro in ambient humidity versus higher humidity, more like that encountered during oral inhalation.

Tailoring Pickering Double Emulsions by in Situ Particle Surface Modification

Fundamental studies on the formation and stability of Pickering double emulsions are crucial for their industrial applications. Available methods of double emulsion preparation involve multiple tedious steps and can formulate a particular type of double emulsion, that is, water-in-oil-in-water (w/o/w) or oil-in-water-in-oil (o/w/o). In this work, we proposed a simple single-step in situ surface modification method to stabilize different types of double emulsions using hematite and silica particle systems which involves the addition of oleic acid. In the emulsification studies, we use (i) a combination of hematite and oleic acid, which is termed the binary system, and (ii) a mixture of hematite and silica particles together with oleic acid, which is designated as the ternary system. The wettability of hematite particles is tuned by direct or sequential addition of oleic acid to the water-decane medium. The direct surface modification (which involves the addition of a known quantity of oleic acid to the oil-water mixtures at once) of hematite particles in both binary and ternary systems shows transitional phase inversion from oil-in-water (o/w) to water-in-oil (w/o) emulsions. However, sequential surface modification results in the transition of a single emulsion to double emulsions. In the case of the binary system, the sequential surface modification of the hematite-particle-stabilized o/w emulsion can be converted into double emulsions of o/w/o type. However, in the case of the ternary system, i.e., in the presence of silica particles, sequential surface modification of hematite particles stabilizes both single (o/w) and double (w/o/w and o/w/o) emulsions. The critical concentration of oleic acid required to form a double emulsion is observed to be dependent on the ratio of the surface area of the silica particle to the total surface area of particles (S) and mixing protocols. A study of the size distribution of oil and water droplets of double emulsions shows that droplet size can be controlled by oleic acid concentration and magnitude of S. The arrangements of the particles at interfaces are visualized by SEM imaging. In this way, we developed an easy and novel single-step method of double emulsion preparation and provide a strategy to tailor the formation of different types of emulsions with a single/binary particle system by sequential in situ surface modification of the particles.

Solid-state characterization of ibuprofen-isonicotinamide cocrystals prepared by electrospraying and solvent evaporation.

Aim: Electrospraying (ELS) was used to prepare micronized ibuprofen-isonicotinamide cocrystal (IBU-INA-ELS) and its properties were compared with the solvent evaporated cocrystal (IBU-INA-SE). Methods: Solid-state characterization of crystalline phase, production yield, particle size, powder flow, wettability, solution mediated phase transformation (SMPT), and dissolution rate were measured. Results: The ELS produced phase pure particles of IBU-INA with a size of 1.46μm and yield of 72.3%. This cocrystal improved the intrinsic dissolution rate and powder dissolution rate of IBU by 3.6- and 1.7-fold, respectively. Our experiments showed that the dissolution of IBU-INA was affected by particle size, solubility, SMPT and wettability. Conclusion: ELS produced micronized cocrystals for improving dissolution of ibuprofen with a high yield in a single step and mild conditions.

Modeling of radiation heat transfer in dense-bed flows of solids in indirectly heated rotary kilns

• modification and implementation of a DOM-radiation model which combines all required physical submodels to simulate heat radiation to dense beds of particles. • Full time and space resolved simulation of thermal conversion of wet moving bulk in a large-scale rotary kiln reactor. • Analytical validation of model and justification with laboratory-scale experiments. • Efficiency optimization of the numerical solver for industrial-scale and long-time simulations on parallel supercomputers. • Parameter studies for large-scale reactors to investigate conversion rate and product quality. This work presents further development and validation of the Discrete Ordinates Model for thermal radiation implemented in OpenFOAM® for application to packed beds of particles. The radiation model is an important part of a more comprehensive model for simulating the thermochemical conversion of the discrete phase (here for instance wet biomass particles). The comprehensive Eulerian-Lagrangian model is part of a three-dimensional, time-resolved simulation of the essential chemical and physical processes occurring within and in-between particles in a moving bed. For the thermal treatment of solid particles, convective and radiative heat transfer couple the energy exchange between the reactor wall, gas- and disperse phase. The original implementation of the finite volume Discrete Ordinate Model (fvDOM) present in OpenFOAM® is valid for a dilute particulate phase and neglects the effect of local opacity due to the existence of individual particles. In the present application, a dense-packed bed of the particulate phase exists in the reactor and, therefore, this direction-based radiation model is adjusted for a computational cell with arbitrary particle volume fractions. To validate the results with the present thermal radiation model, a simple test case is first presented, where a bed of particles is heated from the top of the computational domain. A second test case relates to an experimentally investigated laboratory-scale reactor. The results of the improved fvDOM are compared to the original implementation in OpenFOAM® and the more simple and computationally cheap P-1 radiation model. In the presence of a packed bed, the P-1 model largely overpredicts the radiative heat transfer while the original fvDOM underpredicts the heat flux by about 15 % for the first test case. The new improved model delivers results within 1% deviation at the expense of maximum of 10 % increase in the computational time. Large-scale parallel simulations of real setups are crucial tools to predict the efficiency of a process and improve the operational parameters. To achieve the pre-defined product quality at minimum cost, an example of the implemented radiation model in thermochemical conversion of wet biomass in a rotary drum is been given and the importance of the radiation heat transport to the bulk is highlighted.