Actual Particle Size Distribution Research Articles

Effect of Size Distribution of Solid Electrolyte on Tortuosity of Ionic Conductivity

Solid state batteries (SSBs) are expected to be the next-generation of batteries due to their high energy density and safety. To emphasize the battery performance of SSBs, it is crucial to analyze and design the electrode structure. The powder compression process is one of the most important processes for determining the battery structure. Powder compression is a molding method used to transform powders into solid and high-density compacts. The powder properties and compression conditions influence the packing structure and density of compacts. In this study, we elucidated the effect of the size distribution of a sulfide solid electrolyte on the ionic conductivity of pellets. The particle size distributions of lithium phosphorus sulfur chloride (LPSCl), a solid electrolyte with high plastic deformability, were prepared to evaluate its effect on the relative density and electrochemical properties. The average particle size of LPSCl was reduced through the milling process, and the resulting compacts were evaluated by impedance measurement after mixing raw and milled LPSCl with different mass fractions. The ionic conductivity of the compacts was found to be improved with the broadening of the particle size distribution of the solid electrolyte. Furthermore, the effect of the particle size distribution of the solid electrolyte on the electrode structure was also investigated numerically. The numerical simulations were performed in consideration of the actual particle size distribution to evaluate the void fraction and tortuosity of the electrodes. A discrete element method (DEM) can simulate the powder behavior by calculating the motion of individual particles based on Newton’s second law. Edinburgh elasto-plastic adhesive (EEPA) model, which can consider particle plasticity and cohesiveness, was applied as the contact force model. Particle plasticity parameter λ p was calibrated based on force-displacement curves obtained by nanoindentation tests. The compression process was calculated assuming an infinite flat plate. Although the calculated relative densities agreed with the experimental trend, the values differed from the experimental values owing to the disregard of particle shape. In addition, tortuosity was evaluated by the shortest path algorithm using the powder bed obtained from the numerical analyses. An effective tortuosity was calculated by weighting the contributions of the conductive paths by its number of particles. The effective tortuosity also increased due to the higher number of particles generated during the LPSCl milling process. The combination of DEM analysis and the shortest path algorithm, taking into account grain boundary resistance, demonstrated that is was possible to correlate the electrode structure of the SSB with its electrochemical performance.

Study on Agglomeration and Plugging Behavior of Fine Particles in Reservoir Based on DEM-CFD Coupling

Abstract Given the particularity, significance, and complexity of particle migration behavior in fine silt sand hydrate reservoirs, the agglomeration and plugging behavior of free fine particles are mainly studied. Based on the discrete element method (DEM) and computational fluid dynamics (CFD), the DEM-CFD coupled 3D wellbore sand production numerical model is established and verified. The DEM module divides the reservoir particles into coarse and fine components according to the actual particle size distribution, and assigns adhesive and non-adhesive rolling resistance linear models, respectively. The CFD module uses the finite volume method to solve the incompressible Darcy flow in coarse grids. The results show that the DEM-CFD coupled numerical model established can effectively simulate the phenomenon of fine particle agglomeration during particle migration; Compared with the condition without particle agglomeration, fine particle agglomeration can lead to lower wellbore sand production and more severe pore blockage and permeability loss in the surrounding reservoir; The influences of different production and reservoir parameters such as flow rate, porosity and mud content on the variation of wellbore sand production and reservoir permeability under the condition of fine particle agglomeration is further determined, and relevant production measures and suggestions are put forward. The research results help to clarify the sand production mechanism and characteristics of fine silt sand reservoirs and are expected to provide theoretical and technical support for the efficient and safe development of natural gas hydrate resources in fine silt sand reservoirs.

A thermal fluid dynamic model for the melt region during the laser powder bed fusion of polyamide 11 (PA11)

Studying the physical characteristics of the melt region in polymer-based laser powder bed fusion (PBF-LB/P) offers good comprehension that is essential for quality control, process optimization, understanding of material behavior, and preserving process consistency. Among the few numerical modelling investigations of PBF-LB/P, this study focuses on 3D multiphysics simulation of melt pool morphologies, beginning with powder bed preparation incorporating the actual particle size distribution using the discrete element method (DEM). A thermal fluid dynamic numerical model is then developed based on the finite volume method (FVM) using Flow-3D Weld to simulate PBF-LB while using polyamide 11 (PA11) as the primary material. The cooling after sintering plays a crucial role for the formation of the melt region due to the high viscosity of the polymer material effectively resulting in creeping flow. Here, we propose a model for both sintering as well as the subsequent cooling step, a two-step model capable of simulating the finished structure accurately with relatively low computational resources. The model's accuracy is verified through a mesh dependency analysis and its predictive power via validation against internal single-track experiments providing dimension data on the melt region width and depth. The simulation results allow for a detailed exploration of the effects of laser settings on melt region morphologies and the occurrence of defects. The model's scope is further extended to multi-track simulation, revealing the connection between surface roughness and laser settings. In general, this study provides significant contributions to the comprehension of PBF-LB/P methodologies which in turn can be used for further process improvement.

Approximation of Any Particle Size Distribution Employing a Bidisperse One Based on Moment Matching

Dispersed phases like colloidal particles and emulsions are characterized by their particle size distribution. Narrow distributions can be represented by the monodisperse distribution. However, this is not the case for broader distributions. The so-called quadrature methods of moments assume any distribution as a bidisperse one in order to solve the corresponding population balance. The generalization of this approach (i.e., approximation of the actual particle size distribution according to a bidisperse one) is proposed in the present work. This approximation helps to compress the amount of numbers for the description of the distribution and facilitates the calculation of the properties of the dispersion (especially convenient in cases of complex calculations). In the present work, the procedure to perform the approximation is evaluated, and the best approach is found. It was shown that the approximation works well for the case of a lognormal distribution (as an example) for a moments order from 0 to 2 and for dispersivity up to 3.

Tricking the fractal nature of granular materials subjected to crushing

When a confined granular material fractures under a high compressive load, its particle size distribution (PSD) evolves to reach the fractal distribution. Small particles fill the volume between the bigger ones. Next, even smaller particles fill the remaining space, repeating this pattern across different scales. Diversification of particle sizes is favourable for packing the material in a small volume which explains the occurrence of such a phenomenon. Here we show that the fractal nature of granular material subjected to crushing can be ‘tricked‘by substituting some of the original grains with uncrushable particles. During the compression, the PSD of such a mixture follows the same rule as the purely crushable material. That means the actual PSD, without uncrushable particles, is modified in a particular manner: unbreakable particles of a given size diminish the number of brittle particles of the same size in the fractured mixture. Our results demonstrate that the PSD of the crushed material can be easily controlled, hence optimized to increase the content of eligible fractions in the final product. We believe this method lays the foundations for developing new comminution techniques applicable to various fields of industry, such as mineral processing or recycling.

Evaluation of the Effect of Multiparticle on Lithium-Ion Battery Performance Using an Electrochemical Model

Dear Editor, This letter focuses on modeling the electrode heterogeneity by extending the pseudo-two-dimensional model (P2D) with actual particle-size distributions (PSD). The effects of different particle characterization techniques, including the area-weighted, volume-weighted, and number-based methods on cell dynamics are compared. The model with number-based PSD achieves better rate capability (maximum 2.0% improvement in capacity, maximum 2.6% increase in energy). Besides, the effectiveness of the multiparticle (MP) model is evaluated against the single-particle model (SPME) and P2D model under fast charging conditions. Results show that the PSD generates greater heterogeneities of cell internal states at higher C-rates current.

Large-Scale Saharan Dust Episode in April 2019: Study of Desert Aerosol Loads over Sofia, Bulgaria, Using Remote Sensing, In Situ, and Modeling Resources

Emissions of immense amounts of desert dust into the atmosphere, spreading over vast geographical areas, are in direct feedback relation with ongoing global climate changes. An extreme large-scale Saharan dust episode occurred over Mediterranean and Europe in April 2019, driven by a dynamic blocking synoptic pattern (omega block) creating conditions for a powerful northeastward circulation of air masses rich in dust and moisture. Here, we study and characterize the effects of related dust intrusion over Sofia, Bulgaria, using lidar remote sensing combined with in situ measurements, satellite imagery, and modeling data. Optical and microphysical parameters of the desert aerosols were obtained and vertically profiled, namely, backscatter coefficients and backscatter-related Ångström exponents, as well as statistical distributions of the latter as qualitative analogs of the actual particle size distributions. Dynamical and topological features of the dust-dominated aerosol layers were determined. Height profiles of the aerosol/dust mass concentration were obtained by synergistic combining and calibrating lidar and in situ data. The comparison of the retrieved mass concentration profiles with the dust modeling ones shows a satisfactory compliance. The local meteorological conditions and the aerosol composition and structure of the troposphere above Sofia during the dust event were seriously affected by the desert air masses.

Effect of particle self-rotation on separation efficiency in mini-hydrocyclones

High-speed particle self-rotation near the wall of a hydrocyclone that causes the radial migration of the particles has been extensively investigated. However, the influence of this radial migration on the separation efficiency of the hydrocyclone remains unclear. Since this influence cannot be easily experimentally verified, we employed computational fluid dynamics to investigate the effect of particle rotation on the separation efficiency of a mini-hydrocyclone. A Reynolds stress model and discrete phase model were used to model the flow field and particle migration within the hydrocyclone. Considering the shear flow field and wall collision causing the rotation of particles, the movement trajectory, rotation velocity, and radial migration characteristics of particles entering from different inlet positions in a mini-hydrocyclone were studied. For the numerical simulation, the actual particle size distribution was considered. The results demonstrated that the particles rotated at a high velocity near the wall; the spiral-orbit radius of rotating particles was smaller than non-rotating particles; and high-speed rotating particles migrated from the wall to the central axis of the hydrocyclone. By including particle rotation into the hydrocyclone simulations, the simulated separation efficiency was consistent with experimental results. Further, the accuracy of the rotating particle simulation was 65% higher than the non-rotating particle simulation. Therefore, particle rotation is crucial for simulating the mini-hydrocyclone performance.

Effect of Particle Size on the Aerobic and Anaerobic Digestion Characteristics of Whole Rice Straw

The effect of reducing particle size on physical properties, the methane yield and energy flow were investigated through the biochemical methane potential (BMP) experiment of aerobic-anaerobic digestion (AAD) of rice straw (RS). The whole straw was crushed through four sieves of different aperture sizes (1, 3, 5, and 7 mm) to obtain the actual and non-uniform particle size distribution (PSD). The results indicated that the actual particle sizes were normally or logarithmic normally distributed. Reducing particle size could significantly promote the aerobic hydrolysis and acidification process, increase the content of volatile fatty acids (VFAs) from 4408.78 to 6225.15 mg/L and the degradation of volatile solids (VS) from 40.56% to 50.49%. The results of path analysis suggested that particle size reduction played an important role in improving lignocellulosic degradability, which was the main factor affecting methane production with the comprehensive decision of 0.4616. The maximum methane production obtained at 1 mm sieve size was 176.47 mLCH4g−1 VS. The phyla of Firmicutes (61.5%), Proteobacteria (9.3%), Chloroflexi (8.3%), Bacteroidetes (4.1%), Cyanobacteria/Chloroplast (4.6%) were mainly responsible for VFAs production and lignocellulose degradation. However, the net negative energy balance was observed at the 1 mm sieve size due to the increased energy input. Therefore, the optimum sieve size for AAD was 3 mm.

Influence of the particle size distribution on dust explosion: How to choose the right metrics?

It is well established that the a diameter' of a powder and its explosivity are strongly correlated. But, in fact, what diameter should be considered? The mass median diameter d50 is often used as an indicator of the particle size distribution (PSD) of a powder, but this choice is not always consistent with the mechanisms involved in a dust explosion. Moreover, authors mainly refer to the initial diameter of the powder, whereas it is more relevant to consider its characteristics at the exact time of the ignition. Many other metrics can be of interest concerning dust explosion: Sauter diameter, d10, solid surface concentration. To highlight these points, tests were performed on raw starch powders of 24 microm d50 and 0.49 m2.g-1 specific surface area. They were mechanically agglomerated with an Instron press and then coarsely ground by a blade mill. Different size classes up to 283 microm d50 and 0.16 m2.g-1 specific surface area were selected by sieving. The PSD of the samples were compared before and during their injection in the explosion vessels. The influence of the actual PSD on their explosion severity and minimum ignition energy (MIE) was determined. It has been demonstrated that the evolution of the MIE with regard to PSD is subject to a threshold phenomenon. Moreover, if the mass median diameter can be interesting for kinetics controlled by homogeneous chemical reaction and directly related to the fuel equivalent ratio, the reactive surface is more relevant when the combustion is controlled by surface reaction or diffusion to the surface as it is the case for the various starch samples. Chromatography measurements of the combustion gases confirm these results. Finally, when the agglomerates are partially fragmented by the injection, both the agglomerate and primary diameters must be considered.

Numerical investigation of segregation behavior of multi-sized particles during pharmaceutical mini-tablet die filling

During pharmaceutical die filling, the quality of the tablet is greatly affected by the uneven distribution of raw powder and the accompanying segregation of multi-sized particles. To improve die filling productivity, a further investigation of the causes of this segregation was imperative. The present study comprises an investigation of segregation in the multi-die of a single-punch tableting machine, using the discrete element method to determine the causes of size segregation behavior during the entire die filling process. Simulation parameters were determined based on the measurement of physical properties and actual particle size distribution. Multi-sized spherical particle simulations were performed to visualize and characterize size segregation in the feeder and dies. The effects of the friction coefficient and the initial charged mass of the particles—which are important physical operating parameters—on the segregation behavior were investigated. To qualitatively and quantitatively characterize size segregation, the segregation index and the average size of the particles in the feeder and dies were evaluated. The present research demonstrated the feasibility of the method for characterizing the segregation phenomenon during the filling process and revealed that the segregation mechanisms during the filling process. Furthermore, it was shown that a lower particle-wall friction coefficient and a higher charging mass in the feeder would suppress the segregation, which can cast light on the controlling of the segregation in the tableting process.

Safer and stronger together? Effects of the agglomeration on nanopowders explosion

Among the factors influencing dust explosion, the particle size distribution (PSD) is both one of the most important and complex to consider. For instance, it is commonly accepted that the explosion sensitivity increases when the particle size decreases. Such an assertion may be questionable for nano-objects which easily agglomerate. However, agglomerates can be broken during the dispersion process. Correlating the explosion parameters to the actual PSD of a dust cloud at the moment of the ignition becomes then essential. The effects of the moisture content and sieving were investigated on a nanocellulose powder and the impact of a mechanical agglomeration was evaluated using a silicon coated by carbon powder. Each sample was characterized before and after dispersion using in situ laser particle size measurement and a fast mobility particle sizer, and explosion and minimum ignition energy tests were conducted respectively in a 20 L sphere and in a modified Hartmann tube. It was observed that drying and/or sieving the nanocellulose mainly led to variations in terms of ignition sensitivity but only slightly modified the explosion severity. In contrast, the mechanical agglomeration of the silicon coated by carbon led to a great decrease in terms of ignition sensitivity, with a minimum ignition energy varying from 5 mJ for the raw powder to more than 1J for the agglomerated samples. The maximum rate of pressure rise also decreased due to modifications in the reaction kinetics, inducing a transition from St2 class to St1 class when agglomerating the dust.

Explosion characteristics of aluminum powder in different mixed gas environments

The explosion characteristics of aluminum powder in air, hydrogen and nitrogen were studied in a 20-L spherical explosion vessel. Particle agglomeration affected the actual particle size distribution in dust clouds. In air, the smaller the actual particle size, the larger was the explosion overpressure. Adding hydrogen increased system explosion risk; the smaller the theoretical particles, the more pronounced was the effect of hydrogen. However, when hydrogen was added at a concentration of ≥ 15%, the explosive properties of the mixture weakened. In a constant volume container, the two-phase explosion of flammable gas and flammable dust caused a secondary explosion. Secondary explosion occurrence was affected by fuel composition. Experimental curve analysis explained the cause of the secondary explosion and the two-phase explosion process mechanism. Nitrogen had obvious detonation suppression effects on dust explosions. The higher the nitrogen concentration, the longer was the combustion time. Nitrogen has great influence on fine particles. These experimental conclusions may aid in preventing aluminum powder explosions during industrial production and reducing the harmful consequences of dust explosions.

Issues related to the retrieval of stratospheric-aerosol particle size information based on optical measurements

Abstract. Stratospheric-sulfate aerosols play an important role in the physics and chemistry of the atmosphere. The radiative and chemical effects of stratospheric-sulfate aerosols depend critically on the aerosol particle size distribution and its variability. Despite extensive research spanning several decades, the scientific understanding of the particle size distribution of stratospheric aerosols is still incomplete. Particle size estimates (often represented by the median radius of an assumed monomodal log-normal distribution with a fixed width or by the effective radius) reported in different studies cover a wide range, even under background stratospheric conditions, and particle size estimates retrieved from satellite solar-occultation measurements in the optical spectral range show a tendency to be systematically larger than retrievals based on other optical methods. In this contribution we suggest a potential reason for these systematic differences. Differences between the actual aerosol particle size distribution and the size distribution function assumed for aerosol size retrievals may lead to systematic differences in retrieved aerosol size estimates. We demonstrate that these systematic differences may differ significantly for different measurement techniques, which is related to the different sensitivities of these measurement techniques to specific parts of the aerosol particle population. In particular, stratospheric-aerosol size retrievals based on solar-occultation observations may yield systematically larger particle size estimates (median or effective radii) compared to, e.g., lidar backscatter measurements. Aerosol concentration, on the other hand, may be systematically smaller in retrievals based on occultation measurements compared to lidar measurements. The results indicate that stratospheric-aerosol size retrievals based on occultation or lidar measurements have to be interpreted with caution, as long as the actual aerosol particle size distribution is not well known.

Precise size distribution measurement of aerosol particles and fog droplets in the open atmosphere.

A precise measurement for the aerosol particle size distribution and fog droplet size distribution simultaneously in the open atmosphere is proposed. The extinction coefficient and small-angle forward scattering measurement are integrated into the detection for particle size distribution in the open atmosphere, and can achieve the fine detection of the particles in the atmosphere with radius between 0.1 to 30 μm. The key technology including optimal scattering angle in small-angle forward scattering measurement and optimal wavelengths selection are discussed and solved in detail. The fourteen different particle size distributions including aerosol size distributions and fog droplet size distributions are used for the determination of optimal forward scattering angle and wavelengths. The optimal forward scattering angle is calculated to be 1.1°. Seven wavelengths for extinction coefficients and five wavelengths for forward scattering coefficients are chosen for the retrieval of particle size distribution in the measurement. The regularization inversion of optical parameters for the retrieval of particle size distribution is described. The aerosol particle size distributions measured by particle spectrometer and actual fog particle size distributions are used for the method test and the reconstructions of particle size distributions. The inversion results show that the method can achieve the precise measurements of aerosol particle size distribution and fog droplet size distribution. The error influence on the inversion results of distributions is discussed. Based on the sensitivity analysis of inversion results, the feasibility of measurement in the real atmosphere is analyzed and discussed, and the scheme of detection system is provided.

Numerical study on the LNG application for start-up fuel in the commercial scale CFBC boiler

We evaluated the applicability of liquid natural gas (LNG) as a start-up fuel in the circulating fluidized bed combustion (CFBC) boiler. A 250 ton/hr scale CFBC boiler, which adopts four LNG over bed burners for the operation at start-up procedure, was investigated through the commercial computational fluid dynamics (CFD) analysis. The complex LNG reactions were simplified and the Eulerian-Granular multiphase model was used to consider the behavior of bed materials and gas-solid interaction. The model reliability was obtained by comparing with design values. The simulation results showed that the bed materials have a significant impact on the internal temperature distribution of boiler despite the cold start-up condition which contains a small amount of bed material. With the consideration of two representative particle size distributions in the modeling, the calculated maximum gas temperature near the refractory was below the allowable temperature of refractory material. Further, it was predicted that the application of the actual particle size distribution on the simulation leads to a decrease of maximum gas temperature adjacent to the refractory wall. Based on the present results, LNG fuel could be acceptable for the start-up operation of CFBC boilers.

Guidelines to adjust particle size distributions by wet comminution of a bioactive glass determined by Taguchi and multivariate analysis

A quaternary bioactive glass of high silica content was used as a model system for flexible design of powder characteristics obtained by ball milling. The dependence on milling time was used to demonstrate consistency with the expected correlation between comminution and cumulative kinetic energy of impacting balls. Additional experiments were based on Taguchi planning of simultaneous changes in milling time, balls-to-powder ratio and ethanol-to-powder ratio, with ethanol used as a process control agent (PCA) to prevent agglomeration and to seek greater flexibility in the design of powder distributions. Plausible physical mechanisms allowed us to obtain improved fitting by multivariate analysis, based on log-log scales. Normal distribution was found to be well-suited to describe the actual particle size distributions, which are very positively skewed. Weibull distributions provided good fitting, mainly by considering the three different contributions from particles in small, medium and large size ranges. These contributions are affected differently by ball milling parameters, as demonstrated by finer analysis. This yields suitable conditions for a flexible design of asymmetric powder size distributions (i.e. bimodal or skewed), in addition to a decrease in average particle size - both highly significant factors when designing glass-ceramic powders for robocasting and additive manufacturing.

Transported probability density function based modelling of soot particle size distributions in non-premixed turbulent jet flames

The need to establish actual particle size distributions (PSDs) of soot emissions from the nanoscale upwards, along with the current global indicators based on soot mass, stems from increasingly strict regulatory demands. In the current work, a mass and number density preserving sectional model is coupled with a transported probability density function (PDF) method to study the evolution of soot PSDs in two non-premixed turbulent jet flames at Reynolds numbers of 10,000 and 20,000. The transported PDF approach is closed at joint-scalar level and includes mass fractions of gas phase species, soot sections, as well as enthalpy, leading to a fully coupled 78-dimensional joint-scalar space, treating interactions between turbulence and gas phase/soot chemistry as well as radiation without further approximation. The gas phase chemistry features 144 reactions, 15 solved and 14 steady-state species and an acetylene-based soot inception model is calibrated using comprehensive detailed chemistry up to pyrene and applied to a well-stirred/plug flow reactor configuration. The derived nucleation rate is subsequently applied in the turbulent flame calculations. Soot surface growth is treated via a PAH analogy and oxidation via O, OH and O2 is accounted for. The sectional model features 62 sections covering particle sizes in the range 0.38 nm ≤ dp ≤ 4.4 µm and includes a model for the collision efficiency of small particles ( ≤ 10 nm) based on the Lennard–Jones potential. The computed results reproduce the evolution of the PSDs with encouraging accuracy. It is also shown that the distribution of soot in mixture fraction space is affected by local extinction events.

Homogenization coarse graining (HCG) of the lattice discrete particle model (LDPM) for the analysis of reinforced concrete structures

In this study, a coarse-graining framework for discrete, fine-scale models is formulated on the basis of multiscale homogenization. The model considered in this paper is the Lattice Discrete Particle Model (LDPM), which simulates concrete at the level of coarse aggregate pieces. In LDPM, the size of the aggregate particles follows the actual particle size distribution. Consequently, modeling large structural systems entirely with LDPM leads to a significant number of degrees of freedom and is not feasible with the currently available computational resources. To overcome this limitation, this paper proposes the formulation of a coarse-grained model obtained by (1) increasing the actual size of the particles in the finescale model by a specific coarsening factor and (2) calibrating the parameters of the coarse grained model by best fitting the macroscopic, average response of the coarse grained model to the corresponding fine scale one for different loading conditions. A Representative Volume Element (RVE) of LDPM is employed to obtain the macroscopic response of the fine scale and coarse grained models through a homogenization procedure. Accuracy and computational efficiency of the developed coarse graining method are verified by comparing the response of fine scale and coarse grained simulations of several reinforced concrete structural systems.

Numerical investigation of water droplets trajectories during natural gas dehydration inside supersonic separator

Reliable estimation of the condensed water droplets trajectories inside Supersonic separators (3Ss) during the dehydration process is essential for proper design and safe operation. Most of previous researches ignored the actual sizes of condensed droplets and predicted the particles trajectories for pre-specified diameters. In this article and for the first time, real trajectories are computed by considering the actual particle size distribution (PSD) of the condensed droplets in the presence of swirl, nucleation and growth processes during the dehydration of methane rich natural gas (MRNG) inside Laval nozzle for various diffuser angles. Furthermore, the injection of water droplets to facilitate the condensation process has not been addressed previously.Our simulation results indicate that even for the most optimal geometry and at extremely large centrifugal accelerations of 500,000 g, the condensed particles from MRNG are exceedingly small and can't reach the 3S walls for practical straight tube lengths. Our findings are verified with several previously reported experimental measurements and theoretical investigations results, borrowed from literature. To ensure proper dehumidification, sufficiently large water droplets are assumed to be injected preferably after the throat location. The computed results indicate that by injecting 5 μm diameter particles into MRNG of Khangiran refinery sweet gas stream and increasing its wetness fraction up to 0.12, the dehydration process is successfully achieved in an optimally designed supersonic separator.