Emulsion Flow Rate Research Articles

Investigation on the heat transfer and charge/discharge performance of phase change material capsule emulsion based on nanoparticles enhanced thermal conductivity

Both internal encapsulation and external added nanoparticles have been employed in this study to enhance thermal conductivity and explore the corresponding heat transfer characteristics. Specifically, the correlation between thermal conductivity and capsule, nanoparticle content, as well as the enhanced heat transfer/thermal energy storage performance facilitated by internal encapsulation are demonstrated through numerical and experimental study. Furthermore, it compares key parameters like heat transfer and pressure drop, providing quantifiable evidence that the addition of nanoparticles, whether internally or externally, leads to an increase of thermal conductivity by 6.63 %/2.75 % (5 wt%) and 5.92 %/4.26 % (10 wt%), respectively. Internal encapsulation was observed to yield a more substantial enhancement in heat transfer. Moreover, higher capsule concentrations tend to induce an inverted concentration profile near the heat exchange wall, particularly at higher flow rates. Furthermore, encapsulating nanoparticles within these capsules enhances heat transfer performance, with the level of enhancement scaling with the nanoparticle quantity. Increasing the flow rate of emulsion from 0.4 m·s−1 to 0.6 m·s−1 in a horizontal tube resulted in a 26.67 % increase in heat transfer and a 41.55 % increase in pressure drop. As a result of the disturbed heating, thermal fluctuations of external addition showed more pronounced thermal fluctuations due to disrupted heating, while a internal encapsulation exhibited a more stable temperature distribution and superior heat storage performance.

Research of the influence of the flow rate and phase composition of gas-water-oil emulsion on the errors of quantity of oil well production measurements

The article describes actual task of determining productivity index of oil and gas fields ‒ flow rate of oil and gas. Important indicator of work of an oil reservoir is average daily flow rate, which establishes technological regulation to carry out oil well products sampling. Qualitative measurement of daily flow rate will optimize and predict preventive work. Objective of the work is to study influence of flow rate, composition of the gasoil emulsion on the error in measuring the amount of oil well production. Measurements of the gas-water-oil emulsion flow rate make it possible to control development and operation modes of the field and minimize the possibility of deviations in the operation of equipment for oil and gas production. Keywords: oil reservoir; well; flow rate; error; emulsion.

Passive droplet sorting engendered by emulsion flow in constricted and parallel microchannels

We bring out a passive droplet sorting perspective engendered by emulsion flow in a parallel microchannel with converging–diverging branches and varying channel constriction ratios (CR) and throat lengths (TL). In one microdevice, the value of TL in both the branches was fixed at 300 μm, while the CR were varied between 0.50 and 0.75. The other microdevice had a constant CR of 0.50, but the TL was changed between 300 μm and 600 μm. Three different emulsions containing mean droplet sizes of 25.65 μm, 36.72 μm, and 39.18 μm are analyzed at three different flow rates of 2 μl/min, 10 μl/min, and 30 μl/min. Depending on the difference in geometric constriction induced flow resistances in two arms, bigger droplets are observed to flow through the less resistive path and smaller droplets move across the other branch. Our results demonstrate that droplet sorting efficacy can be more effectively tuned with constriction ratio instead of the throat length variation keeping other geometric and rheological properties constant. Moreover, droplet separation is found to be facilitated by decreasing the emulsion flow rate and increasing the dispersed phase viscosity from 20 cSt to 350 cSt.

Continuous synthesis of surfactant stabilised water in diesel emulsion by steam condensation

Water in diesel emulsions are known to have superior combustion properties. A critical factor that determines their applicability as a fuel is their stability. In this work we propose a novel method for continuous on-board generation of stable water in oil emulsions that is best suited for direct application in internal combustion engines. Here superheated steam is generated and is brought in contact with the oil phase containing surfactant in a helically coiled tube. The steam continuously condenses resulting in micron size droplets in the oil phase. Controlled experiments were done with dodecane as the organic phase containing a surfactant. The droplets size of the dispersed phase is found to be in the range of 1–12 µm. The emulsions obtained were found to be stable for at least 15 days. The mean droplet size is determined as a function of water volume percentage, surfactant concentration and emulsion flow rate. The droplet size features obtained when diesel is used as the continuous phase is found to be similar to that obtained using dodecane.

Continuous Separation Process of Water-in-Crude Oil Emulsion by Simultaneous Application of an Electrical Field Combined with a Novel Absorbent Based on Functionalised PolyHIPE Polymer

During the extraction process of crude oil, the removal of water from a high stability water-in-crude oil emulsions is life-threatening for the production of a profitable product. However, several technologies of separation exist today, e.g. stripping columns, centrifugal separators, coalescence separators, vacuum distillation systems and gravity separators, almost all of these approaches are not able to completely remove water from water-in-crude oil emulsions besides their high cost.
 In this study, the preparation of a high internal phase emulsion (HIPE) was achieved on a laboratory scale. Subsequently, it was polymerized and sulphonated to produce a hydrophilic macroporous polyHIPE polymer (PHP) called silane (vinyl trimethoxy silane) PHP with a relatively high surface area of 104 m 2/g. It demonstrates high water absorption capability in addition to its ability to remove surface active substances such as Mg, Ca, Na and Cl, from crude oil which cause crude oil emulsification.
 The rates of demulsification of water-in-crude oil emulsions were examined in high AC field under various emulsion inlet flow rates from 100 ml/min to 1500 ml/min and different applied voltages from 1-5 kV (equivalent to 14-69 kV/m) by using a model of an electrostatic separator combined with silane PHP as absorber. It was found that the best separation efficiency was 91% with applied voltage of 5 kV and emulsion inlet flow rate of 100 ml/min. When the spent silane PHP was reused in the demulsification process under similar conditions, a separation efficiency of up to 73% was achieved. Also, it was noticed that the separation efficiency was increased with the increase in applied voltage and reduction in the inlet flow rate of emulsion. Moreover, the original or spent silane PHP were able to remove the undesired metals present in the crude oil.
 Keywords: Demulsification; Emulsion flow rate; Separation efficiency; Electrostatic Separator; Electric field strength.

Evaluation of the energy storage performance of PCM nano-emulsion in a small tubular heat exchanger

PCM emulsions have attracted considerable interest as the media for thermal energy storage (TES) owing to their high thermal storage capacity, desirable fluidity and thermal conductivity. However, the direct transportation of PCM emulsions in TES systems for both charging and discharging is rarely reported. In this work, a PCM-in-water nano-emulsion was prepared with n-hexadecane and suitable surfactants for cooling energy storage at a charging and discharging temperature range of 20–5 °C and 5–15 °C, respectively. It was applied to a tubular heat exchanger system to evaluate its TES performance for a cooling panel of 0.2 m2 total surface area. The thermal storage performance was notably increased with the flow rate of emulsion through the exchanger tube. The volumetric thermal storage capacity of charging was 50% higher than that of water. The cooling energy could be rapidly released in the discharging process, 79% of the stored energy at averaging 25 W during most of the discharging period. The emulsion remained stable throughout the test period. Overall, the results demonstrated that the PCM nano-emulsion has the unique characteristics of high static stability, and high energy releasing efficiency and the promising potential for air-conditioning application in buildings.

Numerical investigation of bubble diameter in branched microchannel

With growing importance of microchannel in notable fields like medical, aerospace, food industry, it is necessary to improve the accuracy of pre-determining the mean droplet size to its maximum. We have analysed the various parameters that can influence the bubble size formed. Our main objective is to derive a relationship between diameter of microchannel, length of the junction, emulsion flow rate, and mean droplet diameter so that we would be able to determine the emulsion properties beforehand. It was found that bubble size increases as flowrate of continuous phase decreases.

Experimental studies on pipeline transportation of high internal phase emulsions using water-lubricated core-annular flow method

High internal phase emulsions (HIPEs) are highly viscous complex fluids and cannot be easily transported through pipelines. In the present work, we report experimental studies on transportation of HIPEs using water-lubricated core-annular flow (CAF) in a horizontal pipe. We explore two sets of w/o HIPEs having different mass fractions of continuous phase (6.5 and 15 wt%, respectively). The rheology of HIPEs is carefully characterized, and both sets of emulsions are found to be shear thinning, having significant yield stress. Using a flow loop, we observe stable CAF regimes for a range of HIPE and water flow rates. Pressure drop in the CAF regime is found to be relatively independent of water flow rate and increases almost linearly with emulsion flow rate. We propose a simplified theory for CAF of non-Newtonian yield-stress fluids, which explains radial compression of core-fluid near the injector, and reduction of holdup with increasing core-to-annulus flow rates.

Encapsulation of yacon (Smallanthus sonchifolius) leaf extract by supercritical fluid extraction of emulsions

Extracts with biological activities need to be preserved, as they can be degraded if exposed to light or heat. This work reports results of microparticles formation of yacon leaf extract with modified maize starch as encapsulated agent using Supercritical Fluid Extraction of Emulsions (SFEE). The variable investigated were pressure (9–13 MPa) and emulsion flow rate (QE) (0.5–1.5 mL/min) on the encapsulation efficiency (EE) and residual ethyl acetate content. The highest EE was 68.2 %, performed at 9 MPa and QE of 1.5 mL/min. The obtained particles were spherical, with size ranging from 92 to 450 nm. Analyses showed that: (i) the particles presented an amorphous characteristic; (ii) there was no degradation of the extract during the encapsulation; (iii) the SFEE improved the preservation of the antioxidant activity of the samples. This study shows the potential of using a new technology for particle production.

Numerical analysis of coolant flow in the grinding zone

The article presents results of research concerning computational fluid dynamics (CFD) of water oil emulsion in grinding zone during sharpening of hob cutter face surface. The numerical simulations made possible to determine the influence of different angular nozzle settings and nominal emulsion flow rate on the quantity of emulsion directly reaching the area of contact between the grinding wheel and the machined material. “SST k-ω” model, available in Ansys CFX program, was used in the numerical analysis; however, Kato and Launder’s modifications were used in the model. Experimental tests were carried out in order to verify results obtained on basis of the numerical simulations. The percentage rate of grinding wheel clogging was used as a verifying parameter. Analysis of the clogging made it possible to indirectly evaluate results of the numerical simulation. The clogging measurements were carried out using optical method by taking microscopic images of the grinding wheel active surface (GWAS), which were later analyzed using an image analysis program. As a result of the conducted numerical simulations, it was concluded that the greatest effectiveness of emulsion provision into the grinding zone was obtained when the nozzle was set at the smallest of the examined angles (30°) and greatest of the examined nominal flow rates (7 l/min). This conclusion was confirmed with results of experimental tests, where it was also observed that increasing the nominal flow rate over 5 l/min does not have significant influence on the amount of clogging on the grinding wheel active surface.

Modeling of the Disk Nozzle Parameters in Biodiesel Production

The design and the technological parameters of the disk nozzle and circulation reactor for biodiesel production are established. The basis of the research is to determine the effective length of the emulsion flow in turbulent regime with minimal energy consumption. The effective length of the emulsion flow was determined on the basis of determination of the axial velocity in the flow sections at different distances from the nozzle. The value of the average axial velocity was carried out using the principle of conservation of the kinetic energy of the flow with the determination of the kinetic energy of the annular elements of the emulsion flow at the beginning and at the end of the flow. To conduct the experimental studies of changes in the emulsion flow rate, a specially designed plant was used, which consisted of a disk nozzle, a working capacity and a hydroelectric station. The conducted research allowed to coordinate the design and the technological parameters of the circulation reactor for high-quality biodiesel production with minimal energy consumption.

Detergency and Its Implications for Oil Emulsion Sieving and Separation.

Separating petroleum hydrocarbons from water is an important problem to address in order to mitigate the disastrous effects of hydrocarbons on aquatic ecosystems. A rational approach to address the problem of marine oil-water separation is to disperse the oil with the aid of surfactants in order to minimize the formation of large slicks at the water surface and to maximize the oil-water interfacial area. Here we investigate the fundamental wetting and transport behavior of such surfactant-stabilized droplets and the flow conditions necessary to perform sieving and separation of these stabilized emulsions. We show that, for water-soluble surfactants, such droplets are completely repelled by a range of materials (intrinsically underwater superoleophobic) due to the detergency effect; therefore, there is no need for surface micro-/nanotexturing or chemical treatment to repel the oil and prevent fouling of the filter. We then simulate and experimentally investigate the effect of emulsion flow rate on the transport and impact behavior of such droplets on rigid meshes to identify the minimum pore opening (w) necessary to filter a droplet with a given diameter (d) in order to minimize the pressure drop across the mesh-and therefore maximize the filtering efficiency, which is strongly dependent on w. We define a range of flow conditions and droplet sizes where minimum droplet deformation is to be expected and therefore find that the condition of w ≈ d is sufficient for efficient separation. With this new understanding, we demonstrate the use of a commercially available filter-without any additional surface engineering or functionalization-to separate oil droplets (d < 100 μm) from a surfactant-stabilized emulsion with a flux of ∼11,000 L m-2 h-1 bar-1. We believe these findings can inform the design of future oil separation materials.

Treatment of surfactant-stabilized oily wastewater using coalescing bed of bagasse fly ash (BFA) as a low-cost filter medium: modelling and optimization of process parameters

In the present study, surfactant-stabilized oily wastewater was separated using a low-cost agricultural waste, bagasse fly ash (BFA) in a packed coalescing bed. Factors such as pH (A), BFA bed height (B) and flow rate of emulsion (C) were the most significant process parameters, affecting the oil separation efficiency by the BFA coalescing bed. The effect of the above parameters on the removal efficiency of BFA coalescing bed was investigated by three-level-three-factor (33) Box–Behnken Design model using response surface methodology. A second-order polynomial model equation was proposed with a high correlation coefficient (R2 = 0.9942), which explained the parametric interactions significantly well. About 84.8% of oil removal efficiency was achieved under optimal parametric conditions: pH0 3, 100 mm bed height and 0.145 dm3/min flow rate. BFA, being almost a free waste material, can be effectively used for the treatment of oily wastewaters.

Analysis of technological conditions influence on efficiency of oilfield treatment

The results of influence of process parameters on oil quality and recommended effective technological modes of oilfield treatment processes are presented in this paper. It is shown that the parameters that significantly affect the efficiency of oil processes are temperature and water-oil emulsion flow rate with a given number of working process units and the structure of flowsheet flows.

Performance of Electrostatic Field in Continuous Demulsification of Simulated Crude Oil Emulsion

Water-in-oil (W/O) emulsion is always formed in crude oil production. In most cases, the presence of water droplets in crude oil is undesirable because they can cause several problems such as corrosion of process equipment and a decrease in crude oil quality, as well as its market price. In this research, a simulated W/O emulsion that consists of kerosene as a continuous oil phase, water as a dispersed phase and SPAN 80 as an emulsifier has been formulated. The feasibility of using Span 80 for W/O emulsion formation and emulsion stability has been investigated. Stability test proved that the emulsions with 2 w/v % of Span 80 were stable and no separation was observed for the first 48 hours of gravitational settling. Besides, this research also aimed to study the effects of several parameters such as frequency, emulsion flow rate, voltage, water content in emulsion, and emulsifier concentration on the demulsification performance under high voltage electric field. The results showed that the best demulsification performance was 90% using electrical method at 1000 Hz of frequency, 10kV of voltage, 0.4 mL/s of emulsion flow rate, 2 w/v % of emulsifier, and 30 % of water portion of simulated crude oil.

Dense Packed Layer Modeling in Oil-Water Dispersions: Model Description, Experimental Verification, and Code Demonstration

In the present research paper modeling principles for the oil-water separation with special emphasis on the modeling of dense packed layer (DPL) is presented. Formation of the DPL is attributed to the difference between sedimentation rate and interfacial coalescence rate. Different submodels resolving for the free sedimentation zone, the DPL, the binary coalescence, and the interfacial coalescence are described. These submodels are implemented in commercial CFD software. Adequate validation and calibration of these submodels are necessary to be used for understanding the separation processes in industrial separators. Experiments for understanding the water-in-oil separation processes in a horizontal continuous separator were designed and carried out. Results from bottle and decay tests were used only for calibrating the model. CFD simulations using the calibrated model have served to understand the flow phenomena occurring inside the horizontal separator. The prediction of the model seems to be satisfactory except at higher emulsion flow rate and lower water cuts.

Prediction of emulsion drop size distributions in colloid mills

Colloid mills are the most common emulsification devices used in industry for products with high oil content. Drop breakage occurs when the emulsion is flowed through a small gap between rotor and stator under laminar shear conditions. In this paper, we have developed the first full population balance equation (PBE) model for colloid mills and used the model to better understand the relevant drop breakage mechanisms. The PBE model accounted for both drop breakage and coalescence and generated predictions of the drop size distribution after each pass of the emulsion through the colloid mill. Drops were assumed to break due to capillary instability with the distribution of drop sizes resulting from each breakage event studied in detail. A viscosity model was developed to predict the emulsion viscosity as function of the oil fraction and the high shear rates commonly used. Nonlinear optimization was used to estimate adjustable parameters in the breakage and coalescence functions to minimize the least-squares difference between predicted and measured drop size distributions for high oil-to-surfactant emulsions. We concluded that experimentally observed drop volume distributions could not be predicted with daughter drop distribution functions reported in the literature. Improved predictions were obtained using a new bimodal distribution function which captured drop breakage into multiple, nearly uniform daughter drops with a large number of small satellite drops. We also investigated model extensibility for changes in the oil fraction, emulsion flow rate and rotor speed.

Production of stabilized sub-micrometric particles of carotenoids using supercritical fluid extraction of emulsions

Sub-micrometer particles of carotenoids (β-carotene and lycopene) suspended in aqueous media were produced by extraction of the organic solvent from the droplets of an oil-in-water emulsion with supercritical CO 2. The influence of the process parameters emulsion flow rate, concentration of surfactant/carrier material and pressure on product characteristics was evaluated. Suspensions containing stabilized carotenoids with final particle size of 344–366 nm, encapsulation efficiency of 34–89% and degree of isomerization from carotenoid trans to cis forms in the range of 0.02–15%, were obtained. Independently of the type of carotenoid used, emulsion flow rate influenced the production of suspensions of carotenoids, particularly the encapsulation efficiency and the degree of isomerization. Higher encapsulation efficiencies, but also higher degradations were obtained when β-carotene was employed instead of lycopene. The concentration of surfactant/carrier material was the only process parameter that influenced the final particle size, while the encapsulation efficiency and degree of isomerization were influenced also by the concentration of surfactant/carrier material and by pressure.

Microfiltration of water in oil emulsions and evaluation of fouling mechanism

Abstract An analysis of the crossflow microfiltration of water in oil emulsions is reported. The emulsion considered was water, containing copper sulphate with kerosene using Span 80 as surfactant. Three membrane materials were studied: PTFE, PVDF and regenerated cellulose. The effects of crossflow velocity, transmembrane pressure, and temperature are analysed using several cake filtration models. Increases in transmembrane pressure, temperature and flow rate of emulsion all result in an increase in membrane flux. Membrane flux declines initially with time under most conditions of operation, except at a temperature of 50 °C, where values of flux are stable. Analysis of the fall in flux with time for the PTFE and PVDF membranes indicates that cake formation gives the best prediction of behaviour. In the case of PVDF the model does not predict the performance over the complete range of filtration times but rather two stages of filtration appear to occur; possibly cake formation initially followed by some intermediate pore blocking. In the case of the regenerated cellulose membrane, two stages of filtration seem to occur: an initial phase of cake formation or some pore blocking followed by intermediate pore blocking.

Influence of membrane material and corrugation and process conditions on emulsion microfiltration

An investigation of membrane materials for the cross-flow microfiltration of water-in-oil emulsions is reported. The membrane used were, PTFE, PVDF and nitrocellulose. The emulsion considered was water with kerosene using Span 80 as surfactant. The effects of operating conditions: cross-flow velocity, trans-membrane pressure, temperature and emulsion concentration is described and analysed in terms of a fouling index for filtration. An increase in trans-membrane pressure, temperature and flow rate of emulsion all result in an increase in membrane flux. Membrane flux falls initially with time under most conditions of operation, except at a temperature of 50 °C, where flux are stable. The use of corrugated membranes is shown to produce a large increase in flux rate in comparison to the use of flat membranes under the same conditions and cross-flow velocities.