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Chemical Engineering-Particle Technology And Separation Processes
... This minimum velocity is a function of the flow regime and the pressure drop caused by the passage of the fluid through the particle bed. The first can be obtained from the Reynolds number for packed beds [53]: ...
... Correlations for the case of non-laminar flow regime, such as the Ergun correlation, can be found in the specialized literature [53]. A close observation of Equation. ...
... where The drag coefficient is related to the Reynolds number, Re = U f d p ρ f /µ, which represents the ratio of inertial forces to viscous forces within the medium, in the form of standard drag curves, as illustrated in Figure 7b. Four zones are identified according to the flow regime [53,60]: the so-called Stokes' law region (Re < 0.3), where viscous forces are largely dominant; Newton's law zone (500 < Re < 2 x 105) in which inertial forces are predominant; an intermediary region between the Stokes and Newton regions (0.3 < Re < 500); and a turbulent region (Re > 2 x 105) in which the domain of inertial forces is such that the flow becomes unstable and phenomena like boundary layer detachment take place. The most common jigging conditions occur in the intermediate and Newton flow regime [8]. ...
For centuries, jigging has been a workhorse of the mineral processing industry. Recently, it has also found its way into the recycling industry, and the increasing concerns related to water usage has led to a renewed interest in dry jigging. However, the current scenario of increasing ore complexity and the advent of smart sensor technologies, such as sensor-based sorting (SBS), has established increasingly challenging levels for traditional concentration methods, such as jigging. Against this background, the current review attempts to summarize and refresh the key aspects and concepts about jigging available in the literature. The configuration, operational features, applications, types, and theoretical models of jigging are comprehensively reviewed. Three promising paths for future research are presented: (1) using and adapting concepts from granular physics in fundamental studies about the stratification phenomena in jigs; (2) implementing advanced control functions by using machine vision and multivariate data analysis and; (3) further studies to unlock the potential of dry jigs. Pursuing these and other innovations are becoming increasingly essential to keep the role of jigging as a valuable tool in future industry.
... Step 4: Solving for temperature drops across all effects, (∆T i ), and assuming equal heat transfer in all effects McCabe et al., 1993;Coulson et al., 2002): Q 1 = Q 2 = Q 3 = Q 4 = Q 5 , leads to: ...
... Step 6: ∆T₁ was used in Equation (5), to solve for ∆T₂, ∆T₃, ∆T₄, and ∆T₅. Boiling temperatures (T bi ) in all effects were then calculated Coulson et al., 2002;Al-Sahali and Ettouney, 2007): ...
Improving process performance is always important in any processing industry with the aim of reducing operation costs and improving the profit.Vapor bleeding may be used in processing industries using multiple-effect evaporatorsto reduces steam consumption and increases steam economyThe effect of vapor bleeding on separation performance using multiple-effect sugarcane juice evaporator was analyzed. The effect of increasing percent of vapor bled and determination of the most effective bleeding configuration in terms of energy efficiency and operating costs. The performance factors assessed were: steam requirement, total heat transfer area (At), steam economy, total utilized heat (Qt), mass flow rate of bottoms (Bi), percent solids in the bottoms (XBi), and mass flow rate of vapors. To carry out this work, a five-effect evaporator, forward feed computer model was developed based on mass and energy balance equations, calibrated by data from steam tables. Simulations incorporating different configurations of vapor bleeding were carried out. Bleeding from each of the first four effects, Ei , and from a combination of effects (E1&E3, E2&E4) were carried out. The E1&E3 configuration showed a highest decrease in steam consumption by 23.73% and improved steam economy by 31.28%. Also, vapor bleeding reduced At and XBi while increasingBi. This work suggests that to improve energy efficiency during separation of mixtures using evaporators, vapor bleeding should be practiced while maintaining a balance between vapors used to preheat the feed and that used for heating the subsequent effects.
... For 500 < Re < 2 × 10 5 , within the Newtonian zone, the inertial forces are predominant, whereas an intermediate behavior occurs for 0.3 < Re < 500. For Re > 2 × 10 5 (turbulent region), the preponderance of inertial forces is such that the flow becomes unstable and events like boundary layer detachment may occur [20,21]. which the medium is a liquid or solid suspension that is denser than part of the particles ( 0), the particles are denser than the working fluid ( 0) in most cases. ...
... For 500 < < 2 × 10 5 , within the Newtonian zone, the inertial forces are predominant, whereas an intermediate behavior occurs for 0.3 < < 500. For > 2 × 10 5 (turbulent region), the preponderance of inertial forces is such that the flow becomes unstable and events like boundary layer detachment may occur [20,21]. ...
Urban mining has emerged as a concept that goes beyond conventional recycling, as it aims to tackle both the challenges of solid waste generation and management, as well as the scarcity of primary resources. Gravity concentration has gained increasing attention as a promising method for addressing crucial challenges in urban mining applications. In this sense, this review provides a comprehensive and up-to-date overview of gravity concentration in urban mining processes, covering principles, techniques, current applications, recent advancements, challenges, and opportunities. Emphasis was placed on shifting from the commonly found literature focus on ore processing to solid waste processing. Three types of solid waste, namely plastics, construction and demolition waste (CDW), and waste from electrical and electronic equipment (WEEE), were chosen for a more in-depth examination due to their massive production and widespread generation. Discussions also considered the potential of gravity concentration to address the unique challenges in their processing and explored possibilities for future developments.
... Screening and sieving are some of the oldest and extensively used nowadays physical size separation methods for bulk materials [1,2]. The use of such methods is widely present in laboratories for the purpose of particle size distribution analysis, and in the wide range of industries, such as mining, aggregate production, recycling and mineral processing, pharmaceuticals, cosmetics and food, as a unit operation for large scale separation [3,4]. One of the most common devices being applied for the above processes is the vibrating screen. ...
... Interactions of the screen with its suspension (horizontal F sx and vertical F sz forces, torque M s ) and the influence of the gravitational field (vertical force F gsz and torques related to the riddle M gs and the mechanical exciter M ge ) were intentionally generalized in Equations (4). That allowed us to emphasize the internal dynamics of the dynamic screen model and to simplify further model implementations. ...
The article presents a method of vibrating screen trajectory control based on MR (magnetorheological) dampers applied in a screen suspension. A mathematical description of the dynamic screen model was derived, and parameters of this model were estimated based on experimental data from a semi-industrial vibrating screen. The investigated screen included a single mechanical exciter with unbalanced masses, generating a circular vibration trajectory and operating with over-resonant frequency close to 19 Hz. It was experimentally tested in several phases of operation: start-up, nominal operation at a target vibration frequency and shutdown. The implemented screen model was further extended and included several MR dampers oriented horizontally and vertically in the form of Bouc–Wen models. The Bouc–Wen model was identified based on experiments carried out for an MR damper subjected to harmonic excitations generated by the MTS (material testing system). Dominant frequencies of excitation varied by up to 20 Hz during experiments. The main novelty of the reported solution is that according to the proposed control algorithm, the desired forces generated by MR dampers emulate an additional virtual mechanical exciter of the vibrating screen. In turn, it interacts with the available exciter, resulting in conversion of the trajectory from circular to linear, which was validated in the presented study. For the purpose of simulation accuracy, the desired control force was additionally limited within the simulator by MR damper dissipative domain, which maps the constraints of a semi-active damper. The presented approach allows one to obtain a close to linear trajectory with only one exciter and with semi-active control of suspension stiffness. The results were successfully repeated with different configurations of desired trajectory, indicating that the effectiveness of the desired linear trajectory generation depends on its orientation. The reported findings may lead to the design of new vibrating screen constructions, taking advantage of the semi-active control of a suspension in the attenuation of disturbance resulting from varying processed material parameters.
... The characteristic pore length is d ′ is determined by the definition of the equivalent diameter of Coulson and Richardson (1993) as If the porous medium is located in a tube with the cross-sectional area A, and if a flow of an incompressible fluid with the volumetric flow rate V exists through the porous medium, two different definitions of the velocity are common: (i) The so-called superficial velocity v s corresponds to the mean flow velocity through the empty tube without the porous medium. (ii) Alternatively, the so-called mean pore velocity v ′ can be engaged. ...
... This results in the well-known Carman-Kozeny equation (cf. Coulson andRichardson 1993, Carman 1937), i.e. This equation is valid for a creeping flow, whereas the flow regimes, in general, can be categorized by the Reynolds number. ...
The validity of Darcy’s law at very low Reynolds numbers is discussed controversially in literature, as some authors propose a pre–Darcy flow regime below some critical Reynolds number. The scope of this work is to investigate this problem experimentally. Therefore, a packing of glass spheres is perfused by different glycerin–water solutions. A linear behaviour between the flow velocity and the pressure drop through the packed spheres is found in the complete investigated range of Reynolds number Re d ′ , based on the mean-pore diameter d ′ and mean-pore velocity v ′ with 10 - 9 ≤ Re d ′ ≤ 10 - 1 . This contradicts the results of different authors like Fand et al. (1987) or Kececioglu and Jiang (1994), postulating a pre–Darcy regime for Re d ′ ≤ 2.8 · 10 - 6 or Re d ′ ≤ 0.13 , respectively.
Graphical abstract
... The type of fractionating columns used for industrial applications and its mode of operation contributes to how well products are formed [8]. In fractionating towers, column pressures, reflux ratios, boil-up ratios, feed rate, distillate rate, number of plates etc. are all very significant to determining products purity [9]. Employing process integration for the development and modification of new design strategies to optimise plant operations also determines how detailed a designed process is [10] [11]. ...
... Figure8 shows the stage conversions of BTX in COL2. Seventeen (17) theoretical stages were required for the separation the condenser was denoted as stage zero (0) while the reboiler was denoted as the stage eighteen (18), the rest of the stages retained one to seventeen (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17). Benzene was seen to be very low at stages closed to the reboiler. ...
In this work, Aspen HYSYS simulation software was used to develop a process for Benzene-toluene-xylene BTX synthesis; a leading feedstock in the petrochemical industries for the synthesis of several chemicals, from liquefied petroleum gas LPG. The pinch and retrofit analysis as applicable to the developed model was carried out using Energy Analyser V10 in order to develop a network of heat exchanger, possible energy savings and payback period of the process. The result of the simulation showed that benzene, toluene and xylene have compositions of 89.3%, 95.5%, and 100% respectively suggesting that the process is highly favoured by low pressure and high reflux ratio. The energy analysis revealed that fifteen (15) heat exchanger network (HEN) were developed comprising of seven (7) heaters and eight (8) coolers for the base case simulation and about 0.6MWof wasted heat was recovered by incorporating three (3) additional heat exchangers to the base HEN leading to 9.6% total energy savings of the entire system. The retrofit design suggested three case scenarios yielding payback periods of 2.062 years, 1.802 years and 6.579 years respectively among which the one the second case scenario with 1.802 years was selected to be the preferred case scenario.
... In usual magnetic field brownian forces dominates the magnetic forces. [15] Therefore FF offers very less change in viscosity under very high magnetic fields compared to MRF. This make their application limited where small viscosity change is required. ...
... This fluid flow causes suspension of lighter density particles. [15] B. ...
Magnetorheological Fluids (MRFs) are considered as smart fluids because they control viscosity using external magnetic field. It contains ferro-magnetic powder which are aligned in magnetic flux lines. The magnetic force between particles are controlled by magnetic field intensity. This controllable viscosity makes them acceptable in many mechanical applications, but due to difference in density between suspended particles and carrier fluid sedimentation is bound to occur. This thus creates the need of some additives. In our study, silica Nano particles (commercially known as Aerosil 200) is used as stabilizer and Oleic Acid is used as surfactant and their effect on sedimentation is studied in this article. Some other synthesis parameters like particle concentration, stirring duration and material loading also cause some change in sedimentation rate.
... In the present work, we applied pseudo-first-order and pseudo-second-order models [42] to evaluate the adsorption kinetics of nanoparticles. The pseudo-first-order and the pseudo-second-order models were compared with the experimental data to verify which adsorption kinetics model provides the best fit. ...
... To evaluate the equilibrium of adsorption, two typical adsorption isotherm models [42] were used as presented in Table 4. ...
The major challenges in using nanoparticles in oil and gas industry projects are high investment costs and environmental problems. Bio-nanoparticles provide a solution to environmental and economic challenges in the nano-assisted EOR processes. In this work, the potential of natural calcium carbonate nanoparticles containing chitin for wettability alteration in enhanced oil recovery was studied. The adsorption behavior of bio-nanoparticles onto calcite-dolomite rock surface was distinguished through kinetics, equilibrium, and thermodynamics assessments. Besides, oil recovery is measured through forced imbibition experiments. The Taguchi experimental design was conducted to optimize the parameters influencing oil recovery factor in forced imbibition experiments, including nanofluid concentration, temperature, and oil type. Results of the adsorption experiment showed that adsorption kinetics of bio-Ca nanoparticles onto calcite-dolomite surface follows the pseudo-second-order model and monolayer, Langmuir adsorption of bio-nanoparticles. The endothermic heat of physical adsorption (physisorption) was found 3.32 kJ/mol. Based on the experimental design, the optimum parameters that can rise to additional oil displacement are a nanofluid concentration of 0.05 wt.%, normal heptane as liquid phase, minimum salinity (Milli-Q-water), and ambient temperature. The oil recovery factor increased by 17.52% at an optimum nanofluid concentration of 0.05 wt.% in comparison to a base fluid without nanoparticle. The results indicate that synthesized bio-Ca nanoparticles have proper EOR potential in both light oil and heavy oil reservoirs at certain conditions.
... 8 The enthalpies of inlet and outlet air are calculated by the following equation (based on data 7 ): (21) The equation (21) is valid in the range between 20-70 °C. The heat loss by conduction through the reactor wall is given as: (22) where U -overall heat transfer coefficient (J h -1 m -2°C-1 ), A -heat transfer area (m 2 ), T a -ambient temperature. ...
... Normal diffusion mechanism through cell walls is represented in the classic maceration, so this process requires a much longer extraction time 20 . Extraction kinetics curves (Figure 3) are characteristic for extraction from cellular material with two period of extraction 10,12,14,22 . In the first period, fast extraction takes place i.e. washing extractive matter by solvent from the surface of destroyed cells. ...
... The drag force can be modeled by the empirical Khan-Richardson model [33] given that the particles' impact on the flow field is negligible. (18) where a is the particle radius (m), U ! par is the particle velocity (m s À1 ), and Reynolds number is defined by: ...
This chapter focuses specifically on wire-plate-type electrostatic precipitators (ESPs), detailing their fundamental operation principles and the role of electrostatic forces in particle collection. It also outlines the key mathematical models used to simulate ESPs, providing insights into the interactions between electric fields, airflow, and particle dynamics. Furthermore, the chapter investigates the impact of geometric variations—such as electrode spacing, plate length, and channel height—on wire-plate ESP efficacy by utilizing finite element analysis. The findings indicate that optimizing these geometric parameters can substantially enhance collection efficiency, reduce operational costs, and mitigate potential particle re-entrainment. In an industrial context, several key parameters must be considered to maximize the efficiency and cost-effectiveness of the ESP. Factors such as power consumption, inlet flow velocity, specific collection area, plate-to-plate distance, and corona power ratio influence the overall performance of the system. The chapter concludes with practical design and optimization guidelines, demonstrating that an optimal balance between high collection efficiency and low energy usage can be achieved, thereby enhancing the environmental and economic performance of wire-plate ESPs.
... The processes of directional motion, orientation, stretching and sedimentation of particles under the action of Coulomb forces are quite effective for micro and nanoparticles [1][2][3][4][5][6][7][8][9][10][11]. ...
To solve various technical problems, technologies are needed that allow creating new types of functionally graded anisotropic composite materials with directional properties. The formation of such structures based on additive technologies continues to retain its relevance every day. In this context, this paper proposes a new approach to creating a structure with axial symmetry and electrical or mechanical properties. In this case, the possibility of controlling the movement and direction of particles using strong electric fields is used. Taking into account the presence of a strong electric field in a condensed medium located in the interelectrode space, a mathematical model for the formation of a structure with axial symmetry is proposed, based on the analysis of the forces acting on the particles in the medium. For this model, as a result of some simplifications, analytical solutions were found. According to the results obtained, it is believed that a strong electric field also allows forming certain structures of materials and products with certain properties from microparticles, similar to polymer chemistry.
... Calculate the peroxide value from the expression Peroxide value = 10 (ab)/W Where W = weight, in g, of the substance. [4][5][6][7][8][9][10][11][12] The following microorganisms were used for anti-microbial activity. Staphylococcus aureus, Escherichia coli, Salmonella species and Pseudomonas aeruginosa. ...
It has been noted from the past few decades, researchers are striving for the development of natural alternate to antibiotic due to their resistance problems. Bacterial infection and its resistance is a major health issue that affects millions of people throughout the world. Sesamum indicum L. is one of the important seed crops worldwide to get edible seed and oil. In the present study we evaluate the chemical characteristics including refractive index, wt/ml, pH, viscosity, acid value, iodine value and peroxide value and found that the obtained Results are under the specification. The antimicrobial activity of oil shows that the minimum inhibitory concentration (MIC) is in the range of 17 µl to 460 µl. the best MIC is 17 µl against Salmonella species. The zone of inhibition of sesame oil against the tested microorganism is in the range of 18 mm to 25 mm. the best zone of inhibition is 25 mm against Salmonella species. So we can say that the antimicrobial activity of sesame oil is best against Salmonella speciesout of the microorganism which we have taken for activity.
... When the feed enters the column, the feed is slightly vaporized. As the liquid flows down the column, the components with low boiling point are separated as it rises from the top part of the tower [1]. ...
... To evaluate the interfacial friction factor ( i ), due to turbulent gas, Blasius equation [20] is used; ...
A mathematical model was formulated using the absorption of carbon dioxide by monoethanolamine amine as an absorbent in a falling film reactor. A program wrote in Fortran language was used to obtain these profiles via using of multi grid method through programming of kinetic and thermodynamic equation and physical properties of the studied system. Through the formulated model film thickness, surface temperature, velocity, concentration and temperature profiles were obtained. The mathematical analysis validated by a test run in a Baiji refinery through intrusion of liquid flow rate, liquid concentration and gas fraction. In this study we have four factors as independent variables ,they are mole fraction of hydrogen sulfide in gaseous mixture (Y) (0.05, 0.75 and 0.1), molar concentration of absorbent (monoethanolamine) (CMEA) (0.05, 0.075 and 1 M), volumetric flow rate of liquor MEA (QMEA) (5, 10, 15, and 20), and its temperature (T) (30, 35, 40, 45, 50 and 55 C).
... Recommended design values for absorbers and strippers is 15-50 mmH2O/m packing (Coulson and Richardson, 2004). This is because it is advantageous to have a reasonable hold-up in the column as this promotes interphase contact (Coulson and Richardson, 2009). Table 6 shows the effects of percentage flooding velocity on the design parameters. ...
A Computer Aided-Design (CAD) module was developed for the design of packed gas absorption column. The program was tested using a problem statement by supplying specifications such as operating conditions (pressure, temperature), physical properties (density, viscosity, surface tension), the solute to be absorbed, the solvent selected, gas and solvent mole fractions, percentage flooding velocity, pressure drop, gas flow rate ,packing type and size. The design parameters calculated agreed with those obtained from manual solution, with a correlation coefficient of 1.000. The specifications above were varied to obtain the design outputs within the shortest possible time. For example, operating pressure of 760 mmHg, operating temperature of 30 0 C, gas flow rate of 0.126kg/s, flooding velocity of 50%, pressure drop of 21 mm H2O/m of packing, and 0.025m raschig ring ceramic packing gave the following design parameters: cross-sectional area of 0.6209431 m 2 , column diameter of 0.8891045 m, packing height of 2.743771 m, surface area of 22.35612 m 2 , tower height of 7.558167 m, and volume of packing of 1.703726 m 3 .
... There is an urgent need to build more ammonia and urea production plants to curb shortages and inefficient supply of fertilizers (urea). The article is aims to design a processing plant to provide higher production of the required products with lower energy consumption [3][4][5] Researchers work conducted on ammonia revealed that ammonia is an essential raw material use by various industries as well as one of the major raw materials used in the production of 'urea. Ammonia is produced commercially by the reaction between hydrogen gas (H 2 ) and nitrogen gas (N 2 ), while urea (NH 2 CONH 2 ) is synthesized from the reaction between ammonia and carbon dioxide [6]. ...
ABSTRACT
The Design of a Plant for the production of 1800MT/Day of Ammonia and 1400MT/Day of Urea
using aspen hysys was carried out in this work. Ammonia is produced through the Haber-Bosch
process, where hydrogen and nitrogen react in the presence of a catalyst producing mixture
containing ammonia while urea is produced by the reaction between ammonia and carbon IV
oxide. In this work, Aspen HYSYS, chemical Engineering design software was used to design
and perform material and energy balance around the plant. From the design analysis performed
from the software, plant production capacity of 75,063kg/hr of ammonia and 58,343kg/hr of
Urea was obtained. 7,677.6kmole/hr of methane gas, 19,194kmol/hr of steam and 3,584kmol/hr
of air feeds was used to achieve the objective. The overall reaction is exothermic and the primary
reformer process is characterized by a low pressure. Cost estimation carried out showed that the
total purchased cost of equipment was 64,545,522,
gross annual earning was 54,316,685 rate of return
was 38.85% and payback time was 2.5years. Safety consideration for a smooth run of the
ammonia-urea plant is also presented in this work.
... All three types of treatment greatly increased the filtrate flow rate compared with untreated FFT indicating significant improvement in dewatering performance of treated FFT; however, the rate of dewatering vastly different suggesting that floculants, like A3338, and coagualnts, like lime, act in different mechanism to improve filterabiltiy. The specific resistance to filtration (SRF) values of the treated FFT-1 and FFT-2 with different treatments were calculated and compared in Table 5 (Coulson, et al. 1991;Li, et al. 2018). The linear portions of the filtration flow curves in Figure 7 were chosen for the SRF calculation. ...
Fluid fine tailings (FFT) are a byproduct of oil sands mining with present stockpiles
exceeding 1200 Mm3. Upland reclamation of FFT is not achievable until the surface
deposit consolidates and solidifies to provide sufficient strength to support earthmoving equipment. The oil sands industry uses polymers to partially dewater FFT; however, additional postdeposition dewatering mechanisms such as evaporation and freeze-thaw are critical to achieve sufficient strength for eventual reclamation. The development of new tailings strengthening technologies capable of permanently modifying FFT to achieve improved post-deposition dewatering and strength development would be attractive for managing FFT.
Hydrated lime and quicklime are used extensively in soil stabilization to generate long-term strength gain. This study investigated the use of hydrated lime following polymer treatment of FFT to assess strength gain and dewatering with time. The investigation shows lime treatment assisted with further dewatering of flocculated FFT and resulted in superior strength gain with time.
... The calculated specific resistance to filtration (SRF) values are determined by the b value according to Eq. 2 (Coulson, et al. 1991;Li, et al. 2018). The linear portion of the filtration flow curves indicates the filterability of the materials and the corresponding linear b portion in the Eq. 2 can be used to calculate the SRF values. ...
Filter press is a low-cost and easily operated equipment to assess the filtration
performance of tailings. Direct air pressure (20, 30 or 100psi) was applied to a tailings sample and the rate of the filtration was measured either for a fixed time or until the filtered cake dewatered sufficiently but unevenly to crack. The cracking of the filtered cake limits the ability to evaluate the dewaterability of different tailings. In this study, a filter press was modified to use an elastic film or a piston cylinder in between the high-pressure gas and the tailings sample. This applies the same gas pressure to the sample but removes the limitation on dewatering time due to cracking. This permits an assessment of dewatering performance of different tailings treatments at much higher solid contents.
This study showed that the modified filter press produced highly repeatable results. The test can discern differences in different fluid fine tailings (FFT) treatments at a given pressure. The treated FFT can achieve the plastic limit in hours or 1-2 days compared to months or years by settling tests through the column. Furthermore, the release water from pressure filtration can be easily filtered for water chemistry assessment allowing more insight into the behavior of the tailings. We believe that pressure filtration can be an indicator of long-term consolidation trends.
... In addition, both freeze drying and spray drying produced almost the same TGA curve (Fig. 5), suggesting that spray drying had no noticeable in uence on the gravimetric curve of the dried biomass compared to freeze drying. As the temperature remained below the wet bulb temperature of the drying gas until drying was almost complete [44], the spray-drying conditions did not affect the quality of proteins, lipids or carbohydrates, con rming previous conclusions. ...
Spray drying is a very popular method for microalgal biomass drying, however, systematic research on the responsion of biochemical composition during the process of spray drying has not been addressed so far. This study investigated the influence of the inlet temperature and initial solid content on the biochemical composition of spray dried Scenedesmus acuminatus biomass. The fatty acid composition and contents of CHNS, lipid, carbohydrate, protein, starch and pigments were analysed to characterize the quality and bioactivity of dried product. Results showed that the moisture content of dried microalgal powder decreased with the increase of inlet temperature and initial solid content, and the lowest moisture content of 2.37% with a higher drying yield of 84% was achieved at the optimized inlet temperature of 220°C and initial solid content of 16%. The biochemical compositions of CHNS total lipids, carbohydrates, protein, starch and fatty acid were similar with those dried by freeze drying, and were barely altered during the process of spray drying. However, the pigment would be partly degraded as the inlet temperature increased, which could be alleviated by increasing the initial solid content of the microalgal suspension due to the protection of cell aggregates. Thermogravimetric analysis (TGA) further confirmed that spray drying didn’t affect the quality of proteins, lipids and carbohydrates, suggesting that spray-drying technique could be applied to S. acuminatus for the production of both biofuels and nutritional supplements. These results may serve as a reference for the selection of drying method, utilization of the nutritional components in S. acuminatus and selection of biochemical parameters for spray-drying performance evaluation.
... Nanotechnology is an unconventional method which in recently had several presentations in various arenas like industry biotechnology [7], environment and energy… etc. [8,9]. Nano-zinc oxide (ZnO) has recently achieved special consideration concerning possible electronic uses due to its exclusive electrical, optical, and chemical characteristics [10,11]. ...
Nano-zinc oxide (ZnO) has recently achieved special attention because of its unique optical, electrical, and chemical properties. Zinc sulfate heptahydrate and ammonium hydroxide were used as precursor materials for the preparation of Nano-zinc oxide. The current study aimed to investigate the effect of a period of contact on the rate of adsorption of Nano-zinc oxide, the impact of interaction period on the percentage removal, the effect of pH, and the effect of adsorbent dose. Central composite design (CCD) in response surface methodology (RSM) was used to proposed design and augment the elimination of dyes against initial dyes concentration, pH, adsorbent mass, and time, in addition, to study the potential relations among these variables. It was found in this study that when the concentration of Methylene Blue in wastewater increases, the percentage removal decreases. Equilibrium concentration is reached after 40 minutes. The isotherm and kinetics estimations demonstrated that Freundlich models and the second-order used for the isotherm and kinetics of the MB adsorption. Finally, increasing the weight of Nano-zinc oxide increases the percentage removal of Methylene blue dye.
... (Turczyn R, 2008) If particle concentration is high then more is the upward fluid flow, which will keep particles suspended. (Richardson CJF, 2003) This physics works well for the nonstabilizers containing MRFs but observed to have contrast response in the presence of stabilizers. (Turczyn R, 2008) The adsorption isotherm of surfactant on dispersed particle can be used for sedimentation study. ...
... But for the purpose of this investigation, the solidliquid extraction-leaching is employed. Oils extracted from whole seeds were more stable than those extracted from dehulled seeds [14] . The aim of the present study is to extract and characterise the physico-chemical properties of the Sesamum indicum Seed Oil and its medicinal applications. ...
Standardization the process of developing and implementing technical standards and to maximize compatibility, safety, repeatability and quality of the drugs is one of the important measures in view of the various practical problems encountered from time to time especially in the field of herbal drugs and Ayurveda. Scientific data pertaining to the standardization of the herbal drugs could be of immense value to substantiate efficacy, safety or toxicity of an herb. Hence present study was intended to standardize Sesamum indicum L seed extracts, since Sesamum indicum L. (sesame or til) is an important food, oil, medicinal and religious crop in India. Standardization of seeds of Sesamum indicum L. were carried out using organoleptic characterization and chemical characterization as moisture content & ash value to assess the quality and purity of drug. The oil was extracted from seed of Sesamum indicum L. by solvent extraction method using Soxhlet apparatus with suitable solvents as Petroleum ether (40-60°C), ethanol, benzene and n-hexane. The percentage oil yield on weight of the dried seeds was 46% in the ethanol extract and was found to most suitable as the yield is more and is less toxic and economic. The present study assessed phytochemical characteristics of the oil extracted from seeds of Sesamum indicum L. Qualitative phytochemical analysis of extracts revealed presence of alkaloids, flavonoids, glycosides, phenols, anthraquinones, tannins, carbohydrates and proteins extracts. The oil quality parameters were accessed in terms of acid value, free fatty acid value, saponification value, iodine number and peroxide value. Results indicated the authenticity of the herbal drugs used in the study. Study was successful in establishing quality standards for the seeds of Sesamum indicum L. These preliminary studies may offer great help in initial procurement and assessment of quality of the crude drugs when these are being used as raw materials for preparations of herbal formulations.
... C hrom atography is typified by relatively short residence times, fast th roughput and increased productivity. Hence, the products are rarely subjected to therm al degradation (Coulson and R ichardson, 1991). ...
Due to its high selectivity and ability to realise high levels of product(s) purity, chromatographic separation has become an integral technique in the purification of many fine chemicals, pharmaceuticals and biologics. In this work, different feasible column designs and operating policies of high performance liquid chromatographic processes are investi gated so as to minimise the major purification cost elements involved whilst at the same time enhancing the column performance. This overall objective has been demonstrated for mixtures with practical relevance. Dynamic mathematical models for general chromatographic units were employed as the basis for this study so as to take advantage of advances in computational capability currently available. Experimental and mathematical verification of these models has been performed to increase the accuracy and reliability of the simulations. Recognising the importance of the isotherm model in chromatography separation, a systematic procedure for isotherm determination which requires only minimal experimental effort and offers significant reduction in time, has been developed. The mathematical models coupled with a rigorous dynamic optimisation technique have been employed to determine the best column design configuration for a series of representative chromatographic processes. This approach exploits the full potential of the chromatographic separation process by taking into account key design parameters and operating variables such as column length, column diameter, particle size, flow rate, valve switching action etc. The optimal design leads to improvements in production rate as well as in separation power. Significant effort is allocated to the investigation of different operating policies for chro matographic separations including: conventional recycling, a peak shaving technique and multiple feed injection. Optimisation results show that by application of the described op erating policies, the column performance can be enhanced whilst keeping the volume of the matrix constant, hence leading to substantial cost savings. The optimal solution is shown to be highly dependent on the separation conditions. As a result, careful consideration is required to decide which policy and which separation conditions should be adopted for a given process. The thesis concludes with recommendations on how best to implement the results of the study in an industrial context and outlines areas for future study.
... When the feed enters the column, the feed is slightly vaporized. As the liquid flows down the column, the components with low boiling point are separated as it rises from the top part of the tower [1]. ...
Currently, shell and tube heat exchangers comprise a group of equipment called profitable interest due to their usefulness in various industrial sectors. Its appropriate design is coupled to processes in a sustainable development scenario, mainly for use in laboratories or home services. The semi-analytical analysis of these complex systems currently allows for achieving temperature control objectives in the substances used, such as water, without detailed modeling of the hydrodynamics that develop due to the flow conditions. For this purpose, the development of computational tools that implement algorithms based on correlations for determining Nusselt numbers is proposed. Specifying key correlations that determine optimal operating conditions can be used to define process efficiency and contribute to the concept of net zero energy. Simultaneously, the transfer of thermal energy can continue in subprocesses, contributing to reuse and reducing the carbon footprint if the source of the energy comes from fuels or to efficiency if it comes from renewable energies.
Мета: Визначення впливу конструктивних параметрів газорозрядної системи на основі перфорованої трубки на розподіл тиску азоту між електродами, а також моделювання фізико-топологічних характеристик цієї системи для покращення її ефективності. Методика: Моделювання газорозрядного процесу здійснено з використанням чисельних методів розрахунку тиску і швидкості газу в коаксіальній розрядній системі. Основою методики є рівняння Нав'є-Стокса для однофазного потоку азоту через перфоровану трубку, враховуючи різні режими протікання (ламінарний і турбулентний), а також варіації температури, в'язкості та густини газу. Число Рейнольдса застосовується для класифікації режимів потоку. Результати: Моделювання показало, що розподіл газу в розрядній системі залежить від параметрів трубки і розташування отворів в аноді. Газ протікає нерівномірно через отвори, що спричиняє нерівномірність горіння розряду по осі системи. Для покращення рівномірності розподілу газу рекомендується застосовувати більш складні конструкції системи. Наукова новизна: Вперше проведено моделювання газорозрядної системи з перфорованою трубкою з використанням фізико-топологічного підходу для дослідження впливу конструктивних параметрів на розподіл тиску газу, що дозволило виявити критичні аспекти, які впливають на рівномірність потоку і, відповідно, стабільність розряду. Практична значимість: Отримані результати можуть бути використані для оптимізації конструкцій газорозрядних систем у промислових і наукових установках, зокрема для забезпечення стабільності і рівномірності розряду в коаксіальних системах. Це дозволить підвищити ефективність роботи таких установок.
Six different commercial powders, finer than 45 μm, were used for examining the effects of particle characteristics on mean particle size and specific surface area. The measurements were carried out using the most commonly used air permeability- and laser light diffraction (scattering) techniques. As the air permeability method has been used as a benchmark for decades in the powder metallurgy (P/M) industry, the physical phenomena that govern the passage of gas through the powder bed under laminar flow conditions were also presented. The experimental data indicate that both methods give similar results for spherical powders. The advantage of laser light systems over gas permeameters is the ability to provide additional information on particle size distribution. Irregularly shaped powders should be analyzed by both techniques, relying on gas permeametry for surface area measurements and on laser light diffraction for the estimation of mean particle size and size distribution. Application of scanning electron microscopy as a complementary technique was found very helpful in the interpretation of data through visualization of individual particles.
The sugar industry plays a crucial role in numerous economies worldwide, and projections indicate an increase in sugar demand in the coming years. Sugar manufacturing is a complex and highly energy-demanding process, encompassing various sub-processes, including the milling of sugarcane, clarification of raw cane juice, evaporation of syrup, crystallization of syrup, and centrifugation. The crystallization process involves extracting solid sucrose crystals from a supersaturated solution, with supersaturation being a crucial variable. Most previous review articles have focused on specific topics of the crystallization process in the sugar industry. This review aims to provide a broader and updated discussion. It explores various aspects, such as the fundamentals of the process in the sugar industry, a technological description of the three-stage operation, and an analysis of the role of supersaturation. The review examines the main process variables, the most commonly used industrial sensors, and their limitations. Additionally, it discusses the main proposals and approaches found in the literature related to monitoring, modeling, and control of crystallization in the sugar industry. The article identifies and analyzes some limitations present in the literature, including the selection of instruments for industrial monitoring, confusing references to supersaturation sensors, and the need for proper error analysis in the design of process-focused estimators. In particular, there is an emphasis on including information about error bounds for supersaturation estimators.
Enhancing heat transfer within a gas-solid fluidized bed on glass beads using nanomaterials has gained considerable attention due to its potential applications across various industrial processes. This study explores the impact of nanocoating on heat transfer efficiency in fluidized bed glass beads and a heating element, employing diverse operational parameters.
The experimental setup includes a study of hydrodynamic in fluidized bed column with a height of 1.5 m and an internal diameter of 0.1 m. Three sizes of glass beads (200, 400, and 600 μm) were used. The air distributor is designed according to Kuni levenspel and is positioned above the entry point at a distance of 0.05 meters. A 600 W Heating element with a diameter of 0.02 m and a height of 0.3 m was used as the heat source and was centrally placed inside the column at a height of 0.1 m from the air distributor. Hydrodynamic studies, including minimum fluidization velocity, bed height, void fraction, and pressure difference, were carried out.
Glass beads were coated with nano-iron oxide through a chemical deposition method for all particle sizes, while 200 and 400-micrometer glass beads underwent nano-copper oxide coating using the adhesion method. The heat transfer coefficient was computed under varied operating conditions before and after nanomaterial coating.
The work included coating and characterizing the thin layer on glass bead surfaces using XRD, TEM, BET, SEM, and EDX. Coated glass beads exhibited significant alterations in surface properties, morphology, and surface area, thereby enhancing thermal conductivity. A notable enhancement in the heat transfer coefficient was observed using nanosized iron oxide and nanosized copper oxide-coated glass beads. For nanosized iron oxide and nanosized copper oxide, the heat transfer coefficient increased by approximately 10-15% and 18-23%, respectively, across all bead sizes.
The effect of heating element height was studied three heights of (10, 15 and 20) cm above the distributor by using 600µm beads. It was found that the value of the heat transfer coefficient was better which was closer to the distributor plate the.
The modeling and simulation process begins with the typical equation for the heat transfer coefficient based on the Nusselt number using the Lab fit program.
Nu=23〖Re〗^0.467 Pr^3.242
The experimental model equation shows a difference of 5 to 10%- between the experimental and real results for all conditions.
A successful CFD simulation was performed using COMSOL software of the fluidized bed before and after coating using the Euler-Euler model and heat transfer phenomena. The temperature was varied with 2-5% error of the experimental findings which shows the model was accurate and acceptable.
The results, such as void fraction and bed height effect, were modeled using response surface methodology (RSM) using Minitab software and the equation for heat transfer effect on these parameters were
HTC=398.2−968V−3.212P−25.26H+686V2+0.00707P2+0.307H2+5.73VP+43.54VH+0.1075PH
The application of these models contributes to a deeper understanding of heat transfer mechanisms within the fluidized bed.
The relative delay of the flow of solids in a pipe, holdup, is shown to be an important factor in the evaluation of the flow of settling particle-bearing liquids. Holdup can be determined using a new, modified interpretation of the two-layer model, originally published in the 1970s. In the original model, particles in the upper layer of the flow are supported by hydrodynamic forces only, while those in the lower layer are also supported by hindered settling and wall reactions. This concept has been retained in the new model. An initial approximated value of holdup can be refined to allow an increasingly accurate value to be calculated. Innovative coding of the new model overcomes instability and interface positioning problems. Applications for determinations of holdup and the model are examined. Pressure loss, flow rate and the prediction of the pipe velocity to avoid a stationary bed are established. The model allows a locus of stationary bed conditions to be plotted for a family of holdup values. A method to obtain the centre of concentration in the cross section is demonstrated. The locus of centre of concentration (LCC) gives an indication of the position and size of the particle burden as conditions change.
Due to their many purposes and functions for mankind, oils from fruits and seeds are given a lot of importance today. As a result, there is a higher demand for cashew, avocado, and bush pear oils. The Soxhlet extractor and petroleum ether as the extracting solvent are used in this work to extract and characterize the oils from the seeds of Cashew, Avocado, and Bush pear. Physical and chemical studies of the extracted oil were performed alongside with the identification of any trace metals. The findings assessed the yield, color, relative density, refractive index, acid value, peroxide value, iodine value, and saponification value free fatty acid for Bush pear, Avocado pear, and Cashew seeds. The yield (%) of the oil produced from the various seeds of cashew, avocado, and bush pear oils is of specific significance. This finding reveals highest oil yield of 38.2% in Avocado pear oil, compared to 34.4% and 27.4% oil yield in Bush pear seed, and Cashew seed, respectively. In addition to being edible, Bush pear and Cashew oil's low acid value of 6.4 mg KOH/g and 7.7 mg KOH/g, respectively compared to Avocado oil's low acid value of 14.6 mg KOH/g avocado suggests that Bush pear and Cashew oils finds good applications in the paint industry. The study also showed that potassium had the highest concentration of any metal, with 45.8 mg/100g in avocado oil, compared 24.9 mg/100g and 1.68 mg/100g for Cashew seed oil and Bush pear, respectively. Zinc had the lowest concentration, with a value of 0.38 mg/100g observed in Cashew compared with 1.32 mg/100g and 2.06 mg/100g for Bush pear and Avocado, respectively. Hence, this reveals that Oils extracted from Cashew finds good applications in the production of hydraulic oil with exceptional lubrication properties. The FTIR study shows that functional groups including alkanes, alkenes, carbonyls, etc. are present in the seed oils of Bush pear, Avocado pear, and Cashew seeds.
This paper presents the performance evaluation of locally prepared activated carbon from rice husk and saw dust. The raw materials were carbonized at different temperatures (600-800 o C) using sodium hydroxide (NaOH) as the activating agent. The study includes moisture content determination of the raw materials used in the activation and carbonization processes. The effects of variations in carbonization temperature and concentration of activating agent on various performance indices for good quality absorbent were investigated. The percentage yield of the activated carbon from the raw materials as well as iodine number and adsorption of heavy metals from aqueous solutions were also determined. The experimental data which make a comparative assessment of activated carbon obtained from rice husk and saw dust were also presented. Preliminary examination of the raw materials showed that rice husk and saw dust had a moisture content of 14.6% and 5.8% respectively. Increase in carbonization temperature decreases yield of the active carbon. The highest yield of about 48% was obtained from rice husk at 600 o C, with moisture content of 26%. The rice husk at 800 o C gave a yield of 47.2% with moisture content of 26.5%. Whilst the yield of the saw dust was 44% at 600 o C and 40% at 800 o C with moisture content of 17% and 19% respectively. A detailed study of mass transfer processes indicated that activated carbon from these materials show good performance. @JASEM
Waste valorization is of utmost importance due to the scarcity of natural raw materials. In Europe, up to 150 kton/y of eggshells waste are generated and, usually, landfilling is the only option. This work aims to develop eco-ceramic wall tiles using bio-calcium carbonate from eggshells waste as a raw material. Several pastes were prepared by replacing limestone, the natural raw material used nowadays, with eggshell waste (0, 25, 50, 75 and 100 wt%). Through specimens’ characterization, the total substitution by bio-calcium carbonate with the same granulometry leads to an increase, of 19%, in the flexural strength, without affecting the other properties (linear thermal coefficient, weight loss, firing shrinkage, water absorption, density, colour coordinates), and all values are within industrial limits. Therefore, this work proved that limestone can be totally substituted by eggshell waste. The developed eco-ceramic wall tiles consume less natural raw materials and promote a decrease in the landfilled wastes quantity.
The Humidification Dehumidification (HDH) desalination system is a promising method for production of potable water in isolated locations. Among different component constituting the HDH desalination system, humidifier and its packing are paramount factors in determining system productivity. Several experimental investigations were conducted to study the influence of packing on humidifier performance. However, numerical analysis dealing with performance of humidifier packing is still not available. Such an investigation will be useful to select the optimized packing for a humidifier. In the present work, performance analyses of 15 different types of random packing have been carried out using Scilab software. From this study, it is concluded that metal packing with highest surface area to volume ratio, lowest packing factor and smallest packing diameter functions as the best humidifier packing. Experimental study was also conducted in a pilot plant of open air open water HDH cycle using pall ring 25 mm diameter metal packing, which has shown the highest performance index in the numerical study. Experimental results obtained were found to be in agreement with the numerical results. Present work is a useful tool in designing new packing material of desired properties since the packing performance is a strong function of its geometrical properties.
It is widely accepted that the implementation of model-based predictive controllers (MPC) ensures optimal operation if an accurate model of the process is available. In the case of froth flotation, modelling for control purposes is a challenging task due to inherent process instabilities. Most models for control have only focused on the pulp phase rather than the froth phase, which is usually oversimplified or even neglected. Despite the fact that froth stability can significantly affect the overall performance of flotation cells, there is still a gap in literature regarding flotation models for control purposes that properly include froth physics.
In this paper we describe the development of a dynamic flotation model suitable for model predictive control, incorporating equations that describe the physics of flotation froths. Unlike other flotation models for control in the literature, the model proposed here includes important variables related to froth stability, such as bursting rate and air recovery, as well as simplified equations to calculate froth recovery and entrainment. These model equations allow estimating the amount of valuable material reporting to the concentrate, which can be used as a proxy to estimate grade and recovery. Additionally, pulp-froth interface physics was also included in our model, which enables a more accurate prediction of relevant flotation variables.
A sensitivity analysis of the parameters showed that two out of seven parameters were highly sensitive. The highly sensitive parameters are the exponential factor n of the equation for the overflowing bubble size, and the constant value a of the equation for the bursting rate. Although the other parameters showed a reasonably lower sensitivity than n and a, the results also revealed that there is a significant difference in the prediction accuracy if the parameters are poorly estimated. Further simulations of important variables for control exhibited a good adaptability to changes in typical variables, such as air and feed flowrates.
An analysis of degrees of freedom of the model established that two variables need to be fixed to have a completely determined system. This means that two variables are available for control purposes, which can be air and tailings flowrates (through the manipulation of the respective control valves). This study therefore paves the way for the implementation of a robust dynamic model for flotation predictive control, incorporating important froth phenomena.
The paper presents the kinetics of two-step ellagitannin (ET) extraction with an aqueous acetone solution from two technological types of pomace from selected berry fruits of the Rosaceae family. ETs were identified and quantified using HPLC–MS and HPLC–DAD. The results revealed the extraction kinetics of total ETs, their high and low molecular weight fractions (≤ 1569 Da and > 1569 Da), and individual ETs characteristic of the examined fruits. ET extraction proceeded at a faster rate in the first step, regardless of the tested pomace. For all pomace variants, the mean extraction half time t 1/2 was 48 min in the first step and 70 min in the second step. The fruit species and the technological type of pomace were not found to exert a definite effect on the kinetics of ET extraction. Statistical analysis demonstrated that the molecular weight of ETs did not influence the kinetics of their extraction, either. It was shown that the technological type of pomace had a significant impact on the extraction rate of both low molecular weight (LMW) and high molecular weight (HMW) ETs in the first extraction step, with the mean t 1/2 being 44 min for pomace from juice production and 63 min for pomace from puree production.
This paper presents a breakage model of particulate solids under impact loading based on a mechanical approach. Existing breakage models are assessed using the experimental data from single particle impact tests, indicating a more general breakage model is required. Indentation fracture mechanics is used to account for surface damage under dynamic loading. The effect of impact angle is considered in the model, which rationalizes the contributions of both the normal and tangential impact velocity. A unified curve of breakage propensity is constructed using the equivalent velocity under oblique impact based on the experimental data from this study and the literature. This model provides a basis to evaluate breakage propensity of brittle/semi-brittle particles subject to oblique impact and the proposed equivalent velocity has a potential to improve the description of impact energy spectra for milling processes where oblique impact of particle is common and typically ignored.
The aim of present research work is to treat the tannery wastewater (TWW) using catalytic thermal treatment process. The treatment of TWW was done on the basis of removal of COD and color in a batch system. All the experiments have been carried out in a batch system. Effect of various process parameters such as pH (2–9), thermolysis time (0–6 h), temperature (55°C–95°C), catalyst loading (Cw) (1–6 g/L), and two types of catalysts (copper sulfate and copper oxide) was studied on the removal efficiency of COD and color from wastewater. Copper sulfate was found to be a better catalyst as compared with copper oxide during thermolysis for TWW. The observed results exhibited that maximum COD removal of 71.36% and color removal of 77.56% were achieved using copper sulfate at the optimized conditions of pH of 4, catalyst loading of 4 g/L, temperature of 95°C, and thermolysis time of 6 h. Kinetic study followed the first order kinetics model and it was observed that the COD reduction was found to be two steps (fast and slow steps) mechanisms. The observed higher values of rate constant (k1) showed that rate of reaction was fast in the first step of thermolysis. Initial pH played an important role in COD removal. The settling rate of the slurry was good and strongly affected by pH values. It has been observed that treated wastewa-ter provided the best (fastest) filterability at the pH 12. The energy consumption was found to be 2,619 kWh/kg of COD removal under the optimized process conditions. Overall, it can be said that thermolysis process can be employed for the treatment of industrial wastewater.
The filtration properties in solid–liquid separation mainly depend upon the filter cake properties, for instance, cake resistance. However, particle size distribution, particle shape, and their arrangements significantly impact cake filtration. This paper aims to review the work done so far and collate both fundamental and applied work with regard to the quantification of cake properties. The cake resistance and cake porosity in terms of shape, as well as varying particle size distribution width, are discussed here. This work summarizes the current state of the technology and recommends advancements and improvements for future research.
Edible oils are currently largely obtained by solvent extraction using hexane. Despite the fact that this petroleum solvent is known to be neurotoxic, hexane extraction remains the accepted standard process for seed oil extraction and particularly, but not exclusively, for soybean oil extraction. This study evaluates an alternative replacement of hexane with a bio-based and safe solvent, 2-methyloxolane (2-MeOx), either in its dry or in its water-saturated (4.5%w) aqueous form, referred to as 2-MeOx 95.5% in this paper. The analyses focused on extraction yields, composition, and quality of the extraction products. This study also evaluates the feasibility to substitute hexane in industrial extraction processes. Therefore, a kinetic study and multistage cross-current extractions were performed. The work concluded that both 2-MeOx and 2-MeOx 95.5% are good candidates to replace hexane in industrial processes for the extraction of soybean oil, as they gave similar compositions for oil and defatted meal. Hexane and 2-MeOx also gave similar results in terms of extraction rate and performances. 2-MeOx 95.5% exhibited a slightly different behavior during extraction, which was attributed to water diffusion from the solvent to the solid matrix due to its high water activity.
Aminoethers of boric acid (AEBA) were studied as potential extractants for the separation of aqueous–alcoholic azeotropic mixtures by extractive distillation. The conditions of vapor–liquid equilibrium in aqueous solutions of ethanol and isopropanol in the presence of AEBA were studied. The division of AEBA molecules into group components was proposed, and previously unknown geometric parameters of the boron group and the energetic pair parameters of the boron group with the alkane group, ether group, amine-3d group, and alcohol group were determined within the framework of the Universal Functional Group Activity Coefficient (UNIFAC) model. The modeling of the extractive rectification process of an ethanol–water mixture with AEBA as extractant has been carried out. The dependences of the cost function on the extractant flow rate, the residual water content in it and the number of theoretical trays were obtained. A technological scheme for ethanol dehydration has been proposed, and its technological characteristics have been calculated.
Waste will become the major resource in the future circular economy. In particular, E-waste is a major sector growing at an annual rate of about 2 million tonnes (Mt) with rising users of electrical and electronic items worldwide. This is a consequence of versatility and affordability of technological innovation, thus resulting in massive sales and e-waste increases. Most end-users lack knowledge on proper recycling or reuse, often disposing of e-waste as domestic waste. Such improper disposals are threatening life and ecosystems because e-waste is rich in toxic metals and other pollutants. Here we review e-waste generation, policies and recycling methods. In 2019, the world e-waste production reached 53.6 Mt, including 24.9 Mt in Asia, 13.1 Mt in USA, 12 Mt in Europe. In Asia, China (10.1 Mt), India (3.23 Mt), Japan (2.57 Mt) and Indonesia (1.62 Mt) are the largest producers contributing to about 70% of the total world e-waste generated. Only 17.4% (9.3 Mt) of the world e-waste was recycled by formal means, and the remaining 82.6% (44.3 Mt) was left untreated or processed informally. As a consequence, most countries have framed policies to provide regulatory guidelines to producers, end-users and recyclers. Yet the efficiency of these local policies are limited by the transfer of products across borders in a globalized world. Among formal recycling techniques, biohydrometallurgy appears most promising compared to pyrometallurgy and hydrometallurgy, because biohydrometallurgy overcomes limitations such as poor yield, high capital cost, toxic chemicals, release of toxic gases and secondary waste generation. Challenges include consumer’s contempt on e-waste disposal, the deficit of recycling firms and technology barriers.
Brine is a hyper-saline by-product that is produced in the desalination process. This by-product has an adverse environmental impact due to its high salinity and therefore its treatment is considered necessary. The minimum energy consumption (MEC) has been studied in seawater desalination, but not in brine treatment. In this regard, this research study introduces a mathematical model to calculate the MEC in the desalination brine treatment. Furthermore, the actual energy consumption (AEC) of the desalination technologies is presented. In this model, various parameters, such as the recovery rate, the salinity and the temperature of the feed brine, the purity of the freshwater produced and the dissolved salt nature, are considered. The analysis revealed that the MEC increases by increasing the recovery rate, the feed brine salinity, the feed brine temperature and the purity of the freshwater produced. On the other side, the MEC decreases by increasing the molar mass of the dissolved salt. The AEC is at least two times higher than the MEC due to irreversibility. Most membrane-based technologies are less energy-intensive than thermal-based technologies; however, they cannot currently treat significantly high-saline brine as do thermal-based technologies. Future advances in materials/system designs are expected to reduce the AECs.
ABSTRAKSalah satu usaha untuk memperbaiki kualitas air Sungai Musi dari pencemaran yang terus meningkat yaitu dengan mentreatmentnya melalui proses filtrasi. Filter yang digunakan pada penelitian kali ini adalah   jenis membran keramik. Proses filtrasi dilakukan dengan beda tekanan 32 psi dan   36 psi. Waktu pengambilan permeate dilakukan pada 15, 30, 45 dan 60 menit. valuasi kinerja membran keramik bisa dilihat dari nilai fluks yang dihitung berdasarkan volume permeate yang didapat per luas penampang membran. Nilai fluks terbaik adalah 2937,28 l/m2.jam. Kata kunci : Air Sungai Musi, Filtrasi, Membran keramik, Fluks membran
In this study, the mineralogical, chemical characterization and physical properties of Sudanese iron ore in west of Omdurman city were studied using microscopic investigations, X-ray Diffraction analysis (XRD), X-ray Fluorescence (XRF) analysis, Atomic Absorption Spectrophotometer analysis (AAS) and the test of Bulk density. As well as, the Bond Work Index (BWI) and consumed power to grind one tone of iron ore were determined via standard Bond mill. The results showed that the ore is hematitic ore with Goethite and quartz minerals. The ore is low grade containing 41.41 % Fe2O3 and 50.88 SiO2. The bond work index test obtained high work index 52.60 kw.h/t and consumed power 11.72 kw.h/t to grind one ton of low grade iron ore and this attributed to the high concentration and hardness of quartz mineral which is considered the main gangue of the ore in study area.
Water is one of the scarcest resources in the world, and it is becoming rarer fast, year after year. Chemical engineers are particularly suited to addressing the challenges of saving water and producing more fresh water. Proper education is then critical to prepare them for the upcoming decades. All student laboratories need distilled water, which is typically produced using commercial distillation units, which consume up to 70 L of fresh water per liter of distillated water. This work reports the design, construction, optimization, and operation of a water distillation unit that produces 10 liters per hour at 4 µS∙cm⁻¹ and wastes no fresh water. Developed by a committed team made up of students, lab technicians, and instructors, this unit saves ca. 550 m³ of fresh water annually while spending less electrical power.
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