Paraffin Layer Research Articles

Preparation and properties of ultra-thin-walled energy storage paraffin microcapsules for naval applications

Due to the special nature of weather conditions at sea, the tricky status quo of heat loss in readiness or operational clothing, there is an urgent need for special insulated clothing materials to withstand harsh environments, maintain body temperature, and increase comfort for naval personnel who have been at sea for a long period of time in preparation for battle or combat. Paraffin is a special kind of phase change energy storage material, And the preparation of paraffin microcapsules is an effective way to solve the above problems, in which the ultra-thin-walled energy storage paraffin capsules have the advantages of large volume, accommodating more paraffin phase change materials, good energy storage effect and low cost. In this study, three kinds of paraffin microcapsules with core-shell structure were prepared by encapsulating a membrane with stable performance on the surface of paraffin particles using microencapsulation and layer-by-layer self-assembly techniques. We characterized their thermal storage capacity, composition and morphology by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier infrared spectroscopy, and optical microscopy, and compared their performances. The results show that the paraffin microcapsules prepared by layer-by-layer (LBL) self-assembly technique in this study have good thermal storage performance and stability, and their thickness increases with the increase of the number of layers, and the materials used in the experiment wrapped the liquid paraffin layer by layer, which is expected to be practically applied in the field of naval energy storage materials.

Thermal performance of phase-change wall of a hotel building under hot-summer and cold-winter climate

ABSTRACT In China, the energy consumption in the building sector has increased tremendously in the past decades. It is important to investigate advanced passive energy-saving technologies for buildings. By applying phase-change materials in walls, the peak cooling/heating load can be significantly reduced. In the present study, a numerical model of one-dimensional heat transfer within a phase-change wall was developed and solved by Matlab, which was successfully validated with published data. Subsequently, the model was used to simulate the thermal performance of a phase-change wall in a hotel building in Shanghai, China. Simulation results demonstrate that the performance of the phase-change wall is optimized when the phase-change material is applied to both sides of the wall. Year-round heat transfer is minimized using layers of paraffin (C16-C28) and capric acid (2 cm), with phase-change temperatures of 43℃ and 16.3℃, respectively. The PCM wall reduces inwardthe inward heat transfer by 26.9% compared with a common wall without phase-change material. The outward heat loss is also reduced by 15.7% during the heating season. This study demonstrates that the PCM wall can effectively reduce indoor heat gain in summerin the summer and heat loss in winterin the winter. The numerical model has proven to be feasible for optimizing construction design.

Heat transfer through a three-layer wall considering the contribution of phase change: A novel approach to the modelling of the process

A novel analytical solution to the time-dependent heat transfer equation for a multi-layer wall considering the contribution of phase change is obtained. Based on this solution a new numerical algorithm is developed for the analysis of variations in temperature and heat flux in a three-layer wall of a building in the presence of transient ambient temperature. In this algorithm, the new analytical solution at the end of the previous time step is used as the initial condition for the following time step with adjusted values of input parameters (ambient temperature). The novel algorithm is verified based on a comparison of the predictions of COMSOL Multiphysics (version 6.1) with its predictions for the same input parameters assuming that the time dependence of the ambient temperature follows the sine law. The new code is used for the analysis of heat transfer through a three-layer building wall assuming typical continental climate conditions. The inner and outer layers were filled with polyurethane foam, while a thin middle layer, located in the centre of the wall, was filled with the phase-change material (paraffin). Using the new numerical algorithm it is demonstrated that the presence of the thin paraffin layer in the wall leads to two orders of magnitude reduction in the amplitude of temperature oscillations on the room side of the wall compared to those on its outer side. It is shown that the presence of paraffin layer in the wall leads to an increase in the phase shift between the temperature on the outer side of the wall and the heat flux on the room side from about 1 hour (homogeneous wall) to about 5.5 hours (wall with the paraffin layer).

Solution-mediated phase transition of protein crystals

A snapshot of the evidence of solution-mediated phase transition of glucose isomerase (GI) crystals more than 7 months after the start of an experiment was successfully captured. The transition to [Formula: see text] crystals started about 2 months after the first I222 crystals nucleated. To conduct such long-term experiments, we developed novel observation cells with liquid paraffin layers to prevent aqueous GI solutions from evaporation of water. Changes in the weights of cells were measured, and much less evaporation was successfully achieved by continuously adding liquid paraffin as a liquid sealant.

Simulation of integration of photovoltaic solar system with storage unit incorporating mixture of paraffin and nanoparticles

In this study, we conducted a simulation of the cooling process for a silicon layer within a Photovoltaic (PV) system, integrating a paraffin layer. To augment the cooling rate and expedite the melting process, we introduced nanoparticles into the paraffin (specifically, RT28HC). The dynamic nature of the process was accurately modeled using an implicit method. To further enhance the melting rate, the container was equipped with fins. The incorporation of a Phase Change Material (PCM) like paraffin with PV technology represents a novel approach in this research. This combination not only improves the cooling efficiency but also addresses the issue of expedited melting, offering a significant advancement in the field. By effectively utilizing the latent heat features of the paraffin, we can enhance the overall performance and reliability of PV systems, potentially leading to more efficient energy conversion and utilization. The equations were explained using FVM, accounting for the positioning of the hot wall. Gravity was omitted from the model, and a uniform approximation was applied for mixture characteristics. The introduction of fins led to a notable increase in the melting rate by approximately 42.9 %. Additionally, the incorporation of nano-powders resulted in a reduction of melting time by about 6.27 % and 4.39 % in scenarios both with and without fins, respectively. These outcomes signify that the presence of fins and the inclusion of nano-powders significantly influence the charging process. Fins enrich the rate of melting, while the adding of nano-powders accelerates the overall melting time. This research highlights the potential benefits of utilizing these enhancements in practical applications, potentially leading to more efficient and effective melting processes.

Experimental study on a novel waterless solar collector

This study is an endeavour to introduce a novel approach to enhance the performance of solar collectors. The sun emits sufficient power of solar radiation to meet the demand of en-ergy. Harvesting the renewable solar energy needs advanced technologies and requirements. Solar ponds including salinity gradient solar ponds (SGSPs) are common solar collectors. These ponds are one of the solar energy applications used for many industrial and domestic purposes. However, challenges of the conventional SGSPs such as evaporation, salt diffusion, temperature discrepancy, and layer mixing profoundly and significantly affected their expan-sion globally. A novel experimental solar collector configuration to overcome the challenges of the conventional solar ponds (solar collectors) is investigated, there is no water body and no salinity gradient to build; it is entirely a collector with no water body. The experimental unit was constructed in an arid area. It is basically a cylindrical tank with a total depth of 1.4 m with three zones or layers to store heat namely, paraffin wax layer (10 cm thickness). The paraffin layer was covered with a layer of coal with a thickness of 30 cm. On the top of coal layer, an air gap with a thickness of 80 cm was left. A clear plastic cover with a thickness of 0.2 cm was utilized to cover the constructed layers and making the air gap. The experimental unit was monitored, and temperature measurements were collected for the period of 17/7/2021- 30/9/2021. The results demonstrated that temperature of the paraffin wax layer reached more than 48 °C in a short period and with a small day and night discrepancy (1 °C). Temperature of the paraffin layer remained constant around 43 °C even in night-time during the period of the study. Furthermore, the results showed that temperatures of coal layer and air gap reached the maximum at the daytime of 53 °C and 71 °C respectively with a clear discrepancy between day and night. The results of the present study are encouraging for more investigations in this new direction of solar collectors.

Performance augmentation and machine learning-based modeling of wavy corrugated solar air collector embedded with thermal energy storage: Support vector machine combined with Monte Carlo simulation

At present, artificial intelligence methods have been effectively utilized for predicting the complex performance of storage-based solar thermal technologies for cooling/heating applications. It is crucial to have accurate energy storage-based sustainable system estimation, which would contribute to increased operational time, thus maximizing the overall efficiency of solar energy-based storage systems. Hence, this work introduces a comparative experimental investigation and support vector machine (SVM) modeling on a wavy corrugated solar air collector (WCSAC) with and without using a paraffin wax storage container. Experiments on the WCSAC were performed under three air flow rates of 0.540, 1.68, and 3.72 kg/min and two paraffin layer thicknesses of 2 cm and 4 cm, respectively. Moreover, improved SVM models implemented in MATLAB software are developed for predicting the thermal performance parameters; including air temperature ratio, average air temperature, convective heat transfer coefficient, and energy efficiency for the WCSAC. The optimal solution of the SVM modeling is developed by incorporating the Karush-Kuhn-Tucker conditions and several kernel functions. In addition, a sensitivity analysis is also conducted to explore the significance of model input parameters (air inlet temperature, time, solar irradiance, air flowrate, PCM layer thickness) on the output parameters prediction using the Monte Carlo simulation technique. The experimental results presented that the daily energy efficiencies of the WCSAC equipped with 4 cm paraffin layer thickness are 24.0 %, 20.39 %, and 16.37 % higher than that of the WCSAC without PCM at airflow rates of 3.72, 1.68, and 0.54 kg/min, respectively. Moreover, the connective heat transfer coefficient of the WCSAC with PCM is more than 1.20 times that yielded with the WCSAC without PCM. Additionally, the SVM simulations showed that the optimal solution of the SVM model is developed by incorporating the Karush-Kuhn-Tucker conditions and Lagrangian function kernel function, which revealed a superior accuracy with the highest coefficient of determination of 0.990 and 0.950 for training and test processes, respectively.

Effective removal of paraffin deposits using oil-in-water microemulsion systems

This study investigates the effectiveness of using oil-in-water microemulsions, formulated with nonionic surfactant, for the removal of paraffin deposits. Experiments were conducted in a cylindrical steel cell, where a thin layer of paraffin was applied to the walls and exposed to various microemulsion systems. The microemulsions systems were formulated with kerosene (MESK), xylene (MESX), and diesel (MESD), and the removal efficiency was compared to that of pure solvents. Our results demonstrate that the efficiency of paraffin deposit removal using microemulsion systems is influenced by the concentration of both the active matter and oil component. Specifically, microemulsions containing kerosene in the oil phase exhibited the highest removal performance, with a removal efficiency of 66.78%, compared to 48.74% for pure kerosene solvent. Furthermore, our findings suggest that high removal efficiency can be achieved with low concentrations of oil phase (2–6 wt%), making microemulsions a more environmentally friendly and safer alternative to the use of pure solvents. We observe that increasing the liquid volume in the tubular can lead to a reduction in removal efficiency due to the reduced fluid shear. Overall, our study provides important insights into the potential applications of microemulsion systems for paraffin removal, with implications for various industrial processes and environmental remediation efforts. The results highlight the importance of optimizing microemulsion composition to achieve optimal removal efficiency and promote the use of more environmentally friendly solvents in paraffin removal operations.

Nanoscale paraffin layer fabricated using spin coating technique for on-demand removable passivation

Passivation is an essential process in the research and application of reactive and air-sensitive materials, and there has been an increasing demand to develop materials for stable but readily removable temporary passivation layers. Paraffin coating has been suggested as a possible candidate for such applications, which, however, further requires the demonstration of thin paraffin coating with complete surface coverage as well as effective depassivation performance. In this study, we demonstrate on-demand removable passivation using nanoscale paraffin layers fabricated using a spin-coating technique. Based on the Emslie Bonner and Peck's and Mark-Houwink-Sakurada (MHS) equations, eicosane and hexane were selected as the solute and solvent, respectively, to ensure low viscosity for the fabrication of nanoscale paraffin layers, facilitating depassivation process under a vacuum. Optimizing the solution concentration and spin speed generates nanoscale paraffin layers with complete surface coverage, which is confirmed through optical microscopic images and subsequent image processing using Python. The simple removal of the nanoscale paraffin layer through vacuum treatment allows us to revisit a passivated surface underneath, and subsequent contact resistance and x-ray photoelectron spectroscopy measurements evince the suppressed surface oxidation of paraffin-coated silicon samples. These results further attest to the applicability of paraffin coating as an on-demand removable passivation technique.

Copper–Alumina Capsules for High-Temperature Thermal Energy Storage

High corrosivity, leakage, and oxidation of metallic phase-change materials (PCMs) have limited their applications in high-temperature thermal energy storage (TES) systems, regardless of their favorable benefits for high-temperature TES applications of over 1000 °C. To overcome these major challenges, this work presents a facile paraffin sacrificial layer approach for directly encapsulating copper (Cu) sphere PCMs with the alumina (Al2O3) shell, considering a buffer inner cavity. The cavity is formed by the decomposition of the paraffin layer through a pre-sintered process. It plays a key role in accommodating the volume expansion of the Cu core, thereby preventing the breakage of the shell and the leakage of the liquid PCM. A series of macrocapsules with different sizes (9.5–21 mm) containing the Cu core, cavity, and Al2O3 shell are successfully produced using the paraffin sacrificial layer method and deploying a two-step heat treatment. The experimental results show that the Al2O3 shell possesses a good structure, which can prevent the leakage of the Cu core. The Al2O3 shell also has strong compatibility with the Cu core without any chemical reaction between two materials. In a temperature range of 1000–1100 °C, the calculated mass and volume energy storage densities of the PCM macrocapsule with 21 mm outer diameter are found to be 222 kJ/kg and 745 J/cm3, which are 1.83 and 1.76 times, respectively, higher than those for the Al2O3 ceramic. After thermal cycle tests, the encapsulated Cu PCM shows superior shape stability, chemical stability, and thermal durability, which can be applied in long-term thermal storage systems for high-temperature TES systems.

A novel multilayer composite structure based battery thermal management system

The battery thermal management system (BTMS) utilizing phase change materials (PCM) has shown promising performance in high heat flux heat dissipation. However, conventional PCM systems do not fully exploit the latent thermal properties of paraffin wax to enhance battery cooling efficiency. To address this issue, this paper proposes a novel multilayer composite material for BTMS, aiming to improve the thermal performance of the battery and overcome the low thermal conductivity of paraffin wax. The preparation process involves positioning the battery at the center of a triangular container, melting paraffin wax and pouring it into a 100 mm high container to form a 20 mm paraffin layer, placing copper foils and graphite layers on the paraffin surface, and repeating this step once. Finally, pour the 40 mm paraffin wax into the container, resulting in a sandwich-like structure with two layers of graphite. The cooling performance of the multilayer composite structure was experimentally tested at different ambient temperatures (15°C and 20°C) and discharge rates, and compared with a conventional BTMS based on pure paraffin wax. The results demonstrate that the multilayer composite structure exhibits superior heat dissipation compared to the pure paraffin structure, significantly reducing battery temperature rise, particularly at higher discharge rates. At an ambient temperature of 20°C and a discharge rate of 5°C, the battery temperature rise is only 14.97°C, with a remarkable cooling effect of 32.6%. Moreover, optimization of the number and thickness of graphite layers in the composite structure reveals that the 6-layer graphite structure outperforms the 2-layer, 4-layer, 8-layer, and 10-layer graphite structures. Additionally, a relatively lower battery surface temperature is observed with a graphite thickness of 0.5 mm on the basis of the 6-layer graphite structure. These findings indicate that the proposed novel layout structure exhibits excellent thermal performance, effectively addressing the low thermal conductivity limitation of traditional paraffin cooling systems, and providing a new approach for thermal management of lithium batteries.

Analyzing efficiency of solar heat storage unit within a building including trombe wall equipped with phase change material in existence of fins

Trombe wall can be applied for solar energy saving for ventilation purpose and to boost the performance of classic unit, it was combined with paraffin layer and fins in this study. The nanoparticles of alumina have been loaded into pure paraffin (RT18HC). To involve the existence of solar irradiation, two heat generation terms were added in governing equations of glass and absorber layers. Also, radiative and convective heat losses have been involved in boundary condition. Unsteady turbulent air flow within the domain has been simulated and for modeling of various layers, temperature equations with incorporating heat sources have been applied. Two shapes of fins (I and Y) with various numbers have been applied. The impacts of thickness and length of the fins as well as position of paraffin layers have been scrutinized. With assuming equal volume of paraffin, comparison of two configurations showed that system with Y-shaped fins leads to higher liquid fraction. Also, temperature of domain in existence of Y-shaped fins has lower value which leads to lower heat loss. With implement of best configuration, the amount of heat capacity augments about 28.41% at 17:00.

An Improved Technique for Trimethylamine Detection in Animal-Derived Medicine by Headspace Gas Chromatography-Tandem Quadrupole Mass Spectrometry.

Animal-derived medicines have distinctive characteristics and significant curative effects, but most of them have an obvious fishy odor, resulting in the poor compliance of clinical patients. Trimethylamine (TMA) is one of the key fishy odor components in animal-derived medicine. It is difficult to identify TMA accurately using the existing detection method due to the increased pressure in the headspace vial caused by the rapid acid-base reaction after the addition of lye, which causes TMA to escape from the headspace vial, stalling the research progress of the fishy odor of animal-derived medicine. In this study, we proposed a controlled detection method that introduced a paraffin layer as an isolation layer between acid and lye. The rate of TMA production could be effectively controlled by slowly liquefying the paraffin layer through thermostatic furnace heating. This method showed satisfactory linearity, precision experiments, and recoveries with good reproducibility and high sensitivity. It provided technical support for the deodorization of animal-derived medicine.

Zero‐temperature‐coefficient of capacitance in BaTiO3/PI composite films using paraffin as barrier layer

AbstractFirstly, the BaTiO3 nanoparticles were coated with a layer of paraffin, forming a core shell structure. Then, as‐prepared paraffin@BaTiO3 nanofillers were directly blended with polyimide (PI) prepolymer to fabricate paraffin@BaTiO3/PI composite films. The microstructure, thermal, and dielectric properties were investigated in detail. The surface‐modified paraffin@BaTiO3 nanoparticles exhibited a typical core shell structure with uniform and complete coverage. The char yield of the composite film with 10 wt% paraffin@BaTiO3 increased from 56.40% to 70.73%. It is obvious that the paraffin@BaTiO3 nanofillers have a positive effect on ablative performance of the composite film. Compared with pure PI, the εr of paraffin@BaTiO3/PI composites with 40% mass fraction increased from 3.41 to 9.35 (1 kHz). The tanδ of paraffin@BaTiO3/PI composites was just 0.0065 (1 kHz) when the filler loading was 40 wt%. Temperature dependency of the permittivity of the composites reveals a zero‐temperature‐coefficient from 80°C to 180°C.

Development of over 3000 cycles durable macro-encapsulated aluminum with cavity by a sacrificial layer method for high temperature latent heat storage

The high-temperature metallic phase change materials (PCMs) are attracting great attentions as alternatives to sensible heat storage materials in thermal energy storage (TES) systems. However, the high corrosivity, easy leakage and oxidation phenomena of metallic PCMs have limited their applications. This work reports a facile and novel sacrificial layer method with the purpose to create macro-encapsulating aluminum (Al) PCM by alumina (Al2O3) shell characterized by a ‘buffer’ inner cavity. The inner cavity could offer buffer space to accommodate the huge thermal volume expansion of Al core PCM during heating and melting, thereby preventing the breakage of the capsules and ensuring the long-term stability. A series of Al balls with diameters of 4–25 mm were firstly coated with paraffin sacrificial layer then by Al2O3 dough shell, which was finally conducted by the two-step heat treatment, in which a low-temperature stage aimed at removing the paraffin layer while the high-temperature stage aimed at the capsule sintering formation. The final macrocapsules with diameters of 6.5–31.5 mm were obtained, in which the capsules with Al core balls larger than 15 mm showed superior gravimetric and volumetric heat storage density because of their high core–shell ratio. For example, the 25 mm@0.75 mm@2.5 mm macrocapsules could present high heat storage density of 348 kJ/kg and 902 J/cm3 at the temperature range of 600–700 °C. The macrocapsules also showed a long-time thermal cycling stability, since that no damage or leakage was observed over 3000 times of melting and solidification under air atmosphere, indicating that they can be used over 8 years without any degradation of thermophysical properties. This demonstrates the potential application of the Al2O3 encapsulated Al macrocapsules with inner cavity in high-temperature TES systems.

The Numerical Simulation of Thermal Efficiency of Triple Pipe Heat Exchanger Using PCMs (Paraffin and Lauric Acid) System

COMSOL Multiphysics is used to adequately study the numerical modeling of phase change material behavior in a triple heat exchanger. The triple heat exchanger comprises three sides: an interior pipe for water cooling and heating, an annular space between the second and first interior pipes conveying Paraffin, and a third side annular space between the outer pipe and the second pipe holding Lauric acid. The dimensions of the triple heat exchanger are as follows: 30 cm length and side diameters of (0.5 in: 2.5 in: 3.5 in). Overall, the patterns reveal that the CFD and experimental work are in perfect agreement. PCM 2 is more reliable than paraffin. As the flow rate rises, the validity decreases; the maximum validation is obtained at 11 L/min. The results shows that the number of fins enhances efficiency by 5% (from 6 to 4); any number of fins over 6 promotes no more efficiency percentage. The additional fins are considered to produce increased heat transfer resistance, resulting in a significant increase in heat transmission. Copper slightly conducts heat better than aluminum and iron. Aluminum is the best material; its efficiency is equivalent to copper's. The diameter of the pipe has no effect on the percentage of paraffin efficiency. The better the heat resistance with an uniform heat transfer area between the paraffin and lauric acid layers, the broader the diameter of the lauric acid layer. Improving the outer diameter of the heat charge process implies increasing the efficiency percentage. The highest efficiency% is seen at 4.5 in.

Modification of heat storage system involving Trombe wall in existence of paraffin enhanced with nanoparticles

Unsteady flow within a solar system with the Trombe wall technique has been scrutinized in current paper. To enhance the productivity of the classic Trombe wall, the paraffin layer has been combined with other layers (insulation, absorber, and concrete layers). The type of paraffin is RT18, and the conditions of the surrounding in the simulation have been selected according to a sunny day in autumn. Adding alumina nanoparticles into RT18 makes the conduction mode of paraffin enhance. The regime for the air zone is turbulent, and circulation via buoyancy force makes the domain warmer, therefore, the k-ε RNG technique was utilized for this region. The heat loss from glass due to radiation and convection has been involved in modeling. A verification test has been done not only in view of modeling of classic Trombe wall but also for modeling of melting of paraffin in ventilation application. The time step and grid size were optimized to reduce the cost of computing. A comparison of results for 3D simulation and 2D modeling indicates that there is no sensible change, therefore, considering the 2D model is logical. Among various scrutinized positions of the PCM layer, the first case (PCM near the absorber) has a greater liquid fraction. Moreover, if the PCM layer has been utilized in the middle, the minimum heat loss from the walls can be obtained.

A paraffin-wax-infused porous membrane with thermo-responsive properties for fouling-release microfiltration

Membrane fouling is one of the major problems in microfiltration processes. Slippery liquid infused surface with outstanding antifouling property provides a new strategy to solve membrane fouling, however, the loss of the lubricant hinders its long-term application underwater. Here we demonstrate a thermo-responsive paraffin-wax-infused membrane, which accommodates both stability and slippery feature of lubricant by adjusting the temperature. The membrane is prepared by filling melted paraffin wax in the rough structures of the silica coatings on the polyethersulfone (PES) membrane surface through suction filtration. The paraffin layer can cover the whole membrane surface, including the micropore wall. The paraffin wax of solid phase leads to a hydrophobic surface, and shows highly stability on the membrane, which can withstand shear from spinning, flowing water or filtration. When paraffin wax turns to liquid phase at temperatures above its melting point, the membrane surface transforms to slippery state that can resist bovine serum albumin (BSA) and bacterial adhesion. In the cross-flow microfiltration, excellent fouling-release performance and durability are achieved by the temperature responsive switching between the hydrophobic and slippery state; after three cycles of fouling by BSA and cleaning with water of 60 °C, the membrane with optimum amount of paraffin wax shows much higher flux and flux recovery (>90%) compared to the control membrane without paraffin wax.

Self-Transportation of Superparamagnetic Droplets on a Magnetic Gradient Slippery Surface with On/Off Sliding Controllability.

Recently, research about droplet self-transportation on slippery surfaces has become a hotspot. However, to achieve on/off sliding control during the self-transportation process is still difficult. Herein, we report a magnetic slippery surface, and demonstrate on/off sliding control during the self-transportation of superparamagnetic droplets. The surface is prepared through integrating a substrate that has a gradient magnetic region with a layer of paraffin infused hydrophobic SiO2 nanoparticles. On the surface, a superparamagnetic droplet is pinned at room temperature (about 25 °C), while it can self-transport directionally as the temperature is increased to about 70 °C. When the temperature is cooled down again, the droplet would return to the pinned state, indicating that on/off sliding control during the self-transportation process can be achieved. Furthermore, based on the excellent controllability, controllable coalescence of two droplets from opposite direction is displayed, demonstrating its potential application in numerous areas.

Kinetic Regularities Research of the Convective Concentration Process of a Hexane-Paraffinic Composition for the Food Paraffin Production

Film structures, used for the production of biodegradable packaging materials, are hydrophilic in nature. Their paraffinization reduced the influence of external factors, primarily moisture, for them, i.e. applying a thin layer of molten food paraffin to the film surface for subsequent protection of packaged food products from moisture and sunlight. While producing the moisture-repellent compositions, a man pays much attention to the quality of the final food paraffin. One of its important safety indicators is the absence of carcinogenic aromatic hydrocarbons in it. The kinetic regularities study of the convective concentration processes of a technical paraffin solution in n-hexane is necessary to analyze their mechanism and speed, depending on the operating parameters, making possible to determine the rational duration of these procedures and the specific yield of the resulting product. To rationalize the convective concentration of a hexane solution, it is necessary to select such operating parameters enabling not only to remove hexane with toxic components dissolved in it from the study object in a relatively simple apparatus, but also to significantly reduce the time for this process. The study aim was to determine the rational modes of hexane-paraffin mixture concentration, as an object for the food paraffin production with convective energy supply. The concentration curve nature, although it is typical for the interacting materials, in particular n-hexane and paraffin, has a certain specificity, determined by the physicochemical parameters of the research object, which is a true solution included various toxic substances. The specific features of the study object are to be reflected not only on the solution concentration mechanism, but also on the temperature fields evolution in it and, as a result, determine the original approaches to modeling the process of removing the solvent together with toxic substances, particularly, benz-α-pyrene.