The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Ahmet Sari - One of the best experts on this subject based on the ideXlab platform.
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High density polyethylene/Paraffin composites as form-stable phase change material for thermal energy storage
Energy Sources Part a-Recovery Utilization and Environmental Effects, 2007Co-Authors: Kamil Kaygusuz, Ahmet SariAbstract:This article focuses on the preparation and thermo-physical properties of Paraffin/high density polyethylene (HDPE) composites as form-stable solid-liquid phase change material (PCM) for thermal energy storage. In the Paraffin/HDPE blend, the Paraffin (P) dispersed into the HDPE serves as a latent heat storage material when the HDPE, as a supporting material, prevents the melted Paraffin leakage thanks to its structural strength. Therefore, this type composite is form-stable and can be used as a PCM without encapsulation for thermal energy storage. In this study, two Paraffins with melting temperatures of 48 degrees C-50 degrees C and 63 degrees C-65 degrees C were used. The mass percentages of Paraffins in the composites could go high as 76% without any seepage of the Paraffin in melted state. The dispersion of the Paraffin into the network of the solid HDPE was investigated using scanning electronic microscope (SEM). The melting temperatures and latent heats of the form-stable P1/HDPE and P2/HDPE composite PCMs were determined as 44.32 degrees C and 61.66 degrees C, and 179.63 and 198.14 Jg(-1), by the technique of differential scanning calorimetry (DSC), respectively. Furthermore, the thermal conductivity of the composite PCMs were improved as about 33.3% for the P1/HDPE and 52.3% for the P2/HDPE by introducing the expanded and exfoliated graphite to the samples in the ratio of 3 wt%. The results reveal that the prepared form-stable composite PCMs have great potential for thermal energy storage applications in terms of their satisfactory thermal properties, improved thermal conductivity and cost-efficiency because of no encapsulation for enhancing heat transfer in Paraffin.
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form stable Paraffin high density polyethylene composites as solid liquid phase change material for thermal energy storage preparation and thermal properties
Energy Conversion and Management, 2004Co-Authors: Ahmet SariAbstract:Abstract This paper deals with the preparation of Paraffin/high density polyethylene (HDPE) composites as form-stable, solid–liquid phase change material (PCM) for thermal energy storage and with determination of their thermal properties. In such a composite, the Paraffin (P) serves as a latent heat storage material and the HDPE acts as a supporting material, which prevents leakage of the melted Paraffin because of providing structural strength. Therefore, it is named form-stable composite PCM. In this study, two kinds of Paraffins with melting temperatures of 42–44 °C (type P1) and 56–58 °C (type P2) and latent heats of 192.8 and 212.4 J g −1 were used. The maximum weight percentage for both Paraffin types in the PCM composites without any seepage of the Paraffin in the melted state were found as high as 77%. It is observed that the Paraffin is dispersed into the network of the solid HDPE by investigation of the structure of the composite PCMs using a scanning electronic microscope (SEM). The melting temperatures and latent heats of the form-stable P1/HDPE and P2/HDPE composite PCMs were determined as 37.8 and 55.7 °C, and 147.6 and 162.2 J g −1 , respectively, by the technique of differential scanning calorimetry (DSC). Furthermore, to improve the thermal conductivity of the form-stable P/HDPE composite PCMs, expanded and exfoliated graphite (EG) by heat treatment was added to the samples in the ratio of 3 wt.%. Thereby, the thermal conductivity was increased about 14% for the form-stable P1/HDPE and about 24% for the P2/HDPE composite PCMs. Based on the results, it is concluded that the prepared form-stable P/HDPE blends as composite type PCM have great potential for thermal energy storage applications in terms of their satisfactory thermal properties and improved thermal conductivity. Furthermore, these composite PCMs added with EG can be considered cost effective latent heat storage materials since they do not require encapsulation and extra cost to enhance heat transfer in the Paraffin.
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Form-stable Paraffin/high density polyethylene composites as solid-liquid phase change material for thermal energy storage: Preparation and thermal properties
Energy Conversion and Management, 2004Co-Authors: Ahmet SariAbstract:This paper deals with the preparation of Paraffin/high density polyethylene (HDPE) composites as form-stable, solid-liquid phase change material (PCM) for thermal energy storage and with determination of their thermal properties. In such a composite, the Paraffin (P) serves as a latent heat storage material and the HDPE acts as a supporting material, which prevents leakage of the melted Paraffin because of providing structural strength. Therefore, it is named form-stable composite PCM. In this study, two kinds of Paraffins with melting temperatures of 42-44 °C (type P1) and 56-58 °C (type P2) and latent heats of 192.8 and 212.4 Jg-1were used. The maximum weight percentage for both Paraffin types in the PCM composites without any seepage of the Paraffin in the melted state were found as high as 77%. It is observed that the Paraffin is dispersed into the network of the solid HDPE by investigation of the structure of the composite PCMs using a scanning electronic microscope (SEM). The melting temperatures and latent heats of the form-stable P1/HDPE and P2/HDPE composite PCMs were determined as 37.8 and 55.7 °C, and 147.6 and 162.2 Jg-1, respectively, by the technique of differential scanning calorimetry (DSC). Furthermore, to improve the thermal conductivity of the form-stable P/HDPE composite PCMs, expanded and exfoliated graphite (EG) by heat treatment was added to the samples in the ratio of 3 wt.%. Thereby, the thermal conductivity was increased about 14% for the form-stable P1/HDPE and about 24% for the P2/HDPE composite PCMs. Based on the results, it is concluded that the prepared form-stable P/HDPE blends as composite type PCM have great potential for thermal energy storage applications in terms of their satisfactory thermal properties and improved thermal conductivity. Furthermore, these composite PCMs added with EG can be considered cost effective latent heat storage materials since they do not require encapsulation and extra cost to enhance heat transfer in the Paraffin. © 2003 Elsevier Ltd. All rights reserved.
I. Barrio - One of the best experts on this subject based on the ideXlab platform.
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Modelling of the separation of long-chain normal Paraffins from kerosene in a simulated moving bed process: effect of the desorbent
Adsorption, 2020Co-Authors: D. Aranda, V. I. Águeda, J. A. Delgado, M. A. Uguina, I. D. López, J. J. Lázaro, J. C. Perdomo, I. BarrioAbstract:Linear Paraffins can be selectively separated from the rest of components of kerosene (branched hydrocarbons, aromatics and naphthenes) by means of liquid phase adsorption on 5A zeolite using the technology of simulated moving bed (SMB). In previous works, the kinetic and equilibrium parameters required for modelling and design of the SMB unit were obtained for pure n-Paraffins and n-Paraffin mixtures. However, the simulation of the SMB process indicated the presence of n-C_5, used as a desorbent, in the separation zone, especially after the feed mixture is introduced. This finding motivated this work, in which n-Paraffin mixtures (n-C_10, n-C_12, n-C_14) including n-C_5 were studied to address its influence in the process. The kinetic and equilibrium parameters for these mixtures were obtained and included in the model for the simulation of an SMB unit. While mixtures without n-C_5 preferentially adsorbed shorter n-Paraffins, it was found that including n-C_5 in the mixtures reverses the selectivity of the adsorbent. In this case, longer n-Paraffins are preferentially adsorbed, matching the trend observed for pure n-Paraffins. In addition, n-C_5 significantly increases the mobility of n-Paraffins, as indicated in their higher mass transfer coefficients. The model was validated by comparing the predicted performance with the reported separation achieved by a commercial SMB unit that separates n-Paraffins from hydrotreated kerosene fractions. The predicted separation performance is very similar to that achieved in our previous works, slightly improving the purity (99.6%) of the extract as a trade for a small loss in recovery (95.4%).
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Modelling of the separation of normal Paraffins from kerosene fractions by a simulated moving bed process
Adsorption, 2018Co-Authors: D. Aranda, V. I. Águeda, J. A. Delgado, M. A. Uguina, I. D. López, J. J. Lázaro, J. C. Perdomo, M. T. Holik, I. BarrioAbstract:Linear Paraffins are widely used in the manufacturing of industrial and domestic detergents. Some adsorbents selectively separate these linear hydrocarbons by adsorption from petroleum feedstocks. LTA molecular sieves (5A zeolite) adsorb linear Paraffins while excluding the rest of the components of kerosene (branched hydrocarbons and aromatics). Equilibrium and kinetic parameters are available in the literature for light Paraffins in the vapour phase, however, there is scarce information concerning high molecular weight Paraffins in liquid phase, especially at the operating conditions of commercial processes. In a previous work, the equilibrium and kinetics of high molecular weight n -Paraffins C5, C10, C14 and C18 were studied for the adsorption in liquid phase on 5A zeolite. The aim of this work is to study the equilibrium and kinetics of n -Paraffins C12 and C16, as well as mixtures of n -Paraffins C10, C12 and C14 in the same conditions. n -pentane has been included in the study as it is mainly used as desorbent in the cyclic simulated moving bed (SMB) commercial process. Pure component isotherms were obtained, as well as a multicomponent isotherm. By comparing them, it was observed that selectivities are significantly lower in mixtures (for example, selectivity towards C14 with respect to C12 is lowered from 2.84 for pure Paraffins to 1.05 for mixtures). A theoretical model has been developed to describe the column adsorption dynamics of the studied systems. The model has been included in an SMB simulation program (SMBSIM), and the model prediction has been validated by comparison with the separation performance data reported for a commercial SMB unit that separates normal Paraffins from a hydrotreated kerosene fraction The model predicts the separation of linear Paraffins with 99.2% purity and 96.3% recovery (5% error obtained for n -Paraffin concentration in the extract and non-adsorptives in the raffinate).
Ahmet Sar - One of the best experts on this subject based on the ideXlab platform.
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Form-stable Paraffin/high density polyethylene composites as solid-liquid phase change material for thermal energy storage: preparation and thermal properties
Energy.Convers.Manage., 2004Co-Authors: Ahmet SarAbstract:This paper deals with the preparation of Paraffin/high density polyethylene (HDPE) composites as form-stable, solid–liquid phase change material (PCM) for thermal energy storage and with determination of their thermal properties. In such a composite, the Paraffin (P) serves as a latent heat storage material and the HDPE acts as a supporting material, which prevents leakage of the melted Paraffin because of providing structural strength. Therefore, it is named form-stable composite PCM. In this study, two kinds of Paraffins with melting temperatures of 42–44 -ÝC (type P1) and 56–58 -ÝC (type P2) and latent heats of 192.8 and 212.4 J g−1 were used. The maximum weight percentage for both Paraffin types in the PCM composites without any seepage of the Paraffin in the melted state were found as high as 77%. It is observed that the Paraffin is dispersed into the network of the solid HDPE by investigation of the structure of the composite PCMs using a scanning electronic microscope (SEM). The melting temperatures and latent heats of the form-stable P1/HDPE and P2/HDPE composite PCMs were determined as 37.8 and 55.7 -ÝC, and 147.6 and 162.2 J g−1, respectively, by the technique of differential scanning calorimetry (DSC). Furthermore, to improve the thermal conductivity of the form-stable P/HDPE composite PCMs, expanded and exfoliated graphite (EG) by heat treatment was added to the samples in the ratio of 3 wt.%. Thereby, the thermal conductivity was increased about 14% for the form-stable P1/HDPE and about 24% for the P2/HDPE composite PCMs. Based on the results, it is concluded that the prepared form-stable P/HDPE blends as composite type PCM have great potential for thermal energy storage applications in terms of their satisfactory thermal properties and improved thermal conductivity. Furthermore, these composite PCMs added with EG can be considered cost effective latent heat storage materials since they do not require encapsulation and extra cost to enhance heat transfer in the Paraffin
D. Aranda - One of the best experts on this subject based on the ideXlab platform.
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Modelling of the separation of long-chain normal Paraffins from kerosene in a simulated moving bed process: effect of the desorbent
Adsorption, 2020Co-Authors: D. Aranda, V. I. Águeda, J. A. Delgado, M. A. Uguina, I. D. López, J. J. Lázaro, J. C. Perdomo, I. BarrioAbstract:Linear Paraffins can be selectively separated from the rest of components of kerosene (branched hydrocarbons, aromatics and naphthenes) by means of liquid phase adsorption on 5A zeolite using the technology of simulated moving bed (SMB). In previous works, the kinetic and equilibrium parameters required for modelling and design of the SMB unit were obtained for pure n-Paraffins and n-Paraffin mixtures. However, the simulation of the SMB process indicated the presence of n-C_5, used as a desorbent, in the separation zone, especially after the feed mixture is introduced. This finding motivated this work, in which n-Paraffin mixtures (n-C_10, n-C_12, n-C_14) including n-C_5 were studied to address its influence in the process. The kinetic and equilibrium parameters for these mixtures were obtained and included in the model for the simulation of an SMB unit. While mixtures without n-C_5 preferentially adsorbed shorter n-Paraffins, it was found that including n-C_5 in the mixtures reverses the selectivity of the adsorbent. In this case, longer n-Paraffins are preferentially adsorbed, matching the trend observed for pure n-Paraffins. In addition, n-C_5 significantly increases the mobility of n-Paraffins, as indicated in their higher mass transfer coefficients. The model was validated by comparing the predicted performance with the reported separation achieved by a commercial SMB unit that separates n-Paraffins from hydrotreated kerosene fractions. The predicted separation performance is very similar to that achieved in our previous works, slightly improving the purity (99.6%) of the extract as a trade for a small loss in recovery (95.4%).
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Modelling of the separation of normal Paraffins from kerosene fractions by a simulated moving bed process
Adsorption, 2018Co-Authors: D. Aranda, V. I. Águeda, J. A. Delgado, M. A. Uguina, I. D. López, J. J. Lázaro, J. C. Perdomo, M. T. Holik, I. BarrioAbstract:Linear Paraffins are widely used in the manufacturing of industrial and domestic detergents. Some adsorbents selectively separate these linear hydrocarbons by adsorption from petroleum feedstocks. LTA molecular sieves (5A zeolite) adsorb linear Paraffins while excluding the rest of the components of kerosene (branched hydrocarbons and aromatics). Equilibrium and kinetic parameters are available in the literature for light Paraffins in the vapour phase, however, there is scarce information concerning high molecular weight Paraffins in liquid phase, especially at the operating conditions of commercial processes. In a previous work, the equilibrium and kinetics of high molecular weight n -Paraffins C5, C10, C14 and C18 were studied for the adsorption in liquid phase on 5A zeolite. The aim of this work is to study the equilibrium and kinetics of n -Paraffins C12 and C16, as well as mixtures of n -Paraffins C10, C12 and C14 in the same conditions. n -pentane has been included in the study as it is mainly used as desorbent in the cyclic simulated moving bed (SMB) commercial process. Pure component isotherms were obtained, as well as a multicomponent isotherm. By comparing them, it was observed that selectivities are significantly lower in mixtures (for example, selectivity towards C14 with respect to C12 is lowered from 2.84 for pure Paraffins to 1.05 for mixtures). A theoretical model has been developed to describe the column adsorption dynamics of the studied systems. The model has been included in an SMB simulation program (SMBSIM), and the model prediction has been validated by comparison with the separation performance data reported for a commercial SMB unit that separates normal Paraffins from a hydrotreated kerosene fraction The model predicts the separation of linear Paraffins with 99.2% purity and 96.3% recovery (5% error obtained for n -Paraffin concentration in the extract and non-adsorptives in the raffinate).
Kamil Kaygusuz - One of the best experts on this subject based on the ideXlab platform.
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thermal energy storage performance of Paraffin in a novel tube in shell system
Applied Thermal Engineering, 2008Co-Authors: Mithat Akgun, Orhan Aydin, Kamil KaygusuzAbstract:In this study, the latent heat thermal energy storage system of the shell-and-tube type is analyzed experimentally. A novel design for the storage unit whose geometry is consistent with the melting/solidification characteristics of phase change materials (PCMs) is introduced. Three kinds of Paraffin with different melting temperatures are used as PCMs. Water is used as the heat transfer fluid (HTF). At first, the thermophysical properties of the Paraffins used are determined through the differential scanning calorimeter (DSC) analysis. The effects of the Reynolds number and the Stefan number on the melting and solidification behaviors are determined. It is disclosed the novel tube-in-shell storage geometry introduced in this study suggests promising results.
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High density polyethylene/Paraffin composites as form-stable phase change material for thermal energy storage
Energy Sources Part a-Recovery Utilization and Environmental Effects, 2007Co-Authors: Kamil Kaygusuz, Ahmet SariAbstract:This article focuses on the preparation and thermo-physical properties of Paraffin/high density polyethylene (HDPE) composites as form-stable solid-liquid phase change material (PCM) for thermal energy storage. In the Paraffin/HDPE blend, the Paraffin (P) dispersed into the HDPE serves as a latent heat storage material when the HDPE, as a supporting material, prevents the melted Paraffin leakage thanks to its structural strength. Therefore, this type composite is form-stable and can be used as a PCM without encapsulation for thermal energy storage. In this study, two Paraffins with melting temperatures of 48 degrees C-50 degrees C and 63 degrees C-65 degrees C were used. The mass percentages of Paraffins in the composites could go high as 76% without any seepage of the Paraffin in melted state. The dispersion of the Paraffin into the network of the solid HDPE was investigated using scanning electronic microscope (SEM). The melting temperatures and latent heats of the form-stable P1/HDPE and P2/HDPE composite PCMs were determined as 44.32 degrees C and 61.66 degrees C, and 179.63 and 198.14 Jg(-1), by the technique of differential scanning calorimetry (DSC), respectively. Furthermore, the thermal conductivity of the composite PCMs were improved as about 33.3% for the P1/HDPE and 52.3% for the P2/HDPE by introducing the expanded and exfoliated graphite to the samples in the ratio of 3 wt%. The results reveal that the prepared form-stable composite PCMs have great potential for thermal energy storage applications in terms of their satisfactory thermal properties, improved thermal conductivity and cost-efficiency because of no encapsulation for enhancing heat transfer in Paraffin.
