The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Jinjun Zhang - One of the best experts on this subject based on the ideXlab platform.
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Influence of asphaltenes on the performance of Electrical Treatment of waxy oils
Journal of Petroleum Science and Engineering, 2019Co-Authors: Jinjun Zhang, Feng Kai, Chaohui Chen, Qian HuangAbstract:Abstract Electrical Treatment is emerging as an efficient approach to improve the cold flowability of crude oils. In this work, waxy model oils under static state were Electrically treated by an in-house apparatus. The influence of asphaltenes, the most aromatic of the heaviest components of crude oil, on the performance of Electrical Treatment was systematically examined for the first time. The presence of asphaltenes was found to significantly undermine the effectiveness of Electrical Treatment on waxy oils, and this negative influence became more pronounced at higher asphaltene contents. The effect of asphaltenes was largely independent on their aggregation state. Interestingly, although asphaltenes generally have a negative effect on Electrical Treatment of waxy oils, increasing polarity of asphaltenes alleviates this unfavorable effect. The results from microscopic analysis suggest that the less pronounced change in the size distribution of wax crystals might be one of the reasons for the unfavorable effects of asphaltenes on Electrical Treatment of waxy oils.
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Effect of Electrical Treatment on structural behaviors of gelled waxy crude oil
Fuel, 2019Co-Authors: Wang Xinyi, Chaohui Chen, Shanpeng Han, Jinjun ZhangAbstract:Abstract Waxy crude oil presents poor flowability and complicated rheological behaviors near and below its gelation temperature. In recent years, high voltage direct current electric field has emerged as a novel approach to significantly reduce the viscosity of waxy crude oil below its wax appearance temperature, but the effect of Electrical Treatment on the structural behaviors of gelled waxy crude oil remains unknown. In the present study, the viscoelasticity, yielding behavior, and thixotropy of gelled waxy crude oil experienced Electrically-Treatment were investigated over a range of Electrical field strength of 0–0.8 kV/mm and Treatment temperature between the wax appearance temperature and the pour point. We demonstrate for the first time that the structural strength of gelled waxy crude oil can be significantly weakened after Electrical Treatment below its wax appearance temperature. The magnitude of the reduction increases with the electric field strength increasing and Treatment temperature decreasing. However, no significant influence was found on the wax appearance temperature, wax disappearance temperature, and the amount of precipitated and dissolved wax, revealing the phase equilibrium of wax in crude oil not affected. The investigation of the wax crystal microscopy shows that the wax crystals in the Electrically-treated waxy gels are generally larger, and have larger aspect ratio and boundary box fractal dimension, which indicates that the size and morphology of wax crystals are varied by the influence of the Electrical Treatment.
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Electrical Treatment of Waxy Crude Oil To Improve Its Cold Flowability
Industrial & Engineering Chemistry Research, 2017Co-Authors: Chaohui Chen, Feng Kai, Wang Xinyi, Jinjun ZhangAbstract:We demonstrate that the cold flowability of the waxy crude oil can be significantly improved via Electrical Treatment. A novel apparatus was assembled to Electrically treat the waxy crude oil while simultaneously measuring its rheological properties. A method was developed to calculate the oil’s viscosity by using non-Newtonian fluid mechanics and rheological principles. Lower Treatment temperatures, higher electric field strengths, and lower shear rates provided greater viscosity reduction. Notably, a viscosity reduction of 70% was obtained when the oil was Electrically treated near its pour point for 90 s. Microscopic examinations indicate that the broader size distribution of wax particles in the treated oil might be responsible for the observed viscosity reduction. Besides, the energy consumption of the Electrical Treatment was estimated to be less than 1% of that of the conventional heating method to achieve the same viscosity reduction performance.
Chaohui Chen - One of the best experts on this subject based on the ideXlab platform.
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Influence of asphaltenes on the performance of Electrical Treatment of waxy oils
Journal of Petroleum Science and Engineering, 2019Co-Authors: Jinjun Zhang, Feng Kai, Chaohui Chen, Qian HuangAbstract:Abstract Electrical Treatment is emerging as an efficient approach to improve the cold flowability of crude oils. In this work, waxy model oils under static state were Electrically treated by an in-house apparatus. The influence of asphaltenes, the most aromatic of the heaviest components of crude oil, on the performance of Electrical Treatment was systematically examined for the first time. The presence of asphaltenes was found to significantly undermine the effectiveness of Electrical Treatment on waxy oils, and this negative influence became more pronounced at higher asphaltene contents. The effect of asphaltenes was largely independent on their aggregation state. Interestingly, although asphaltenes generally have a negative effect on Electrical Treatment of waxy oils, increasing polarity of asphaltenes alleviates this unfavorable effect. The results from microscopic analysis suggest that the less pronounced change in the size distribution of wax crystals might be one of the reasons for the unfavorable effects of asphaltenes on Electrical Treatment of waxy oils.
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Effect of Electrical Treatment on structural behaviors of gelled waxy crude oil
Fuel, 2019Co-Authors: Wang Xinyi, Chaohui Chen, Shanpeng Han, Jinjun ZhangAbstract:Abstract Waxy crude oil presents poor flowability and complicated rheological behaviors near and below its gelation temperature. In recent years, high voltage direct current electric field has emerged as a novel approach to significantly reduce the viscosity of waxy crude oil below its wax appearance temperature, but the effect of Electrical Treatment on the structural behaviors of gelled waxy crude oil remains unknown. In the present study, the viscoelasticity, yielding behavior, and thixotropy of gelled waxy crude oil experienced Electrically-Treatment were investigated over a range of Electrical field strength of 0–0.8 kV/mm and Treatment temperature between the wax appearance temperature and the pour point. We demonstrate for the first time that the structural strength of gelled waxy crude oil can be significantly weakened after Electrical Treatment below its wax appearance temperature. The magnitude of the reduction increases with the electric field strength increasing and Treatment temperature decreasing. However, no significant influence was found on the wax appearance temperature, wax disappearance temperature, and the amount of precipitated and dissolved wax, revealing the phase equilibrium of wax in crude oil not affected. The investigation of the wax crystal microscopy shows that the wax crystals in the Electrically-treated waxy gels are generally larger, and have larger aspect ratio and boundary box fractal dimension, which indicates that the size and morphology of wax crystals are varied by the influence of the Electrical Treatment.
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Electrical Treatment of Waxy Crude Oil To Improve Its Cold Flowability
Industrial & Engineering Chemistry Research, 2017Co-Authors: Chaohui Chen, Feng Kai, Wang Xinyi, Jinjun ZhangAbstract:We demonstrate that the cold flowability of the waxy crude oil can be significantly improved via Electrical Treatment. A novel apparatus was assembled to Electrically treat the waxy crude oil while simultaneously measuring its rheological properties. A method was developed to calculate the oil’s viscosity by using non-Newtonian fluid mechanics and rheological principles. Lower Treatment temperatures, higher electric field strengths, and lower shear rates provided greater viscosity reduction. Notably, a viscosity reduction of 70% was obtained when the oil was Electrically treated near its pour point for 90 s. Microscopic examinations indicate that the broader size distribution of wax particles in the treated oil might be responsible for the observed viscosity reduction. Besides, the energy consumption of the Electrical Treatment was estimated to be less than 1% of that of the conventional heating method to achieve the same viscosity reduction performance.
Wang Xinyi - One of the best experts on this subject based on the ideXlab platform.
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Effect of Electrical Treatment on structural behaviors of gelled waxy crude oil
Fuel, 2019Co-Authors: Wang Xinyi, Chaohui Chen, Shanpeng Han, Jinjun ZhangAbstract:Abstract Waxy crude oil presents poor flowability and complicated rheological behaviors near and below its gelation temperature. In recent years, high voltage direct current electric field has emerged as a novel approach to significantly reduce the viscosity of waxy crude oil below its wax appearance temperature, but the effect of Electrical Treatment on the structural behaviors of gelled waxy crude oil remains unknown. In the present study, the viscoelasticity, yielding behavior, and thixotropy of gelled waxy crude oil experienced Electrically-Treatment were investigated over a range of Electrical field strength of 0–0.8 kV/mm and Treatment temperature between the wax appearance temperature and the pour point. We demonstrate for the first time that the structural strength of gelled waxy crude oil can be significantly weakened after Electrical Treatment below its wax appearance temperature. The magnitude of the reduction increases with the electric field strength increasing and Treatment temperature decreasing. However, no significant influence was found on the wax appearance temperature, wax disappearance temperature, and the amount of precipitated and dissolved wax, revealing the phase equilibrium of wax in crude oil not affected. The investigation of the wax crystal microscopy shows that the wax crystals in the Electrically-treated waxy gels are generally larger, and have larger aspect ratio and boundary box fractal dimension, which indicates that the size and morphology of wax crystals are varied by the influence of the Electrical Treatment.
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Electrical Treatment of Waxy Crude Oil To Improve Its Cold Flowability
Industrial & Engineering Chemistry Research, 2017Co-Authors: Chaohui Chen, Feng Kai, Wang Xinyi, Jinjun ZhangAbstract:We demonstrate that the cold flowability of the waxy crude oil can be significantly improved via Electrical Treatment. A novel apparatus was assembled to Electrically treat the waxy crude oil while simultaneously measuring its rheological properties. A method was developed to calculate the oil’s viscosity by using non-Newtonian fluid mechanics and rheological principles. Lower Treatment temperatures, higher electric field strengths, and lower shear rates provided greater viscosity reduction. Notably, a viscosity reduction of 70% was obtained when the oil was Electrically treated near its pour point for 90 s. Microscopic examinations indicate that the broader size distribution of wax particles in the treated oil might be responsible for the observed viscosity reduction. Besides, the energy consumption of the Electrical Treatment was estimated to be less than 1% of that of the conventional heating method to achieve the same viscosity reduction performance.
Shigeo Satokawa - One of the best experts on this subject based on the ideXlab platform.
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Effect of annealing on the separation of resin from CFRP cross-ply laminate via Electrical Treatment
Composite Structures, 2020Co-Authors: Shinya Matsuda, Kazumasa Oshima, Masaki Hosaka, Shigeo SatokawaAbstract:Abstract Carbon fiber reinforced plastics (CFRP) are desirable owing to their high specific strength and rigidity. Traditional recycling methods for these products such as thermal decomposition cause considerable damage to the carbon fibers. In search for better recycling methods, we explored the use of Electrical Treatment for the separation of resin. Herein, we investigated the effects of annealing on the separation of resin from a CFRP cross-ply laminate molded from unidirectional prepreg (carbon fiber/epoxy) using Electrical Treatment. The annealing of the CFRP cross-ply laminate [0°/90°]2s was performed at temperatures ranging from 60 °C to 450 °C, followed by the Electrical Treatment. Experimental results demonstrated that the separation of resin, without the carbon fiber damage, could be achieved by annealing at temperatures close to the epoxy decomposition temperature. For the non-annealed CFRP specimens, the separation of resin was achieved with considerable damage to the carbon fibers.
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Rapid removal of resin from a unidirectional carbon fiber reinforced plastic laminate by a high-voltage Electrical Treatment
Separation and Purification Technology, 2020Co-Authors: Kazumasa Oshima, Shinya Matsuda, Masaki Hosaka, Shigeo SatokawaAbstract:Abstract Removal of epoxy resin from a unidirectional carbon fiber reinforced plastic (CFRP) laminate was achieved with an Electrical Treatment. The Treatment was carried out using a two-electrode cell with the CFRP laminate as the anode, and the effect of applying a high voltage was investigated to reduce the Treatment time. The results showed that a high voltage in the Electrical Treatment leads to high weight loss of the unidirectional CFRP laminate. In the digital microscope images of the residue obtained from the electrolyte after the Treatment, fragments assumed to be resin were observed. The removal mechanism involved an electrochemical reaction; however, no decomposition product related to the resin was detected in the electrolyte after the Treatment. The results supposed that the removal mechanism of the Electrical Treatment involved peeling off the resin by gas generated by water electrolysis.
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Removal mechanism of epoxy resin from CFRP composites triggered by water electrolysis gas generation
Separation and Purification Technology, 2020Co-Authors: Kazumasa Oshima, Shinya Matsuda, Masaki Hosaka, Shigeo SatokawaAbstract:Abstract To promote recycling of carbon fiber reinforced plastics (CFRPs), we investigated the removal mechanism of resin by Electrical Treatment at high voltage. Using the pseudo in-situ observations, we found that resin removal was triggered by Electrical Treatment. Based on the observations and current dependency, the resin was removed by a mechanical approach that employed the oxygen gas generated from water electrolysis, i.e., the gas peeled the resin. Moreover, the cathodic Treatment was unable to achieve the resin removal because of the high diffusion of hydrogen gas into the epoxy resin. During anodic Treatment, CO, CO2, and oxygen gases were generated from the specimen, and damage to the carbon fiber (CF) was observed on the specimen after Treatment for 180 min. The mechanism of the resin removal was governed by the resin peeling off from the CFRP composite, which was triggered by the oxygen gas generated from the water electrolysis. During Electrical conduction, the peeling was initiated at the voids that were formed by the oxidation of the locally heated resin spots. At low resin content levels, the CF was subjected to damage due to the Electrical conduction, which was accompanied by the application of a high voltage.
Kazumasa Oshima - One of the best experts on this subject based on the ideXlab platform.
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Effect of annealing on the separation of resin from CFRP cross-ply laminate via Electrical Treatment
Composite Structures, 2020Co-Authors: Shinya Matsuda, Kazumasa Oshima, Masaki Hosaka, Shigeo SatokawaAbstract:Abstract Carbon fiber reinforced plastics (CFRP) are desirable owing to their high specific strength and rigidity. Traditional recycling methods for these products such as thermal decomposition cause considerable damage to the carbon fibers. In search for better recycling methods, we explored the use of Electrical Treatment for the separation of resin. Herein, we investigated the effects of annealing on the separation of resin from a CFRP cross-ply laminate molded from unidirectional prepreg (carbon fiber/epoxy) using Electrical Treatment. The annealing of the CFRP cross-ply laminate [0°/90°]2s was performed at temperatures ranging from 60 °C to 450 °C, followed by the Electrical Treatment. Experimental results demonstrated that the separation of resin, without the carbon fiber damage, could be achieved by annealing at temperatures close to the epoxy decomposition temperature. For the non-annealed CFRP specimens, the separation of resin was achieved with considerable damage to the carbon fibers.
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Rapid removal of resin from a unidirectional carbon fiber reinforced plastic laminate by a high-voltage Electrical Treatment
Separation and Purification Technology, 2020Co-Authors: Kazumasa Oshima, Shinya Matsuda, Masaki Hosaka, Shigeo SatokawaAbstract:Abstract Removal of epoxy resin from a unidirectional carbon fiber reinforced plastic (CFRP) laminate was achieved with an Electrical Treatment. The Treatment was carried out using a two-electrode cell with the CFRP laminate as the anode, and the effect of applying a high voltage was investigated to reduce the Treatment time. The results showed that a high voltage in the Electrical Treatment leads to high weight loss of the unidirectional CFRP laminate. In the digital microscope images of the residue obtained from the electrolyte after the Treatment, fragments assumed to be resin were observed. The removal mechanism involved an electrochemical reaction; however, no decomposition product related to the resin was detected in the electrolyte after the Treatment. The results supposed that the removal mechanism of the Electrical Treatment involved peeling off the resin by gas generated by water electrolysis.
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Removal mechanism of epoxy resin from CFRP composites triggered by water electrolysis gas generation
Separation and Purification Technology, 2020Co-Authors: Kazumasa Oshima, Shinya Matsuda, Masaki Hosaka, Shigeo SatokawaAbstract:Abstract To promote recycling of carbon fiber reinforced plastics (CFRPs), we investigated the removal mechanism of resin by Electrical Treatment at high voltage. Using the pseudo in-situ observations, we found that resin removal was triggered by Electrical Treatment. Based on the observations and current dependency, the resin was removed by a mechanical approach that employed the oxygen gas generated from water electrolysis, i.e., the gas peeled the resin. Moreover, the cathodic Treatment was unable to achieve the resin removal because of the high diffusion of hydrogen gas into the epoxy resin. During anodic Treatment, CO, CO2, and oxygen gases were generated from the specimen, and damage to the carbon fiber (CF) was observed on the specimen after Treatment for 180 min. The mechanism of the resin removal was governed by the resin peeling off from the CFRP composite, which was triggered by the oxygen gas generated from the water electrolysis. During Electrical conduction, the peeling was initiated at the voids that were formed by the oxidation of the locally heated resin spots. At low resin content levels, the CF was subjected to damage due to the Electrical conduction, which was accompanied by the application of a high voltage.