In order to resolve the issues related to the recycling of asphalt concrete, this study focuses o... more In order to resolve the issues related to the recycling of asphalt concrete, this study focuses on the application of pulsed power technology and subcritical water to the recovery of asphalt from asphalt concrete lumps. At the result, the recycled aggregate over 5mm with asphalt content of approximately 0.99% was produced using pulsed power technology. Furthermore, the application of subcritical water to recover asphalt from the residues of pulsed power discharge inside of asphalt concrete lumps resulted in an about 91% pure asphalt recovery rate and recycled fine aggregate with pure asphalt content of less than 0.5%.
Large-capacity discharge plasmas have great capability of many applications such as sterilization... more Large-capacity discharge plasmas have great capability of many applications such as sterilization, deodorization, dioxin treatment, and water treatment. We have tried to generate large-capacity discharge plasmas in high-pressure and high-temperature fluids including their supercritical states and recently found that the discharge plasmas could be generated in supercritical carbon dioxide. For this purpose, we designed and manufactured an experimental apparatus, and tried to explore the operating conditions where the plasmas could be generated through the experiments at various conditions (305-333 K and 0.1-20.0 MPa) in supercritical CO2. As a result, it was found that discharge plasmas could be produced in supercritical CO2 as well as in gaseous CO2 and the brightness of the plasmas became higher as the pressure increased at a constant temperature. It was also found that the breakdown voltage depended upon the density of CO2 at nearand supercritical pressures at above the critical t...
Ganoderma lucidum, a polypore group fungus, provides polysaccharides in which beta-glucans are co... more Ganoderma lucidum, a polypore group fungus, provides polysaccharides in which beta-glucans are core structures that claim to possess cancerous and immunomodulatory properties. The objective of this work has been to establish a method of extraction from grinded form of Ganoderma lucidum with water in sub-critical conditions and with SCCO 2 at distinct temperatures to obtain extracts rich in water soluble organic compounds (WSOC), including mostly beta glucans and triterpenoids including ganoderic acids and alcohols respectively. For hydrothermal treatment, increase in temperatures showed positive effect on the recovery efficiency for water soluble organic compounds. It was demonstrated that the modified SCCO 2 extraction is suitable for the extraction of Ganoderma lucidum. It was also seen that molecular weights of extracts became smaller for high temperatures having increasing values for SCCO 2 extraction in comparison to hydrothermal treatment.
ABSTRACT Bitumens were mainly obtained as a residue of the petroleum refining process and general... more ABSTRACT Bitumens were mainly obtained as a residue of the petroleum refining process and generally they are used for paving roads, roofing, coating, insulation, etc. In fact, bitumens are of great importance to the chemical industry because of their great variety of special properties, which has favored the development of a wide field of applications. They can be considered as colloidal systems in which micelles of high-molecular-weight organic molecules (asphaltenes) are dispersed in an oily phase (maltenes) consisting of low-molecular-weight saturated and aromatic hydrocarbons together with resins. The development of process has been proposed to recover chemical resources from bitumens that can accomplish the destruction of the bitumens into harmless to produce useful compounds. It was well known that water at hydrothermal condition is considered a promising and an environmentally acceptable solvent for a wide variety of chemical reactions such as organic syntheses and decomposition of hazardous waste into harmless compounds. In these works, water at supercritical conditions was applied as a solvent for degradation of swelled biomass resources and solid waste polymers or upgrading of bitumen without catalyst. The experiments were conducted using a batch-type reactor at temperature of 673 K. During the reaction, the reactor was shaken using a mechanical device. The chemical species in the aqueous products were analyzed by gas chromatography mass spectrometry and gas chromatography flame ionization detector. The effect of pressure and reaction time on the decomposition process was presented. Ultimate analysis of solid residue was also conducted using a CHN analyzer. Moreover, this method could become an efficient method for upgrading bitumen into harmless and high yield of valuable chemical intermediates on the basis of the experimental results.
ABSTRACT The aim of this work was to develop new process for extracting and separating hydrophili... more ABSTRACT The aim of this work was to develop new process for extracting and separating hydrophilic and hydrophobic compounds from coffee beans using supercritical CO2 in water. In this work, experiments and simulation of the process has been conducted. Chlorogenic acid and caffeine from coffee beans were used as model compounds of hydrophilic and hydrophobic compounds, respectively. Experiment was conducted in the semi-continuous flow extractor at various densities and ratios of coffee mass and water mass (C/W). Extracted compounds in SC-CO2 and in water were analyzed by HPLC-PDA detector, respectively. As expected, the extracted compound in SC-CO2 was containing 100% purity of caffeine. However, the extracted compound in water was containing caffeine and chlorogenic acid. It was due to the solubility of caffeine in water is higher than that in SC-CO2. Recovery of caffeine in SC-CO2 increased with increasing density and decreasing ratio of coffee mass and water mass (C/W). In addition, this process was also simulated using model based on mass transfer balance to estimate recovery of caffeine and to describe concentration profile inside of the extractor (both in SC-CO2 phase and water phase). Simulation was conducted using Visual Basic in Excel 2003. As in the experimental result, the recovery of caffeine in SC-CO2 increased with the increase in density. However, the effect of C/W on the recovery of caffeine in SC-CO2 yielded adversative result. In the simulation result, the recovery of caffeine in SC-CO2 decreased with decreasing C/W. The result can be explained that increasing mass of water caused increasing mass transfer rate of caffeine in water, thus the increasing mass transfer resistance in SC-CO2. Concentration profile of caffeine in SC-CO2 phase and in water phase inside of the extractor have also been simulated.
In order to resolve the issues related to the recycling of asphalt concrete, this study focuses o... more In order to resolve the issues related to the recycling of asphalt concrete, this study focuses on the application of pulsed power technology and subcritical water to the recovery of asphalt from asphalt concrete lumps. At the result, the recycled aggregate over 5mm with asphalt content of approximately 0.99% was produced using pulsed power technology. Furthermore, the application of subcritical water to recover asphalt from the residues of pulsed power discharge inside of asphalt concrete lumps resulted in an about 91% pure asphalt recovery rate and recycled fine aggregate with pure asphalt content of less than 0.5%.
Large-capacity discharge plasmas have great capability of many applications such as sterilization... more Large-capacity discharge plasmas have great capability of many applications such as sterilization, deodorization, dioxin treatment, and water treatment. We have tried to generate large-capacity discharge plasmas in high-pressure and high-temperature fluids including their supercritical states and recently found that the discharge plasmas could be generated in supercritical carbon dioxide. For this purpose, we designed and manufactured an experimental apparatus, and tried to explore the operating conditions where the plasmas could be generated through the experiments at various conditions (305-333 K and 0.1-20.0 MPa) in supercritical CO2. As a result, it was found that discharge plasmas could be produced in supercritical CO2 as well as in gaseous CO2 and the brightness of the plasmas became higher as the pressure increased at a constant temperature. It was also found that the breakdown voltage depended upon the density of CO2 at nearand supercritical pressures at above the critical t...
Ganoderma lucidum, a polypore group fungus, provides polysaccharides in which beta-glucans are co... more Ganoderma lucidum, a polypore group fungus, provides polysaccharides in which beta-glucans are core structures that claim to possess cancerous and immunomodulatory properties. The objective of this work has been to establish a method of extraction from grinded form of Ganoderma lucidum with water in sub-critical conditions and with SCCO 2 at distinct temperatures to obtain extracts rich in water soluble organic compounds (WSOC), including mostly beta glucans and triterpenoids including ganoderic acids and alcohols respectively. For hydrothermal treatment, increase in temperatures showed positive effect on the recovery efficiency for water soluble organic compounds. It was demonstrated that the modified SCCO 2 extraction is suitable for the extraction of Ganoderma lucidum. It was also seen that molecular weights of extracts became smaller for high temperatures having increasing values for SCCO 2 extraction in comparison to hydrothermal treatment.
ABSTRACT Bitumens were mainly obtained as a residue of the petroleum refining process and general... more ABSTRACT Bitumens were mainly obtained as a residue of the petroleum refining process and generally they are used for paving roads, roofing, coating, insulation, etc. In fact, bitumens are of great importance to the chemical industry because of their great variety of special properties, which has favored the development of a wide field of applications. They can be considered as colloidal systems in which micelles of high-molecular-weight organic molecules (asphaltenes) are dispersed in an oily phase (maltenes) consisting of low-molecular-weight saturated and aromatic hydrocarbons together with resins. The development of process has been proposed to recover chemical resources from bitumens that can accomplish the destruction of the bitumens into harmless to produce useful compounds. It was well known that water at hydrothermal condition is considered a promising and an environmentally acceptable solvent for a wide variety of chemical reactions such as organic syntheses and decomposition of hazardous waste into harmless compounds. In these works, water at supercritical conditions was applied as a solvent for degradation of swelled biomass resources and solid waste polymers or upgrading of bitumen without catalyst. The experiments were conducted using a batch-type reactor at temperature of 673 K. During the reaction, the reactor was shaken using a mechanical device. The chemical species in the aqueous products were analyzed by gas chromatography mass spectrometry and gas chromatography flame ionization detector. The effect of pressure and reaction time on the decomposition process was presented. Ultimate analysis of solid residue was also conducted using a CHN analyzer. Moreover, this method could become an efficient method for upgrading bitumen into harmless and high yield of valuable chemical intermediates on the basis of the experimental results.
ABSTRACT The aim of this work was to develop new process for extracting and separating hydrophili... more ABSTRACT The aim of this work was to develop new process for extracting and separating hydrophilic and hydrophobic compounds from coffee beans using supercritical CO2 in water. In this work, experiments and simulation of the process has been conducted. Chlorogenic acid and caffeine from coffee beans were used as model compounds of hydrophilic and hydrophobic compounds, respectively. Experiment was conducted in the semi-continuous flow extractor at various densities and ratios of coffee mass and water mass (C/W). Extracted compounds in SC-CO2 and in water were analyzed by HPLC-PDA detector, respectively. As expected, the extracted compound in SC-CO2 was containing 100% purity of caffeine. However, the extracted compound in water was containing caffeine and chlorogenic acid. It was due to the solubility of caffeine in water is higher than that in SC-CO2. Recovery of caffeine in SC-CO2 increased with increasing density and decreasing ratio of coffee mass and water mass (C/W). In addition, this process was also simulated using model based on mass transfer balance to estimate recovery of caffeine and to describe concentration profile inside of the extractor (both in SC-CO2 phase and water phase). Simulation was conducted using Visual Basic in Excel 2003. As in the experimental result, the recovery of caffeine in SC-CO2 increased with the increase in density. However, the effect of C/W on the recovery of caffeine in SC-CO2 yielded adversative result. In the simulation result, the recovery of caffeine in SC-CO2 decreased with decreasing C/W. The result can be explained that increasing mass of water caused increasing mass transfer rate of caffeine in water, thus the increasing mass transfer resistance in SC-CO2. Concentration profile of caffeine in SC-CO2 phase and in water phase inside of the extractor have also been simulated.
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Papers by Mitsuru Sasaki