The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Ki Young Park - One of the best experts on this subject based on the ideXlab platform.
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hydrothermal Carbonization of anaerobically digested sludge for solid fuel production and energy recovery
Fuel, 2014Co-Authors: Daegi Kim, Kwanyong Lee, Ki Young ParkAbstract:Abstract The hydrothermal Carbonization was investigated to convert anaerobically digested sludge to clean solid fuels. The effects of hydrothermal Carbonization were evaluated by varying the reaction temperatures in the range of 180–250 °C. Hydrothermal Carbonization increased the heating value though the reduction of the hydrogen and oxygen content of solid fuel in addition to investigating drying performance, and it can do energy saving on treatment processes. Therefore, after the hydrothermal Carbonization, the H/C and O/C ratios decreased because of the chemical conversion. These results suggest that the hydrothermal Carbonization process is advantageous technology in improving the properties of sewage sludge as an alternative solid fuel product as clean energy by converting the physical and chemical structure of the sludge in addition to also providing other benefits to treat organic and biomass waste.
Daegi Kim - One of the best experts on this subject based on the ideXlab platform.
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hydrothermal Carbonization of anaerobically digested sludge for solid fuel production and energy recovery
Fuel, 2014Co-Authors: Daegi Kim, Kwanyong Lee, Ki Young ParkAbstract:Abstract The hydrothermal Carbonization was investigated to convert anaerobically digested sludge to clean solid fuels. The effects of hydrothermal Carbonization were evaluated by varying the reaction temperatures in the range of 180–250 °C. Hydrothermal Carbonization increased the heating value though the reduction of the hydrogen and oxygen content of solid fuel in addition to investigating drying performance, and it can do energy saving on treatment processes. Therefore, after the hydrothermal Carbonization, the H/C and O/C ratios decreased because of the chemical conversion. These results suggest that the hydrothermal Carbonization process is advantageous technology in improving the properties of sewage sludge as an alternative solid fuel product as clean energy by converting the physical and chemical structure of the sludge in addition to also providing other benefits to treat organic and biomass waste.
Isao Mochida - One of the best experts on this subject based on the ideXlab platform.
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Formation scheme of needle coke from FCC-decant oil
Carbon, 2003Co-Authors: Isao Mochida, Takashi Oyama, Yozo KoraiAbstract:Abstract The Carbonization process of FCC-decant oil in a tube bomb has been studied by sequential observation of carbons produced at different Carbonization times and pressures to establish the Carbonization scheme, leading to a needle coke. The amount of gas evolution was also followed during Carbonization. The formation of anisotropic spheres was followed by their growth, coalescence, and precipitation to form bulk mesophase first at the bottom of bomb and gradually to the whole region. The bulk mesophase was rearranged into the flow texture parallel to the bomb axis by the gas evolution just at the solidification of the mesophase into a solid lump of needle coke. This timing was strongly influenced by the Carbonization pressure to control the extent of orientation in the resultant coke. Only a range of pressure (around 16 kg/cm2) could provide an excellent flow texture in the coke of the lowest coefficient of thermal expansion at 500°C. Such a scheme provides the three-dimensional structure of a lump of coke that may define its structural change at the calcination stage and its properties.
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Carbonization in the tube bomb leading to needle coke: III. Carbonization properties of several coal-tar pitches
Carbon, 2003Co-Authors: Isao Mochida, Yozo Korai, You Qing Fei, Fujimoto Kenichi, Ryo YamashitaAbstract:Abstract Carbonization properties of several coal-tar pitches of different origins were studied, by using tube bomb, to correlate their analytical characteristics with their Carbonization properties and to find their respective optimum Carbonization conditions for the production of excellent needle coke. The pitch rich in naphthenic structure produced an excellent needle coke of low CTE and uni-axially arranged flow texture under a wider range of Carbonization conditions, whereas the pitches of high oxygen and alkyl contents or of very high aromaticity gave cokes of larger CTE under the standard Carbonization conditions of 500 °C, 8 kg/cm2, because of more mosaic texture or poor uni-axial orientation in the resultant cokes. However, the two kinds of poor pitches were found to produce better cokes under their respective appropriate conditions. The former one did at a slightly lower Carbonization temperature of 480 °C and the latter one did under a lower Carbonization pressure of 4 kg/cm2. A lower temperature allowed the development of bulk mesophase through the moderation of Carbonization reactions for the former reactive pitch. The lower pressure improved uni-axial arrangement of mesophase molecules at the solidification stage through the sufficient gas evolution of good timing for the latter highly aromatic pitch. The higher pressure of Carbonization delayed the solidification to be off-timing to the gas evolution. The mechanism of needle coke formation was discussed to explain the respective optimum conditions for the pitches of different analytical characteristics.
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Catalytic Carbonization of aromatic hydrocarbons—IX: Carbonization mechanism of heterocyclic sulfur compounds leading to the anisotropic coke
Carbon, 2003Co-Authors: Isao Mochida, Takashi Ando, Keiko Maeda, Hiroshi Fujitsu, Kenjiro TakeshitaAbstract:Abstract Carbonization mechanisms of three heterocyclic sulfur compounds catalyzed by aluminium chloride were investigated in order to resolve the factors which influence the optical texture of the coke produced from these compounds. The extent and rate of sulfur elimination, the rate of Carbonization as measured by the increase of benzene insolubles, the temperature region of fusion, and the intermediate structure were assumed influencial during the Carbonization. Thioxanthene, which produced a mosaic coke, showed a similar fused region to that of diphenylene sulfide which formed a needle coke, however the rate of Carbonization of the former compound was much faster than that of the latter. Thianthrene, which produced a fine mosaic coke with some isotropic portions, had the narrowest region of fusion. The importance of the intermediate structure in understanding the Carbonization mechanisms of the compounds in modifying the Carbonization reaction is emphasized. The desulfurization mechanism is also discussed to some extent, relating it to that of Carbonization.
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Carbonization in the tube bomb leading to needle coke. I: CoCarbonization of a petroleum vacuum residue and a FCC-decant oil into better needle coke
Carbon, 2003Co-Authors: Isao Mochida, Yozo Korai, Takashi Oyama, Yasuhiro Nesumi, Yoshio TodoAbstract:The coCarbonization of a Fluidized Catalytic Cracking decant oil (FCCDO) with a petroleum low sulfur vacuum residue (LSVR) was studied at a temperature range of 460 to 480°C by evaluating the qualities of coke lumps produced in a tube bomb in terms of their CTE and anisotropic development. The coCarbonization certainly improved the orientation of flow texture and CTE of the resultant coke, providing the smallest CTE as low as 0.10 × 10−6/°C and 0.36 × 10−6/°C at particular FCCDO/LSVR mixing ratios of 55 and 73 according to the respective Carbonization temperatures of 460 and 480°C. The natures of bulk mesophase and gas evolution at the solidification stage for the axial-rearrangement of mesophase aromatic component, both of which essentially define the coke quality, are strongly influenced by the Carbonization reactivities of blended feedstocks and Carbonization conditions. FCCDO may moderate the Carbonization progress of reactive LSVR and LSVR supply the sufficient gas evolution during the solidification, leading to excellent flow texture of axial arrangement. The formation of mosaic coke in the bottom part of the lump which may deteriolate the quality of the coke produced in a commercial coker appeared to be caused by the phase separation between the paraffin and asphaltene fractions. Such a separation at a early stage of the Carbonization was found to be controlled by the blending and the Carbonization conditions.
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Co-Carbonization of ethylene tar pitch and coal tar pitch to form needle coke
Fuel, 1990Co-Authors: Isao Mochida, Yozo Korai, Taiji OishiAbstract:Abstract The co-Carbonization of ethylene tar pitch (ETP) and coal tar pitch (CTP) was studied in a tube bomb. A small amount of CTP was found to effectively modify the Carbonization properties of ETP to produce excellent needle coke of low nitrogen content without formation of mosaic coke at the reactor bottom (bottom mosaic coke) in a wide range of Carbonization temperatures and pressures. Blending 30–50 wt% CTP into ETP provided lump coke of thin lamellar flow texture, with a good CTE value and nitrogen content after calcination at 1000 °C. The influences of Carbonization temperature and pressure on the nitrogen remaining in the coke were also investigated.
Kwanyong Lee - One of the best experts on this subject based on the ideXlab platform.
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hydrothermal Carbonization of anaerobically digested sludge for solid fuel production and energy recovery
Fuel, 2014Co-Authors: Daegi Kim, Kwanyong Lee, Ki Young ParkAbstract:Abstract The hydrothermal Carbonization was investigated to convert anaerobically digested sludge to clean solid fuels. The effects of hydrothermal Carbonization were evaluated by varying the reaction temperatures in the range of 180–250 °C. Hydrothermal Carbonization increased the heating value though the reduction of the hydrogen and oxygen content of solid fuel in addition to investigating drying performance, and it can do energy saving on treatment processes. Therefore, after the hydrothermal Carbonization, the H/C and O/C ratios decreased because of the chemical conversion. These results suggest that the hydrothermal Carbonization process is advantageous technology in improving the properties of sewage sludge as an alternative solid fuel product as clean energy by converting the physical and chemical structure of the sludge in addition to also providing other benefits to treat organic and biomass waste.
Yozo Korai - One of the best experts on this subject based on the ideXlab platform.
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Formation scheme of needle coke from FCC-decant oil
Carbon, 2003Co-Authors: Isao Mochida, Takashi Oyama, Yozo KoraiAbstract:Abstract The Carbonization process of FCC-decant oil in a tube bomb has been studied by sequential observation of carbons produced at different Carbonization times and pressures to establish the Carbonization scheme, leading to a needle coke. The amount of gas evolution was also followed during Carbonization. The formation of anisotropic spheres was followed by their growth, coalescence, and precipitation to form bulk mesophase first at the bottom of bomb and gradually to the whole region. The bulk mesophase was rearranged into the flow texture parallel to the bomb axis by the gas evolution just at the solidification of the mesophase into a solid lump of needle coke. This timing was strongly influenced by the Carbonization pressure to control the extent of orientation in the resultant coke. Only a range of pressure (around 16 kg/cm2) could provide an excellent flow texture in the coke of the lowest coefficient of thermal expansion at 500°C. Such a scheme provides the three-dimensional structure of a lump of coke that may define its structural change at the calcination stage and its properties.
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Carbonization in the tube bomb leading to needle coke: III. Carbonization properties of several coal-tar pitches
Carbon, 2003Co-Authors: Isao Mochida, Yozo Korai, You Qing Fei, Fujimoto Kenichi, Ryo YamashitaAbstract:Abstract Carbonization properties of several coal-tar pitches of different origins were studied, by using tube bomb, to correlate their analytical characteristics with their Carbonization properties and to find their respective optimum Carbonization conditions for the production of excellent needle coke. The pitch rich in naphthenic structure produced an excellent needle coke of low CTE and uni-axially arranged flow texture under a wider range of Carbonization conditions, whereas the pitches of high oxygen and alkyl contents or of very high aromaticity gave cokes of larger CTE under the standard Carbonization conditions of 500 °C, 8 kg/cm2, because of more mosaic texture or poor uni-axial orientation in the resultant cokes. However, the two kinds of poor pitches were found to produce better cokes under their respective appropriate conditions. The former one did at a slightly lower Carbonization temperature of 480 °C and the latter one did under a lower Carbonization pressure of 4 kg/cm2. A lower temperature allowed the development of bulk mesophase through the moderation of Carbonization reactions for the former reactive pitch. The lower pressure improved uni-axial arrangement of mesophase molecules at the solidification stage through the sufficient gas evolution of good timing for the latter highly aromatic pitch. The higher pressure of Carbonization delayed the solidification to be off-timing to the gas evolution. The mechanism of needle coke formation was discussed to explain the respective optimum conditions for the pitches of different analytical characteristics.
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Carbonization in the tube bomb leading to needle coke. I: CoCarbonization of a petroleum vacuum residue and a FCC-decant oil into better needle coke
Carbon, 2003Co-Authors: Isao Mochida, Yozo Korai, Takashi Oyama, Yasuhiro Nesumi, Yoshio TodoAbstract:The coCarbonization of a Fluidized Catalytic Cracking decant oil (FCCDO) with a petroleum low sulfur vacuum residue (LSVR) was studied at a temperature range of 460 to 480°C by evaluating the qualities of coke lumps produced in a tube bomb in terms of their CTE and anisotropic development. The coCarbonization certainly improved the orientation of flow texture and CTE of the resultant coke, providing the smallest CTE as low as 0.10 × 10−6/°C and 0.36 × 10−6/°C at particular FCCDO/LSVR mixing ratios of 55 and 73 according to the respective Carbonization temperatures of 460 and 480°C. The natures of bulk mesophase and gas evolution at the solidification stage for the axial-rearrangement of mesophase aromatic component, both of which essentially define the coke quality, are strongly influenced by the Carbonization reactivities of blended feedstocks and Carbonization conditions. FCCDO may moderate the Carbonization progress of reactive LSVR and LSVR supply the sufficient gas evolution during the solidification, leading to excellent flow texture of axial arrangement. The formation of mosaic coke in the bottom part of the lump which may deteriolate the quality of the coke produced in a commercial coker appeared to be caused by the phase separation between the paraffin and asphaltene fractions. Such a separation at a early stage of the Carbonization was found to be controlled by the blending and the Carbonization conditions.
-
Co-Carbonization of ethylene tar pitch and coal tar pitch to form needle coke
Fuel, 1990Co-Authors: Isao Mochida, Yozo Korai, Taiji OishiAbstract:Abstract The co-Carbonization of ethylene tar pitch (ETP) and coal tar pitch (CTP) was studied in a tube bomb. A small amount of CTP was found to effectively modify the Carbonization properties of ETP to produce excellent needle coke of low nitrogen content without formation of mosaic coke at the reactor bottom (bottom mosaic coke) in a wide range of Carbonization temperatures and pressures. Blending 30–50 wt% CTP into ETP provided lump coke of thin lamellar flow texture, with a good CTE value and nitrogen content after calcination at 1000 °C. The influences of Carbonization temperature and pressure on the nitrogen remaining in the coke were also investigated.