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Isao Komasawa - One of the best experts on this subject based on the ideXlab platform.
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visible Light induced deep desulfurization process for Light Oils by photochemical electron transfer oxidation in an organic two phase extraction system
Industrial & Engineering Chemistry Research, 1999Co-Authors: Yasuhiro Shiraishi, Takayuki Hirai, Yasuto Taki, Isao KomasawaAbstract:A novel deep desulfurization process for Light Oils, based on visible Light-induced electron-transfer oxidation using 9,10-dicyanoanthracene (DCA) in an organic two-phase liquid−liquid extraction system, has been investigated. Sulfur-containing compounds, when dissolved in acetonitrile, are successfully oxidized by photoirradiation at wavelengths of λ > 400 nm in the presence of DCA, to form highly polarized compounds, which do not distribute into the nonpolar Light Oil. When Light Oil and acetonitrile are mixed and are photoirradiated with DCA, the sulfur-containing compounds are extracted successively and are photooxidized in the acetonitrile phase. In this way, a deep desulfurization is achieved: the sulfur content in Light Oil being reduced from 0.18 wt % to less than 0.005 wt %. The DCA and the aromatic hydrocarbons in the acetonitrile are able to be recovered by the addition of water, followed by extraction with n-hexane. The DCA distributed into the Light Oil is strongly adsorbed by silica gel and...
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a deep desulfurization process for Light Oil by photochemical reaction in an organic two phase liquid liquid extraction system
Industrial & Engineering Chemistry Research, 1998Co-Authors: Yasuhiro Shiraishi, Takayuki Hirai And, Isao KomasawaAbstract:A novel deep desulfurization process of Light Oil, effected by a combination of photochemical reaction and organic two-phase liquid−liquid extraction, has been investigated. The process is comprised of two stages. The first consists of the transfer of the sulfur-containing compounds from the Light Oil to an aqueous-soluble polar solvent. This is then followed by the photooxidation and photodecomposition of the sulfur-containing compounds in the solvent by UV irradiation, using a high-pressure mercury lamp. The operations are carried out under conditions of room temperature and atmospheric pressure. Acetonitrile was found to be the most suitable polar solvent for the process. In acetonitrile, dibenzothiophene (DBT) is converted to DBT 5-monoxide and then to DBT 5,5-dioxide, dibenz[c,e][1,2]oxathiin 6-oxide, and aromatic sulfonate or sulfinate anion by the UV irradiation. These products are highly polarized and are therefore not distributed into the nonpolar Light Oil phase. An adverse effect of naphthalene...
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effect of photosensitizer and hydrogen peroxide on desulfurization of Light Oil by photochemical reaction and liquid liquid extraction
Industrial & Engineering Chemistry Research, 1997Co-Authors: Takayuki Hirai, Yasuhiro Shiraishi, Ken Ogawa, Isao KomasawaAbstract:A desulfurization process for dibenzothiophene (DBT) by a combination of photochemical reaction and liquid-liquid extraction has been investigated. The DBT dissolved in tetradecane was photodecomposed by the use of a high-pressure mercury lamp and removed into the water phase at conditions of room temperature and atmospheric pressure. The addition of benzophenone (BZP), a triplet photosensitizer, enhanced the removal of DBT from tetradecane. This reaction, however, hardly proceeded in the presence of naphthalene (NP), probably because of triplet energy transfer from photoexcited DBT or BZP to ground-state NP. The addition of hydrogen peroxide enhanced the desulfurization of commercial Light Oil as well as the removal of DBT from tetradecane, since H{sub 2}O{sub 2} acted as a weak oxidizing agent for photoexcited DBT and interrupted the energy transfer from excited DBT to NP to some extent. In the case using a 30% H{sub 2}O{sub 2} solution, the desulfurization yield of commercial Light Oil was 75% following 24 h of photoirradiation and the sulfur content in the Light Oil was reduced from 0.2 wt % to less than 0.05 wt %.
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desulfurization process for dibenzothiophenes from Light Oil by photochemical reaction and liquid liquid extraction
Industrial & Engineering Chemistry Research, 1996Co-Authors: Takayuki Hirai, Ken Ogawa, Isao KomasawaAbstract:A desulfurization process for dibenzothiophene (DBT) and its derivatives such as 4-methyldibenzothiophene (4-MDBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) by combination of photochemical reaction and liquid−liquid extraction has been investigated. In this, the DBTs dissolved in tetradecane were quantitatively photodecomposed by the use of a high-pressure mercury lamp and were removed to the water phase as SO42- at conditions of room temperature and atmospheric pressure. The order of reactivity for the DBTs was DBT < 4-MDBT < 4,6-DMDBT, thus indicating a different tendency from that reported for the hydrodesulfurization method. The desulfurization yield of commercial Light Oil, however, by the proposed method was only 22% following 30 h irradiation and was caused mainly by the depression of the photoreaction of DBT by the presence of aromatic compounds in the Light Oil.
Yasuhiro Shiraishi - One of the best experts on this subject based on the ideXlab platform.
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visible Light induced deep desulfurization process for Light Oils by photochemical electron transfer oxidation in an organic two phase extraction system
Industrial & Engineering Chemistry Research, 1999Co-Authors: Yasuhiro Shiraishi, Takayuki Hirai, Yasuto Taki, Isao KomasawaAbstract:A novel deep desulfurization process for Light Oils, based on visible Light-induced electron-transfer oxidation using 9,10-dicyanoanthracene (DCA) in an organic two-phase liquid−liquid extraction system, has been investigated. Sulfur-containing compounds, when dissolved in acetonitrile, are successfully oxidized by photoirradiation at wavelengths of λ > 400 nm in the presence of DCA, to form highly polarized compounds, which do not distribute into the nonpolar Light Oil. When Light Oil and acetonitrile are mixed and are photoirradiated with DCA, the sulfur-containing compounds are extracted successively and are photooxidized in the acetonitrile phase. In this way, a deep desulfurization is achieved: the sulfur content in Light Oil being reduced from 0.18 wt % to less than 0.005 wt %. The DCA and the aromatic hydrocarbons in the acetonitrile are able to be recovered by the addition of water, followed by extraction with n-hexane. The DCA distributed into the Light Oil is strongly adsorbed by silica gel and...
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a deep desulfurization process for Light Oil by photochemical reaction in an organic two phase liquid liquid extraction system
Industrial & Engineering Chemistry Research, 1998Co-Authors: Yasuhiro Shiraishi, Takayuki Hirai And, Isao KomasawaAbstract:A novel deep desulfurization process of Light Oil, effected by a combination of photochemical reaction and organic two-phase liquid−liquid extraction, has been investigated. The process is comprised of two stages. The first consists of the transfer of the sulfur-containing compounds from the Light Oil to an aqueous-soluble polar solvent. This is then followed by the photooxidation and photodecomposition of the sulfur-containing compounds in the solvent by UV irradiation, using a high-pressure mercury lamp. The operations are carried out under conditions of room temperature and atmospheric pressure. Acetonitrile was found to be the most suitable polar solvent for the process. In acetonitrile, dibenzothiophene (DBT) is converted to DBT 5-monoxide and then to DBT 5,5-dioxide, dibenz[c,e][1,2]oxathiin 6-oxide, and aromatic sulfonate or sulfinate anion by the UV irradiation. These products are highly polarized and are therefore not distributed into the nonpolar Light Oil phase. An adverse effect of naphthalene...
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effect of photosensitizer and hydrogen peroxide on desulfurization of Light Oil by photochemical reaction and liquid liquid extraction
Industrial & Engineering Chemistry Research, 1997Co-Authors: Takayuki Hirai, Yasuhiro Shiraishi, Ken Ogawa, Isao KomasawaAbstract:A desulfurization process for dibenzothiophene (DBT) by a combination of photochemical reaction and liquid-liquid extraction has been investigated. The DBT dissolved in tetradecane was photodecomposed by the use of a high-pressure mercury lamp and removed into the water phase at conditions of room temperature and atmospheric pressure. The addition of benzophenone (BZP), a triplet photosensitizer, enhanced the removal of DBT from tetradecane. This reaction, however, hardly proceeded in the presence of naphthalene (NP), probably because of triplet energy transfer from photoexcited DBT or BZP to ground-state NP. The addition of hydrogen peroxide enhanced the desulfurization of commercial Light Oil as well as the removal of DBT from tetradecane, since H{sub 2}O{sub 2} acted as a weak oxidizing agent for photoexcited DBT and interrupted the energy transfer from excited DBT to NP to some extent. In the case using a 30% H{sub 2}O{sub 2} solution, the desulfurization yield of commercial Light Oil was 75% following 24 h of photoirradiation and the sulfur content in the Light Oil was reduced from 0.2 wt % to less than 0.05 wt %.
Takayuki Hirai - One of the best experts on this subject based on the ideXlab platform.
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visible Light induced deep desulfurization process for Light Oils by photochemical electron transfer oxidation in an organic two phase extraction system
Industrial & Engineering Chemistry Research, 1999Co-Authors: Yasuhiro Shiraishi, Takayuki Hirai, Yasuto Taki, Isao KomasawaAbstract:A novel deep desulfurization process for Light Oils, based on visible Light-induced electron-transfer oxidation using 9,10-dicyanoanthracene (DCA) in an organic two-phase liquid−liquid extraction system, has been investigated. Sulfur-containing compounds, when dissolved in acetonitrile, are successfully oxidized by photoirradiation at wavelengths of λ > 400 nm in the presence of DCA, to form highly polarized compounds, which do not distribute into the nonpolar Light Oil. When Light Oil and acetonitrile are mixed and are photoirradiated with DCA, the sulfur-containing compounds are extracted successively and are photooxidized in the acetonitrile phase. In this way, a deep desulfurization is achieved: the sulfur content in Light Oil being reduced from 0.18 wt % to less than 0.005 wt %. The DCA and the aromatic hydrocarbons in the acetonitrile are able to be recovered by the addition of water, followed by extraction with n-hexane. The DCA distributed into the Light Oil is strongly adsorbed by silica gel and...
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effect of photosensitizer and hydrogen peroxide on desulfurization of Light Oil by photochemical reaction and liquid liquid extraction
Industrial & Engineering Chemistry Research, 1997Co-Authors: Takayuki Hirai, Yasuhiro Shiraishi, Ken Ogawa, Isao KomasawaAbstract:A desulfurization process for dibenzothiophene (DBT) by a combination of photochemical reaction and liquid-liquid extraction has been investigated. The DBT dissolved in tetradecane was photodecomposed by the use of a high-pressure mercury lamp and removed into the water phase at conditions of room temperature and atmospheric pressure. The addition of benzophenone (BZP), a triplet photosensitizer, enhanced the removal of DBT from tetradecane. This reaction, however, hardly proceeded in the presence of naphthalene (NP), probably because of triplet energy transfer from photoexcited DBT or BZP to ground-state NP. The addition of hydrogen peroxide enhanced the desulfurization of commercial Light Oil as well as the removal of DBT from tetradecane, since H{sub 2}O{sub 2} acted as a weak oxidizing agent for photoexcited DBT and interrupted the energy transfer from excited DBT to NP to some extent. In the case using a 30% H{sub 2}O{sub 2} solution, the desulfurization yield of commercial Light Oil was 75% following 24 h of photoirradiation and the sulfur content in the Light Oil was reduced from 0.2 wt % to less than 0.05 wt %.
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desulfurization process for dibenzothiophenes from Light Oil by photochemical reaction and liquid liquid extraction
Industrial & Engineering Chemistry Research, 1996Co-Authors: Takayuki Hirai, Ken Ogawa, Isao KomasawaAbstract:A desulfurization process for dibenzothiophene (DBT) and its derivatives such as 4-methyldibenzothiophene (4-MDBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) by combination of photochemical reaction and liquid−liquid extraction has been investigated. In this, the DBTs dissolved in tetradecane were quantitatively photodecomposed by the use of a high-pressure mercury lamp and were removed to the water phase as SO42- at conditions of room temperature and atmospheric pressure. The order of reactivity for the DBTs was DBT < 4-MDBT < 4,6-DMDBT, thus indicating a different tendency from that reported for the hydrodesulfurization method. The desulfurization yield of commercial Light Oil, however, by the proposed method was only 22% following 30 h irradiation and was caused mainly by the depression of the photoreaction of DBT by the presence of aromatic compounds in the Light Oil.
Chaohe Zheng - One of the best experts on this subject based on the ideXlab platform.
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moderate or intense low oxygen dilution oxy combustion characteristics of Light Oil and pulverized coal in a pilot scale furnace
Energy & Fuels, 2014Co-Authors: Feifei Wang, Zhenfeng Mei, Jie Zhang, Ying Zheng, Huping Liu, Zhaohui Liu, Chaohe ZhengAbstract:This study investigates by experiment the global characteristics of both moderate or intense low-oxygen dilution (MILD) oxy-combustion and air combustion of firing Light Oil and pulverized coal in a pilot-scale furnace. There are three burner configurations used, i.e., (I) central straight (primary) jet + swirl (secondary) jet, (II) central straight (primary) jet + two side symmetrical (secondary) jets, and (III) central straight (primary) jet + side asymmetrical jet. The furnace centerline temperature, species concentrations, and exhaust emissions are measured and compared for the MILD and conventional combustion cases. For Light Oil and pulverized coal, the MILD air combustion or oxy-combustion occurs with burner II or III, while the conventional combustion takes place when using burner I. For the Light Oil, the MILD oxy-combustion can be reached even using pure oxygen. As the MILD combustion is reached, a fairly uniform temperature distribution and low emissions of NO and CO are obtained. Note that burner III produces the largest internal recirculation of the flue gas, lowest peak temperature, and most uniform temperature, whereas the opposite occurs for burner I. Importantly, the MILD combustion is found to reduce the NO emission much more effectively in the oxy-combustion case than in the air combustion case. Moreover, the appearance of the MILD combustion of Light Oil and pulverized coal differs from the invisible MILD combustion of gaseous fuels. Dark sparks from burning Oil droplets or char particles are present in the MILD combustion of Light Oil or pulverized coal. It is also revealed that the char burnout under the MILD combustion is weaker than that under the conventional combustion.
Zheng C. - One of the best experts on this subject based on the ideXlab platform.
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Moderate or Intense Low-Oxygen Dilution Oxy-combustion Characteristics of Light Oil and Pulverized Coal in a Pilot-Scale Furnace
energy and fuels, 2014Co-Authors: Li P., Mei Z., Mi J., Wang F., Zhang J., Tu Y., Zheng Y., Liu H., Liu Z., Zheng C.Abstract:This study investigates by experiment the global characteristics of both moderate or intense low-oxygen dilution (MILD) oxy-combustion and air combustion of firing Light Oil and pulverized coal in a pilot-scale furnace. There are three burner configurations used, i.e., (I) central straight (primary) jet + swirl (secondary) jet, (II) central straight (primary) jet + two side symmetrical (secondary) jets, and (III) central straight (primary) jet + side asymmetrical jet. The furnace centerline temperature, species concentrations, and exhaust emissions are measured and compared for the MILD and conventional combustion cases. For Light Oil and pulverized coal, the MILD air combustion or oxy-combustion occurs with burner II or III, while the conventional combustion takes place when using burner I. For the Light Oil, the MILD oxy-combustion can be reached even using pure oxygen. As the MILD combustion is reached, a fairly uniform temperature distribution and low emissions of NO and CO are obtained. Note that burner III produces the largest internal recirculation of the flue gas, lowest peak temperature, and most uniform temperature, whereas the opposite occurs for burner I. Importantly, the MILD combustion is found to reduce the NO emission much more effectively in the oxy-combustion case than in the air combustion case. Moreover, the appearance of the MILD combustion of Light Oil and pulverized coal differs from the invisible MILD combustion of gaseous fuels. Dark sparks from burning Oil droplets or char particles are present in the MILD combustion of Light Oil or pulverized coal. It is also revealed that the char burnout under the MILD combustion is weaker than that under the conventional combustion.Energy & FuelsEngineering, ChemicalSCI(E)EI3ARTICLEjcmi@coe.pku.edu.cn21524-15352