E. Fumoto, Y. Sugimoto, Shinya Sato, T. Takanohashi
Upgrading of heavy oil is an important process in the petroleum industry to produce light oil for transportation fuels. The conventional processes of treating heavy oil, such as petroleum residual oil, include thermal cracking, residue fluidized catalytic cracking (RFCC), and hydrocracking1). Gas, liquid, and coke are produced by the thermal cracking of heavy oil in a coking process. Large amounts of light oil are generated at high temperature with long residence time, but the coke yield increases. The process requires hydrogenation of light oil to stabilize the product through the addition of hydrogen to the double bonds of the components. Hydrocracking is useful for producing stabilized light oil with low coke yield, but the use of hydrogen gas is expensive. The use of water as a hydrogen source has good potential for upgrading heavy oil. Several studies have reported the use of steam and supercritical water2)~7). Supercritical water can dilute the heavy oil, although the process requires high pressure and high temperature2),3). Aquaconversion is a catalytic steam conversion process to upgrade heavy oil into transportable oil, in which hydrogen is transferred from steam to hydrocarbons4). Catalytic cracking of heavy oil was achieved with iron oxide-based catalyst using steam5)~7). Oxidative decomposition of heavy oil occurred over the iron oxide-based catalysts containing zirconia and alumina to produce light oil. After the lattice oxygen of iron oxide reacted with the heavy oil, the oxygen species derived from steam were incorporated into the iron oxide lattice and reacted with the heavy oil. Zirconia promoted the generation of oxygen species from steam, and alumina suppressed the phase change of iron oxide. Generation of oxygen species from steam occurs simultaneously with generation of hydrogen species. One previous study briefly reported that hydrogen species could be incorporated into light oil7). The present study further investigated the transfer of hydrogen species from steam to product using a model compound and petroleum residual oil, and examined the effect of the flow rate ratio of steam to feedstock, as well as the effect of the zirconia content of the catalyst on hydrogen transfer. 329 Journal of the Japan Petroleum Institute, 58, (5), 329-335 (2015)
{"title":"Catalytic Cracking of Heavy Oil with Iron Oxide-based Catalysts Using Hydrogen and Oxygen Species from Steam","authors":"E. Fumoto, Y. Sugimoto, Shinya Sato, T. Takanohashi","doi":"10.1627/jpi.58.329","DOIUrl":"https://doi.org/10.1627/jpi.58.329","url":null,"abstract":"Upgrading of heavy oil is an important process in the petroleum industry to produce light oil for transportation fuels. The conventional processes of treating heavy oil, such as petroleum residual oil, include thermal cracking, residue fluidized catalytic cracking (RFCC), and hydrocracking1). Gas, liquid, and coke are produced by the thermal cracking of heavy oil in a coking process. Large amounts of light oil are generated at high temperature with long residence time, but the coke yield increases. The process requires hydrogenation of light oil to stabilize the product through the addition of hydrogen to the double bonds of the components. Hydrocracking is useful for producing stabilized light oil with low coke yield, but the use of hydrogen gas is expensive. The use of water as a hydrogen source has good potential for upgrading heavy oil. Several studies have reported the use of steam and supercritical water2)~7). Supercritical water can dilute the heavy oil, although the process requires high pressure and high temperature2),3). Aquaconversion is a catalytic steam conversion process to upgrade heavy oil into transportable oil, in which hydrogen is transferred from steam to hydrocarbons4). Catalytic cracking of heavy oil was achieved with iron oxide-based catalyst using steam5)~7). Oxidative decomposition of heavy oil occurred over the iron oxide-based catalysts containing zirconia and alumina to produce light oil. After the lattice oxygen of iron oxide reacted with the heavy oil, the oxygen species derived from steam were incorporated into the iron oxide lattice and reacted with the heavy oil. Zirconia promoted the generation of oxygen species from steam, and alumina suppressed the phase change of iron oxide. Generation of oxygen species from steam occurs simultaneously with generation of hydrogen species. One previous study briefly reported that hydrogen species could be incorporated into light oil7). The present study further investigated the transfer of hydrogen species from steam to product using a model compound and petroleum residual oil, and examined the effect of the flow rate ratio of steam to feedstock, as well as the effect of the zirconia content of the catalyst on hydrogen transfer. 329 Journal of the Japan Petroleum Institute, 58, (5), 329-335 (2015)","PeriodicalId":9596,"journal":{"name":"Bulletin of The Japan Petroleum Institute","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80721069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Petroleum refineries utilize thermal cracking, catalytic cracking and hydrogenation processes to produce high quality oil products. Hydrodesulfurization is one of the most important methods to remove sulfur from petroleum fractions. Heavy oil contains various types of sulfur compound. The structure of the sulfur compounds affects the ease of sulfur removal1). Acyclic sulfur compounds including thiols and disulfides can be easily removed. In contrast, cyclic sulfur compounds containing a thiophene ring have lower reactivity, which decreases with a higher number of aromatic rings. The ease of sulfur removal follows the order: acyclic sulfur compounds>thiophene>benzothiophene> dibenzothiophene (DBT). The cost of sulfur removal in heavy oil upgrading may be reduced by the use of water as an alternative hydrogen source. Several studies have reported desulfurization of heavy oil using water2)~5). Benzothiophene and DBT were decomposed by hydrothermal reaction with alkali2). Upgrading of oil sand bitumen using supercritical water showed similar trends in sulfur content as upgrading in high-pressure nitrogen3), but addition of MoS2 catalysts improved the sulfur removal from Arabian Heavy crude oil in supercritical water4). Hematite nanoparticles were catalytically active to desulfurize thiophene in aquathermolysis5). We previously reported that catalytic cracking of atmospheric residual oil (AR) with iron oxide-based catalysts containing zirconia and alumina produced light oil using the oxygen and hydrogen species derived from steam6),7). The oxygen species were incorporated from steam into the iron oxide lattice, and reacted with heavy hydrocarbons. The oxygen species were transferred from steam to carbon dioxide and a small amount of oxygen-containing compounds6). This reaction produced the hydrogen species from steam. Some of the hydrogen species were added to product hydrocarbons, suppressing alkene generation6). The present study investigated desulfurization of heavy oil with iron oxide-based catalyst using hydrogen and oxygen species derived from steam, and examined desulfurization of AR and reactivity of cyclic sulfur compounds using DBT as a model compound.
{"title":"Desulfurization of Heavy Oil with Iron Oxide-based Catalysts Using Steam","authors":"E. Fumoto, Shinya Sato, T. Takanohashi","doi":"10.1627/jpi.58.336","DOIUrl":"https://doi.org/10.1627/jpi.58.336","url":null,"abstract":"Petroleum refineries utilize thermal cracking, catalytic cracking and hydrogenation processes to produce high quality oil products. Hydrodesulfurization is one of the most important methods to remove sulfur from petroleum fractions. Heavy oil contains various types of sulfur compound. The structure of the sulfur compounds affects the ease of sulfur removal1). Acyclic sulfur compounds including thiols and disulfides can be easily removed. In contrast, cyclic sulfur compounds containing a thiophene ring have lower reactivity, which decreases with a higher number of aromatic rings. The ease of sulfur removal follows the order: acyclic sulfur compounds>thiophene>benzothiophene> dibenzothiophene (DBT). The cost of sulfur removal in heavy oil upgrading may be reduced by the use of water as an alternative hydrogen source. Several studies have reported desulfurization of heavy oil using water2)~5). Benzothiophene and DBT were decomposed by hydrothermal reaction with alkali2). Upgrading of oil sand bitumen using supercritical water showed similar trends in sulfur content as upgrading in high-pressure nitrogen3), but addition of MoS2 catalysts improved the sulfur removal from Arabian Heavy crude oil in supercritical water4). Hematite nanoparticles were catalytically active to desulfurize thiophene in aquathermolysis5). We previously reported that catalytic cracking of atmospheric residual oil (AR) with iron oxide-based catalysts containing zirconia and alumina produced light oil using the oxygen and hydrogen species derived from steam6),7). The oxygen species were incorporated from steam into the iron oxide lattice, and reacted with heavy hydrocarbons. The oxygen species were transferred from steam to carbon dioxide and a small amount of oxygen-containing compounds6). This reaction produced the hydrogen species from steam. Some of the hydrogen species were added to product hydrocarbons, suppressing alkene generation6). The present study investigated desulfurization of heavy oil with iron oxide-based catalyst using hydrogen and oxygen species derived from steam, and examined desulfurization of AR and reactivity of cyclic sulfur compounds using DBT as a model compound.","PeriodicalId":9596,"journal":{"name":"Bulletin of The Japan Petroleum Institute","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82967294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Uchisawa, A. Obuchi, T. Tango, Tatsuro Murakami
Precious metals, primarily Pt and Pd, are indispensable as active components in industrial catalysts intended for practical applications. In particular, they are very commonly utilized in diesel exhaust gas purification catalysts, and hence an increase in the demand for these precious metals is expected as the number of vehicles in use worldwide continues to grow and as emission controls in various countries become increasingly stringent1). A typical diesel after-treatment system is shown in Fig. 1, in which the diesel oxidation catalyst (DOC) is situated on the inlet side of a series of units within the system. The DOC is necessary for the removal of the soluble organic fraction in the particulate matter (PM), as well as the removal of CO and hydrocarbons (HCs) present in the gas phase. Furthermore, to allow the regeneration of a diesel particulate filter (DPF) placed downstream of the DOC by burn-out of the filtered PM, DOCs with high catalytic activity for fuel oxidation are required so as to allow for active heating. This is performed by the catalytic combustion of fuel in the DOC, supplied by retarded combustion in the engine, by post injection into the engine cylinders, or by direct injection into the exhaust pipe. Additionally, the DOC works to oxidize NO to NO2 to promote the regeneration of the DPF through oxidation of the PM and the selective catalytic reduction of NOx using NH3 as a reductant2). In this catalytic system, precious metals are primarily employed in the DOC and DPF, in particular the DOC which may contain large quantities of such metals. Therefore, to reduce the amounts of such metals required in diesel exhaust systems, it is necessary to improve the efficiency with which they function in the DOC. A DOC is composed primarily of a support material such as Al2O3 and an active component such as Pt or Pd, the latter being dispersed as nano-scale particles over the interior pore surfaces of the former. In this study, we focused our attention on the support material. To date, extensive research has been carried out to improve DOC support materials with regard to their compositions and pore structures. In terms of the composition, the addition of secondary components such as Fe3), Mn4), W5), and Si6),7) to Al2O3 has been investigated as a means of improving thermal durability and controlling the acidity/basicity balance. With regard to pore structure, multidimensional-structured Al2O3 materials possessing pores of different size scales, such as micro-meso8),9), meso-macro10),11), and micro-meso9 Journal of the Japan Petroleum Institute, 58, (1), 9-19 (2015)
{"title":"Improvement of Silica–alumina Supports for Diesel Oxidation Catalysts through Control of Both Composition and Pore Structure","authors":"J. Uchisawa, A. Obuchi, T. Tango, Tatsuro Murakami","doi":"10.1627/jpi.58.185","DOIUrl":"https://doi.org/10.1627/jpi.58.185","url":null,"abstract":"Precious metals, primarily Pt and Pd, are indispensable as active components in industrial catalysts intended for practical applications. In particular, they are very commonly utilized in diesel exhaust gas purification catalysts, and hence an increase in the demand for these precious metals is expected as the number of vehicles in use worldwide continues to grow and as emission controls in various countries become increasingly stringent1). A typical diesel after-treatment system is shown in Fig. 1, in which the diesel oxidation catalyst (DOC) is situated on the inlet side of a series of units within the system. The DOC is necessary for the removal of the soluble organic fraction in the particulate matter (PM), as well as the removal of CO and hydrocarbons (HCs) present in the gas phase. Furthermore, to allow the regeneration of a diesel particulate filter (DPF) placed downstream of the DOC by burn-out of the filtered PM, DOCs with high catalytic activity for fuel oxidation are required so as to allow for active heating. This is performed by the catalytic combustion of fuel in the DOC, supplied by retarded combustion in the engine, by post injection into the engine cylinders, or by direct injection into the exhaust pipe. Additionally, the DOC works to oxidize NO to NO2 to promote the regeneration of the DPF through oxidation of the PM and the selective catalytic reduction of NOx using NH3 as a reductant2). In this catalytic system, precious metals are primarily employed in the DOC and DPF, in particular the DOC which may contain large quantities of such metals. Therefore, to reduce the amounts of such metals required in diesel exhaust systems, it is necessary to improve the efficiency with which they function in the DOC. A DOC is composed primarily of a support material such as Al2O3 and an active component such as Pt or Pd, the latter being dispersed as nano-scale particles over the interior pore surfaces of the former. In this study, we focused our attention on the support material. To date, extensive research has been carried out to improve DOC support materials with regard to their compositions and pore structures. In terms of the composition, the addition of secondary components such as Fe3), Mn4), W5), and Si6),7) to Al2O3 has been investigated as a means of improving thermal durability and controlling the acidity/basicity balance. With regard to pore structure, multidimensional-structured Al2O3 materials possessing pores of different size scales, such as micro-meso8),9), meso-macro10),11), and micro-meso9 Journal of the Japan Petroleum Institute, 58, (1), 9-19 (2015)","PeriodicalId":9596,"journal":{"name":"Bulletin of The Japan Petroleum Institute","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75058664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ethanol produced from lignocellulosic biomass (bioethanol) is a promising alternative fuel to gasoline. Production of bioethanol from lignocellulose requires various steps, including pretreatment, enzymatic hydrolysis and fermentation. However, many fermentation inhibitors, including furfural and 5-hydroxymethyl furfural, are generated during the hydrothermal pretreatment of lignocellulose. Recent studies have identified techniques for removing fermentation inhibitors from lignocellulosic hydrolysate. The present study focused on the effect of low-concentration furfural on ethanol production by Saccharomyces cerevisiae . Specifically, gene expression of furfural-inducible genes was analyzed using a S. cerevisiae DNA microarray. The expression of most sulfur amino acid biosynthesis genes increased in response to furfural. To determine whether furfural induces the depletion of sulfur-containing amino acids, the effect of the addition of methionine on yeast growth was investigated. However, exogenous addition of methionine did not compensate for the inhibitory effect. The findings of this study show that furfural affects amino acid synthesis, even at low concentrations, and may be important in the development of high-efficiency processes for large-scale bioethanol production from lignocellulosic biomass.
{"title":"Effect of Low-concentration Furfural on Sulfur Amino Acid Biosynthesis in Saccharomyces cerevisiae","authors":"M. Kanna, Y. Matsumura","doi":"10.1627/jpi.58.165","DOIUrl":"https://doi.org/10.1627/jpi.58.165","url":null,"abstract":"Ethanol produced from lignocellulosic biomass (bioethanol) is a promising alternative fuel to gasoline. Production of bioethanol from lignocellulose requires various steps, including pretreatment, enzymatic hydrolysis and fermentation. However, many fermentation inhibitors, including furfural and 5-hydroxymethyl furfural, are generated during the hydrothermal pretreatment of lignocellulose. Recent studies have identified techniques for removing fermentation inhibitors from lignocellulosic hydrolysate. The present study focused on the effect of low-concentration furfural on ethanol production by Saccharomyces cerevisiae . Specifically, gene expression of furfural-inducible genes was analyzed using a S. cerevisiae DNA microarray. The expression of most sulfur amino acid biosynthesis genes increased in response to furfural. To determine whether furfural induces the depletion of sulfur-containing amino acids, the effect of the addition of methionine on yeast growth was investigated. However, exogenous addition of methionine did not compensate for the inhibitory effect. The findings of this study show that furfural affects amino acid synthesis, even at low concentrations, and may be important in the development of high-efficiency processes for large-scale bioethanol production from lignocellulosic biomass.","PeriodicalId":9596,"journal":{"name":"Bulletin of The Japan Petroleum Institute","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84045097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
They are clean and highly efficient energy sources without emission of global warming CO2 gas. PEFCs are operated at low temperatures in the range of room temperature to 80 °C, and are thereby suitable for electric power sources in small-scale stationary co-generation systems and in electric motor-driven vehicles (so-called the fuel cell vehicles (FCVs)). In Japan, 1 kW-class stationary co-generation systems (called ENE-FARM) have been already commercialized since 2009, and quite recently Japanese motor companies announced that they are planning to commercialize FCVs in FY2014. In PEFCs, platinum is used as catalysts for both the anode and the cathode. Though hydrogen oxidation reaction (HOR) at the anode is facile, oxygen reduction reaction (ORR) at the cathode is a slow reaction. Therefore a large amount of Pt is currently used at the cathode (typically, 0.5 mg cm2). The natural resource of Pt is extremely small (probable reserve: 70,000 tons) and the price of Pt is very expensive (>5000 Yen g1 in Apr. 2014). If we continue to use Pt catalyst at the present level, the scarcity of Pt as well as its high cost will disturb the world-wide spread of FCVs in the near future. Therefore a drastic reduction of Pt usage at the cathode by improving the ORR activity of the Pt catalyst is one of the most important issues in the development of FCVs1). There have been several methods to improve the ORR activity of Pt catalysts, which include Pt_M (M: 3d transition metals such as Co, Ni, Cu, etc.) alloy catalysts2)~5) and core-shell structured catalysts in which Pt monolayer (ML) is formed on non-Pt metal core nanoparticles6)~8). We have so far developed PtML core-shell catalysts using Au and Pd core materials in a research project supported by New Energy and Industrial Technology Development Organization (NEDO), Japan with 11 academic and industrial institutions since FY20089)~13). Here we first review the concept and characteristics of PtML core-shell catalysts. We overview a novel preparation method of PtML coreshell catalysts that is suitable for mass production developed by us, and the results on the activity and durability of the resulting core-shell catalysts. On the basis of these results, the potentials and difficulties of the 55 Journal of the Japan Petroleum Institute, 58, (2), 55-63 (2015)
{"title":"Development of Highly Active and Durable Platinum Core-shell Catalysts for Polymer Electrolyte Fuel Cells","authors":"M. Inaba, H. Daimon","doi":"10.1627/jpi.58.55","DOIUrl":"https://doi.org/10.1627/jpi.58.55","url":null,"abstract":"They are clean and highly efficient energy sources without emission of global warming CO2 gas. PEFCs are operated at low temperatures in the range of room temperature to 80 °C, and are thereby suitable for electric power sources in small-scale stationary co-generation systems and in electric motor-driven vehicles (so-called the fuel cell vehicles (FCVs)). In Japan, 1 kW-class stationary co-generation systems (called ENE-FARM) have been already commercialized since 2009, and quite recently Japanese motor companies announced that they are planning to commercialize FCVs in FY2014. In PEFCs, platinum is used as catalysts for both the anode and the cathode. Though hydrogen oxidation reaction (HOR) at the anode is facile, oxygen reduction reaction (ORR) at the cathode is a slow reaction. Therefore a large amount of Pt is currently used at the cathode (typically, 0.5 mg cm2). The natural resource of Pt is extremely small (probable reserve: 70,000 tons) and the price of Pt is very expensive (>5000 Yen g1 in Apr. 2014). If we continue to use Pt catalyst at the present level, the scarcity of Pt as well as its high cost will disturb the world-wide spread of FCVs in the near future. Therefore a drastic reduction of Pt usage at the cathode by improving the ORR activity of the Pt catalyst is one of the most important issues in the development of FCVs1). There have been several methods to improve the ORR activity of Pt catalysts, which include Pt_M (M: 3d transition metals such as Co, Ni, Cu, etc.) alloy catalysts2)~5) and core-shell structured catalysts in which Pt monolayer (ML) is formed on non-Pt metal core nanoparticles6)~8). We have so far developed PtML core-shell catalysts using Au and Pd core materials in a research project supported by New Energy and Industrial Technology Development Organization (NEDO), Japan with 11 academic and industrial institutions since FY20089)~13). Here we first review the concept and characteristics of PtML core-shell catalysts. We overview a novel preparation method of PtML coreshell catalysts that is suitable for mass production developed by us, and the results on the activity and durability of the resulting core-shell catalysts. On the basis of these results, the potentials and difficulties of the 55 Journal of the Japan Petroleum Institute, 58, (2), 55-63 (2015)","PeriodicalId":9596,"journal":{"name":"Bulletin of The Japan Petroleum Institute","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85695033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The asphaltene components of heavy oil can become serious problems during fractionation, particularly the toluene-soluble and pentane-insoluble fractions. Asphaltenes are composed of mixtures of thousands of different molecules with complicated chemical structures that form three-dimensionally entangled macromolecular structures. In general, a “supra-molecule” refers to a molecular assembly in which each molecule cooperatively interacts with the others through different types of noncovalent bonds. The resulting supramolecule can express several complicated and specific properties. Asphaltene may form such a supramolecular structure, because asphaltene molecules interact cooperatively with each other through interactions related to poly-aromatic rings such as aromaticaromatic and charge-transfer ones. Every asphaltene supra-molecule exhibits distinct, characteristic properties and different reactivities. The chemical reactions of each individual molecule determine the reactivity of the entire assembly. Therefore, an understanding of these molecular and supra-molecular structures is essential for developing strategies to control their reactivity. Although structural analyses have been performed on asphaltenes, the true molecular weight of asphaltenes has not yet been determined. Vapor pressure osmometry (VPO) and size exclusion chromatography (SEC) 61 Journal of the Japan Petroleum Institute, 56, (2), 61-68 (2013)
{"title":"Supra-Molecular Asphaltene Relaxation Technology","authors":"T. Takanohashi, Shinya Sato, R. Tanaka","doi":"10.1627/jpi.56.61","DOIUrl":"https://doi.org/10.1627/jpi.56.61","url":null,"abstract":"The asphaltene components of heavy oil can become serious problems during fractionation, particularly the toluene-soluble and pentane-insoluble fractions. Asphaltenes are composed of mixtures of thousands of different molecules with complicated chemical structures that form three-dimensionally entangled macromolecular structures. In general, a “supra-molecule” refers to a molecular assembly in which each molecule cooperatively interacts with the others through different types of noncovalent bonds. The resulting supramolecule can express several complicated and specific properties. Asphaltene may form such a supramolecular structure, because asphaltene molecules interact cooperatively with each other through interactions related to poly-aromatic rings such as aromaticaromatic and charge-transfer ones. Every asphaltene supra-molecule exhibits distinct, characteristic properties and different reactivities. The chemical reactions of each individual molecule determine the reactivity of the entire assembly. Therefore, an understanding of these molecular and supra-molecular structures is essential for developing strategies to control their reactivity. Although structural analyses have been performed on asphaltenes, the true molecular weight of asphaltenes has not yet been determined. Vapor pressure osmometry (VPO) and size exclusion chromatography (SEC) 61 Journal of the Japan Petroleum Institute, 56, (2), 61-68 (2013)","PeriodicalId":9596,"journal":{"name":"Bulletin of The Japan Petroleum Institute","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90205038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Active Site Distribution of Nitrided CoMo/Al_2O_3 Catalyst during Hydrodesulfurization of Dibenzothiophene : A Non-parametric Study","authors":"M. Nagai, Hiroyuki Tominaga, Shigetaka Kai","doi":"10.1627/jpi.56.80","DOIUrl":"https://doi.org/10.1627/jpi.56.80","url":null,"abstract":"","PeriodicalId":9596,"journal":{"name":"Bulletin of The Japan Petroleum Institute","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77992276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Matsuhashi, H. Taniguchi, Misako Hirai, Keita Yamamoto, Junpei Suzuki
Cobalt is one of the important components in hydrodesulfurization catalysts. The acidity of the support for the active elements is important to increase hydrodesulfurization activity1),2), but few studies have investigated the acid properties of simple cobalt oxides3),4). In contrast, Co ions have been incorporated into many sulfated zirconia and sulfated iron oxides5)~9) to increase catalytic activity as a promoter. The acidity of metal oxides can be increased by the addition of sulfate ion to an oxide surface followed by heat treatment at elevated temperatures10). The acid strength of the metal oxides was greatly increased by such sulfation. A representative example is sulfation of iron oxide, which resulted in a large increase in acidity. Several chemical properties of iron oxide resemble those of cobalt oxide. For example, Co3O4 and Fe3O4 are the more stable s tates of each oxide. Therefore, the acidity of cobalt oxide may be increased by introducing sulfate ions on the oxide surface and heat treatment at a higher temperature. CoO has a promotion effect on sulfated iron oxide9). This study investigated the preparation of sulfated cobalt oxide and the increase in surface acidity. In general, sulfation of zirconia is performed by soaking the metal oxide in dilute sulfuric acid in the equilibrium adsorption method. However, cobalt oxide dissolves in acidic water solution. Therefore, the equilibrium adsorption method cannot be applied to introduce sulfate ions onto the cobalt oxide surface. In this study, sulfate ions were introduced onto the cobalt oxide surface by impregnation of cobalt sulfate6),11). To evaluate the effectiveness of the sulfate salt impregnation method, four types of zirconium oxides were sulfated by the impregnation method. Catalytic activities of the prepared catalysts for pentane isomerization and ethanol dehydration were compared. The order of catalytic activities for several acid-catalyzed reactions and the properties of zirconia gels are known12). The effectiveness of the sulfate salt impregnation method was confirmed by comparing the order of activities in prepared sulfated zirconia samples with reported activities. The ethanol dehydration activity of prepared sulfated cobalt oxide was compared with that of proton-type zeolites and SiO2Al2O3 to estimate its acidity.
{"title":"Effect of Sulfation Using Sulfate Salt Impregnation Method on Acidity of Cobalt Oxide","authors":"H. Matsuhashi, H. Taniguchi, Misako Hirai, Keita Yamamoto, Junpei Suzuki","doi":"10.1627/JPI.56.381","DOIUrl":"https://doi.org/10.1627/JPI.56.381","url":null,"abstract":"Cobalt is one of the important components in hydrodesulfurization catalysts. The acidity of the support for the active elements is important to increase hydrodesulfurization activity1),2), but few studies have investigated the acid properties of simple cobalt oxides3),4). In contrast, Co ions have been incorporated into many sulfated zirconia and sulfated iron oxides5)~9) to increase catalytic activity as a promoter. The acidity of metal oxides can be increased by the addition of sulfate ion to an oxide surface followed by heat treatment at elevated temperatures10). The acid strength of the metal oxides was greatly increased by such sulfation. A representative example is sulfation of iron oxide, which resulted in a large increase in acidity. Several chemical properties of iron oxide resemble those of cobalt oxide. For example, Co3O4 and Fe3O4 are the more stable s tates of each oxide. Therefore, the acidity of cobalt oxide may be increased by introducing sulfate ions on the oxide surface and heat treatment at a higher temperature. CoO has a promotion effect on sulfated iron oxide9). This study investigated the preparation of sulfated cobalt oxide and the increase in surface acidity. In general, sulfation of zirconia is performed by soaking the metal oxide in dilute sulfuric acid in the equilibrium adsorption method. However, cobalt oxide dissolves in acidic water solution. Therefore, the equilibrium adsorption method cannot be applied to introduce sulfate ions onto the cobalt oxide surface. In this study, sulfate ions were introduced onto the cobalt oxide surface by impregnation of cobalt sulfate6),11). To evaluate the effectiveness of the sulfate salt impregnation method, four types of zirconium oxides were sulfated by the impregnation method. Catalytic activities of the prepared catalysts for pentane isomerization and ethanol dehydration were compared. The order of catalytic activities for several acid-catalyzed reactions and the properties of zirconia gels are known12). The effectiveness of the sulfate salt impregnation method was confirmed by comparing the order of activities in prepared sulfated zirconia samples with reported activities. The ethanol dehydration activity of prepared sulfated cobalt oxide was compared with that of proton-type zeolites and SiO2Al2O3 to estimate its acidity.","PeriodicalId":9596,"journal":{"name":"Bulletin of The Japan Petroleum Institute","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83987884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zeolites are crystalline aluminosilicate materials and possess intracrystalline pores and nanospaces of similar sizes to the molecules of the lighter hydrocarbons. Moreover, zeolites have strong acid sites on the nanopore surfaces within and on the external surfaces of the crystalline structure. These properties enable zeolites to be used as in reaction and separation processes, and these potential uses have led to the development of zeolite-based structured materials, such as zeolite films and membranes1)~3). Zeolite membranes combine the properties of zeolites with those of inorganic membranes, so are attractive materials for various applications, such as selective reaction membranes4),5) and separation membranes6)~9). ZSM-5 zeolite membranes were first prepared by Sano et al.10),11), and a great deal of subsequent research has focused on the use of zeolite membranes for reaction and separation. To prepare a zeolite membrane by hydrothermal synthesis, zeolite seed crystals are deposited on a porous support, then secondary growth of the zeolite occurs to form the zeolite membrane. The uniformity of the membrane affects the reaction/separation properties, so the seeding of the zeolite crystals and the secondary growth process must occur uniformly12)~16). Therefore, nano-sized zeolite crystals are expected to have good properties as seed crystals, because the smaller size allows for greater control of the seeding and growth processes. Mono-dispersed zeolite nanocrystals are expected to form uniform zeolite membranes. This review describes a method for preparing nanocrystalline zeolites in a solution consisting of a surfactant, an organic solvent, and water (called the emulsion method17)~21)), and a method based on the catalytic cracking of silane22) (called the CCS method) for the regioselective deactivation of acid sites using silane compounds with various organic substituents. An MFI zeolite (ZSM-5) membrane was applied to the reaction of methanol to olefins23),24), to investigate the effect of the regioselective deactivation of acid sites by the CCS method on the olefin yields. A hydrophilic silicalite-1 membrane25) was prepared using silicalite-1 nanocrystals, to examine the effect of the crystal size on the separation properties26),27).
{"title":"Synthesis of Nano-crystalline Zeolites and Applications to Zeolite Membranes","authors":"T. Tago, Y. Nakasaka, T. Masuda","doi":"10.1627/JPI.55.149","DOIUrl":"https://doi.org/10.1627/JPI.55.149","url":null,"abstract":"Zeolites are crystalline aluminosilicate materials and possess intracrystalline pores and nanospaces of similar sizes to the molecules of the lighter hydrocarbons. Moreover, zeolites have strong acid sites on the nanopore surfaces within and on the external surfaces of the crystalline structure. These properties enable zeolites to be used as in reaction and separation processes, and these potential uses have led to the development of zeolite-based structured materials, such as zeolite films and membranes1)~3). Zeolite membranes combine the properties of zeolites with those of inorganic membranes, so are attractive materials for various applications, such as selective reaction membranes4),5) and separation membranes6)~9). ZSM-5 zeolite membranes were first prepared by Sano et al.10),11), and a great deal of subsequent research has focused on the use of zeolite membranes for reaction and separation. To prepare a zeolite membrane by hydrothermal synthesis, zeolite seed crystals are deposited on a porous support, then secondary growth of the zeolite occurs to form the zeolite membrane. The uniformity of the membrane affects the reaction/separation properties, so the seeding of the zeolite crystals and the secondary growth process must occur uniformly12)~16). Therefore, nano-sized zeolite crystals are expected to have good properties as seed crystals, because the smaller size allows for greater control of the seeding and growth processes. Mono-dispersed zeolite nanocrystals are expected to form uniform zeolite membranes. This review describes a method for preparing nanocrystalline zeolites in a solution consisting of a surfactant, an organic solvent, and water (called the emulsion method17)~21)), and a method based on the catalytic cracking of silane22) (called the CCS method) for the regioselective deactivation of acid sites using silane compounds with various organic substituents. An MFI zeolite (ZSM-5) membrane was applied to the reaction of methanol to olefins23),24), to investigate the effect of the regioselective deactivation of acid sites by the CCS method on the olefin yields. A hydrophilic silicalite-1 membrane25) was prepared using silicalite-1 nanocrystals, to examine the effect of the crystal size on the separation properties26),27).","PeriodicalId":9596,"journal":{"name":"Bulletin of The Japan Petroleum Institute","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76492520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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