Physical modeling,numerical simulation and field case analysis were carried out to find out the subsurface thermal oxidation state,thermal oxidation front characteristics and production dynamic characteristics of high...Physical modeling,numerical simulation and field case analysis were carried out to find out the subsurface thermal oxidation state,thermal oxidation front characteristics and production dynamic characteristics of high pressure air injection thermal oxidation miscible flooding technology.The lighter the composition and the lower the viscosity of the crude oil,the lower the fuel consumption and the combustion temperature are.The thermal oxidation front of light oil and volatile oil can advance stably,and a medium-temperature thermal oxidation stable displacement state can be formed in the light oil reservoir under high pressure conditions.With strong thermal gasification and distillation,light oil and volatile oil are likely to form a single phase zone of gasification and distillation with thermal flue gas at the high-temperature and high-pressure heat front,finally,an air-injection thermal miscible front.In light oil reservoirs,the development process of high-pressure air-injection thermal miscible flooding can be divided into three stages:boosting pressure stage,low gas-oil ratio and high-efficiency stable production stage and high gas-oil ratio production stage.Approximately 70%of crude oil is produced during the boosting pressure stage and low gas-oil ratio high-efficiency and stable production stage.展开更多
The effects of Pd loading, cerium content, the special surface area of the support and calcination temperature on the catalytic properties of Pd-loaded zirconia-ceria mixed oxide were studied.The results show that loa...The effects of Pd loading, cerium content, the special surface area of the support and calcination temperature on the catalytic properties of Pd-loaded zirconia-ceria mixed oxide were studied.The results show that loading Pd and increasing cerium content in the mixed oxides can enhance the catalytic activity.There is a little effect of calcination temperature on catalytic activities, implying that these catalysts are effective with good thermal stability.展开更多
Due to the dispersed distribution of the titanium component in various mineral phases and very fine grain size, it is difficult to recover the titanium component from the slag. In order to utilize titanium resources, ...Due to the dispersed distribution of the titanium component in various mineral phases and very fine grain size, it is difficult to recover the titanium component from the slag. In order to utilize titanium resources, selective enriching and selective growing of the titanium component from the molten slag is expected. In this paper, the selection of the best tita- nium enrichment phase and the effect of oxidization on the enrichment of titanium by blowing air into the molten slag were studied. The results showed that through oxidizing the slag, the content of the perovskite phase increases while that of the other titanium-bearing mineral phases decreases until they disappear. Most titania resources were enriched into the perovskite phase and increase in size. The process of enrichment and growth is easily carried out.展开更多
The non-thermal plasma as one of the most promising technologies for removingNO_x and SO_2 has attracted much attention.In this study,a new plasma reactor combined withcatalyst and additive was developed to effectivel...The non-thermal plasma as one of the most promising technologies for removingNO_x and SO_2 has attracted much attention.In this study,a new plasma reactor combined withcatalyst and additive was developed to effectively oxidize and remove NO_x and SO_2 in the fluegas.The experimental results showed that TiO_2 could improve the oxidation efficiency of SO_2 inthe case of applying plasma while having a negative effect on the oxidation process of NO andNO_x.With the addition of NH_3,the oxidation rates of NO_x,NO and SO_2 were slightly increased.However,the effect of adding NH_3 on NO_x oxidation was negative when the temperature wasabove 200℃.展开更多
Effects of reaction parameter on yield of benzaldehyde produced from toluene oxidization using hydrogen peroxide in subcritical water are investigated. The experimental results show that if the molar ratio of hydrogen...Effects of reaction parameter on yield of benzaldehyde produced from toluene oxidization using hydrogen peroxide in subcritical water are investigated. The experimental results show that if the molar ratio of hydrogen peroxide to toluene is controlled within a reasonable range, the by-products may be neglected. The optimum technology of toluene oxidization to benzaldehyde is reaction time 60 min,reaction temperature 350 °C, molar ratio of hydrogen peroxide to toluene 3.5. The yield of benzaldehyde can reach 17.2% under the optimum condition. Research results of chemical reaction kinetics show that the consecutive reaction consists of two first-order reaction,and activation energy of these two reactions are 89 kJ·mol -1 and 76 kJ·mol -1 respectively.展开更多
For the purpose of obtaining small molecular and oxygen-containing aromatic compounds,taking a toluene-extracted coal pitch as the research object,the oxidation of coal–pitch by ozone(O_3) in formic acid was studied....For the purpose of obtaining small molecular and oxygen-containing aromatic compounds,taking a toluene-extracted coal pitch as the research object,the oxidation of coal–pitch by ozone(O_3) in formic acid was studied.The coal–pitch sample and the oxidized pitch residue were characterized by elementary analysis and Fourier transform infrared spectroscopy(FTIR),while the small molecular products were analyzed by a gas chromatography–mass spectrometer(GC–MS).The results show that the highest oxygen content of oxidized coal pitch had been acquired at a reaction temperature of 50 °C,an O_3 flow rate of6300 mg/h and a reaction time of 4 h.Quite a lot of hydroxyls and carbonyls were introduced into the structure of the oxidized coal–pitch,while the small molecules produced mainly involve nonpolar aromatic compounds,aromatic anhydride and quinone compounds.It is speculated that the mechanism is direct electrophilic oxidation in which the molecules of O_3 directly attack the aromatic ring at its carbon atoms with high electron density,and then generate hydroxyl or carbonyl until the aromatic ring cracks.This study shows that O_3 can make the fused aromatic ring of coal–pitch become oxidized and depolymerized,and hence the ozonization of coal–pitch can be a potential method for obtaining oxygencontaining aromatic compounds.展开更多
The technique of micro-electrolysis-contact oxidization was exploited to treat chitin-producing wastewater.Results showed that Fe-C micro-electrolysis can remove about 30% CODcr, raise pH from 0.7 to 5.5.The CODcr rem...The technique of micro-electrolysis-contact oxidization was exploited to treat chitin-producing wastewater.Results showed that Fe-C micro-electrolysis can remove about 30% CODcr, raise pH from 0.7 to 5.5.The CODcr removal efficiency by biochemical process can be more than 80%. During a half year's operation,the whole system worked very stably and had good results, as proved by the fact that every quality indicator of effluent met the expected discharge standards; which means that chitin wastewater can be treated by the technique of micro-electrolysis, contact oxidization.展开更多
Oxidization mechanism in CaO-FeOx-SiO2 slag with high iron content was investigated by blowing oxygen into molten slag so as to oxidize Fe（Ⅱ）. The relationship between Fe（Ⅱ） content and oxidizing time at differe...Oxidization mechanism in CaO-FeOx-SiO2 slag with high iron content was investigated by blowing oxygen into molten slag so as to oxidize Fe（Ⅱ）. The relationship between Fe（Ⅱ） content and oxidizing time at different temperatures was obtained by chemical analysis. Microstructure of slag was observed by metallographic microscope and SEM. Phases compositions were ascertained by EDXS and XRD. Grain size and crystallizing quantity of magnetite（Fe3O4） were determined by image analyzer. The oxidizing kinetic equations were deduced. Confirmed by graphical construction method, Fe（Ⅱ） oxidizing reaction in CaO-FeOx-SiO2 slag system is of first order, and the reaction apparent energy Ea is 296.67kJ/mol in the pure oxygen and 340.30kJ/mol in air. The enrichment and crystal growth mechanism of magnetite（Fe3O4） phases were investigated. In oxidizing process, content of fayalite declines, while that of magnetite（Fe3O4） increases, and iron resources enrich into magnetite（Fe3O4） phase. All these provide a theoretical base for compressive utilizing of those slags.展开更多
In-situ pure TiO 2 and Fe-doped TiO 2 thin films were synthesized on Ti plates via the micro-arc oxidation(MAO) technique.The as-fabricated anatase TiO 2 thin film-based conductometric sensors were employed to measure...In-situ pure TiO 2 and Fe-doped TiO 2 thin films were synthesized on Ti plates via the micro-arc oxidation(MAO) technique.The as-fabricated anatase TiO 2 thin film-based conductometric sensors were employed to measure the gas sensitivity to ethanol.The results showed that Fe ions could be easily introduced into the MAO-TiO 2 thin films by adding precursor K 4(FeCN) 6 ·3H 2 O into the Na 3 PO 4 electrolyte.The amount of doped Fe ions increased almost linearly with the concentration of K 4(FeCN) 6 ·3H 2 O increasing,eventually affecting the ethanol sensing performances of TiO 2 thin films.It was found that the enhanced sensor signals obtained had an optimal concentration of Fe dopant(1.28at%),by which the maximal gas sensor signal to 1000 ppm ethanol was estimated to be 7.91 at 275°C.The response time was generally reduced by doped Fe ions,which could be ascribed to the increase of oxygen vacancies caused by Fe 3+ substituting for Ti 4+.展开更多
The processes of directly recycling high density tungsten alloy by oxidation reduction technique were investigated. The particle size of recycled powder is fine, and the shape of powder particle is regular when the fi...The processes of directly recycling high density tungsten alloy by oxidation reduction technique were investigated. The particle size of recycled powder is fine, and the shape of powder particle is regular when the final reduction temperature is 850?℃, in which the average size of the tungsten alloy particles reduced is about 1.5?μm. The average size of the alloy particles increase to 6?μm and 9?μm when increasing the reduction temperature to 900?℃ and 950?℃, respectively. However, if the reduction temperature is higher than 900?℃, the surface feature of powder is complicated. Increasing reduction temperature from 900?℃ to 950?℃, the content of oxygen of recycled powder decreases from 0.231?4% to 0.170?0%, and powder particles grow slightly. It has been also found that the chemical composition of the recycled alloy powder is the same as the initial powder.展开更多
Three approaches of treating carbon nanotubes (CNTs) including acid treatment, air oxidization and heat treatment at high temperature were studied to enhance the crystalline degree of carbon nanotubes. High temperatur...Three approaches of treating carbon nanotubes (CNTs) including acid treatment, air oxidization and heat treatment at high temperature were studied to enhance the crystalline degree of carbon nanotubes. High temperature heat-treatment elevates the crystalline degree of carbon nanotubes. Acid treatment removes parts of amorphous carbonaceous matter through its oxidization effect.Air oxidization disperses carbon nanotubes and amorphous carbonaceous matter. The treatment of combining acid treatment with heat-treatment further elevates the crystalline degree of carbon nanotubes comparing with acid treatment or heat-treatment. The combination of the three treatments creates the thorough effects of enhancing the crystalline degree of carbon nanotubes.展开更多
The oxidization resistance of the Ni76Cr19AlTi alloy was studied by a static oxidization experiment at 600-800°C. The results show that the oxidation behavior of the alloy can be explained by a kinetic equation: ...The oxidization resistance of the Ni76Cr19AlTi alloy was studied by a static oxidization experiment at 600-800°C. The results show that the oxidation behavior of the alloy can be explained by a kinetic equation: (■m/S)2 = Kpt + C, where Kp is a kinetic constant of the nickel-base alloy. The higher the experimental temperature, the higher the value of Kp. It is discovered that the microstructure of the oxide scales is compact and the thickness of it is less than 10 μm. The oxi-dization of the alloy is in the first grade. It is also found that the oxide scales are mainly composed of Cr2O3 and TiO2. Chrome and titanium react more easily with oxygen at temperatures under the operating mode.展开更多
基金Supported by the Science and Technology Project of PetroChina Exploration and Production Company.
文摘Physical modeling,numerical simulation and field case analysis were carried out to find out the subsurface thermal oxidation state,thermal oxidation front characteristics and production dynamic characteristics of high pressure air injection thermal oxidation miscible flooding technology.The lighter the composition and the lower the viscosity of the crude oil,the lower the fuel consumption and the combustion temperature are.The thermal oxidation front of light oil and volatile oil can advance stably,and a medium-temperature thermal oxidation stable displacement state can be formed in the light oil reservoir under high pressure conditions.With strong thermal gasification and distillation,light oil and volatile oil are likely to form a single phase zone of gasification and distillation with thermal flue gas at the high-temperature and high-pressure heat front,finally,an air-injection thermal miscible front.In light oil reservoirs,the development process of high-pressure air-injection thermal miscible flooding can be divided into three stages:boosting pressure stage,low gas-oil ratio and high-efficiency stable production stage and high gas-oil ratio production stage.Approximately 70%of crude oil is produced during the boosting pressure stage and low gas-oil ratio high-efficiency and stable production stage.
文摘The effects of Pd loading, cerium content, the special surface area of the support and calcination temperature on the catalytic properties of Pd-loaded zirconia-ceria mixed oxide were studied.The results show that loading Pd and increasing cerium content in the mixed oxides can enhance the catalytic activity.There is a little effect of calcination temperature on catalytic activities, implying that these catalysts are effective with good thermal stability.
基金This work was financially supported by the National Natural Science Foundation of China (No.50234040)
文摘Due to the dispersed distribution of the titanium component in various mineral phases and very fine grain size, it is difficult to recover the titanium component from the slag. In order to utilize titanium resources, selective enriching and selective growing of the titanium component from the molten slag is expected. In this paper, the selection of the best tita- nium enrichment phase and the effect of oxidization on the enrichment of titanium by blowing air into the molten slag were studied. The results showed that through oxidizing the slag, the content of the perovskite phase increases while that of the other titanium-bearing mineral phases decreases until they disappear. Most titania resources were enriched into the perovskite phase and increase in size. The process of enrichment and growth is easily carried out.
文摘The non-thermal plasma as one of the most promising technologies for removingNO_x and SO_2 has attracted much attention.In this study,a new plasma reactor combined withcatalyst and additive was developed to effectively oxidize and remove NO_x and SO_2 in the fluegas.The experimental results showed that TiO_2 could improve the oxidation efficiency of SO_2 inthe case of applying plasma while having a negative effect on the oxidation process of NO andNO_x.With the addition of NH_3,the oxidation rates of NO_x,NO and SO_2 were slightly increased.However,the effect of adding NH_3 on NO_x oxidation was negative when the temperature wasabove 200℃.
文摘Effects of reaction parameter on yield of benzaldehyde produced from toluene oxidization using hydrogen peroxide in subcritical water are investigated. The experimental results show that if the molar ratio of hydrogen peroxide to toluene is controlled within a reasonable range, the by-products may be neglected. The optimum technology of toluene oxidization to benzaldehyde is reaction time 60 min,reaction temperature 350 °C, molar ratio of hydrogen peroxide to toluene 3.5. The yield of benzaldehyde can reach 17.2% under the optimum condition. Research results of chemical reaction kinetics show that the consecutive reaction consists of two first-order reaction,and activation energy of these two reactions are 89 kJ·mol -1 and 76 kJ·mol -1 respectively.
基金financially supported by the Key Project of Science and Technology of Universities of Henan Province (No.14A530003)the Key Project of Science and Technology of Henan Province (No.152102310090)
文摘For the purpose of obtaining small molecular and oxygen-containing aromatic compounds,taking a toluene-extracted coal pitch as the research object,the oxidation of coal–pitch by ozone(O_3) in formic acid was studied.The coal–pitch sample and the oxidized pitch residue were characterized by elementary analysis and Fourier transform infrared spectroscopy(FTIR),while the small molecular products were analyzed by a gas chromatography–mass spectrometer(GC–MS).The results show that the highest oxygen content of oxidized coal pitch had been acquired at a reaction temperature of 50 °C,an O_3 flow rate of6300 mg/h and a reaction time of 4 h.Quite a lot of hydroxyls and carbonyls were introduced into the structure of the oxidized coal–pitch,while the small molecules produced mainly involve nonpolar aromatic compounds,aromatic anhydride and quinone compounds.It is speculated that the mechanism is direct electrophilic oxidation in which the molecules of O_3 directly attack the aromatic ring at its carbon atoms with high electron density,and then generate hydroxyl or carbonyl until the aromatic ring cracks.This study shows that O_3 can make the fused aromatic ring of coal–pitch become oxidized and depolymerized,and hence the ozonization of coal–pitch can be a potential method for obtaining oxygencontaining aromatic compounds.
文摘The technique of micro-electrolysis-contact oxidization was exploited to treat chitin-producing wastewater.Results showed that Fe-C micro-electrolysis can remove about 30% CODcr, raise pH from 0.7 to 5.5.The CODcr removal efficiency by biochemical process can be more than 80%. During a half year's operation,the whole system worked very stably and had good results, as proved by the fact that every quality indicator of effluent met the expected discharge standards; which means that chitin wastewater can be treated by the technique of micro-electrolysis, contact oxidization.
基金Key Project(50234040) supported by the National Natural Science Foundation of China
文摘Oxidization mechanism in CaO-FeOx-SiO2 slag with high iron content was investigated by blowing oxygen into molten slag so as to oxidize Fe（Ⅱ）. The relationship between Fe（Ⅱ） content and oxidizing time at different temperatures was obtained by chemical analysis. Microstructure of slag was observed by metallographic microscope and SEM. Phases compositions were ascertained by EDXS and XRD. Grain size and crystallizing quantity of magnetite（Fe3O4） were determined by image analyzer. The oxidizing kinetic equations were deduced. Confirmed by graphical construction method, Fe（Ⅱ） oxidizing reaction in CaO-FeOx-SiO2 slag system is of first order, and the reaction apparent energy Ea is 296.67kJ/mol in the pure oxygen and 340.30kJ/mol in air. The enrichment and crystal growth mechanism of magnetite（Fe3O4） phases were investigated. In oxidizing process, content of fayalite declines, while that of magnetite（Fe3O4） increases, and iron resources enrich into magnetite（Fe3O4） phase. All these provide a theoretical base for compressive utilizing of those slags.
基金supported by the National Basic Research Priorities Program of China (No.2007CB936601)the National Natural Science Foundation of China (Nos.10876017 and 91023037)
文摘In-situ pure TiO 2 and Fe-doped TiO 2 thin films were synthesized on Ti plates via the micro-arc oxidation(MAO) technique.The as-fabricated anatase TiO 2 thin film-based conductometric sensors were employed to measure the gas sensitivity to ethanol.The results showed that Fe ions could be easily introduced into the MAO-TiO 2 thin films by adding precursor K 4(FeCN) 6 ·3H 2 O into the Na 3 PO 4 electrolyte.The amount of doped Fe ions increased almost linearly with the concentration of K 4(FeCN) 6 ·3H 2 O increasing,eventually affecting the ethanol sensing performances of TiO 2 thin films.It was found that the enhanced sensor signals obtained had an optimal concentration of Fe dopant(1.28at%),by which the maximal gas sensor signal to 1000 ppm ethanol was estimated to be 7.91 at 275°C.The response time was generally reduced by doped Fe ions,which could be ascribed to the increase of oxygen vacancies caused by Fe 3+ substituting for Ti 4+.
文摘The processes of directly recycling high density tungsten alloy by oxidation reduction technique were investigated. The particle size of recycled powder is fine, and the shape of powder particle is regular when the final reduction temperature is 850?℃, in which the average size of the tungsten alloy particles reduced is about 1.5?μm. The average size of the alloy particles increase to 6?μm and 9?μm when increasing the reduction temperature to 900?℃ and 950?℃, respectively. However, if the reduction temperature is higher than 900?℃, the surface feature of powder is complicated. Increasing reduction temperature from 900?℃ to 950?℃, the content of oxygen of recycled powder decreases from 0.231?4% to 0.170?0%, and powder particles grow slightly. It has been also found that the chemical composition of the recycled alloy powder is the same as the initial powder.
文摘Three approaches of treating carbon nanotubes (CNTs) including acid treatment, air oxidization and heat treatment at high temperature were studied to enhance the crystalline degree of carbon nanotubes. High temperature heat-treatment elevates the crystalline degree of carbon nanotubes. Acid treatment removes parts of amorphous carbonaceous matter through its oxidization effect.Air oxidization disperses carbon nanotubes and amorphous carbonaceous matter. The treatment of combining acid treatment with heat-treatment further elevates the crystalline degree of carbon nanotubes comparing with acid treatment or heat-treatment. The combination of the three treatments creates the thorough effects of enhancing the crystalline degree of carbon nanotubes.
文摘The oxidization resistance of the Ni76Cr19AlTi alloy was studied by a static oxidization experiment at 600-800°C. The results show that the oxidation behavior of the alloy can be explained by a kinetic equation: (■m/S)2 = Kpt + C, where Kp is a kinetic constant of the nickel-base alloy. The higher the experimental temperature, the higher the value of Kp. It is discovered that the microstructure of the oxide scales is compact and the thickness of it is less than 10 μm. The oxi-dization of the alloy is in the first grade. It is also found that the oxide scales are mainly composed of Cr2O3 and TiO2. Chrome and titanium react more easily with oxygen at temperatures under the operating mode.
