It is important to remove the impurities, such as copper and cadmium, from leaching solution in zinc hydrometallurgy. To improve purification efficiency, a replacement-column purification device was proposed and its m...It is important to remove the impurities, such as copper and cadmium, from leaching solution in zinc hydrometallurgy. To improve purification efficiency, a replacement-column purification device was proposed and its mass transfer characteristics and purification efficiency were experimentally studied. The results show that purification efficiency increases with the decrease of the zinc powder diameter and decreases with the increase of solution velocity. If appropriate structure and operation parameters are used, it is possible to make purification efficiency more than 99%, but the diameter of zinc powder should be larger than 0.45 mm. For the velocity of 0.05-0.7 cm/s, mass transfer coefficient kc is in the range of 3.94×10-7-2.76×10-6 m/s, and increases with the decrease of zinc powder diameter and the increase of solution velocity. Moreover, it can be derived by mass transfer correlations of Sherwood number:Sh=0.1069Re0.5Sc0.33, for 0.3<Re<6.展开更多
The metabolism of copper and arsenic in a copper pyrometallurgy process was studied through substance flow analysis method.The mass balance accounts and substance flow charts of copper and arsenic were established,ind...The metabolism of copper and arsenic in a copper pyrometallurgy process was studied through substance flow analysis method.The mass balance accounts and substance flow charts of copper and arsenic were established,indicators including direct recovery,waste recycle ratio,and resource efficiency were used to evaluate the metabolism efficiency of the system.The results showed that,the resource efficiency of copper was 97.58%,the direct recovery of copper in smelting,converting,and refining processes was 91.96%,97.13%and 99.47%,respectively.Meanwhile,for producing 1 t of copper,10 kg of arsenic was carried into the system,with the generation of 1.07 kg of arsenic in flotation tailing,8.50 kg of arsenic in arsenic waste residue,and 0.05 kg of arsenic in waste water.The distribution and transformation behaviors of arsenic in the smelting,converting,and refining processes were also analyzed,and some recommendations for improving copper resource efficiency and pollution control were proposed based on substance flow analysis.展开更多
The concentrates with different maceral contents were obtained from Kailuan coking coals with different coal ranks(Ro;ranvarying from 0.88%to 1.73%)by float–sink separation in lab.Then these concentrates were charact...The concentrates with different maceral contents were obtained from Kailuan coking coals with different coal ranks(Ro;ranvarying from 0.88%to 1.73%)by float–sink separation in lab.Then these concentrates were characterized by proximate analysis,ultimate analysis,petrography analysis and coking index determination.The results show that the vitrinite is characterized as nature of lower carbon content,higher hydrogen content,higher volatile matter and stronger caking property compared to inertinite.The relationships between variation rate of volatile matter and maximum volatile matter and coal ranks are identified,and a linear model is developed for fast determination of the maceral contents.Compared to inertinite-rich concentrate,the blending ratio of vitrinite-rich concentrate is increased by 13%,which is considered to be a potential technique based on maceral separation for expanding the coking coal resources.展开更多
Deoxygenative upgrading of 5-hydromethylfurfural(HMF)into valuable chemicals has attracted intensive research interest in recent years,with product selectivity control remaining an important topic.Herein,TiO_(2) suppo...Deoxygenative upgrading of 5-hydromethylfurfural(HMF)into valuable chemicals has attracted intensive research interest in recent years,with product selectivity control remaining an important topic.Herein,TiO_(2) supported gold catalysts coated with a thin N-doped porous carbon(NPC)layer were developed via a polydopamine-coating-carbonization strategy and utilized for pathway-specific conversion of HMF into 5-methylfurfural(5-MF)with the use of renewable formic acid(FA)as the deoxygenation reagent.The as-fabricated Au/TiO_(2)@NPC exhibited excellent catalytic performance with a high yield of 5-MF(>95%).The catalytic behavior of Au@NPC-based catalysts was shown to be correlated with the suitable combination of highly dispersed Au nanoparticles and favorable interfacial interactions in the Au@NPC core-shell hetero-nanoarchitectures,thereby facilitating the preferential esterification of HMF with FA and suppressing unproductive FA dehydrogenation,which promoted the selective formylation/decarboxylation of hydroxy-methyl group in HMF in a pathway-specific manner.The present NPC/metal interfacial engineering strategy may provide a potential guide for the rational design of advanced catalysts for a wide variety of heterogeneous catalysis processes in terms of the conversion of biomass source.展开更多
The organic phase separated from the interfacial crud provided by Dexing copper mine in Jiangxi, China, was analyzed by combined gas chromatography-mass spectroscopy. The results show that many kinds of emphiphiles co...The organic phase separated from the interfacial crud provided by Dexing copper mine in Jiangxi, China, was analyzed by combined gas chromatography-mass spectroscopy. The results show that many kinds of emphiphiles containing such hydrophilic groups as carbonyl, carboxyl, sulphonyl or acylamine exist in organic phase. Conclusively, Lix984N would degrade gradually during a long-term contact with the acidic aqueous feed and strip reagents. Lix84 and nonylphenol as effective components of Lix984N degraded almost completely after long-term recycling. Lix984N degraded through such reactions as Beck.mann rearrange, hydrolysis and sulphofication. The degradation of Lix984N would deteriorate solvent extraction and disengagement performance, and result in a more stable interracial emulsion.展开更多
If assortment priee parity of Clase coking coal and its qtalty price danrcnee is nonreasonable, it deren't gulde in Anprotrig tbe quallry metaliurgical coking coal and may be influence theeconomic benefit of me...If assortment priee parity of Clase coking coal and its qtalty price danrcnee is nonreasonable, it deren't gulde in Anprotrig tbe quallry metaliurgical coking coal and may be influence theeconomic benefit of metallurgical enterprises. This paper propose the principles and mathematicmodel for determination aseortment party of clean cokingcoal and its quality difference of ash content in clean coking coal in order to urge wasbenes into producing superior clean coking cleal whichis under condition of consideration both interest waskeries and interest metallurgicai industry. It canbe used as a method in theory to make price strategies under condition of socialism maket economicfor washeries of clean coking coal展开更多
Schools and parents should pay attention to health education for students' health awareness and good health habits, to establish a correct concept of health. School mental health education should be the first place; ...Schools and parents should pay attention to health education for students' health awareness and good health habits, to establish a correct concept of health. School mental health education should be the first place; school should create a positive learning environment for students to get knowledge and skills of exercising. Especially in the nine years of compulsory education stage, we should ensure necessary physical exercise, reasonable arrangements for extracurricular activities to improve students' physical fitness. We should improve the school' s sports facilities, and create a good campus atmosphere. Schools should actively carry out extra-curricular sports activities, improve the level of quality of physical education teachers, develop students' sports consciousness, and improve material conditions for the students to create a good learning environment, meanwhile, we should increase the content of education, and enrich the content of physical education to enable students to select and reach more sports.展开更多
In coking process, the production quality, equipment life, energy consumption, and process safety are all influenced by the pressure in gas collector pipe of coke oven, which is frequently influenced by disturbances.T...In coking process, the production quality, equipment life, energy consumption, and process safety are all influenced by the pressure in gas collector pipe of coke oven, which is frequently influenced by disturbances.The main control objectives for the gas collector pressure system are keeping the pressures in collector pipes at appropriate operating point. In this paper, model predictive control(MPC) strategy is introduced to control the collector pressure system due to its ability to handle constraint and good control performance. Based on a method proposed to simplify the system model, an extended state space model predictive control is designed,which combines the feedforward strategy to eliminate the disturbance. The simulation results in a system with two coke ovens show the feasibility and effectiveness of the control scheme.展开更多
The equilibrium distribution coefficients of 12 impurities (As,Fe,Ca,Co,Al,Cr,Cu,Mg,Mn,Ni,Pb,Zn) in phosphorus were obtained by measuring their effective distribution coefficients at zone travel rate of 3,5,10,15,an...The equilibrium distribution coefficients of 12 impurities (As,Fe,Ca,Co,Al,Cr,Cu,Mg,Mn,Ni,Pb,Zn) in phosphorus were obtained by measuring their effective distribution coefficients at zone travel rate of 3,5,10,15,and 20 mm·h-1 in the purification process with vertical zone-melting technique.The results indicate that the method is reliable.The equilibrium distribution coefficients are below 0.3 except arsenic.展开更多
This research was performed in order to allow the study of the chemical composition influence of the coking process load on the efficiency and the quality of coke. For this reason, the coking of the following loads wa...This research was performed in order to allow the study of the chemical composition influence of the coking process load on the efficiency and the quality of coke. For this reason, the coking of the following loads was realized: Atmospheric residue (RAT), vacuum Residue (RSV) and catalytic Residue of cracking (RCC). (The residues are obtained from an Algerian crude oil). As the oil residues are rich for their strongly polar composition, such as the asphaltene resins, and complex structures units (SCU), which has a role in the formation of coke, and as the dispersion of these latter improves the quality of coke, a study on the stability of aggregation was carried out by the addition of one stabilizer (oil Extract) in the coking process load, The Compounding (Extracted from/RCC oil) has been drived to the best efficiency of coke. The study consists of the influence this is characterized by the analyses Infra-red (IR) and x-ray diffraction (XRD).展开更多
A coaxial mixer meeting the actual demand of a system with high and variable viscosity is investigated. It has an outer wall-scraping frame and a double inner impeller consisting of a four-pitched-blade turbine and Ru...A coaxial mixer meeting the actual demand of a system with high and variable viscosity is investigated. It has an outer wall-scraping frame and a double inner impeller consisting of a four-pitched-blade turbine and Rushton turbine. The power consumption and flow field characteristics of the coaxial mixer in laminar and transitional flow are simulated numerically, and then the distribution of velocity field, shear rate and mass flow rate are analyzed. The simulation results indicate that the outer frame has little effect on the power consumption of the double inner impeller whether in laminar or transitional flow, whereas the inner combined impeller has a great effect on the power consumption of the outer frame. Compared with the single rotation mode, the power consumption of the outer frame will decrease in co-rotation mode and increase in counter-rotation mode. The velocity, shear rate and mass flow rate are relatively high near the inner impeller in all operating modes, and only under double-shaft agitation will the mixing performance near the free surface be improved.In addition, these distributions in the co-rotation and counter-rotation modes show little difference, but the co-rotation mode is recommended for the advantage of low power consumption.展开更多
It is necessary to reduce hydrogen consumption to meet increasingly strict environmental and product-quality regulations for refinery plants. In this paper, the concentration potential concepts proposed for design of ...It is necessary to reduce hydrogen consumption to meet increasingly strict environmental and product-quality regulations for refinery plants. In this paper, the concentration potential concepts proposed for design of water-using networks are extended to synthesis of hydrogen networks with multiple contaminants. In the design procedure, the precedence of processes is determined by the values of concentration potential of demands.The usage of complementary source pair(s) to reduce utility consumption is investigated. Three case studies are presented to illustrate the effectiveness of the method. It is shown that the design procedure has clear engineering meaning.展开更多
Focusing on human health in the 21st century is the common theme of the international community, with the continuous development of human society, the continuous improvement of quality of life, new health problems con...Focusing on human health in the 21st century is the common theme of the international community, with the continuous development of human society, the continuous improvement of quality of life, new health problems continue to appear, threatening human health, which has aroused great attention from the international community, it has taken the appropriate strategy, intervention effects of the disease on human health caused by the literature review, methods of induction and deduction in the current life of health, the impact of lifestyle on health, sports health effects were discussed with, so that people have a more clear understanding, of the health and quality of life of people.展开更多
This pilot study intended to investigate the application of Mixing Zone Guidelines in northern Sweden. The EC (European Commission)-Mixing Zone Guidelines were applied to seven effluent discharges. The effluents wer...This pilot study intended to investigate the application of Mixing Zone Guidelines in northern Sweden. The EC (European Commission)-Mixing Zone Guidelines were applied to seven effluent discharges. The effluents were from industrial processes used in the Ronnskar smelter, in northern Sweden. Each outlet in the smelter area discharges water into the Bothnian bay of the Baltic Sea. Cadmium (Cd), mercury (Hg), nickel (Ni) and lead (Pb) were the primary substances present in the effluents. A "Tiered Approach" was followed for mixing zone assessments in each of the discharge points. Discharge Test was used at Tier 2 and CORMIX (Cornell Mixing Zone Expert System model), version 7, at Tier 3. At each discharge point, the AA-EQS (annual average-environmental quality standard) for each metal was met within a distance of 500 m from the outfalls. This distance was exceeded to meet the MAC-EQS (maximum allowable concentration-environmental quality standard) criteria at points 1 and 3 for total Hg concentrations. However, for the proper application of Mixing Zone Guidelines, a version of the Discharge Test for coastal waters should be developed and used. The decision at which tier the dissolved metal concentration should be compared with EQS values could depend on the effluent characteristics. For Swedish coastal waters, some consideration should be given to the background concentration of metals.展开更多
The biorefinery concept will be important to the energy industry as it allows a multi-process, multi-product biomass based industry. Continued increases in the prices of fossil fuels, the uncertainty of their availabi...The biorefinery concept will be important to the energy industry as it allows a multi-process, multi-product biomass based industry. Continued increases in the prices of fossil fuels, the uncertainty of their availability and the environmental impacts of their extraction are favouring the implementation of sustainable energy production. This article provides a literature review of algal biomass utilisation, process utilisation, technological and economic factors when applying the biorefinery concept to energy intensive industries (whether retro-fitting or new buildings). This report focuses on opportunities in Finland for innovation, process integration and the development of supply chains whilst using flue gases as a feedstock for the microalgae. Currently, most research is on thermal combustion technologies. Microalgae provide an excellent opportunity to reduce carbon dioxide emissions by mitigation in such industries as pulp and paper. However, a beneficial driver would be feed-in tariffs or green trade certificates but are not necessary for the potential success within the industry. Reducing the overall economic costs with process integration and efficient technologies is beneficial for commercialisation of microalgae biorefineries. Microalgae biorefinery with a high efficiency could help improve the cost effectiveness of microalgae derived biofuels. The remaining algae after harvesting could be used for biogas production, which could be upgraded for vehicle fuel or the production of heat and power. An economically viable microalgae biorefinery with appropriate technologies and integrated for optimum efficiency is therefore possible.展开更多
In this paper, multi-refinery using the same heavy crude oils as raw materials is studied, while a new nonlinear model for mixed heavy crude distillation is proposed. In practical crude distillation operation, the dis...In this paper, multi-refinery using the same heavy crude oils as raw materials is studied, while a new nonlinear model for mixed heavy crude distillation is proposed. In practical crude distillation operation, the distillate yield and product distribution of distillation units are different due to their various equipment and operating parameters, even the same ratio of raw materials is provided, so different process models for multi-refinery planning is therefore required. For process modeling, the relationships between total yields and mixing ratio of different refineries were determined, which is combined with process simulation using production data. Then,the yields and properties of crude distillation unit(CDU) fractions were calculated with the use of true boiling point(TBP) curves and property curves respectively when the initial cutting temperatures were given. Finally,in order to maximize the economic benefit of distillation, the optimal product distribution and the best mixing ratio of crude oil were calculated under the constraints of different properties of fractions. Comparing to previous models, the proposed model takes the influence of different refinery parameters on production process into account, while avoiding the complex process for determining the cutting points, which is considered more efficient and more accurate with respect to heavy crude refinery. Model was successfully verified by a case study,allowing a significant improvement of the refinery profit to be achieved.展开更多
TOR (Tema oil refinery) is the only petroleum refinery in Ghana. To assess the quality of the wastewater, wastewater samples taken from three points of discharge into the treatment plant and the treated effluent wer...TOR (Tema oil refinery) is the only petroleum refinery in Ghana. To assess the quality of the wastewater, wastewater samples taken from three points of discharge into the treatment plant and the treated effluent were analyzed for physico-chemical characteristics. The levels of the pH, temperature, conductivity, COD (Chemical Oxygen Demand), TDS (Total Dissolved Solids), TSS (Total Suspended Solids) and phenol were assessed from January to June, 2011. The results obtained indicate varied levels of contaminants in both the untreated and treated wastewater. The average values of the treated effluent parameters analyzed were 38 ℃, 6,258 μs.cm-1, 314 mg-L-1, 115 mg.L-1, 2,689 mg-L-1 and 1 mg.L-1 for the temperature, conductivity, COD, TDS, TSS and phenol, respectively. The results suggest that both the raw wastewater and the treated effluent did not meet the discharge limit set by Ghana Environmental Protection Agency. Therefore, the treated effluent required additional treatment before it can be discharged into the environment. This suggests that the wastewater treatment plant of TOR is ineffective for the type of wastewater produced.展开更多
In order to meet the needs of social development of the situation and the quality of education, college physical education must continue to reform, so that students in school can fully grasp the basic knowledge of spo...In order to meet the needs of social development of the situation and the quality of education, college physical education must continue to reform, so that students in school can fully grasp the basic knowledge of sports, improve exercise motivation, and cultivate good habits of lifelong physical exercise to lay a solid foundation. With greater development of university sports, teaching lifetime sports has had a major breakthrough.展开更多
基金Project(Y2010-1-005)supported by the Collaborative Fund of Hunan Nonferrous Metals Holding Group-Central South University,China
文摘It is important to remove the impurities, such as copper and cadmium, from leaching solution in zinc hydrometallurgy. To improve purification efficiency, a replacement-column purification device was proposed and its mass transfer characteristics and purification efficiency were experimentally studied. The results show that purification efficiency increases with the decrease of the zinc powder diameter and decreases with the increase of solution velocity. If appropriate structure and operation parameters are used, it is possible to make purification efficiency more than 99%, but the diameter of zinc powder should be larger than 0.45 mm. For the velocity of 0.05-0.7 cm/s, mass transfer coefficient kc is in the range of 3.94×10-7-2.76×10-6 m/s, and increases with the decrease of zinc powder diameter and the increase of solution velocity. Moreover, it can be derived by mass transfer correlations of Sherwood number:Sh=0.1069Re0.5Sc0.33, for 0.3<Re<6.
基金financial supports from the National Key R&D Program of China(No.2019YFC1907400)the National Natural Science Foundation of China(Nos.51904351,51620105013)。
文摘The metabolism of copper and arsenic in a copper pyrometallurgy process was studied through substance flow analysis method.The mass balance accounts and substance flow charts of copper and arsenic were established,indicators including direct recovery,waste recycle ratio,and resource efficiency were used to evaluate the metabolism efficiency of the system.The results showed that,the resource efficiency of copper was 97.58%,the direct recovery of copper in smelting,converting,and refining processes was 91.96%,97.13%and 99.47%,respectively.Meanwhile,for producing 1 t of copper,10 kg of arsenic was carried into the system,with the generation of 1.07 kg of arsenic in flotation tailing,8.50 kg of arsenic in arsenic waste residue,and 0.05 kg of arsenic in waste water.The distribution and transformation behaviors of arsenic in the smelting,converting,and refining processes were also analyzed,and some recommendations for improving copper resource efficiency and pollution control were proposed based on substance flow analysis.
基金financially supported by the Fundamental Research Funds for the Central Universities of China (No.2010YH11)
文摘The concentrates with different maceral contents were obtained from Kailuan coking coals with different coal ranks(Ro;ranvarying from 0.88%to 1.73%)by float–sink separation in lab.Then these concentrates were characterized by proximate analysis,ultimate analysis,petrography analysis and coking index determination.The results show that the vitrinite is characterized as nature of lower carbon content,higher hydrogen content,higher volatile matter and stronger caking property compared to inertinite.The relationships between variation rate of volatile matter and maximum volatile matter and coal ranks are identified,and a linear model is developed for fast determination of the maceral contents.Compared to inertinite-rich concentrate,the blending ratio of vitrinite-rich concentrate is increased by 13%,which is considered to be a potential technique based on maceral separation for expanding the coking coal resources.
文摘Deoxygenative upgrading of 5-hydromethylfurfural(HMF)into valuable chemicals has attracted intensive research interest in recent years,with product selectivity control remaining an important topic.Herein,TiO_(2) supported gold catalysts coated with a thin N-doped porous carbon(NPC)layer were developed via a polydopamine-coating-carbonization strategy and utilized for pathway-specific conversion of HMF into 5-methylfurfural(5-MF)with the use of renewable formic acid(FA)as the deoxygenation reagent.The as-fabricated Au/TiO_(2)@NPC exhibited excellent catalytic performance with a high yield of 5-MF(>95%).The catalytic behavior of Au@NPC-based catalysts was shown to be correlated with the suitable combination of highly dispersed Au nanoparticles and favorable interfacial interactions in the Au@NPC core-shell hetero-nanoarchitectures,thereby facilitating the preferential esterification of HMF with FA and suppressing unproductive FA dehydrogenation,which promoted the selective formylation/decarboxylation of hydroxy-methyl group in HMF in a pathway-specific manner.The present NPC/metal interfacial engineering strategy may provide a potential guide for the rational design of advanced catalysts for a wide variety of heterogeneous catalysis processes in terms of the conversion of biomass source.
基金Project (P1502) supported by Shanghai Leading Academic Discipline
文摘The organic phase separated from the interfacial crud provided by Dexing copper mine in Jiangxi, China, was analyzed by combined gas chromatography-mass spectroscopy. The results show that many kinds of emphiphiles containing such hydrophilic groups as carbonyl, carboxyl, sulphonyl or acylamine exist in organic phase. Conclusively, Lix984N would degrade gradually during a long-term contact with the acidic aqueous feed and strip reagents. Lix84 and nonylphenol as effective components of Lix984N degraded almost completely after long-term recycling. Lix984N degraded through such reactions as Beck.mann rearrange, hydrolysis and sulphofication. The degradation of Lix984N would deteriorate solvent extraction and disengagement performance, and result in a more stable interracial emulsion.
文摘If assortment priee parity of Clase coking coal and its qtalty price danrcnee is nonreasonable, it deren't gulde in Anprotrig tbe quallry metaliurgical coking coal and may be influence theeconomic benefit of metallurgical enterprises. This paper propose the principles and mathematicmodel for determination aseortment party of clean cokingcoal and its quality difference of ash content in clean coking coal in order to urge wasbenes into producing superior clean coking cleal whichis under condition of consideration both interest waskeries and interest metallurgicai industry. It canbe used as a method in theory to make price strategies under condition of socialism maket economicfor washeries of clean coking coal
文摘Schools and parents should pay attention to health education for students' health awareness and good health habits, to establish a correct concept of health. School mental health education should be the first place; school should create a positive learning environment for students to get knowledge and skills of exercising. Especially in the nine years of compulsory education stage, we should ensure necessary physical exercise, reasonable arrangements for extracurricular activities to improve students' physical fitness. We should improve the school' s sports facilities, and create a good campus atmosphere. Schools should actively carry out extra-curricular sports activities, improve the level of quality of physical education teachers, develop students' sports consciousness, and improve material conditions for the students to create a good learning environment, meanwhile, we should increase the content of education, and enrich the content of physical education to enable students to select and reach more sports.
基金Supported by the State Key Laboratory of Synthetical Automation for Process Industriesthe National Natural Science Foundation of China(61374110,61333009,61104078,61221003)the Minhang Technology Project of Shanghai(2012MH211)
文摘In coking process, the production quality, equipment life, energy consumption, and process safety are all influenced by the pressure in gas collector pipe of coke oven, which is frequently influenced by disturbances.The main control objectives for the gas collector pressure system are keeping the pressures in collector pipes at appropriate operating point. In this paper, model predictive control(MPC) strategy is introduced to control the collector pressure system due to its ability to handle constraint and good control performance. Based on a method proposed to simplify the system model, an extended state space model predictive control is designed,which combines the feedforward strategy to eliminate the disturbance. The simulation results in a system with two coke ovens show the feasibility and effectiveness of the control scheme.
基金Supported by the Eleventh Five-year National Key Technology Research and Development Program of China (2007BAE58B01)
文摘The equilibrium distribution coefficients of 12 impurities (As,Fe,Ca,Co,Al,Cr,Cu,Mg,Mn,Ni,Pb,Zn) in phosphorus were obtained by measuring their effective distribution coefficients at zone travel rate of 3,5,10,15,and 20 mm·h-1 in the purification process with vertical zone-melting technique.The results indicate that the method is reliable.The equilibrium distribution coefficients are below 0.3 except arsenic.
文摘This research was performed in order to allow the study of the chemical composition influence of the coking process load on the efficiency and the quality of coke. For this reason, the coking of the following loads was realized: Atmospheric residue (RAT), vacuum Residue (RSV) and catalytic Residue of cracking (RCC). (The residues are obtained from an Algerian crude oil). As the oil residues are rich for their strongly polar composition, such as the asphaltene resins, and complex structures units (SCU), which has a role in the formation of coke, and as the dispersion of these latter improves the quality of coke, a study on the stability of aggregation was carried out by the addition of one stabilizer (oil Extract) in the coking process load, The Compounding (Extracted from/RCC oil) has been drived to the best efficiency of coke. The study consists of the influence this is characterized by the analyses Infra-red (IR) and x-ray diffraction (XRD).
基金Supported by the Fundamental Research Funds for the Central Universities(2012QNA4018)the National Natural Science foundation of China(21206144)the Program for Zhejiang Leading Team of S&T Innovation(2011R50005)
文摘A coaxial mixer meeting the actual demand of a system with high and variable viscosity is investigated. It has an outer wall-scraping frame and a double inner impeller consisting of a four-pitched-blade turbine and Rushton turbine. The power consumption and flow field characteristics of the coaxial mixer in laminar and transitional flow are simulated numerically, and then the distribution of velocity field, shear rate and mass flow rate are analyzed. The simulation results indicate that the outer frame has little effect on the power consumption of the double inner impeller whether in laminar or transitional flow, whereas the inner combined impeller has a great effect on the power consumption of the outer frame. Compared with the single rotation mode, the power consumption of the outer frame will decrease in co-rotation mode and increase in counter-rotation mode. The velocity, shear rate and mass flow rate are relatively high near the inner impeller in all operating modes, and only under double-shaft agitation will the mixing performance near the free surface be improved.In addition, these distributions in the co-rotation and counter-rotation modes show little difference, but the co-rotation mode is recommended for the advantage of low power consumption.
基金Supported by the National Natural Science Foundation of China(21176057)the National Basic Research Program of China(2012CB720305)the State Key Laboratory of Chemical Engineering(Open Research Project Skloche-K-2011-04)
文摘It is necessary to reduce hydrogen consumption to meet increasingly strict environmental and product-quality regulations for refinery plants. In this paper, the concentration potential concepts proposed for design of water-using networks are extended to synthesis of hydrogen networks with multiple contaminants. In the design procedure, the precedence of processes is determined by the values of concentration potential of demands.The usage of complementary source pair(s) to reduce utility consumption is investigated. Three case studies are presented to illustrate the effectiveness of the method. It is shown that the design procedure has clear engineering meaning.
文摘Focusing on human health in the 21st century is the common theme of the international community, with the continuous development of human society, the continuous improvement of quality of life, new health problems continue to appear, threatening human health, which has aroused great attention from the international community, it has taken the appropriate strategy, intervention effects of the disease on human health caused by the literature review, methods of induction and deduction in the current life of health, the impact of lifestyle on health, sports health effects were discussed with, so that people have a more clear understanding, of the health and quality of life of people.
文摘This pilot study intended to investigate the application of Mixing Zone Guidelines in northern Sweden. The EC (European Commission)-Mixing Zone Guidelines were applied to seven effluent discharges. The effluents were from industrial processes used in the Ronnskar smelter, in northern Sweden. Each outlet in the smelter area discharges water into the Bothnian bay of the Baltic Sea. Cadmium (Cd), mercury (Hg), nickel (Ni) and lead (Pb) were the primary substances present in the effluents. A "Tiered Approach" was followed for mixing zone assessments in each of the discharge points. Discharge Test was used at Tier 2 and CORMIX (Cornell Mixing Zone Expert System model), version 7, at Tier 3. At each discharge point, the AA-EQS (annual average-environmental quality standard) for each metal was met within a distance of 500 m from the outfalls. This distance was exceeded to meet the MAC-EQS (maximum allowable concentration-environmental quality standard) criteria at points 1 and 3 for total Hg concentrations. However, for the proper application of Mixing Zone Guidelines, a version of the Discharge Test for coastal waters should be developed and used. The decision at which tier the dissolved metal concentration should be compared with EQS values could depend on the effluent characteristics. For Swedish coastal waters, some consideration should be given to the background concentration of metals.
文摘The biorefinery concept will be important to the energy industry as it allows a multi-process, multi-product biomass based industry. Continued increases in the prices of fossil fuels, the uncertainty of their availability and the environmental impacts of their extraction are favouring the implementation of sustainable energy production. This article provides a literature review of algal biomass utilisation, process utilisation, technological and economic factors when applying the biorefinery concept to energy intensive industries (whether retro-fitting or new buildings). This report focuses on opportunities in Finland for innovation, process integration and the development of supply chains whilst using flue gases as a feedstock for the microalgae. Currently, most research is on thermal combustion technologies. Microalgae provide an excellent opportunity to reduce carbon dioxide emissions by mitigation in such industries as pulp and paper. However, a beneficial driver would be feed-in tariffs or green trade certificates but are not necessary for the potential success within the industry. Reducing the overall economic costs with process integration and efficient technologies is beneficial for commercialisation of microalgae biorefineries. Microalgae biorefinery with a high efficiency could help improve the cost effectiveness of microalgae derived biofuels. The remaining algae after harvesting could be used for biogas production, which could be upgraded for vehicle fuel or the production of heat and power. An economically viable microalgae biorefinery with appropriate technologies and integrated for optimum efficiency is therefore possible.
文摘In this paper, multi-refinery using the same heavy crude oils as raw materials is studied, while a new nonlinear model for mixed heavy crude distillation is proposed. In practical crude distillation operation, the distillate yield and product distribution of distillation units are different due to their various equipment and operating parameters, even the same ratio of raw materials is provided, so different process models for multi-refinery planning is therefore required. For process modeling, the relationships between total yields and mixing ratio of different refineries were determined, which is combined with process simulation using production data. Then,the yields and properties of crude distillation unit(CDU) fractions were calculated with the use of true boiling point(TBP) curves and property curves respectively when the initial cutting temperatures were given. Finally,in order to maximize the economic benefit of distillation, the optimal product distribution and the best mixing ratio of crude oil were calculated under the constraints of different properties of fractions. Comparing to previous models, the proposed model takes the influence of different refinery parameters on production process into account, while avoiding the complex process for determining the cutting points, which is considered more efficient and more accurate with respect to heavy crude refinery. Model was successfully verified by a case study,allowing a significant improvement of the refinery profit to be achieved.
文摘TOR (Tema oil refinery) is the only petroleum refinery in Ghana. To assess the quality of the wastewater, wastewater samples taken from three points of discharge into the treatment plant and the treated effluent were analyzed for physico-chemical characteristics. The levels of the pH, temperature, conductivity, COD (Chemical Oxygen Demand), TDS (Total Dissolved Solids), TSS (Total Suspended Solids) and phenol were assessed from January to June, 2011. The results obtained indicate varied levels of contaminants in both the untreated and treated wastewater. The average values of the treated effluent parameters analyzed were 38 ℃, 6,258 μs.cm-1, 314 mg-L-1, 115 mg.L-1, 2,689 mg-L-1 and 1 mg.L-1 for the temperature, conductivity, COD, TDS, TSS and phenol, respectively. The results suggest that both the raw wastewater and the treated effluent did not meet the discharge limit set by Ghana Environmental Protection Agency. Therefore, the treated effluent required additional treatment before it can be discharged into the environment. This suggests that the wastewater treatment plant of TOR is ineffective for the type of wastewater produced.
文摘In order to meet the needs of social development of the situation and the quality of education, college physical education must continue to reform, so that students in school can fully grasp the basic knowledge of sports, improve exercise motivation, and cultivate good habits of lifelong physical exercise to lay a solid foundation. With greater development of university sports, teaching lifetime sports has had a major breakthrough.