Injecting water into the main pipeline is a common method to prevent the ammonium salt corrosion in hydrogenation units.The use of spray nozzle can enhance the effects of washing ammonium salt and reduce the risk of a...Injecting water into the main pipeline is a common method to prevent the ammonium salt corrosion in hydrogenation units.The use of spray nozzle can enhance the effects of washing ammonium salt and reduce the risk of ammonium salt corrosion.The droplet atomization and evaporation model were used to investigate the mixing process of injecting water and gas-oil mixture in a high-pressure environment.The effects of some key parameters including fluid velocity,temperature,and droplet volume fraction on the mixing and vaporization process were analyzed.Numerical simulation results show that with the increase of injecting water flow rate,the fluid velocity increases and the temperature decreases continuously.When the mass flow rate of injecting water is 1.5 t/h,the droplet has the maximum evaporation efficiency and the volume fraction reaches a minimum value.Besides,with the increase of atomization angle and droplet size,the mean velocity and the temperature of fluid decrease continuously.The increase of atomization angle or the decrease of droplet size will accelerate the evaporation process of droplets and reduce the droplet volume fraction,which indicates that the droplet slip velocity and the contact area are the key factors affecting the droplet evaporation rate.展开更多
Objective To evaluate the performance of vaporized hydrogen peroxide （VHP） for the bio-decontamination of the high efficiency particulate air （HEPA） filter unit. Methods Self-made or commercially available bioindi...Objective To evaluate the performance of vaporized hydrogen peroxide （VHP） for the bio-decontamination of the high efficiency particulate air （HEPA） filter unit. Methods Self-made or commercially available bioindicators were placed at designated locations in the HEPA filter unit under VHP fumigation. The spores on coupons were then extracted by 0.5 h submergence in eluent followed by 200- time violent knocks. Results Due to the presence of HEPA filter in the box, spore recovery from coupons placed at the bottom of the filter downstream was significantly higher than that from coupons placed at the other locations. The gap of decontamination efficiency between the top and the bottom of the filter downstream became narrower with the exposure time extended. The decontamination efficiency of the bottom of the filter downstream only improved gently with the injection rate of H202 increased and the decontamination efficiency decreased instead when the injection rate exceeded 2.5 g/min. The commercially available bioindicators were competent to indicate the disinfection efficiency of VHP for the HEPA filter unit. Conclusion The HEPA filter unit is more difficult than common enclosure to decontaminate using VHP fumigation. Complete decontamination can be achieved by extending fumigation time. VHP fumigation can be applied for in-situ biodecontamination of the HEPA filter unit as an alternative method to formaldehyde fumigation.展开更多
Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing...Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing of large capital investment towards research and development of sustainable alternative energy sources. One of the most promising and abundant of these sources is hydrogen. Firstly, the use of current fossil fuels is. discussed focusing on the emissions and economic sides to emphasize the need for a new, cleaner and renewable fuel with particular reference to hydrogen as a suitable possible alternative. Hydrogen properties, production and storage methods are then reviewed along with its suitability from the economical point of view. Finally, a cost analysis for the use of hydrogen in internal combustion engines is carried out to illustrate the benefits of its use as a replacement for diesel. The outcome of this cost analysis shows that 98% of the capital expenditure is consumed by the equipment, and 68.3% of the total cost of the equipment is spent on the solar photovoltaic cells. The hydrogen plant is classified as a large investment project because of its high initial cost which is about 1 billion US$; but this is justified because hydrogen is produced in a totally green way. When hydrogen is used as a fuel, no harmful emissions are obtained.展开更多
This article mainly refers to a brief introduction on the design and operation of resid hydrogenation units in China's Mainland in order to keep the peers abreast of the basic status of aoolication of resid hydrog...This article mainly refers to a brief introduction on the design and operation of resid hydrogenation units in China's Mainland in order to keep the peers abreast of the basic status of aoolication of resid hydrogenation process in the China's Mainland.展开更多
To design the amorphous hydrogen storage alloy efficiently, the maximum hydrogen capacities for Zr - Ni amorphous alloy were calculated. Based on the Rhomb Unit Structure Model(RUSM) for amorphous alloy and the experi...To design the amorphous hydrogen storage alloy efficiently, the maximum hydrogen capacities for Zr - Ni amorphous alloy were calculated. Based on the Rhomb Unit Structure Model(RUSM) for amorphous alloy and the experimental result that hydrogen atoms exist in 3Zr1Ni and 4Zr tetrahedron interstices in Zr-Ni amolphous alloy, the numbers of 3Zr-1Ni and 4Zr tetrahedron interstices in a RUSM were calculated which correspond to the hydrogen capacity. The two extremum Zr distribution states were calculated, such as highly heterogeneous Zr distribution and homogeneous Zr distribution. The calculated curves of hydrogen capacity with different Zr contents at two states indicate that the hydrogen capacity increases with increasing Zr content and reaches its maximum when Zr is 75%. The theoretical maximum hydrogen capacity for Zr - Ni amorphous alloy is 2.0 (H/M). Meanwhile, the hydrogen capacity of heterogenous Zr distribution alloy is higher than that of homogenous one at the same Zr content. The experimental results prove the calculated results reasonable, and accordingly, the experimental results that the distribution of Zr atom in amorphous alloy occur heterogeneous after a few hydrogen absorption desorption cycles can be explained.展开更多
To investigate the corrosion behaviors and antibacterial effects of sodium hypochlorite(NaClO)and hydrogen peroxide silver ion(HPSI)disinfectants with different concentrations against dental unit waterlines and provid...To investigate the corrosion behaviors and antibacterial effects of sodium hypochlorite(NaClO)and hydrogen peroxide silver ion(HPSI)disinfectants with different concentrations against dental unit waterlines and provide guidance and reference for the use of chemical disinfectants,polyurethane tubes were immersed in ultrapure water(control group),0.1%NaClO,0.5%NaClO,1.0%NaClO,2.5%HPSI,5.0%HPSI,and 10%HPSI solutions for 6,12,and 18 weeks.Contact angles and Fourier transform infrared spectra were detected.Surface morphologies were observed using scanning electron microscopy and antibacterial activity was evaluated using Gram-positive Staphylococcus aureus(S.aureus).The results showed that sodium hypochlorite and hydrogen peroxide silver ion disinfectants presented good antibacterial activity against S.aureus.However,sodium hypochlorite could cause serious damage to the water pipes where corrosion pits and cracks were observed,and increasing the concentration of sodium hypochlorite could accelerate the corrosion process.Hydrogen peroxide silver ion disinfectants had no obvious damage to the water pipes.Therefore,hydrogen peroxide silver ion disinfectants are recommended to use for controlling bacterial infection in dental unit waterlines which can reduce the damage to the water pipes.展开更多
After having expanded its capacity from 300 kt/a to 450 kt/a in 1994, the steam cracking unit of Yanshan Petrochemical Company was still experiencing such problems as low feedstock flexibility, high energy consumption...After having expanded its capacity from 300 kt/a to 450 kt/a in 1994, the steam cracking unit of Yanshan Petrochemical Company was still experiencing such problems as low feedstock flexibility, high energy consumption and smaller production capacity as compared to other ethylene units constructed in the same time. In order to fully improve technical capability, reduce energy consumption, improve feedstock flexibility and increase production capacity of steam crackers, a lot of technical transform schemes on steam cracking were studied and compared with attention focused on the feasibility, safety, operability of the related revamp schemes, as well as the advanced nature and economical features. The transform scheme decided includes following projects. For the pyrolysis quench compression system, the pyrolysis gasoline fractionation tower is retrofitted on the site, quench water tower, pyrolysis gas compressor and steam turbine are replaced by new ones respectively. For the separation system a low pressure methane removal technology is adopted with the demethanizer tower replaced, coupled with the C 3 catalytic rectification/hydrogenation technology, while the high pressure depropanizer is replaced with addition of a propylene rectification tower. The fractionation flow sheet and equipment are adjusted with addition of a propylene compressor and compressor for binary mixture of methane ethylene cooling agents. The revamped complex has expanded the ethylene capacity to the target of 660 kt/a with the actual capacity reaching 710 kt/a, remarkably reduced the energy consumption, and is capable of using naphtha, light diesel fuel, heavy diesel fuel and the hydrocracked tail oil as the steam cracking feedstock. This project is the first to apply refrigeration by means of a mixed cooling agent and has succeeded in using C\-3 catalytic rectification/hydrogenation technology, which has given an impetus to the progress of steam cracking industry in the world.展开更多
炼化企业中,戊烷发泡剂可以利用预加氢装置拔出的轻石脑油组分进行生产,而国家标准GB T 22053—2020对发泡剂质量要求更加严格。通过构建预加氢装置汽提塔、分馏塔及脱戊烷塔的ASPEN PLUS模型,对戊烷发泡剂生产流程的控制参数进行分析测...炼化企业中,戊烷发泡剂可以利用预加氢装置拔出的轻石脑油组分进行生产,而国家标准GB T 22053—2020对发泡剂质量要求更加严格。通过构建预加氢装置汽提塔、分馏塔及脱戊烷塔的ASPEN PLUS模型,对戊烷发泡剂生产流程的控制参数进行分析测算,制定了生产调整方案。工业试验结果表明:戊烷发泡剂组成与脱戊烷塔塔顶灵敏板温度密切相关,保证塔顶发泡剂组分质量分数差值范围为±2%,其塔顶温度变化需控制±0.3℃。同时,从汽提塔操作、产品牌号、加工原油种类等方面入手,对戊烷发泡剂增产效果进行分析,提高企业的经济效益。展开更多
能源电力系统的低碳转型是实现碳达峰碳中和目标的关键所在。为研判“双碳”目标下我国能源电力系统的未来发展趋势,该文构建了考虑绿电替代与绿氢替代的中长期能源电力发展估算模型,基于模型对2020—2060年我国能源电力发展场景进行测...能源电力系统的低碳转型是实现碳达峰碳中和目标的关键所在。为研判“双碳”目标下我国能源电力系统的未来发展趋势,该文构建了考虑绿电替代与绿氢替代的中长期能源电力发展估算模型,基于模型对2020—2060年我国能源电力发展场景进行测算,分析相关核心指标的演化趋势,并针对绿电绿氢与现有能源系统协同发展的多能互补综合能源发展模式提出方案设想。结果表明,以绿电为主、绿氢为辅对传统化石能源的“双替代”,作为实现“双碳”目标的关键措施,将在新型能源体系和新型电力系统建设中发挥决定性作用,分别针对源端能源生产基地和终端消费区域提出的综合能源生产单元(integrated energy production unit,IEPU)和综合能源产消单元(integrated energy production and consumption unit,IECU)设想,可为促进多类型资源协同优化和高效配置、支撑构建新型能源体系与新型电力系统提供方案参考。展开更多
基金The authors acknowledge supports from the National Natural Science Foundation of China(Grant No.51806198,No.U1909216,No.52176048,No.51876194)the Zhejiang Provincial Natural Science Foundation(Grant No.LY21E060011)the Fundamental Research Funds of Zhejiang Sci-Tech University(Grant No.2021Q020).
文摘Injecting water into the main pipeline is a common method to prevent the ammonium salt corrosion in hydrogenation units.The use of spray nozzle can enhance the effects of washing ammonium salt and reduce the risk of ammonium salt corrosion.The droplet atomization and evaporation model were used to investigate the mixing process of injecting water and gas-oil mixture in a high-pressure environment.The effects of some key parameters including fluid velocity,temperature,and droplet volume fraction on the mixing and vaporization process were analyzed.Numerical simulation results show that with the increase of injecting water flow rate,the fluid velocity increases and the temperature decreases continuously.When the mass flow rate of injecting water is 1.5 t/h,the droplet has the maximum evaporation efficiency and the volume fraction reaches a minimum value.Besides,with the increase of atomization angle and droplet size,the mean velocity and the temperature of fluid decrease continuously.The increase of atomization angle or the decrease of droplet size will accelerate the evaporation process of droplets and reduce the droplet volume fraction,which indicates that the droplet slip velocity and the contact area are the key factors affecting the droplet evaporation rate.
基金supported by the Research Fund from the Ministry of Science and Technology of the People’s Republic of China, 2009ZX10004-502 and 2009ZX10004-709
文摘Objective To evaluate the performance of vaporized hydrogen peroxide （VHP） for the bio-decontamination of the high efficiency particulate air （HEPA） filter unit. Methods Self-made or commercially available bioindicators were placed at designated locations in the HEPA filter unit under VHP fumigation. The spores on coupons were then extracted by 0.5 h submergence in eluent followed by 200- time violent knocks. Results Due to the presence of HEPA filter in the box, spore recovery from coupons placed at the bottom of the filter downstream was significantly higher than that from coupons placed at the other locations. The gap of decontamination efficiency between the top and the bottom of the filter downstream became narrower with the exposure time extended. The decontamination efficiency of the bottom of the filter downstream only improved gently with the injection rate of H202 increased and the decontamination efficiency decreased instead when the injection rate exceeded 2.5 g/min. The commercially available bioindicators were competent to indicate the disinfection efficiency of VHP for the HEPA filter unit. Conclusion The HEPA filter unit is more difficult than common enclosure to decontaminate using VHP fumigation. Complete decontamination can be achieved by extending fumigation time. VHP fumigation can be applied for in-situ biodecontamination of the HEPA filter unit as an alternative method to formaldehyde fumigation.
文摘Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing of large capital investment towards research and development of sustainable alternative energy sources. One of the most promising and abundant of these sources is hydrogen. Firstly, the use of current fossil fuels is. discussed focusing on the emissions and economic sides to emphasize the need for a new, cleaner and renewable fuel with particular reference to hydrogen as a suitable possible alternative. Hydrogen properties, production and storage methods are then reviewed along with its suitability from the economical point of view. Finally, a cost analysis for the use of hydrogen in internal combustion engines is carried out to illustrate the benefits of its use as a replacement for diesel. The outcome of this cost analysis shows that 98% of the capital expenditure is consumed by the equipment, and 68.3% of the total cost of the equipment is spent on the solar photovoltaic cells. The hydrogen plant is classified as a large investment project because of its high initial cost which is about 1 billion US$; but this is justified because hydrogen is produced in a totally green way. When hydrogen is used as a fuel, no harmful emissions are obtained.
文摘This article mainly refers to a brief introduction on the design and operation of resid hydrogenation units in China's Mainland in order to keep the peers abreast of the basic status of aoolication of resid hydrogenation process in the China's Mainland.
基金Supported by Foundation of National Nature Science(59872024)
文摘To design the amorphous hydrogen storage alloy efficiently, the maximum hydrogen capacities for Zr - Ni amorphous alloy were calculated. Based on the Rhomb Unit Structure Model(RUSM) for amorphous alloy and the experimental result that hydrogen atoms exist in 3Zr1Ni and 4Zr tetrahedron interstices in Zr-Ni amolphous alloy, the numbers of 3Zr-1Ni and 4Zr tetrahedron interstices in a RUSM were calculated which correspond to the hydrogen capacity. The two extremum Zr distribution states were calculated, such as highly heterogeneous Zr distribution and homogeneous Zr distribution. The calculated curves of hydrogen capacity with different Zr contents at two states indicate that the hydrogen capacity increases with increasing Zr content and reaches its maximum when Zr is 75%. The theoretical maximum hydrogen capacity for Zr - Ni amorphous alloy is 2.0 (H/M). Meanwhile, the hydrogen capacity of heterogenous Zr distribution alloy is higher than that of homogenous one at the same Zr content. The experimental results prove the calculated results reasonable, and accordingly, the experimental results that the distribution of Zr atom in amorphous alloy occur heterogeneous after a few hydrogen absorption desorption cycles can be explained.
基金Funded by the Xuhui District Medical Research Project(No.SHXH201913)the Clinical Research on Health Industry of Shanghai Municipal Health Commission(No.202040085)+1 种基金the Shanghai Medical Key Specialty(No.ZK2019B12)the National Natural Science Foundation of China(No.32000945)。
文摘To investigate the corrosion behaviors and antibacterial effects of sodium hypochlorite(NaClO)and hydrogen peroxide silver ion(HPSI)disinfectants with different concentrations against dental unit waterlines and provide guidance and reference for the use of chemical disinfectants,polyurethane tubes were immersed in ultrapure water(control group),0.1%NaClO,0.5%NaClO,1.0%NaClO,2.5%HPSI,5.0%HPSI,and 10%HPSI solutions for 6,12,and 18 weeks.Contact angles and Fourier transform infrared spectra were detected.Surface morphologies were observed using scanning electron microscopy and antibacterial activity was evaluated using Gram-positive Staphylococcus aureus(S.aureus).The results showed that sodium hypochlorite and hydrogen peroxide silver ion disinfectants presented good antibacterial activity against S.aureus.However,sodium hypochlorite could cause serious damage to the water pipes where corrosion pits and cracks were observed,and increasing the concentration of sodium hypochlorite could accelerate the corrosion process.Hydrogen peroxide silver ion disinfectants had no obvious damage to the water pipes.Therefore,hydrogen peroxide silver ion disinfectants are recommended to use for controlling bacterial infection in dental unit waterlines which can reduce the damage to the water pipes.
文摘After having expanded its capacity from 300 kt/a to 450 kt/a in 1994, the steam cracking unit of Yanshan Petrochemical Company was still experiencing such problems as low feedstock flexibility, high energy consumption and smaller production capacity as compared to other ethylene units constructed in the same time. In order to fully improve technical capability, reduce energy consumption, improve feedstock flexibility and increase production capacity of steam crackers, a lot of technical transform schemes on steam cracking were studied and compared with attention focused on the feasibility, safety, operability of the related revamp schemes, as well as the advanced nature and economical features. The transform scheme decided includes following projects. For the pyrolysis quench compression system, the pyrolysis gasoline fractionation tower is retrofitted on the site, quench water tower, pyrolysis gas compressor and steam turbine are replaced by new ones respectively. For the separation system a low pressure methane removal technology is adopted with the demethanizer tower replaced, coupled with the C 3 catalytic rectification/hydrogenation technology, while the high pressure depropanizer is replaced with addition of a propylene rectification tower. The fractionation flow sheet and equipment are adjusted with addition of a propylene compressor and compressor for binary mixture of methane ethylene cooling agents. The revamped complex has expanded the ethylene capacity to the target of 660 kt/a with the actual capacity reaching 710 kt/a, remarkably reduced the energy consumption, and is capable of using naphtha, light diesel fuel, heavy diesel fuel and the hydrocracked tail oil as the steam cracking feedstock. This project is the first to apply refrigeration by means of a mixed cooling agent and has succeeded in using C\-3 catalytic rectification/hydrogenation technology, which has given an impetus to the progress of steam cracking industry in the world.
文摘炼化企业中,戊烷发泡剂可以利用预加氢装置拔出的轻石脑油组分进行生产,而国家标准GB T 22053—2020对发泡剂质量要求更加严格。通过构建预加氢装置汽提塔、分馏塔及脱戊烷塔的ASPEN PLUS模型,对戊烷发泡剂生产流程的控制参数进行分析测算,制定了生产调整方案。工业试验结果表明:戊烷发泡剂组成与脱戊烷塔塔顶灵敏板温度密切相关,保证塔顶发泡剂组分质量分数差值范围为±2%,其塔顶温度变化需控制±0.3℃。同时,从汽提塔操作、产品牌号、加工原油种类等方面入手,对戊烷发泡剂增产效果进行分析,提高企业的经济效益。
文摘能源电力系统的低碳转型是实现碳达峰碳中和目标的关键所在。为研判“双碳”目标下我国能源电力系统的未来发展趋势,该文构建了考虑绿电替代与绿氢替代的中长期能源电力发展估算模型,基于模型对2020—2060年我国能源电力发展场景进行测算,分析相关核心指标的演化趋势,并针对绿电绿氢与现有能源系统协同发展的多能互补综合能源发展模式提出方案设想。结果表明,以绿电为主、绿氢为辅对传统化石能源的“双替代”,作为实现“双碳”目标的关键措施,将在新型能源体系和新型电力系统建设中发挥决定性作用,分别针对源端能源生产基地和终端消费区域提出的综合能源生产单元(integrated energy production unit,IEPU)和综合能源产消单元(integrated energy production and consumption unit,IECU)设想,可为促进多类型资源协同优化和高效配置、支撑构建新型能源体系与新型电力系统提供方案参考。
