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1.
研究目的：建立2000-2020年中国氮氧化物排放清单,了解中国主要行业和省份氮氧化物的排放情况,为评估氮氧化物的环境影响和制定相关减排政策提供依据。创新要点：分析了中国主要省份产业结构对氮氧化物排放量的影响;根据不同情景分析,预测2020年中国氮氧化物的排放量。研究方法：1．基于自底向上法,根据不同类型化石燃料的氮氧化物排放因子,结合化石燃料消耗量,建立中国2000-2010年氮氧化物排放清单;2．基于IPAT方程,并以中国2000--2010年的国内生产总值增长数据和氮氧化物排放量为依据,分三种情景,分析2011-2020年中国能源消耗和氮氧化物排放趋势。重要结论：2010年中国氮氧化物的排放量约是2000年的两倍：自2009年起,中国氮氧化物总排放量超过,二氧化硫总排放量;主要由于产业结构和地区生产总值的不同,中国东部和西部氮氧化物排放量有明显差异;制造业、电力行业和交通运输业是中国氮氧化物的主要排放源,其中交通运输业氮氧化物排放量呈现逐年增长趋势;预计2020年中国氮氧化物排放量为19．7Mt。  相似文献   

2.
研究目的：预测机动车保有量;根据机动车污染特征,预测机动车污染物排放量;评估不同管理措施下机动车污染物的削减效果。创新要点：综合不同管理措施,整合评价多种管理措施并行条件下,机动车污染物排放量的削减情况。研究方法：通过长期能源替代计划（LEAP）模型对机动车保有量进行预测,相关排放因子采用校正的能源替代（AER）模型进行估算。最后设计四个情景模式,评估不同情景的减排效果,并与基础情景进行对比。重要结论：1.至2015年杭州市机动车将增长60.7%。2.淘汰超标机动车和提高机动车污染排放标准能有效控制CO和VOCs,而对NOx和PM的总量削减效果不明显。3.采用多种控制手段,如淘汰劣化超标机动车、提高机动车排放标准、提供低硫代燃油及引进能源替换型机动车将大大减少机动车污染物的排放量。  相似文献   

3.
In this study, a porous inserted regenerative thermal oxidizer （PRTO） system was developed for a 125 kW industrial copper-melting furnace, due to its advantages of low NOr emissions and high radiant efficiency. Zirconium dioxide （ZrOz） ce- ramic foams were placed into the combustion zone of a regenerative thermal oxidizer （RTO）. Different performance characteris- tics of the RTO and PRTO systems, including pressure drop, temperature distribution, emissions, and energy efficiency, were evaluated to study the effects of the porous inserts on non-premixed CH4 combustion. It was found that the PRTO system achieved a significant reduction in the NOx emission level and a fuel saving of approximately 30% compared to the RTO system. It is most suitable for a lean combustion process at an equivalence ratio 〈0.4 with NOx and CO emission levels within 0.002%~）.003% and 0.001%q3.002%, respectively.  相似文献   

4.
In iron ore sintering, the granulation process is the first and an important step. As the fine particles adhere to the coarse coke particles, the NO x emission generated from coke combustion may be expected to be influenced by that adhering layer. In this study, the granule size distributions and adhering ratios were evaluated by a granulation model. Granulation experiments were also carried out to obtain the granule size distribution and adhering ratio. The influence of the adhering layer on NO x emissions from the combustion of S type granules was studied by tube furnace experiments. Conclusions include: (1) The adhering ratio predicted from the granulation model can be used as a qualitative index for the evaluation of NO x emission from coke combustion. (2) The influence of the adhering layer on NO x emissions was enhanced with increasing adhering layer thickness of S type granules, and the NO x reduction was enhanced at higher temperatures (around 1373 K), but weakened at lower temperatures (around 1173 K).  相似文献   

5.
In this paper, a multi-objective particle swarm optimization （MOPSO） algorithm and a nondominated sorting genetic algorithm II （NSGA-II） are used to optimize the operating parameters of a 1.6 L, spark ignition （SI） gasoline engine. The aim of this optimization is to reduce engine emissions in terms of carbon monoxide （CO）, hydrocarbons （HC）, and nitrogen oxides （NOx）, which are the causes of diverse environmental problems such as air pollution and global warming. Stationary engine tests were performed for data generation, covering 60 operating conditions. Artificial neural networks （ANNs） were used to predict exhaust emissions, whose inputs were from six engine operating parameters, and the outputs were three resulting exhaust emissions. The outputs of ANNs were used to evaluate objective functions within the optimization algorithms： NSGA-II and MOPSO. Then a decision-making process was conducted, using a fuzzy method to select a Pareto solution with which the best emission reductions can be achieved. The NSGA-II algorithm achieved reductions of at least 9.84%, 82.44%, and 13.78% for CO, HC, and NOx, respectively. With a MOPSO algorithm the reached reductions were at least 13.68%, 83.80%, and 7.67% for CO, HC, and NOx, respectively.  相似文献   

6.
An experimental and model-based study of the effect of rich air/fuel ratios （AFRs） and temperature on the NOx slip of a lean NOx trap （LNT） was conducted in a lean-burn gasoline engine with an LNT after-treatment system. The emissions of the engine test bench and the inlet temperature of the LNT were used as the major inlet boundary conditions of the LNT. The engine periodically operated between a constant lean AFR of 23 with alterable rich AFRs of 10, 11, 12, 13, and 14. A decrease in the rich AFR of the engine strengthened the desorption atmosphere in the LNT, an effect closely related to the number of reductants, and further heightened the NOx desorption of the LNT, but with a penalty in fuel consumption. To eliminate that penalty, the inlet boundary conditions of the LNT were varied by adjusting the inlet temperature within a range between 200 ℃ and 400℃. An increase in inlet temperature heightened the NOx desorption of the LNT, and a NOx breakthrough occurred after the inlet tem- perature exceeded 390 ℃. To control NOx breakthrough, the inlet temperature can be adjusted to offset the strong desorption atmosphere in the LNT commonly created by a rich AFR.  相似文献   

7.
Optimizing the operation of coal-fired power plants to reduce nitrogen oxide (NO x ) emissions requires accurate modeling of the NO x emission process. The careful selection of input parameters not only forms the basis of accurate modeling, but can also be used to reduce the complexity of the model. The present study employs the least squares support vector machine-supervised learning method to model NO x emissions based on historical real time data obtained from a 1000-MW once-through boiler. The initial input parameters are determined by expert knowledge and operational experience, while the final input parameters are obtained by sensitivity analysis, where the variation in model accuracy for a given set of data is analyzed as one or several input parameters are successively omitted from the calculations, while retaining all other parameters. Here, model accuracy is evaluated according to the mean relative error (MRE). This process reduces the parameters required for NO x emission modeling from an initial number of 33 to 7, while the corresponding MRE is reduced from 3.09% to 2.23%. Moreover, a correlation of 0.9566 between predicted and measured values was obtained by applying the model with just these seven input parameters to a validation dataset. As such, the proposed method for selecting input parameters serves as a reference for related studies.  相似文献   

8.
Solid oxide fuel cells(SOFCs) offer high energy conversion,low noise,low pollutant emission,and low processing cost.Despite many advantages,SOFCs face a major challenge in competing with other types of fuel cells because of their high operating temperature.The necessity to reduce the operational temperature of SOFCs has led to the development of research into the materials and fabrication technology of fuel cells.The use of composite cathodes significantly reduces the cathode polarization resistance and expands the triple phase boundary area available for oxygen reduction.Powder preparation and composite cathode fabrication also affect the overall performance of composite cathodes and fuel cells.Among many types of cathode materials,lanthanum-based materials such as lanthanum strontium cobalt ferrite(La1-xSrxCo1-yFeyO3- have recently been discovered to offer great compatibility with ceria-based electrolytes in performing as composite cathode materials for intermediate-to low-temperature SOFCs(IT-LTSOFCs).This paper reviews various ceria-based composite cathodes for IT-LTSOFCs and focuses on the aspects of progress and challenges in materials technology.  相似文献   

9.
The issues related to climate change such as depletion of energy resources and continuous high oil prices,global warming,and development of clean energy are adopted and discussed as a national agenda i...  相似文献   

10.
Sheela K. Ramasesha 《Resonance》2013,18(12):1110-1126
Water, biomass and geothermal are also renewable resources for use in power generation stations. Many countries around the world use these energy resources in their energy mix. The technologies needed for each of these renewable resources and how they are applied is discussed in the article. Their scenario in India is also presented. In the concluding remarks, the role of using renewable energy resources in electricity generation in the light of reduction of Green House Gas (GHG) emission into the atmosphere is deliberated. The pros and cons of renewable resources are discussed in detail and how they should be used responsibly is highlighted. The most important step towards reduction of GHG is to reduce consumption of energy in our routine, in addition to using renewable sources to generate the much needed electricity.  相似文献   

11.
Environmental problems have received a great deal of attention in recent years.In particular,CO2 emissions worsen global warming and other environmental problems.The transport sector accounts for 20% of the total CO2 emissions.Therefore,the CO2 emission reduction of the transport sector is of great importance.In order to reduce emissions effectively,it is necessary to change the distribution and transportation processes.The purpose of this study is to minimize both the transportation costs and CO2 emissions during transportation.Our model considers a transportation scheduling problem in which loads are transported from an overseas production base to three domestic demand centers.The need for time-space networks arises naturally to improve the model.It is possible to know the distance carriers are moving,and also consider the timetables of carriers during transportation.Carrier choice,less-than carrier load,and domestic transportation among demand centers are considered as the three target areas to reduce CO2 emissions during the distribution process.The research model was formulated as a mixed integer programming （MIP） problem.It achieves cost reduction,and will contribute to improvement of the natural environment.  相似文献   

12.
This paper presents a method using a large steady-state engine operation data matrix to provide necessary information for successfully training a predictive network, while at the same time eliminating errors produced by the dispersive effects of the emissions measurement system. The steady-state training conditions of compound fuel allow for the correlation of time-averaged in-cylinder combustion variables to the engine-out NO x and HC emissions. The error back-propagation neural network (EBP) is then capable of learning the relationships between these variables and the measured gaseous emissions, and then interpolating between steady-state points in the matrix. This method for NO x method for NO x and HC has been proved highly successful.  相似文献   

13.
文章研究了江苏省2000-2010年建设用地变化与碳排放的关系,运用STIRPAT模型估算人口规模、人均GDP、能耗强度、建设用地面积对碳排放量的效应.借助SPASS软件,采用回归分析方法测算出4种驱动因素对碳排放量的边际弹性系数.研究表明,建设用地是碳排放的主要驱动因素之一,建设用地面积每增加1%,碳排放量将增加4.05%;能耗强度对碳排放的弹性系数为-2.09,表明能耗强度下降对碳排放具有减量效应.最后从碳减排角度提出土地利用的相关政策建议.  相似文献   

14.
In this paper, a novel system using direct contact heat transfer between air and water solution was proposed to generate ice slurry. The heat transfer process and the system performance were studied; energy efficiency coefficients of 0.038, 0.053, and 0.064 were obtained using different solutions. An empirical relationship between the volumetric heat transfer coefficient Uv and the main parameters was obtained by fitting the experimental data. The Uv calculated from the empirical formula agreed with the experimental Uv quite well with a relative error of less than 15%. Based on the empirical formula, a laboratory-scale direct contact ice slurry generator was then constructed, with practical application in mind. If the air flow rate is fixed at 200 m3/h, the ice production rate will be 0.091 kg/min. The experimental results also showed that the cold energy consumption of the air compressor accounted for more than half of the total amount. To improve the system energy efficiency coefficient, it is necessary to increase the air pipes insulation and the solution＇s thermal capacity, and also it is appropriate to utilize the free cold energy of liquefied natural gas （LNG）.  相似文献   

15.
In this study, we used a simple impregnation method to prepare Fe–Ce–O x catalysts and tested them regarding their low-temperature (200–300 °C) selective catalytic reduction (SCR) of NO using NH3. We investigated the effects of Fe/Ce molar ratio, the gas hourly space velocity (GHSV), the stability and SO2/H2O resistance of the catalysts. The results showed that the FeCe(1:6)O x (Ce/Fe molar ratio is 1:6) catalyst, which has some ordered parallel channels, exhibited good SCR performance. The FeCe(1:6)O x catalyst had the highest NO conversion with an activity of 94–99% at temperatures between 200 and 300 °C at a space velocity of 28,800 h?1. The NO conversion for the FeCe(1:6)O x catalyst also reached 80–98% between 200 and 300 °C at a space velocity of 204,000 h?1. In addition, the FeCe(1:6)O x catalyst demonstrated good stability in a 10-h SCR reaction at 200–300 °C. Even in the presence of SO2 and H2O, the FeCe(1:6)O x catalyst exhibited good SCR performance.  相似文献   

16.
Alloying is an effective way to manipulate the composition and physico-chemical properties of functional materials. We demonstrated the syntheses of alloyed Co x Ni1?x O nanocrystals using a nonaqueous approach, with x continuously tuned from 0 to 1 by varying the molar ratios of the cobalt precursor in the reagents. The morphological, structural, and compositional properties of the alloyed Co x Ni1?x O nanocrystals were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), inductively coupled plasma atomic emission spectroscopy (ICP-AES), and energy dispersive X-ray spectroscopy (EDS). The results showed that the cobalt and nickel atoms were homogeneously distributed in the alloyed nanocrystals. The as-prepared Co x Ni1?x O nanocrystals can be applied as the hole-transporting layers in polymer light emitting diodes (PLEDs). Our study provides a good example for the syntheses of alloyed oxide nanocrystals with continuously tunable composition.  相似文献   

17.
利用IPCC提出的碳排放折算系数测算广西能源消费CO2排放,运用卡亚公式和完全分解模型分析人口规模、人均GDP、能源强度和CO2密度对广西能源消费CO2排放量变化的影响,结果发现:在19952011年,对广西能源消费CO2排放量增大起正作用的依次是人均GDP和人口规模,起负作用的依次是能源强度和CO2密度。因此减小广西能源消费CO2排放量,要控制人口规模、改善产业结构、能源结构和推动节能减排技术发展。  相似文献   

18.
介绍了美国目前限制和减少温室气体排放的方法和政策及其影响,并在分析温室气体排放和全球气候变化的科学数据的基础上,对现行政策进行评述并追踪美国在减少温室气体排放方面所做的努力及这些努力中潜在的可能具有的政策效力。  相似文献   

19.
在有效质量近似理论下,利用变分法研究了外电场下圆柱形GaAs/Al_xGa_(1-x)As量子环中类氢施主杂质束缚能。讨论了施主杂质束缚能与量子环尺寸(径向厚度、高度)、杂质位置以及外电场间的变化规律。结果表明:随着量子环径向厚度(高度)的增大,中心施主杂质束缚能先增大后减小,显示有一极大值;施加的电场明显地改变了量子环中电子波函数的分布,导致施主杂质束缚能相应的改变;施主杂质束缚能随杂质位置的变化呈现出规律性。  相似文献   

20.
Although many academic disciplines are now experiencing a process of “greening” as scholars seek to cultivate an ecocritical awareness within disciplinary scholarship, Neil Selwyn notes that such ecocritical concerns rarely feature in the field of educational technology. In this paper, I bring Selwyn's call for ecocritical awareness in the field of educational technology into conversation with emerging scholarly discussions in the fields of ecojustice ethics, ecojustice education, and information and communications technology sustainability. In so doing, I expand the existing conversation about the environmental impact of educational technology consumption to argue that the process of cultivating an ecocritical awareness in the field of educational technology requires refining the discipline's focus to include the full lifespan of educational technology devices and the global inequities that feature during the production and disposal of these devices.

Practitioner Notes

What is already known about this topic
  • Despite substantive scholarship recognizing the environmental impact of the globalized digital technology supply chain, the field of educational technology has minimally considered the ecojustice implications of the material nature of educational technology devices when examining the environmental impact of these devices.
What this paper adds
  • In this paper, I argue that the reason why the field of educational technology has overlooked the environmental impact of device production and disposal is because of its almost exclusive focus on device use. I argue that cultivating an ecocritical awareness in the field of educational technology requires the discipline to expand its focus beyond device use in two ways: (a) to include device production and disposal and (b) to consider the global injustices that occur in these parts of the digital technology life cycle. As such, I build upon Selwyn and others to argue for the cultivation of ecojustice concerns in emerging conversations about ethics in the field of educational technology.
Implications for practice and/or policy
  • The process of cultivating ecocritical awareness within the field of educational technology requires expanding the scope and focus of the discipline beyond device use to include device production and disposal. The planned obsolescence behind these devices maximizes the environmental harm at these stages and the global injustices associated with them. Educators and educational leaders seeking to employ educational technology in ethical and environmentally sustainable ways must consider these implications from the global digital technology supply chain.
  相似文献   

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