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1.
Waste-to-energy is a promising approach to face the current challenge of waste overproduction in Reunion Island, a French territory. In this particular context of an isolated and tropical territory, it is essential to study the properties of potential feedstocks to choose the most appropriate conversion process. This article reports on the composition of Residual Household Waste from Reunion Island and its physico-chemical parameters. Twelve representative samples of Residual Household Waste were subjected to thermal and elemental analysis. The results showed that their composition had a significant influence on the physico-chemical properties, including calorific value. Residual Household Waste from the selective sorting (rich in wood, plastic, and sanitary textiles) as well as dry mixed RHW are the most interesting for energy recovery. Due to their high volatile matter and high carbon content, and their low moisture content, these types of waste have a high calorific value exceeding 18 MJ/kg. Furthermore, the RHW sample comply with the environmental and health criteria applied by French regulations concerning halogen and heavy metal. Thus, it seems that Residual Household Waste can be an alternative to conventional fuels used in incineration or pyro-gasification processes. However, the study also points the need for a pre-treatment process for these wastes. Indeed, it is necessary to sort them correctly in order to avoid the risks of pollution and important maintenance. And more importantly, drying beforehand is unavoidable to improve combustibility and obtain optimal energy conversion.  相似文献   
2.
An experimental device for evaluating the minimum ignition energy (MIE) of LDPE dust/ethylene hybrid mixture was built with the innovative mixing mode. The MIE of the hybrid mixture that contained ethylene below its lower explosive limit (LEL) was studied. The result indicated that adding a small amount of ethylene significantly reduced the MIE of the original dust cloud. All the MIEs with five different particle sizes were found to show similar trends of exponential attenuation with the increase of ethylene concentration; such attenuating effect grew as the dust particle size rose. When ethylene concentration increased and approached to its LEL, the reaction mechanism dominated by combustible dust turned into one dominated by combustible gas. The MIE decreased first and then increased with the dust mass and increased with the dust particle size. A multifactor mathematical correlation model of the MIE with the dust particle size and ethylene concentration was developed.  相似文献   
3.
In this paper, the life span of hydro and nuclear energy generations and the relationship between hydro and nuclear energy generations, environmental pollution, and economic growth were investigated for Japan covering the period of 1960–2018 by employing the Bathtub-Weibull curve and Markov switching-vector error correcting (MSVEC) method, respectively. According to the Bathtub-Weibull curve analysis, a rising failure rate for nuclear energy was found, indicating that the life of nuclear energy has expired, but a decreasing failure rate for hydroelectric energy has been detected. Then two different MSVEC models were used. The MSVEC method, unlike traditional approaches, determines the relationship between variables under different regimes. The results of MSVEC methods indicate three important points. First, regime-dependent asymmetry and regime changes are crucial for policy recommendations. Second, the shocks to hydropower and nuclear energy generations cause temporary deviations from the long-run growth path in both regimes. Lastly, the increase in hydropower generation leads to a decrease in environmental pollution and an increase in GDP, and an increase in nuclear power generation increases pollution and growth in both regimes.  相似文献   
4.
The effect of pyrolysis and oxidation characteristics on the explosion sensitivity and severity parameters, including the minimum ignition energy MIE, minimum ignition temperature MIT, minimum explosion concentration MEC, maximum explosion pressure Pmax, maximum rate of pressure rise (dP/dt)max and deflagration index Kst, of lauric acid and stearic acid dust clouds was experimentally investigated. A synchronous thermal analyser was used to test the particle thermal characteristics. The functional test apparatuses including the 1.2 L Hartmann-tube apparatus, modified Godbert-Greenwald furnace, and 20 L explosion apparatus were used to test the explosion parameters. The results indicated that the rapid and slow weight loss processes of lauric acid dust followed a one-dimensional diffusion model (D1 model) and a 1.5 order chemical reaction model (F1.5 model), respectively. In addition, the rapid and slow weight loss processes of stearic acid followed a 1.5 order chemical reaction model (F1.5 model) and a three-dimensional diffusion model (D3 model), respectively, and the corresponding average apparent activation energy E and pre-exponential factor A were larger than those of lauric acid. The stearic acid dust explosion had higher values of MIE and MIT, which were mainly dependent on the higher pyrolysis and oxidation temperatures and the larger apparent activation energy E determining the slower rate of chemical bond breakage during pyrolysis and oxidation. In contrast, the lauric acid dust explosion had a higher MEC related to a smaller pre-exponential factor A with a lower amount of released reaction heat and a lower heat release rate during pyrolysis and oxidation. Additionally, due to the competition regime of the higher oxidation reaction heat release and greater consumption of oxygen during explosion, the explosion pressure Pm of the stearic acid dust was larger in low concentration ranges and decayed to an even smaller pressure than with lauric acid when the concentration exceeded 500 g/m3. The rate of explosion pressure rise (dP/dt)m of the stearic acid dust was always larger in the experimental concentration range. The stearic acid dust explosion possessed a higher Pmax, (dP/dt)max and Kst mainly because of a larger pre-exponential factor A related to more active sites participating in the pyrolysis and oxidation reaction. Consequently, the active chemical reaction occurred more violently, and the temperature and overpressure rose faster, indicating a higher explosion hazard class for stearic acid dust.  相似文献   
5.
实验测定了林西矿肥煤样品30~900℃煤自燃全过程热动力学特征参数,得出:TG/DTG曲线显示煤样DTG初始临界温度45℃,干裂温度122℃,活性温度195℃,增速温度265℃,质量极大值温度342℃,着火温度465℃,最大热失重速率温度515℃和燃尽温度690℃;DSC曲线显示,煤样初始放热温度60℃、最大热释放速率温度511℃。结合TG-DTG-DSC曲线综合分析可知,煤温达到510℃左右时煤样反应最剧烈。由煤自燃标志气体测定实验系统得出:煤温130℃后CO,CO 2释放量迅速增加,210℃增加速度下降;CH 4,C 2 H 6含量变化具有规律性且两者变化相近;C 2 H 4出现温度为130℃;C 2 H 4/C 2 H 6比值在190~350℃有较强的规律性,呈上升趋势且上升速度较快;350℃之后,CH 4,C 2 H 6,C 2 H 4体积分数均开始急剧增大;C 2 H 4/CO与C 2 H 4/CO 2变化趋势大致相同,在130~350℃时缓慢增长,达到350℃后比值呈指数形式上升。经拟合曲线,得到活化能的3个突变点温度:70,180,220℃,其中180℃与交叉点温度相吻合。通过以上研究,得到了肥煤自燃全过程的热力学特征参数,为实际生产中防治煤自燃提供了理论依据。  相似文献   
6.
目前,我国面临的大气污染问题愈发严重,尤其在"京津冀"地区更为突出。而煤炭相关产业链的能源消耗结构及其污染物排放是导致此问题的重要原因之一。本研究基于2012年"京津冀"地区各省、市的能源平衡表,通过区域间能源调配模型,绘制了煤流和能流桑基图,厘清了"京津冀"地区2012年煤炭相关产业链的物质与能量走向,并运用了投入产出法系统核算了"京津冀"地区煤炭相关产业链的体现能与24种污染物排放量。研究结果表明:(1)"京津冀"地区的原煤主要依赖调运,属于净煤炭进口地区。(2)原煤的直接使用在"京津冀"地区的煤炭相关产业链中占有非常大比重。将体现能角度分析的结果与能量角度分析的结果对比,可以发现煤化工产业在煤炭相关产业链中的潜在能量消耗仍然具有较大的贡献。(3)焦炭是终端消费能量的主要来源,也是体现能的主要贡献源。(4)在煤炭转化能源利用效率上,"京津冀"地区2012年煤炭相关产业链洗选煤、煤制品加工、炼焦三个环节的效率分别为87.77%、92.46%、90.97%,稍低于中国2012年96.16%的利用效率。(5)原煤、焦炭的直接消费和炼焦过程对"京津冀"地区2012年煤炭相关产业链七种主要污染物的贡献率最大。为了有效减少"京津冀"地区煤炭相关产业链的污染物排放,需要对原煤、焦炭的直接消费和炼焦过程采取相应的减排政策和措施。本研究可以为"京津冀"地区煤炭相关产业链提高能源利用效率、减少体现能和污染物排放、采取改进措施提供一定的理论支持和政策建议。  相似文献   
7.
Industrial workplaces pose concurrent hazards to the upper part of the head and the eyes. Under the circumstances, workers may use protective helmets in conjunction with protective goggles or spectacles. In order to assess the compatibility of this equipment, a method and a test stand for evaluating the behavior of safety helmets and protective goggles/spectacles upon the impact of a falling weight were designed. The results of tests concerning the displacement and deformation of helmets and spectacles/goggles, the forces acting on the helmets, as well as the forces exerted by the spectacles/goggles on the headform upon falling weight impact are presented. The results revealed the ways in which the tested equipment interacted with each other. The influence of equipment construction on the test results was analyzed and inferences concerning the safety of the studied protective devices were made. Some general construction guidelines were formulated for the compatibility of the equipment.  相似文献   
8.
有机污染物在被动采样材料与环境介质之间的平衡分配系数(K_P),是测定环境中有机污染物浓度的重要参数,但K_P值大部分都需要经过繁琐的实验测定获取,无法逐个测定数量繁多的污染物,因此需开发一种预测K_P值的方法。为此,搜集整理了一些多环芳香烃(PAHs)和多氯联苯(PCBs)的低密度聚乙烯(LDPE)-空气分配系数(K_PA)的实测值,基于理论线性溶解能(TLSER)和定量结构性质关系(QSPR),利用逐步多元线性回归(MLR)分别构建了预测K_PA值的模型。模型的决定系数R2adj分别为0.927和0.956,交叉验证系数Q2LOO分别为0.915和0.946,外部系数Q2ext分别为0.913和0.960。结果表明,2种模型具有良好的拟合优度、稳健性和预测能力,并解释了模型的机理。所构建的2种模型均可用来预测应用域内有机污染物的LDPE膜-空气分配系数。  相似文献   
9.
Sustainable use of natural resources would entail ensuring that derived economic benefits today do not undermine the welfare of generations to come. On this basis, this study examines the nexus between natural resource rents and carbon dioxide (CO2) emissions disaggregated into production and consumption-based (i.e., trade-adjusted) CO2 emissions for a selected panel of 45 developing and transition economies over the period 1995–2017. The empirical model also incorporates the impacts of population, affluence, and energy intensity. The results show that affluence increases production-based CO2 emissions by 1.407%, with the EKC's predicted inverted U-shaped curve only explaining consumption-based CO2 emissions. Economic reliance on natural resource rents and energy intensification contribute 0.022% and 0.766%, respectively, to CO2 emissions embedded in territorial production inventories and 0.035% and 0.583%, respectively, to CO2 emissions embedded in consumption inventories. The bootstrap non-causality test shows that historical data on each variable has significant predictive power for future CO2 emissions from both sources. The historical information about natural resource rents has significant predictive power over the future levels of affluence and energy intensity. Clearly, the results show that the environmental impact of natural resource rents is stronger when CO2 emissions are adjusted for trade and varies among the countries, with Bangladesh, Guinea, India, Malaysia, Mexico, Nigeria, Pakistan, Saudi Arabia, Vietnam, and Zimbabwe among the most affected countries. Overall, this study provides motivation for policies to keep the use of natural resources within sustainable limits.  相似文献   
10.
余强  李元东  余鹏  严磊  王亮 《四川环境》2021,(1):198-202
车载环境γ能谱测量系统探测器是环境γ能谱测量技术领域研究热点。为提高探测效率,缩短测量时间,针对车载环境γ能谱测量系统设计了双NaI(Tl)晶体探测器,并测试了探测器主要性能指标。研究表明,探测器能量分辨率为6.73%,计数稳定性优于4.2%,可识别238U、232Th、40K等核素,可清晰分辨152Eu各能量峰,温度稳定性优于2.93%。可见,该探测器性能优异,具有较强的能量分辨和稳定性,为车载γ能谱测量系统的设计提供了技术基础,也为大体积探测器的设计提供了实验基础,有望在辐射环境监测等领域推广应用。  相似文献   
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