共查询到20条相似文献,搜索用时 234 毫秒
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塑料包装废弃物的处理方法基本上可分为填埋、焚烧及回收再生利用。填埋是把垃圾作为废物处理,对垃圾资源的利用率低,不符合国家可持续发展战略。焚烧法可将不能再次利用的混杂塑料在焚烧炉中焚化,由其产生的大量热量可再次充分利用。但焚烧的过程中会产生大量的有害气体,对环境及人体造成危害。回收再生利用包括机械再生利用和化学再生利用。机械再生利用包括直接再生利用及改性再生利用;化学再生利用主要有热分解和化学分解两类。塑料再生利用是国家解决资源短缺的一个重大战略问题,我国废塑料回收利用前景看好。 相似文献
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废旧橡胶的回收和循环利用现状 总被引:1,自引:0,他引:1
刘军 《合成材料老化与应用》2008,37(1):51-53
综述了目前废旧橡胶回收和循环利用的现状和发展趋势,主要包括废旧橡胶的直接利用、磨成胶粉后利用、通过再生胶重新利用、热分解后利用以及燃烧等. 相似文献
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城市雨水利用的技术与分析 总被引:7,自引:0,他引:7
城市雨水的利用对社会、环境和经济的可持续发展有重大意义,但我国城市雨水利用还处于初级阶段,而且发展很不平衡。总结了我国城市雨水利用现状;城市雨水径流水质及其影响因素;比较了雨水直接利用和间接利用方式的特点;并通过实例说明城市雨水利用技术的关键,最后对我国城市雨水利用提出了建议。 相似文献
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综述了目前废旧橡胶回收和循环利用的现状和发展趋势,主要包括废旧橡胶的直接利用、磨成胶粉后利用、通过再生胶重新利用、热分解后利用以及燃烧等。 相似文献
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分析了氢气中杂质的来源,影响氢气纯度的一些主要因素,以及如何从各方面去控制氢气纯度。指出,注意监测氢气纯度的变化趋势,并采取严格控制碱液密度等参数,提高装置负荷、定期清洗电解槽等措施可控制氢气纯度在规定范围。 相似文献
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介绍了天然气制氢技术在氯碱生产中的可行性及生产工艺和流程。对开车运行以来的生产进行了总结。此技术的成功应用,为氯碱企业平衡生产中的氯气产能、解决氯气的安全贮运问题提供了经验。 相似文献
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Experimental data are presented concerning the diffusion-limited current density for hydrogen oxidation in a gas diffusion electrode (GDE) under various conditions. These current densities were obtained using mixtures of hydrogen and inert gases. To elucidate the dependence of the overall mass transport coefficient on the gas phase diffusion coefficient and the liquid phase diffusion coefficient of the hydrogen, a simplified model was derived to describe the transport of hydrogen in a GDE based on literature models. The GDE consists of a hydrophobic and a hydrophilic layer, namely a porous backing and a reaction layer. The model involves gas diffusion through the porous backing of the GDE combined with gas diffusion, gas dissolution and reaction in the reaction layer of the electrode. It was found that the transport rate of hydrogen under the experimental circumstances is determined by hydrogen gas diffusion in the pores of the porous backing, as well as in the macropores of the reaction layer. Diffusion of dissolved hydrogen in the micropores of the reaction layer, through the liquid, is shown to be of little significance. 相似文献
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Xueping Song 《Fuel》2005,84(5):525-531
Production of synthesis gas with coal and natural gas co-gasification is a new process based on coupling of methane steam-reforming and coal gasification. The process concept is discussed in this paper. Experiments are carried out in a laboratory fixed-bed gasifying reactor to investigate the effect of feedstock on composition, ratio of hydrogen to carbon monoxide, concentrations of hydrogen and carbon monoxide in the produced raw synthesis gas. Preliminary experimental results indicate that the effect of steam flow rate on component, ratio of hydrogen to carbon monoxide and concentrations of hydrogen and carbon monoxide of the raw synthesis gas is slight, while the effect of oxygen flow rate is pronounced. When the ratio of oxygen to methane in feedstock is below 1, the ratio of hydrogen to carbon monoxide is greater than 1 and the total concentration of hydrogen and carbon monoxide is above 90%. Comparison of experimental results with calculated results shows that the composition of raw synthesis gas is near equilibrium. 相似文献
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干气密封系统中气体通过过滤器、阀门、孔板和密封端面等组件时会发生焦耳-汤姆逊(JT)效应,可能导致密封气温度降低,甚至出现液相凝析。焦耳-汤姆逊效应一般通过焦耳-汤姆逊系数来反映。针对干气密封常面临的氢气、氮气、空气和二氧化碳,利用VDW方程、RK方程、SRK方程和PR方程4个经典状态方程(EOS)分别计算了相应的焦耳-汤姆逊(JT)系数,并与文献实验数据进行了比较,选择最佳状态方程作出各气体的JT系数曲线和焦耳-汤姆逊反转曲线(JTIC),并利用编程计算出空气和氮气通过干气密封端面时,由于JT效应引起的气体温降。结果表明:实际气体的焦耳-汤姆逊效应,对干气密封的节流环节会产生重要影响。常温条件下,氢气发生致热效应,而氮气、空气和二氧化碳气体发生致冷效应。采用4种状态方程计算焦耳-汤姆逊系数时,RK方程的平均相对误差和最大相对误差最低且分别小于4%和10%。干气密封气体的实际气体焦耳-汤姆逊效应能引起较大的温度变化,其中气体介质压力比介质温度对温差的影响更大。压力较小时JT效应引起的温降可以忽略。关键词:干气密封;实际气体;状态方程;焦耳-汤姆逊系数;反转曲线 相似文献
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《Fuel》2006,85(14-15):2041-2045
Cryogenic gas chromatography (GC) combined with isotope labeling was applied to discriminative determination of hydrogen gas formed through consecutive CO2 reforming of methane and water–gas shift reaction. First, hydrogen gas was obtained by using a tandem reaction system, where reforming and shift reaction occurred consecutively. Here, D2O instead of H2O was used for shift reaction to label hydrogen gas generated there. Then, the resulting hydrogen isotopes were analyzed by a cryogenic GC system, in which an oven temperature was maintained at −196 °C by immersing a separation column into liquid nitrogen. On the chromatograms, the peaks of H2 and D2 generated from reforming and shift reaction, respectively, were clearly observed as well-separated peaks. Based on their peak intensities, hydrogen gas formed through the tandem reaction system was precisely determined with differentiating its sources. 相似文献