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Zhu Jie Wang Wei Lian Songjian Hua Xiuning Xia Zhou 《Journal of Material Cycles and Waste Management》2017,19(1):453-462
Journal of Material Cycles and Waste Management - Chemical looping hydrogen generation using iron oxides as oxygen carriers is a novel technology to convert carbonaceous substances into hydrogen.... 相似文献
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流化床O2/CO2燃烧技术和化学链燃烧技术 总被引:3,自引:0,他引:3
O2/CO2燃烧技术不仅能使分离收集CO2和处理SO2容易进行,还能减少NOx排放,是一种能够综合控制燃煤污染物排放的新型洁净燃烧技术。流化床O2/CO2燃烧技术将流化床和O2/CO2燃烧技术的优点结合起来,有可能取得更好的效果。化学链燃烧技术打破了自古以来的火焰燃烧概念,开拓了根除燃料型NOx生成、控制热力型NOx产生与回收CO2的新途径,是解决能源与环境问题的创新性突破口。介绍了流化床O2/CO2燃烧技术和流化床化学链燃烧技术的原理和研究现状,比较了它们之间的差别,展望了发展前景。 相似文献
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多孔CO2吸附剂研究进展 总被引:1,自引:0,他引:1
CO2吸附分为物理吸附和化学吸附。物理吸附主要发生在微孔内,常见的物理吸附剂包括活性炭、沸石、硅胶等。调整多孔材料的结构可以改变吸附性能。通过在多孔材料尤其是介孔材料孔表面接枝或浸渍胺类等碱性物质,将物理吸附转化为新化学吸附,是提高多孔吸附剂吸附性能的有效方法。综述了活性炭、沸石、硅胶和改性介孔材料等多种多孔CO2吸附剂的研究进展,指出了研究和改进的方向。 相似文献
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Chris Pratt Adrian S. Walcroft Julie Deslippe Kevin R. Tate 《Waste management (New York, N.Y.)》2013,33(2):412-419
Landfills that generate too little biogas for economic energy recovery can potentially offset methane (CH4) emissions through biological oxidation by methanotrophic bacteria in cover soils. This study reports on the CH4 oxidation efficiency of a 10-year old landfill cap comprising a volcanic pumice soil. Surface CH4 and CO2 fluxes were measured using field chambers during three sampling intervals over winter and summer. Methane fluxes were temporally and spatially variable (?0.36 to 3044 mg CH4 m?2 h?1); but were at least 15 times lower than typical literature CH4 fluxes reported for older landfills in 45 of the 46 chambers tested. Exposure of soil from this landfill cover to variable CH4 fluxes in laboratory microcosms revealed a very strong correlation between CH4 oxidation efficiency and CH4/CO2 ratios, confirming the utility of this relationship for approximating CH4 oxidation efficiency. CH4/CO2 ratios were applied to gas concentrations from the surface flux chambers and indicated a mean CH4 oxidation efficiency of 72%. To examine CH4 oxidation with soil depth, we collected 10 soil depth profiles at random locations across the landfill. Seven profiles exhibited CH4 removal rates of 70–100% at depths <60 cm, supporting the high oxidation rates observed in the chambers. Based on a conservative 70% CH4 oxidation efficiency occurring at the site, this cover soil is clearly offsetting far greater CH4 quantities than the 10% default value currently adopted by the IPCC. 相似文献
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采用有机物前驱法制备了3种尖晶石型铝酸盐催化剂(CoAl_2O_4,ZnAl_2O_4,CoAl_2O_4)。采用FTIR,XRD,UV-Vis DRS等技术对催化剂进行表征,并将催化剂应用于CO_2的光催化还原。表征结果显示:除CoAl_2O_4外,CoAl_2O_4和ZnAl_2O_4在煅烧时均直接形成尖晶石相;CoAl_2O_4,CoAl_2O_4,ZnAl_2O_4的平均粒径分别为25.21,21.35,23.26 nm,禁带宽度分别为1.77,1.45,3.82 eV。分别以煅烧温度为900℃、煅烧时间为4 h时制得的ZnAl_2O_4,CoAl_2O_4,CoAl_2O_4为催化剂,在催化剂加入量为1.5 g/L、CO_2流量为200 mL/min、反应温度为60℃的条件下光催化反应8 h,甲酸产生量分别为443.54,365.65,241.39μmol/g。 相似文献
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采用巨正则蒙特卡罗方法模拟了CO_2在FAU分子筛上的吸附情况,比较了不同CO_2逸度下,CO_2在分子筛模型上的吸附位、吸附量的变化,拟合了其吸附等温线。结果表明:在吸附饱和状态下,分子筛的孔结构越大,对CO_2的吸附量越大,对于比CO_2分子更小的微孔结构,吸附几乎不发生;在低逸度下,CO_2的吸附主要发生在小孔内,随着逸度的提高,CO_2的吸附量迅速上升;在高逸度下,吸附量的提高主要发生在大孔内;FAU分子筛吸附CO_2的过程符合Ⅰ型Langmuir吸附等温线,在高压下对CO_2的吸附能力远大于低压下的吸附能力。 相似文献
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Landfills are some of the major anthropogenic sources of methane emissions worldwide. The installation and operation of gas extraction systems for many landfills in Europe and the US, often including technical installations for energy recovery, significantly reduced these emissions during the last decades. Residual landfill gas, however, is still continuously produced after the energy recovery became economically unattractive, thus resulting in ongoing methane emissions for many years. By landfill in situ aeration these methane emissions can be widely avoided both, during the aeration process as well as in the subsequent aftercare period. Based on model calculations and online monitoring data the amount of avoided CO2-eq. can be determined. For an in situ aerated landfill in northern Germany, acting as a case study, 83–95% (depending on the kind and quality of top cover) of the greenhouse gas emission potential could be reduced under strictly controlled conditions. Recently the United Nations Framework Convention on Climate Change (UNFCCC) has approved a new methodology on the “Avoidance of landfill gas emissions by in situ aeration of landfills” (UNFCCC, 2009). Based on this methodology landfill aeration projects might be considered for generation of Certified Emission Reductions (CERs) in the course of CDM projects. This paper contributes towards an evaluation of the potential of landfill aeration for methane emissions reduction. 相似文献
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Fly ashes with high-unburned-carbon content, referred to as fly ash carbons, are an increasing problem for the utility industry, since they cannot be marketed as a cement extender and, therefore, have to be disposed. Previous work has explored the potential development of amine-enriched fly ash carbons for CO(2) capture. However, their performance was lower than that of commercially available sorbents, probably because the samples investigated were not activated prior to impregnation and, therefore, had a very low surface area. Accordingly, the work described here focuses on the development of activated fly ash derived sorbents for CO(2) capture. The samples were steam activated at 850 degrees C, resulting in a significant increase of the surface area (1075m(2)/g). The activated samples were impregnated with different amine compounds, and the resultant samples were tested for CO(2) capture at different temperatures. The CO(2) adsorption of the parent and activated samples is typical of a physical adsorption process. The impregnation process results in a decrease of the surface areas, indicating a blocking of the porosity. The highest adsorption capacity at 30 and 70 degrees C for the amine impregnated activated carbons was probably due to a combination of physical adsorption inherent from the parent sample and chemical adsorption of the loaded amine groups. The CO(2) adsorption capacities for the activated amine impregnated samples are higher than those previously published for fly ash carbons without activation (68.6 vs. 45mg CO(2)/g sorbent). 相似文献
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以羟乙基乙二胺(AEEA)为基础吸收剂,分别加入二乙烯三胺(DETA)、三乙烯四胺(TETA)、四乙烯五胺(TEPA)作为活化剂,探讨了不同烯胺体积分数和CO2负载量(吸收的CO2与活化吸收剂的摩尔比)对各烯胺活化的AEEA吸收剂CO2吸收热、解吸热、CO2脱除率的影响。综合对比结果,最优的活化吸收剂为AEEA+5%(φ)DETA,其最低CO2吸收热为63.0 kJ/mol(以每摩尔CO2计),解吸热为82.5 kJ/mol,CO2脱除率为76.2%。 相似文献
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Effects of leachate addition on ammonia volatilization and N2O and CO2 emissions from two different soils were investigated using the 10-day laboratory incubation method at two levels of moisture content. Ammonia volatilization was dominated by soil pH and only occurred in alkaline clay soil, where 0.26–0.32% of soil ammonia could be lost. The N2O emission from the alkaline clay soil was one order of magnitude greater than that from the acidic sandy soil, when either water or leachate was irrigated. Increasing the moisture content from 46% water-filled pore space (WFPS) to 70% WFPS in the alkaline clay soil or the acidic sandy soil by either water or leachate irrigation increased the N2O emission by over twofold. The CO2 emission from each soil sample at the two WFPSs was almost the same. The CO2 emission from the alkaline clay soil with leachate addition was 72% lower than that from the acidic sandy soil with leachate addition, and 6.7 times higher than that from the alkaline clay soil with distilled water addition. Ammonia volatilization and N2O emission under leachate irrigation could be minimized by avoiding the excessively wet condition and by selecting the acidic sandy soil with low organic carbon and total nitrogen content. 相似文献
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Hitoki Matsuda Hiroki Kageyama Yuuki Kawaguchi Shohichi Osada Mitsuhiro Kubota 《Journal of Material Cycles and Waste Management》2014,16(4):677-683
Dynamic studies on the volatilization of lead from CaO–SiO2–Al2O3 molten slags were conducted in a lab-scale melting furnace from 1623 to 1773 K under different mixed gas atmospheres of CO 0.05–0.3 atm to CO2 0–0.3 atm to N2 (balance), HCl 1.7 × 10?3–6.7 × 10?3 atm to N2 (balance), and H2S 3.0 × 10?4 to 1.7 × 10?3 atm to N2 (balance). The slag samples consisted of the mixed powders of 20–50 wt% CaO, 30–60 wt% SiO2, and 10–40 wt% Al2O3, containing 2000 ppm PbO.Results showed that the rates of volatilization of lead from the CaO–SiO2–Al2O3 molten slags under the N2–CO–CO2, N2–HCl, and N2–H2S gas atmospheres were higher than those under the simulated air (N2–O2), which increased with CO, HCl, and H2S partial pressures. At \(p_{{HCl}}\) = \(p_{H_{2}S}\) = 1.7 × 10?3 atm, the apparent rate constants for the volatilization of lead under the N2–H2S and N2–HCl gas atmospheres were nearly equal, which increased with a rise in temperature. Results also showed that the rate of volatilization of lead from the molten slag decreased drastically with the increasing viscosity of the molten slag, in the viscosity range lower than 3 Pa s. Consequently, the volatilization of lead from the CaO–SiO2–Al2O3 molten slag was significantly influenced by CO, HCl, and H2S partial pressures and by the viscosity of the molten slag. 相似文献
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煅烧过程中吸收剂的烧结现象和循环反应过程中的磨损及破碎现象是导致钙基吸收剂循环煅烧/碳酸化捕集CO2性能不稳定的主要原因.针对目前几种常用的提高钙基吸收剂循环捕集性能的方法进行了总结,并对钙基吸收剂顺序脱除SO2/CO2的方法进行解释. 相似文献