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151.
Fenton-混凝法处理生活垃圾沼液试验研究 总被引:3,自引:0,他引:3
以内蒙古某生活垃圾处理厂厌氧发酵后的沼液为研究对象,研究了联合采用Fenton法和混凝法处理该沼液时提高沼液CODCr去除率及其可生化性的影响因素。通过试验分析得出:Fenton阶段,pH值为3,Fe2+的质量浓度为275 mg/L,m(H2O2)/m(Fe2+)为12,反应时间为3 h;混凝阶段,搅拌时间为20 min,pH值为8,聚合氯化铝(PAC)的投加量为10 mg/L,静置1 h。此条件下,CODCr、色度和浊度的去除率分别为69.7%、90.3%、83.3%,m(BOD5)/m(CODCr)约为0.23,可生化性得到提高。 相似文献
152.
助剂对Ni/Co双金属催化剂上沼气重整制氢的影响 总被引:1,自引:1,他引:0
用传统的等体积浸渍法制备了不同助剂掺杂的NiCo/γ-Al2O3双金属催化剂,用V(CH4)/V(CO2)=1的混合气体模拟沼气,考察了助剂对沼气重整制氢催化剂NiCo/γ-Al2O3的催化性能与结构的影响。运用X射线衍射(XRD)、H2程序升温还原(H2-TPR)、BET比表面积与孔结构分析(BET)、热重-差示扫描量热(TG-DSC)、程序升温加氢(TPH)等手段对催化剂进行了表征。结果表明,NiCo/γ-Al2O3催化剂掺杂La2O3、CeO2或CaO后活性较好。CeO2在反应前后发生了晶型转变,ZrO2反应后仍以晶体形式存在,其它助剂以无定形均匀地分散在载体中。除ZrO2外的助剂增强了载体与金属之间的相互作用,使催化剂难以被还原。助剂的添加使催化剂的比表面积、孔容都有所减少,却明显改善了催化剂的抗积炭性能,其中La2O3与CeO2是较好的助剂。 相似文献
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155.
甘氨酸钠溶液提纯沼气性能的试验研究 总被引:1,自引:0,他引:1
对新型有机胺-甘氨酸钠溶液吸收CO2提纯沼气的适宜条件进行了试验研究,并采用加热再生的方法对甘氨酸钠溶液的再生性能进行了研究。考察了不同浓度(0.5~3 mol/L)甘氨酸钠溶液对CO2吸收速率和吸收负荷随时间的变化关系,气流速度对于甘氨酸钠溶液对CO2吸收速率和吸收负荷的影响以及温度对于甘氨酸钠溶液对CO2吸收速率的影响。试验结果表明,甘氨酸钠溶液的浓度越高,吸收量也越大,但吸收负荷越小;气流速度对甘氨酸钠吸收CO2速率影响较为明显;温度对甘氨酸钠吸收CO2速率影响较小。另外,甘氨酸钠溶液具有稳定的再生性能,适宜的再生温度和再生时间分别为108℃和3 h。 相似文献
156.
Adding O2 into biogas to achieve partial oxidation and CO2 mixed reforming can not only increase H2 + CO concentration, but also reduce energy cost for H2 production. In this study, optimized mixed reforming of biogas with O2 addition in spark-discharge plasma was pursued in combination with thermodynamic-equilibrium calculation. With respect to mixed reforming of biogas with O2 addition in spark-discharge plasma, combination coefficients of independent reactions were given to quantitatively evaluate the mixed extent at various O2/(CH4–CO2) ratios. Compared thermodynamic-equilibrium with experimental results, it can be concluded that the optimal O2/(CH4–CO2) ratio for optimized mixed reforming of biogas in spark-discharge plasma was about 0.7. When total-carbon conversion was relatively high (>75%), H2 + CO concentration on wet basis was the highest and energy cost for H2 production was the lowest at O2/(CH4–CO2) = 0.7, and their experimental results were closest to their thermodynamic-equilibrium values. 相似文献
157.
Bin Zhu Xiao-Song LiChuan Shi Jing-Lin LiuTian-Liang Zhao Ai-Min Zhu 《International Journal of Hydrogen Energy》2012
To produce high-concentration syngas (CO + H2) from biogas, the effect of pressurization on dry reforming of biogas (CH4/CO2 = 60%/40%) in kilohertz spark-discharge plasma was reported for the first time by elevating the pressure from 1 bar to 2 bar. It was found that elevating the pressure could not only increase the reactant conversions, but also reduce energy cost and increase fuel-production efficiency at the same specific energy input (SEI). In particular, pressurization exhibited a significantly positive effect on increasing CO2 conversion and decreasing energy cost for converting CO2. Syngas concentration as high as 83% (H2/CO = 1.4) was achieved with a ratio of the flow rates of product gas (dry basis) to feeding gas, 1.7, at 2 bar and SEI = 753 kJ/mol. The by-product, H2O, was produced with only about 5% of hydrogen-based selectivity in this work. At 2 bar, the effect of SEI was investigated by varying the power and flow rate, respectively. Compared with those at 1 bar, with the increase in SEI, reactants conversion increased fast, energy cost rose slowly and fuel-production efficiency decreased slowly at 2 bar. 相似文献
158.
A new anode micromodel for solid oxide fuel cells to predict the electrochemical performance of hydrocarbon‐fuelled porous composite anodes with various microstructures is developed. In this model, the random packing sphere method is used to estimate the anode microstructural properties, and the complex interdependency among the multicomponent mass transport, electron and ion transports, and electrochemical and chemical reactions is taken into account. As a case study, a porous Ni–YSZ composite anode operated with biogas fuel is simulated numerically and distributions of the current density, polarization, and mole fraction and rate of flux of the fuel components along the thickness of the anode are determined. The effect of the anode microstructural variables including the porosity, thickness, particle‐size ratio, and particle size and volume fraction of Ni particles on the anode electrochemical performance is also studied. © 2011 American Institute of Chemical Engineers AIChE J, 58: 1893–1906, 2012 相似文献
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160.
Andres Donoso‐Bravo Francis Mairet 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2012,87(10):1375-1378
The rate‐limiting step concept has been widely used in anaerobic digestion processes as well as in many different biological processes. Sometimes it is described as part of the study introduction, but many times is used to support the specific objectives of the work. However, there is no clear consensus of how to define this step or how to determine it. This review presents a critical revision of several methods and procedures proposed to determine the rate‐limiting step in the anaerobic digestion field. The review is structured as follows: first, the justification of this revision is presented, followed by the very basic original definition and the latest applications in determining the rate‐limiting step. It ends with a discussion about the existing methodologies and the possible directions for addressing this issue. Different experimental approaches have been used for determining the rate‐limiting step which, in general terms, can be grouped into two procedures: steady states and batch test evaluation. Modeling applications have rarely been employed despite them allowing a more detailed picture of the anaerobic digestion system Copyright © 2012 Society of Chemical Industry 相似文献