2×130t/h热电锅炉烟气脱硫工程调试及优化

分析了2×130t/h锅炉配套石灰石—石膏脱硫系统调试过程中出现的问题,提出了解决措施并对运行参数进行了优化。结果表明,在实际工况下,燃用中低硫煤,控制吸收塔液位为7.3m,pH值为5.4,投运2台循环泵时,脱硫系统运行最为经济有效。     

半干法脱除球团烟气中的SO2及Hg0

采用钙基吸收剂及复合氧化剂半干法脱除模拟球团烟气中的SO_2及Hg~0,考察了多因素条件对吸收效果的影响。实验结果表明,在以NaClO和NaClO_2为复合氧化剂、 NaClO与NaClO_2体积比1∶0.5、复合氧化剂质量分数3%、反应温度110℃、钙基吸收剂质量3.0 g、模拟烟气进气流量1.2 L/min的条件下,SO_2和Hg~0的脱除率分别为98%和93%,证明钙基吸收剂与复合氧化剂对污染物球团烟气中的SO_2和Hg~0有良好的脱除作用。     

CeO2/TiO2纳米管催化剂脱硝性能研究

利用废气中本身含有的CO催化还原烟气中的NO_x,可以实现以废治废。采用TiO₂纳米管负载CeO₂,制备CeO₂/TiO₂纳米管催化剂,并对其进行了SEM表征及影响因素实验。实验结果表明：在n（Ce）∶n（Ti）=3∶7、焙烧温度500 ℃、焙烧时间3 h时制备的CeO₂/TiO₂纳米管催化剂形貌较好,表面颗粒分布相对均匀;反应温度400~600 ℃时NO脱除率达98%;该催化剂具有一定的抗氧性能;当n（SO₂）∶n（NO）=（1∶2）~（2∶1）时,NO脱除率仍然在95%以上。     

生物滴滤塔处理模拟甲硫醚废气

在常温条件下,采用生物滴滤塔处理模拟甲硫醚废气,考察了气体空床停留时间(EBRT)、容积负荷、喷淋密度及营养液pH对生物滴滤塔性能的影响。实验结果表明:当EBRT为90 s、进气甲硫醚质量浓度为150 mg/m~3、喷淋密度为0.65 m~3/(m~2·h),营养液pH为6.8时,甲硫醚去除率为90%;容积负荷高于15 g/(m~3·h)时,对生物滴滤塔的性能产生抑制作用;EBRT为90 s及60 s时,最佳喷淋密度分别为0.56~0.65 m~3/(m~2·h)及0.65~0.75 m~3/(m~2·h);降解甲硫醚的微生物对pH的变化较敏感,最适营养液pH为6~7。     

Investigation of titanium liquid/gas diffusion layers in proton exchange membrane electrolyzer cells

In a proton exchange membrane electrolyzer cell (PEMEC), liquid/gas diffusion layer (LGDL) is expected to transport electrons, heat, and reactants/products to and from the catalyst layer with minimum voltage, current, thermal, interfacial, and fluidic losses. In addition, carbon materials, which are typically used in PEM fuel cells (PEMFCs), are unsuitable in PEMECs due to the high ohmic potential and highly oxidative environment of the oxygen electrode. In this study, a set of titanium gas diffusion layers with different thicknesses and porosities are designed and examined coupled with the development of a robust titanium bipolar plate. It has been found that the performance of electrolyzer improves along with a decrease in thickness or porosity of the anode LGDL of titanium woven meshes. The ohmic resistance of anode LGDL and contact resistance between anode LGDL and the anode catalyst play dominant roles in electrolyzer performance, and better performance can be obtained by reducing ohmic resistance. Thin titanium LGDLs with straight-through pores and optimal pore morphologies are recommended for the future developments of low-cost LGDLs with minimum ohmic/transport losses.     

Hydraulic fracturing as an interpretive policy problem: lessons on energy controversies in Europe and the U.S.A.

This special issue addresses hydraulic fracturing for shale gas extraction as an interpretive policy problem. Bringing together empirical cases from the U.S.A., the Netherlands, the U.K., Poland, and Germany, we identify three approaches to the interpretation of hydraulic fracturing in the article: understanding its meaning, contextual explanation of the institutionalization of its meaning, and policy design as intervention to alter its meaning. By exploring differences and similarities across these cases, we identified two central tensions in the meaning of shale gas in all cases: (1) economic opportunity or environmental threat and (2) transition toward a more carbon-free energy future or perpetuation of a fossil fuel system. We found that when actors shift the meaning of hydraulic fracturing to consider it predominantly an issue of threat, this explains the dominance of risk governance as an approach to managing the controversy. Alternately, when the meaning of fracking shifts from consideration as an economic opportunity or a bridge fuel to consideration of it as a barrier to an energy transition, this explains the decision to ban fracking. Therefore, a comparative assessment of the papers demonstrates the ways interpretive dimensions of politics can influence the governance of public policy.     

工业烟气氨法-络合法同时脱硫脱硝

在脱硫脱硝喷淋装置上采用氨法-络合法处理工业烟气。考察了吸收液pH、Fe(Ⅱ)EDTA浓度、初始烟气浓度、液气比对烟气同时脱硫脱硝效果的影响。实验结果表明:吸收液的酸碱度通过影响Fe(Ⅱ)与EDTA的络合形式进而影响NO去除率;SO_2去除率主要受吸收液pH和初始SO_2质量浓度的影响;当吸收液pH大于8、吸收液Fe(Ⅱ)EDTA浓度大于0.100 mol/L、初始SO_2质量浓度小于1 500 mg/m3、初始NO质量浓度为1 200 mg/m3时,SO_2去除率均在95%以上,NO去除率为54%;当液气比由1 L/m3增大至4 L/m3时,有效脱硫时间和有效脱硝时间分别增长了7 min和4 min。     

降低FCC再生烟气NOx排放助剂的实验室评价

通过采用ACE装置与烟气NOx分析仪器联用的实验室评价方法,可在更接近实际催化裂化反应-再生过程的条件下,评价助剂对再生烟气中NOx的催化转化性能,同时还可考察助剂的加入对催化裂化产品分布的影响。采用该方法对几种降NOx助剂的性能进行了评价,结果表明,在催化剂体系中含有Pt基CO助燃剂的情况下,加入4％的RDNO;助剂后,烟气NOx降低幅度约30％～40％,且催化裂化产品分布基本不受影响。     

模拟车用工况下5kW燃料电池尾气净化系统

模拟了车用工况下燃料电池发动机脉冲式排氢的特点,设计开发了一套质子交换膜燃料电池的尾气净化系统,并以5 kW燃料电池的尾气排放为例,研究其净化效果。研究了电池阳极排放氢气缓冲前后尾气中氢气浓度的变化,以及不同空速条件下氢气的去除效果。结果表明：电堆阳极排放氢气经过缓冲处理后,尾气中氢气浓度趋于平稳,大部分工况下处在2%以下,达到了安全处理的要求;尾气中氢气的去除效果与空速密切相关。对自制的整体式催化剂而言,当空速低于20000 h^-1时,氢气的去除率能达到约95%,而当空速达到39270 h^-1时,氢气的去除率仅为10.9%。鉴于这一问题,提出通过采用尾排空气的分流手段调整催化燃烧反应器对空速的要求,以提高尾气中氢气的去除率。     

Corruption in natural resource management: Implications for policy makers

Corruption is the main reason why resource-rich countries perform badly in economic terms. Corruption in resource-rich countries takes two main forms, rent-seeking and patronage. Resource rents induce rent-seeking as individuals compete for a share of the rents rather than use their time and skills more productively. And resource revenues induce patronage as governments pay off supporters to stay in power, resulting in reduced accountability and an inferior allocation of public funds. This paper systematically reviews the literature on natural resources and corruption, and outlines the main policy implications for donors and domestic policy makers. A main conclusion is that priority should be given to policies that address rent-seeking and patronage. In other words, policy in resource-rich countries should be less about macro-economic management and more about institutions to prevent rent-seeking and patronage, and about giving the right incentives to players in the resource sector. Moreover, all policies need to take into account their impact on rent-seeking and patronage, and some current policies may actually be harmful in this respect.