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1.
采用连续式超临界水反应装置,以褐煤和焦化废水配制的水煤浆为原料,考察了温度(450℃~600℃)和水煤浆浓度(20%~50%)对褐煤-焦化废水在超临界水中连续气化制氢的影响.结果表明,在褐煤一焦化废水超临界水共气化制氢过程中,存在明显的协同效应.在浆浓度为20%,600℃,25 MPa条件下,褐煤-焦化废水共气化的氢气产率和碳气化率比相同条件下二者单独气化的加权平均值分别增加了141.9 mL/g和6.1%.反应温度是影响褐煤-焦化废水超临界水共气化制氢的关键因素,随着反应温度从450℃提高到600℃,氢气的体积分数与产率分别由21.5%和85.3 mL/g增加到42.3%和371.8 mL/g,碳气化率由18.2%增大到29.8%.碳的气化率随水煤浆浓度的升高而降低,最高进浆浓度可达50%(质量分数),无堵塞现象发生.  相似文献   

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为拓宽反应吸附强化水蒸气重整制氢(ReSER)原料的应用范围,采用化工流程模拟软件Aspen Plus,针对包括C2H4、C2H6、C3H6、C3H8的C2/C3轻烃ReSER制氢反应可行性和优化条件进行热力学分析计算。在选择的反应压力0.1~5 MPa,温度200~800℃,水碳摩尔比(S/C)1~8和吸附剂中氧化钙和原料碳摩尔比(Ca/C)0~5条件下进行热力学分析计算。计算结果表明:在优选的水碳比(S/C)4,钙碳比(Ca/C)2.5,温度200~650℃,压力0.1~1.8 MPa的条件下,C2H4、C2H6、C3H6、C3H8均可分别通过ReSER反应获得H2含量在95%以上的产物,产物中H2浓度均随着水碳比和钙碳比的增大而提高。在假设的水碳比4,钙碳比2.5条件下,当CO2脱除率达到0.9以上,C2H4、C2H6、C3H6、C3H8的反应温度分别高于250、400、250、350℃时,产物中H2摩尔分数均可达到95%以上,产物中的H2浓度随着反应温度的升高和CO2脱除率的增加而提高。当CO2脱除率低于0.9,产物H2摩尔分数要达到95%时,C2H4、C2H6、C3H6、C3H8的反应温度均需升高50℃。在相同长度C链的烃类中,烯烃比烷烃更容易发生ReSER反应。而原料的碳链越长,则越容易发生ReSER制氢反应。  相似文献   

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采用吸附强化技术强化了乙醇水重整制氢过程。考察了温度、水醇比、液空速对无强化乙醇水重整制氢反应特性的影响,在此基础上研究了吸附强化乙醇水重整制氢反应特性。通过响应面法确定了吸附强化乙醇水重整制氢最优工艺条件为温度422~444 ℃、水醇比10.2~10.8、液空速0.13 h?1,在此条件下的氢产率为3.2 mol/mol,同比提高了51.7%,氢含量为88.91%,同比提高了22.9%,反应温度降低了178 ℃,降低了能耗,控制了CO2排放。  相似文献   

4.
吴嵘  吴素芳 《化工学报》2014,65(6):1961-1970
为拓宽反应吸附强化水蒸气重整制氢(ReSER)原料的应用范围,采用化工流程模拟软件Aspen Plus,针对包括C2H4、C2H6、C3H6、C3H8 的C2/C3轻烃 ReSER制氢反应可行性和优化条件进行热力学分析计算。在选择的反应压力0.1~5 MPa,温度200~800℃,水碳摩尔比(S/C)1~8和吸附剂中氧化钙和原料碳摩尔比(Ca/C)0~5条件下进行热力学分析计算。计算结果表明:在优选的水碳比(S/C)4,钙碳比(Ca/C)2.5,温度200~650℃,压力0.1~1.8 MPa的条件下, C2H4、C2H6、C3H6、C3H8均可分别通过ReSER反应获得H2含量在95%以上的产物,产物中H2浓度均随着水碳比和钙碳比的增大而提高。在假设的水碳比4,钙碳比2.5条件下,当CO2脱除率达到0.9以上,C2H4、C2H6、C3H6、C3H8的反应温度分别高于250、400、250、350℃时,产物中H2摩尔分数均可达到95%以上,产物中的H2浓度随着反应温度的升高和CO2脱除率的增加而提高。当CO2脱除率低于0.9,产物H2摩尔分数要达到95%时,C2H4、C2H6、C3H6、C3H8的反应温度均需升高50℃。在相同长度C链的烃类中,烯烃比烷烃更容易发生ReSER反应。而原料的碳链越长,则越容易发生ReSER制氢反应。  相似文献   

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用于PEMFC的天然气水蒸气制氢系统   总被引:1,自引:0,他引:1       下载免费PDF全文
代磊  李明  胡鸣若 《化工学报》2009,60(Z1):90-94
针对质子交换膜燃料电池(PEMFC)的应用要求,开发了一个包括天然气水蒸气重整、CO变换和变压吸附净化的制氢工艺过程,并着重对重整反应和变压吸附的操作条件进行了实验研究。考察了温度、空速和水碳比对重整反应的影响,得到适宜的工艺操作条件,实验结果表明:温度650℃、水碳比6、空速42h-1时,氢气含量为70.21%,甲烷转化率为77.41%;分析了温度、流速对变压吸附脱除CO效果的影响,结果表明:在0.2MPa、40℃和吸附、脱附时间120s的条件下,产品气中CO浓度接近于1×10-6,经过多次循环后产品气质量稳定,可以连续获得满足80W质子交换膜燃料电池要求的高纯度氢气。  相似文献   

6.
为制备具有大比表面积和高金属分散度的复合催化剂,研究了水热沉淀法制备Ni-CaO/Al2O3复合催化剂的工艺条件,实验考察了制备反应温度、尿素溶液溶度和焙烧温度对复合催化剂比表面积和Ni金属分散度的影响。结果表明,反应温度150℃、尿素溶液浓度3 mol/L、焙烧温度500℃时得到的复合催化剂有最大的比表面积134.4 m2/g和最高的Ni金属分散度9.45%。将该条件下制备的复合催化剂应用于固定床反应吸附强化甲烷水蒸气重整过程制氢评价,在0.1 MPa,600℃,H2O/CH4物质的量比为4,体积空速340 h-1条件下,得到氢气浓度为97.5%,甲烷转化率95.3%,均高于文献已报道水平。  相似文献   

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以超细氧化硅为载体,高硅铝比的ZSM-5分子筛为活性组分,挤条制成催化剂,用氧化钙和氧化镧的前驱体化合物改性,分别在800℃焙烧和600℃水蒸汽的条件下进行处理,在500℃、0.1MPa、水与碳四质量比0.2和碳四空速3 h-1的条件下,对催化剂性能进行评价.对成型、改性、水热处理和再生后的催化剂采用BET、NH3-T...  相似文献   

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制备了一组高催化活性的NiO-CaO/Al2O3复合催化剂并将其应用于反应吸附强化甲烷水蒸气重整制氢(ReSER)过程中。采用水热沉淀法制备了具有层状复合金属氢氧化物结构(NiAl-LDHs)的复合催化剂前驱体,高温焙烧后得到NiO-CaO/Al2O3复合催化剂hd-cat。通过传统浸渍法制备了另一组相同组分含量的NiO-CaO/Al2O3复合催化剂ci-cat作为对比。BET测得催化剂hd-cat比表面积为134.4 m2·g-1,H2-TPD测得其Ni金属分散度为9.25%,分别为催化剂ci-cat的3.8倍和1.3倍。CO2反应吸附性能(TGA)测试结果表明hd-cat吸附容量和吸附速率分别是ci-cat的1.8倍和2.7倍。在固定床反应器上,反应压力0.1 MPa、温度600℃、H2O/CH4摩尔比4:1条件下,评价了不同体积空速下复合催化剂ReSER制氢效果。hd-cat能达到的最大体积空速为2376 h-1,在此条件下能得到94.4%浓度的H2和98.4%的CH4转化率,十次反应-再生循环中,H2浓度和CH4转化率均保持在90%以上。相同反应条件下,复合催化剂ci-cat在体积空速1188 h-1时便失去制氢活性。实验结果证明水热沉淀法制备的高活性的复合催化剂hd-cat能适于高空速下的ReSER循环制氢要求。  相似文献   

9.
研究了吸附增强技术对甲醇水重整制氢过程的作用效果。对商业水滑石、Ca基吸附剂、负载型MgO吸附剂3种吸附剂进行了CO2-TPD考察。考察了反应温度、液空速、水醇摩尔比对甲醇水重整制氢的影响。在此基础上,选择Ca基吸附剂,利用响应面法,进行了吸附强化甲醇水重整制氢条件考察。研究结果表明,适宜的工艺条件为反应温度245~247℃,液空速0.30~0.31 h-1,水醇摩尔比3.15~3.19。在此条件下,与无强化的甲醇水重整制氢相比,氢产率为2.528 mol/mol,提高了32.77%,氢含量为92.1451%,提高了26.49%,氢产率相同则反应温度可降低57℃,是一条高效节能减排的制氢路线。  相似文献   

10.
李维  韩大超  张红  马超  蓝兴旺  张雪平 《化工进展》2013,32(10):2316-2318
以活性氧化铝为吸附剂材料,选取5.5~6.5 mm及4~5 mm两种粒径的活性氧化铝对压缩空气进行除湿实验研究,为活性氧化铝在压缩空气除湿系统中的运行提供依据。结果表明:在温度120℃、压力0.2 MPa、流量40 m3/h的条件下,5.5~6.5 mm活性氧化铝的再生性能优于4~5 mm活性氧化铝;在温度120 ℃、压力0.7 MPa、流量15 m3/h的条件下,前期在1200 s时间内,两者的吸附速率都很快,后期4~5 mm粒径的活性氧化铝的吸附稳定性更好。在给定的工况条件下,5.5~6.5 mm活性氧化铝再生效果比4~5 mm活性氧化铝要好,但吸附效果不如后者。  相似文献   

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Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.  相似文献   

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Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.  相似文献   

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In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.  相似文献   

18.
Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.  相似文献   

19.
收集了2007年7月~2008年6月世界塑料工业的相关资料,介绍了2007~2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.  相似文献   

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收集了2005年7月~2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、通用热固性树脂(酚醛、聚氨酯、不饱和树脂、环氧树脂)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。  相似文献   

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