首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 458 毫秒
1.
采用液固反应法合成了负载AlCl3催化剂,用于催化桥式四氢双环戊二烯异构化合成挂式四氢双环戊二烯的反应。通过考察载体、负载量对催化剂活性的影响,选定SiO2作载体、负载量为60%的催化剂用于该反应;研究了负载催化剂用量、溶剂种类及反应时间对异构化反应的影响,得到了最佳反应条件:以挂式四氢双环戊二烯作溶剂,催化剂质量分数14%,反应时间2 h。在此条件下桥式四氢双环戊二烯的转化率为99%,挂式四氢双环戊二烯的选择性为97.9%。该过程反应后处理简单,环境友好。  相似文献   

2.
制备了Ni/沸石双功能催化剂,筛选了催化剂载体,并以Ni/HY为催化剂、双环戊二烯为原料,考察异构化温度和催化剂用量对一步反应合成挂式四氢双环戊二烯转化率和选择性的影响,结果表明,双环戊二烯转化率大于96%,挂式四氢双环戊二烯收率达到21.4%,并关联了催化剂酸性与活性。  相似文献   

3.
采用过量浸渍法制备了一系列的氢型β沸石(Hβ)负载磷钨酸(PW),用于桥式四氢双环戊二烯(endo-TCD)异构化合成金刚烷(ADH)反应.X射线衍射(XRD)、氨程序升温脱附(NH3-TPD)等表征方法对催化剂进行表征.表征结果表明:PW在Hβ表面呈高度分散状态,10%PW/Hβ具有最大的酸量.对异构化反应中的焙烧温度、反应温度、时间、初压、溶剂用量和催化剂用量等工艺条件进行了考察,得出在适宜的操作条件下即催化剂10%PW/Hβ焙烧温度350℃、反应温度240℃、n(环己烷)/n(endo-TCD)=5、m(催化剂)/m(endo-TCD)=0.8、初压0.8MPa、反应时间3 h,endo-TCD转化率达到99.3%,金刚烷的收率达到22.4%.  相似文献   

4.
分子筛催化endo-THDCPD异构制备exo-THDCPD   总被引:5,自引:0,他引:5       下载免费PDF全文
张香文  苗谦  邹吉军  邢恩会  王莅  米镇涛 《化工学报》2007,58(12):3059-3063
挂式四氢双环戊二烯是重要的高能量密度液体燃料,通过桥式四氢双环戊二烯异构反应制得,原有工艺采用污染严重的AlCl3作为催化剂,本文采用分子筛催化剂取代AlCl3,对分子筛筛选、表面酸性调节、反应条件优化和催化剂再生进行了研究。结果表明,具有较大孔径的Y型分子筛具有较高的活性,具有较多弱酸性中心的HUSY效果较佳,负载氟元素可以抑制中强酸位、增加弱酸位,提高反应选择性。最佳反应条件为:催化剂6. 6%F/HSSY,反应温度195℃,催化剂浓度20%。在此条件下异构反应转化率为94. 0%,选择性为98. 4%,高温焙烧可以有效地使催化剂再生而不影响活性。  相似文献   

5.
PW/USY复合型催化剂上金刚烷的合成   总被引:1,自引:1,他引:1  
在100 mL间歇式不锈钢高压反应釜中,考察了超稳Y沸石负载磷钨酸(PW)用于桥式四氢双环戊二烯(endo-TCD)异构化合成金刚烷反应中的催化性能,并用X射线衍射、氨程序升温脱附和FT-IR等表征方法对催化剂进行表征.结果表明,当PW负载量为10%时PW/USY酸量最大,催化剂的酸性质和孔结构是影响催化性能的重要因素.在适宜的操作条件下即10%PW/USY催化剂焙烧温度450℃、反应温度260℃、n(环己烷)/n(endo-TCD)=5、w(cat.)/w(endo-TCD)=0.2、初压0.8 MPa、反应时间6 h,endo-TCD的转化率达到99.5%,金刚烷的收率达到28.3%.  相似文献   

6.
四氢双环戊二烯异构化过程的溶剂效应   总被引:4,自引:0,他引:4  
采用无水AlCl3为催化剂,考察了使用不同溶剂对桥式四氢双环戊二烯(endo-THDCPD)异构化为挂式四氢双环戊二烯(exo-THDCPD)过程中反应速率、反应转化率、收率、选择性及杂质生成量的影响。采用气相色谱对反应原料、产物及杂质进行定量分析。结果表明溶剂的使用对于异构化反应有显著的影响:甲苯作溶剂时对反应有很大的抑制作用,而1,2-二氯乙烷作溶剂时,则有明显改善,在催化剂浓度3%(wt)、最佳反应温度60℃条件下,反应结果:转化率97.73%、收率97.66%、选择性99.93%。同无溶剂反应时相比,最佳反应温度降低、产物中金刚烷生成量减少同时无焦油产生。实验中以原料endo-THDCPD为对象考察1,2-二氯乙烷作溶剂时的反应动力学,得到了动力学方程。  相似文献   

7.
高密度烃燃料挂式四氢双环戊二烯的研究进展   总被引:2,自引:0,他引:2  
综述了由双环戊二烯加氢、异构化制备挂式四氢双环戊二烯的合成方法,概括了双环戊二烯加氢催化剂的种类,比较了几种催化剂的优缺点,并对连续式和间歇式加氢工艺发展现状进行了总结。对桥式四氢双环戊二烯异构化反应催化剂和Lewis酸催化反应过程及机理进行了介绍。提出了加氢及异构化催化剂的发展方向,并提出了改进挂式四氢双环戊二烯合成工艺的建议。  相似文献   

8.
催化异构化合成挂式四氢双环戊二烯   总被引:2,自引:0,他引:2  
杜咏梅  李春迎  石强  吕剑 《工业催化》2005,13(11):47-49
对催化异构化桥式四氢双环戊二烯合成挂式四氢双环戊二烯的反应进行了研究。考察了无水AlCl3催化下,溶剂、溶剂用量、催化剂用量和反应时间对转化率以及选择性的影响。结果表明,以CH2Cl2为溶剂,CH2Cl2和桥式四氢双环戊二烯的用量比为0.8,催化剂用量为20%,反应时间为3 h,桥式四氢双环戊二烯的转化率为97.12%,挂式四氢双环戊二烯的选择性为99.28%。  相似文献   

9.
四氢环戊二烯三聚体的合成   总被引:1,自引:0,他引:1  
李春迎  杜咏梅  吕剑 《化学试剂》2007,29(6):353-354,357
双环戊二烯与环戊二烯反应,经两步合成了标题化合物。考察了环戊二烯与双环戊二烯反应中温度、压力、反应时间及溶剂用量对转化率和环戊二烯三聚体收率的影响,最佳条件220℃,0.5 MPa,m(溶剂)∶m(原料)为50%,反应4 h,双环戊二烯转化率85.4%,环戊二烯三聚体收率76.5%。考察了环戊二烯三聚体加氢反应中催化剂用量、温度、氢气压对反应的影响,在m(Raney Ni)∶m(原料)为25%,90℃,4.0 MPa的最佳条件下反应540 min,收率99.6%。两步反应总收率76.2%,产物经质谱、红外光谱等进行了表征。  相似文献   

10.
以对甲苯磺酸为催化剂,用双环戊二烯水合制得羟基二氢双环戊二烯。考察了蒸馏水/双环戊二烯(摩尔比)、反应时间、反应温度及对甲苯磺酸(质量比)等主要因素对实验的影响,确立了最佳的工艺条件为:蒸馏水/双环戊二烯(摩尔比)为10:1,反应时间9h,反应温度100℃,对甲苯磺酸质量分数1%。在此条件下产品收率可达到83%,经减压蒸馏之后物质纯度可达到97%。并对所得到的产品进行折光率测定和红外谱图表征。  相似文献   

11.
The hydrogenation of CO2 was studied over composite catalysts obtained by mixing Cu-based methanol synthesis catalyst and HY zeolite. A mechanism associating methanol synthesis and MTG (methanol to gasoline) reaction allowed the formation of C1-C4 hydrocarbons. It was found that the catalytic behaviors of the composite catalysts were favorably influenced by the characteristics of the methanol synthesis catalysts. The Cu-La2Zr2O7 catalyst we recently developed associated with HY zeolite exhibited interesting performances in hydrocarbon synthesis. The addition of ZrO2 to Cu---La2Zr2O7/HY enhanced the ability to produce hydrocarbons. Comparing composite catalyst systems prepared with different Cu-based methanol synthesis catalysts, the effect of Na contamination on methanol and hydrocarbon formation over composite catalysts were also discussed.  相似文献   

12.
研究了以异丁醛和2,2,4-三甲基-1,3-戊二醇(TMPD)为原料,HY沸石分子筛为催化剂合成了青叶口恶烷的反应,考察了醛醇比、反应时间、带水剂、催化剂用量与其循环使用性对该反应的影响。结果表明:与传统催化体系相比,该体系不仅具有相当的转化率和选择性,而且具有催化剂分离简单、可循环使用的优点。  相似文献   

13.
张美德  王丰  王吉德 《工业催化》2015,23(10):758-762
以水热法合成HY分子筛为载体,等体积浸渍法制备HY型分子筛负载Pd催化剂(Pd/HY)。在反应温度160℃、空速120 h-1和V(HCl)∶V(C2H2)=1.1∶1条件下,考察催化剂用于乙炔氢氯化反应制氯乙烯的催化性能及载体中硅铝比对催化剂催化性能的影响。用XRD、FI-IR、SEM和BET对Pd/HY催化剂的物化性质进行表征,结果表明,Pd/HY(HY分子筛的Si/Al=8)催化剂表现出较好的催化活性,乙炔转化率为97.67%,氯乙烯选择性为98.44%。与工业HY型分子筛为载体的催化剂相比,乙炔转化率提高29%,寿命较长,稳定性良好。  相似文献   

14.
The synthesis of MTBE was studied in the gas phase at elevated temperatures (up to 175°C) and low pressures (150 kPa) where the MTBE formation rate is limited by thermodynamic equilibrium, using various solid acid catalysts (Amberlyst-15 resin, silica-alumina, HY and H-ZSM-5 zeolites). All the zeolites studied were found to exhibit better selectivities to MTBE than the commercially used Amberlyst-15 resin catalyst. The formation of byproducts increased with increasing temperature and appeared to have a strong enhancing effect on catalyst deactivation. H-ZSM-5 seems to be more suitable for high temperature formation of MTBE because of its excellent selectivity towards MTBE and low deactivation behavior.  相似文献   

15.
Y/composite titania-silica (CTS) support was prepared by the in situ growth of CTS on HY zeolite. The effects of HY zeolite pretreatment and Y/CTS modification with P and F for adjusting the acidity of the support were studied. The results showed that the structure of Y/CTS was in the form of CTS as shell and HY zeolite particles as core. The content of HY zeolite affected the acidity, acidity distribution and pore structure of Y/CTS. The density of strong acid sites on the HY zeolite surface could be partly reduced by dealumination with citric acid. This reduced the CTS coverage on the outer surface of the HY zeolite, leading to the increased acidity of Y/CTS. The acidity distribution of the support could also be adjusted by P and F modification. Hydrotreating catalysts were prepared with Y/CTS as support. The catalysts were tested using the hydrotreating reaction of a coker gas oil (CGO). The experimental results showed that the catalyst hydrodenitrogenation (HDN) performance could be remarkably improved by adjusting the acidity of the catalyst support via HY zeolite pretreatment and P and F modification. The catalysts with proper Brönsted (B) acidity and Lewis (L) acidity behaved well in hydrodesulfurization (HDS) and HDN performances.  相似文献   

16.
采用高温高压反应釜研究了十氢萘在低硅铝比HY分子筛[n(Si)/n(Al)=3.2]、Beta分子筛n(Si)/n(Al)=9.7]和双功能催化剂Pt-HY、Pt-Beta上的加氢开环反应,考察了分子筛孔道结构及酸性质、贵金属Pt及反应温度等因素对十氢萘转化率和产物选择性的影响。结果表明,十氢萘在Beta分子筛上的转化率较高,且有大量脱氢缩合产物(DHC)生成。Pt引入HY和Beta分子筛后,初始反应速率升高,十氢萘转化率增加,C10产物中开环异构比增大,Beta分子筛上的脱氢缩合反应得到抑制。反应温度升高可以提高十氢萘在HY分子筛上的转化率,使得C10产物选择性下降,而开环异构比(ROP/Iso)增大。  相似文献   

17.
Vapor phase alkylation of catechol with t-butyl alcohol (TBA) has been studied over HY and dealuminated HY zeolites (obtained by controlled steaming) in the temperature range 120–200 °C. The predominantly formed product over these catalysts is 4-t-butylcatechol (4-TBC) with more than 86% selectivity, the minor products being 3-t-butylcatechol (3-TBC) and 3,5-di-t-butylcatechol (3,5-DTBC). Moderately steam-treated HY zeolites (steamed at 550 and 700 °C) showed marked increase in catechol conversion and 4-TBC yield. The influence of various reaction parameters such as temperature, space velocity and molar ratio of the reactants are discussed.  相似文献   

18.
Zeolite Y in sodium form (NaY) was synthesized using silica source from rice husk, transformed to ammonium form (NH4Y), and calcined to convert to proton form (HY). The direct conversion of NH4Y to HY resulted in loss of the zeolite crystallinity and lower surface area. Thus, the NH4Y was further used in the preparation of cerium (Ce) catalysts. The NH4Y was also treated with a basic solution in an attempt to generate mesopores but only site defects were likely formed. The supported Ce catalysts with good Ce dispersion were prepared by wetness impregnation of Ce precursor solution on NaY, NH4Y, and base-treated NH4Y. Upon calcination, the generated catalysts were notated as Ce/NaY, Ce/HY, and Ce/YB. In catalytic testing on ethanol oxidation at varying temperature in a continuous laboratory-scale fixed-bed reactor, all the zeolites gave low ethanol conversion at 100–300 °C. The catalytic activity significantly improved with the presence of Ce. The Ce/YB showed the higher ethanol conversion and CO2 yield than Ce/NaY and Ce/HY probably because of the presence of more local site defects on the zeolite.  相似文献   

19.
李杰  刘杰 《云南化工》2004,31(3):1-3,13
甲基叔丁基醚(MTBE)作为烷基化剂,以改性HY分子筛为催化剂,在常压连续流动固定床反应器上,对苯酚烷基化合成对叔丁基和2,4 二叔丁基苯酚(2,4 DTBP)的反应规律进行了较为系统的研究。以不同改性物及其含量改性HY分子筛,可调节其表面酸量、酸分布及孔道尺寸,从而改变催化剂的反应活性及产物选择性。苯酚与MTBE烷基化反应主要在中等强度和弱的B酸中心上进行。催化剂表面的酸量和酸分布不但影响活性,同时影响2,4 DTBP的选择性。对单组分氧化物改性的HY分子筛催化剂研究表明,每种改性物均存在一个最佳含量,P2O5改性后HY催化剂的性能最优越。苯酚的转化率达99.60%,2,4 DTBP选择性达63.90%。这一结果是目前分子筛作催化剂合成2,4 DTBP的最好结果,具有潜在的应用前景。  相似文献   

20.
In this present paper, we report catalytic decomposition of methane over Ni/HY catalysts, with varying Ni loading at 550 °C and atmospheric pressure. The relationships between catalyst performance and characterization of the fresh and used form of catalysts are discussed from the data obtained by scanning electron microscopy, X-ray diffraction analysis, temperature programmed reduction, O2 pulse chemisorption and carbon elemental analyses. It is observed that, the catalytic activity of Ni/HY catalysts is high at initial stages and gradually decreased with time and finally deactivated completely. The yield of hydrogen and carbon nanofibers is strongly dependent on Ni loading. It is found that 20 wt% Ni/HY catalyst showed higher hydrogen yield over the other loadings.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号