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1.
采用室温过量浸渍法,制备不同F用量改性的HY分子筛催化剂。采用氨程序升温脱附法(NH3-TPD)、X线衍射仪(XRD)、傅里叶变换红外光谱仪(FT-IR)对催化剂的结构及酸性质进行表征,并在桥式四氢双环戊二烯(endo-TCD)制备挂式四氢双环戊二烯(exo-TCD)的反应中考察催化剂的催化性能。结果表明:最适宜的反应条件为以1.0%F/HY为催化剂,活化温度300℃,反应温度240℃,催化剂与原料质量比0.25∶1,溶剂环己烷与endo-TCD的摩尔比10∶1,初始压力1.0 MPa,反应时间1.5 h。最优条件下桥式四氢双环戊二烯的转化率达到92.6%,挂式四氢双环戊二烯的收率达到了59.4%。失活的催化剂可以通过550℃高温焙烧再生,其活性变化不大。  相似文献   

2.
以等体积浸渍法制备不同负载量的AgHY分子筛,利用物理吸附仪和X射线衍射(XRD)技术对分子筛吸附剂进行表征.BET结果表明改性分子筛的比表面积和孔容随Ag的负载量的增加而降低,XRD图谱的变化表明,银的负载仅降低了衍射峰强度,而对HY的骨架结构没有影响,并且也没有Ag2O的特征峰出现.在静态吸附条件下考察了改性AgHY分子筛吸附剂对二苯并噻吩(DBT)的脱除性能.结果表明,Ag改性的HY分子筛具有较好的吸附脱硫性能和再生性能.应用Ag负载量为10%的Ag10HY吸附剂,在吸附时间2h、吸附温度60℃的条件下,二苯并噻吩的脱除率可达90%,硫含量由最初的330μg·g-1降至33 μg·g-1.吸附后的Ag10HY吸附剂在温度400℃、空气介质中再生后,吸附脱除效果仍可达到89.4%.  相似文献   

3.
研究环戊二烯二聚体在雷尼镍催化剂存在下加氢合成桥式四氢双环戊二烯的反应条件,本文对温度、压力、时间及催化剂重复使用情况进行了实验考查,实验结果表明,在雷尼镍催化剂存在下,溶剂与环戊二烯二聚体的质量比2∶1、反应温度110~120℃、氢气压力3.5~4.0 MPa下反应4 h,加氢反应转化率为100%,桥式四氢双环戊二烯的收率在96%以上,纯度98.3%。随反应次数增加,催化剂活性降低,反应3次以后需要补充新鲜催化剂。  相似文献   

4.
采用静态水热法合成一系列Mn骨架改性的杂原子β分子筛,将其作为载体通过浸渍法负载Pt制备双功能催化剂,用X线衍射(XRD)、比表面积测定(BET)、电感耦合等离子发射光谱(ICP)、NH3程序升温脱附(NH3-TPD)、CO-化学吸附等手段对催化剂进行表征,并在常压固定床反应器上考察催化剂的正庚烷临氢异构化反应性能。结果表明:由骨架Mn改性的β分子筛负载Pt的催化剂显示出良好的催化活性,选择性明显高于通过Mn浸渍或Mn交换β分子筛得到的催化剂。催化剂最佳的组成为Pt负载量0.4%,n(MnO)/n(SiO2)=0.011,在230℃、空速2.7 h-1、氢料摩尔比值7.9时,正庚烷的转化率为62.1%,异构化选择性达到92.0%。骨架中引入杂原子Mn不仅可以调节孔道结构,还可以提高催化剂表面Pt的分散度,从而提高催化剂的异构化选择性。  相似文献   

5.
作者用2%的氟化铵溶液对A1PO_(4-5)和A1PO(4_11)分子筛进行了改性。产物经X射线粉末衍射、红外光谱、吸附水后的热重—失重速率等方法进行分析,结果表明氟化后分子筛的骨架发生改变.表面酸性研究表明氟化后分子筛不具B酸中心和L酸中心。  相似文献   

6.
采用机械混合法,利用ZrO2和WOx/ZrO2对Pt/HY分子筛进行了改性,考察了改性催化剂Pt/Zr—HY和Pt/WZr—HY上的正庚烷临氢异构化反应性能,探讨了改性催化剂影响催化反应活性和异构化选择性的原因。结果表明,改性后的Pt/HY催化剂,在反应活性下降的同时,异构化选择性显著提高,且异构化产物向裂解产物的转化温度明显提高,其中Pt/WZr—HY催化剂的这一效果尤为显著。但改性并不改变反应历程。同时改性也使:HY的酸量明显减少,酸强度改变,造成转化率减少及异构化选择性增大。  相似文献   

7.
利用液相压力微型反应系统,在150℃、液体空速40h~(-1)的条件下,对各种Y型分子筛作为十二烯-苯烷基化反应催化剂的稳定性进行了考察。结果表明,用碱土金属离子或稀土金属离子交换改性的HY分子筛在烷基化反应中具有比HY更好的稳定性。其中以SrHY分子筛的稳定性最好,在维持烯烃转化率在98%以上时,单周期的处理量可达160公斤烷基苯/公斤他化剂。研究还表明,在Y型分子筛中引入Sr~(2+)后能增强分子筛对苯的吸附能力,在反应温度下使苯仍能维持活化吸附状态。  相似文献   

8.
以HCl为Cl源经催化氧化,制备不同组成的HCl和Cl_2等的混合气体。考察在分子筛催化下混合气体中Cl_2浓度对苯氯化反应速率和Cl_2利用率的影响。比较不同氢型分子筛HY、HZSM-5、Hβ和稀土改性Y型分子筛(REY)的孔道结构、酸性对苯氯化反应的催化性能。通过BET、NH3程序升温脱附(NH3-TPD)、吡啶吸附傅里叶红外光谱(Py-FT-IR)等技术对催化剂进行表征。结果表明:混合气体中Cl_2浓度对苯氯化反应影响很小,分子筛的孔道结构及其酸种类是影响苯转化率的关键因素;Hβ分子筛由于其具有三维特殊孔道、合适的酸强度和较多的Lewis酸(L酸)酸量,其催化活性明显优于HY、HZSM-5分子筛;REY分子筛含L酸最多,催化活性最高。当Cl_2质量分数为15%,反应3 h时,在REY分子筛催化下,氯化苯的平均生成速率为8.4 g/(g·h)。  相似文献   

9.
通过对ZSM-5分子筛颗粒表面改性的方法,使之与聚二甲基硅氧烷(PDMS)形成更好的接触面结构,再将其涂覆在聚醚酰亚胺(PEI)基膜上,制备了表面改性ZSM-5分子筛填充的PDMS/PEI复合膜。将复合膜用于CO2/CH4体系与O2/N2体系的气体分离研究,实验结果表明:填充经过表面改性的ZSM-5分子筛的复合膜与填充未改性分子筛的复合膜相比,改性后分子筛在聚合物中的分散更加均匀,分子筛与聚合物基体之间的联结更加紧密,这都增强了分子筛的筛分作用;填充改性后分子筛的复合膜对气体的渗透能力略有增大,改性分子筛填充量(质量分数)为20%的复合膜对两种体系的分离效果最佳,CO2/CH4体系的分离系数提升23.8%,O2/N2体系提升28.6%。  相似文献   

10.
苯酚双环戊二烯环氧树脂的合成与固化性能研究   总被引:2,自引:0,他引:2  
以苯酚和双环戊二烯为原料,通过Friedel-Crafts反应,合成了双环戊二烯酚树脂(DPR)。用环氧氯丙烷对该树脂进行环氧化,还制得了含有双环戊二烯结构的环氧树脂(DER)。系统地考察了合成反应的条件,所得环氧树脂的最大环氧值为0.31~0.35,有机氯含量小于0.02mol/100g。用红外光谱考察了以甲基六氢苯酐(MeHHPA)为固化剂时该树脂在180 ℃时的固化速度,固化3.5 h时, 环氧开环的转化率大于92%。DSC的分析表明DER与双酚A环氧树脂E51混合(质量比为1:1),固化树脂的玻璃化转变温度Tg比E51固化树脂的玻璃化转变温度高15 ℃。  相似文献   

11.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

14.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

15.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

16.
17.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

18.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

19.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

20.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

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