Unipol气相法聚乙烯工艺技术进展

Unipol工艺是生产线型低密度聚乙烯(LLDPE)的常用方法,是高效催化剂与气相流化床相结合的工艺。美国联合碳化物公司(UCC公司)的冷凝态技术可极大提高反应器的撤热能力,从而大幅提高了时空产率;UCC公司开发的UnipolⅡ工艺采用两个串联的反应器可生产双峰聚乙烯,但装置的设备投资大、使用效率低、操作费用高。美国ExxonMobil化学公司的超冷凝技术是在循环气流中加入高浓度的惰性冷凝介质,操作时冷凝液的质量分数可高达15%~50%,生产能力可提高到250%以上.美国Univation公司研发的一种新型催化剂,实现了在单个反应器里生产双峰高密度聚乙烯,降低了约40%的成本;该公司采用其开发的第二代茂金属催化剂生产的茂金属LLDPE,其制品具有优异的加工性能、光学性能和力学性能及良好的热封性。     

茂金属聚乙烯加工技术评述

综述了几种茂金属聚乙烯加工技术的特点及进展情况,指出在单反应器中用茂－茂复配催化剂生产双峰或宽峰聚乙烯是解决茂金属聚乙烯加工困难的最优技术,开发这一技术应是今后努力的方向。     

气相法聚乙烯流化床反应器冷凝模式操作工艺

综述了气相法聚乙烯流化床反应器冷凝模式操作工艺方面的最新专利技术动态。阐明了流化床聚合反应器中气液导流器和喷雾器的设计原理和方法，详细分析了操作工艺条件与产品质量和产率之间的关系。还进一步指出茂金属催化剂与冷凝工艺的结合是一条最优的技术路线。     

聚乙烯生产技术及其催化剂的研究进展

阐述了当今世界聚乙烯（PE）催化剂，即铬系、钛系、茂金属和非茂金属单活性中心催化剂技术的发展，推动了PE生产过程和产品的技术进步，PE生产工艺和催化剂技术的进步使PE的性能进一步改进，更易于加工成型。新的生产技术主要包括：双峰PE生产技术、反应器新配置技术、冷凝态和超冷凝态技术等。通过对国内PE生产技术进步、催化剂的研发和装置国产化现状分析，指出与国外相比还存在较大差距，对今后我国PE工业的发展提出了建议。     

Univation技术公司高性能催化剂实现工业化

据海外媒体报道，Univation技术公司的高性能催化剂Prodigy BMC100最近实现工业化生产成功。采用这种催化剂可在一个单一反应器中生产具有双峰分子量分布的高密度聚乙烯（HDPE）薄膜级树脂。与以往采用两个串联淤浆反应器生产双峰HDPE的工艺相比，采用Prodigy催化剂可用单一的气相聚乙烯反应器生产HDPE，通过使用这种催化剂可使产品具有双峰能力，     

聚乙烯气相流化床生产技术进展

介绍了近几年聚乙烯气相工艺四个主要进展，即ＵｎｉｐｏｌⅡ工艺、冷凝态操作技术、Ｓｐｈｅｒｉｌｅｎｅ工艺和茂金属催化剂的应用及它们的特点，并提出了在我国聚乙烯发展过程中，优先采用气相流化床工艺的建议。     

茂金属加合物技术首次工业试验

采用中国石油化工股份有限公司茂金属加合物技术制备茂金属加合物,并进行负载化研究;完成了茂金属加合物催化剂催化乙烯聚合以及乙烯与α-烯烃共聚合的淤浆、环管淤浆、气相流化床工艺的中试;在中试的基础上,茂金属加合物催化剂于60kt／a气相流化床聚乙烯生产装置上成功进行了工业试验。探索了茂金属催化剂与Ziegler催化剂的切换技术,研究了催化剂组成和聚合工艺参数对聚乙烯树脂性能的影响。用所得茂金属聚乙烯树脂加工成的薄膜具有较好的透明性,并表现出了优异的落镖冲击强度和撕裂强度。     

茂金属加合物技术的工业应用试验

根据中国石化集团公司开发的茂金属加合物专利技术,进行了活性组分负载化研究,完成了茂金属加合物催化剂催化乙烯以及乙烯与α-烯烃共聚的淤浆、环管淤浆、气相流化床工艺的中试试验.在中试的基础上进行了茂金属加合物催化剂气相流化床聚乙烯工艺的工业应用试验,探索了茂金属催化剂与Ziegler催化剂之间的切换技术,开发了催化剂结构和配方以及聚合工艺参数对聚乙烯树脂牌号的调控技术.得到百吨级薄膜牌号的茂金属聚乙烯树脂,并对工业应用试验产品进行了加工研究.     

线性聚乙烯的主要生产技术及进展

PROCESSTECHNOLOGYANDPROGESSPOLYETHYLENE1前言线性聚乙烯（LLDPE）从70年代末实现工业化生产以来,迅速变成聚乙烯产品中的第三大品种。全球生产LLDPE主要采用的工艺有气相工艺、溶液工艺、浆液工艺。国际上各大公司为了提高竞争能力,保持竞争中的优势,除了开发极低密度（VLDPE）、超低密度聚乙烯（ULDP）、“双峰”树脂、宽分子量分布树脂新的产品外,还加大力度对催化剂技术、工艺技术和MXIPE的功能化进行专门开发和研究。象茂金属催化剂、冷凝态循环撤热技术、超临界浆液法技术和球形粒子树脂技术都是各大…     

茂金属催化剂首用于高密度聚乙烯

正中沙(天津)石化公司高密度聚乙烯装置使用茂金属催化剂产出合格产品。这是茂金属催化剂在国内液相法高密度聚乙烯装置的首次应用,将进一步带动高密度聚乙烯装置降本增效。高密度聚乙烯装置采用双环管淤浆生产工艺,可以生产单峰和双峰聚乙烯产品,催化剂为齐格勒和镉系催化剂。为了满足市场需求和技术储备,在中沙(天津)石化公司主     

Silica-Based Ziegler-Natta Catalysts: A Patent Review

Silica-based Ziegler-Natta catalysts are important industrially in the manufacture of polyethylene and polypropylene. They are scientifically very interesting because of the complex effects of porous silica on catalyst performance. This patent review explains how silica-based Ziegler-Natta catalysts are related to Phillips chromium-silica catalysts and explores their value for the gas phase and slurry processes for the manufacture of polyolefins. The subcategories dealt with are the following: magnesium-titanium-silica catalysts, which are valuable for high-density polyethylene, for the ethylene copolymers called linear low-density polyethylene;and ethylene-propylene rubber, and for isotactic polypropylene; vanadium-silica catalysts, which are useful in the polymerization and copolymerization of ethylene; and vanadium plus titanium-silica catalysts which often exhibit reactivity synergism. Dual-site and multisite catalysts are also reviewed.     

Silica-Based Ziegler–Natta Catalysts: A Patent Review

Silica-based Ziegler–Natta catalysts are important industrially in the manufacture of polyethylene and polypropylene. They are scientifically very interesting because of the complex effects of porous silica on catalyst performance. This patent review explains how silica–based Ziegler–Natta catalysts are related to Phillips chromium–silica catalysts and explores their value for the gas phase and slurry processes for the manufacture of polyolefins. The subcategories dealt with are the following: magnesium–titanium–silica catalysts, which are valuable for high-density polyethylene, for the ethylene copolymers called linear low-density polyethylene;and ethylene–propylene rubber, and for isotactic polypropylene; vanadium–silica catalysts, which are useful in the polymerization and copolymerization of ethylene; and vanadium plus titanium–silica catalysts which often exhibit reactivity synergism. Dual-site and multisite catalysts are also reviewed.     

Silica gel supported zirconocene dichloride/methylalumoxane catalysts for ethylene polymerization: Effects of heterogenation on activity,polymer microstructure and product morphology

The system zirconocene dichloride/methylalumoxane was supported on silica in order to provide ethylene polymerization catalysts for suspension or gas phase processes. Highest activity was found for a sandwich-like, three layer anchoring of the zirconium centers on the support surface. The new catalyst systems show a decrease of activity compared to polymerization experiments in homogeneous phase. However, the molecular weights are increased and the weight distributions remain narrow by immobilization of the active catalyst sites. Those supported metallocene catalysts could find application for the synthesis of polyethylene materials with controlled rheology.     

降冰片烯的合成研究进展

目前,降冰片烯合成方面的研究报道多为专利且年代跨度大,缺乏较为系统的综述。本文首先介绍了由（双）环戊二烯与乙烯合成降冰片烯的Diels-Alder反应机理,针对乙烯反应活性不足所采取的高压及高温两类补偿措施分别加以评述,并列举了其反应热及常见副反应等。结合高温高压及反应放热量大等特点,系统阐述了相关动力学研究方面的进展情况,为调控反应进程提供参考,以确保安全生产。本文还回顾了降冰片烯合成技术的发展过程,对比了现有液相工艺和气相工艺的优缺点,虽然气相工艺可以有效遏制副反应的发生,但由于气相工艺产量较低,目前实际生产中大多采用液相反应工艺,如何通过设计特殊结构的反应器以提高其混合效果是未来研究的关键所在。     

气相法聚乙烯高效催化剂的进展

综述了国内外气相法聚乙烯高效催化剂研究进展概况,以及各种新型高效催化剂制备技术和性能,并对开发我国新型高效推化剂提出了看法。     

Functionalization of polyethylene using borane reagents and metallocene catalysts

A new method to prepare functionalized polyethylene involving borane intermediates and transition metal catalysts is described. Two processes, direct and post polymerizations, were employed to prepare borane-containing polyethylene (PE-B), which can be transformed to functionalized polyethylene (LLDPE-f) with various functional groups, such as ? BR₂, ? OH, ? NH₂, ? OSi(CH₃)₃. In the direct process, the PE-B copolymers were prepared in one step by copolymerization of ethylene with a borane monomer (ω-borane-α-olefin). The post polymerization process requires two steps: copolymerization of ethylene and 1,4-hexadiene, and subsequential hydroboration reaction of unsaturated PE. Three transition metal catalysts, including two homogeneous metallocene (Cp₂ZrCl₂ [bis(cyclopentadienyl) zirconium dichloride] and Et(Ind)₂ZrCl₂ [1,1′-ethylenedi-η⁵-indenyl-zirconium dichloride] with MAO (methylaluminoxane)) and one heterogeneous (TiCl₃·AA/Et₂AlCl) ones, were studied in the copolymerization reactions. The single site Et(Ind)₂ZrCl₂/MAO homogeneous catalyst, with a strained ligand geometry and opened active site, is by far the most effective system in the incorporation of high olefins into polyethylene structures.     

当今世界聚烯烃工业的重点技术

叙述和分析了９０年代以来世界聚烯烃工业的重点技术，包括高效催化剂技术，无溶剂聚合技术，气相流化床聚乙烯工艺的冷凝态进料技术，共聚技术，生产分子量双峰分布聚乙烯树脂技术以及不造粒技术。     

Polymerization of olefines through heterogeneous catalysis IV. Modeling of heat and mass transfer resistance in the polymer particle boundary layer

Propylene and ethylene polymerization in liquid and gas media are described by a multigrain particle model. External boundary layer heat and mass transfer effects are investigated for various catalysts and operating conditions. For high-activity catalysts used in slurry, external film mass transfer effects may be significant. For gas-phase polymerization of propylene or ethylene, the model predicts significant particle overheating at short times, which may explain the particle sticking and agglomeration problems sometimes observed in industrial reactors.     

茂金属聚乙烯催化剂工业应用研究

北京化工研究院合成了50余种新型茂金属化合物,在茂金属催化剂均相乙烯聚合的系统研究基础上,深入研究了载体茂金属催化剂的制备方法和制备条件等因素与载体催化剂性能的关系,研制出性能优异的载体茂金属催化剂。采用载体茂金属催化剂进行了浆液法和气相法乙烯聚合中试研究,还进行了茂金属聚乙烯树脂的加工应用研究,树脂性能与国外同类产品相当。