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对比分析了3种浆液进料钛系催化剂(分别记作催化剂A、催化剂B、催化剂C)在Unipol聚乙烯装置上生产线型低密度聚乙烯DFDA-7042的工业应用情况。结果表明:3种催化剂的组成基本相同,氢调性能和共聚合性能相当,使用期间反应器均运行平稳,生产的DFDA-7042产品质量满足优等品要求;催化剂A质量稳定,制备的粉料下料能力好,但催化剂消耗成本比催化剂B高16.59元/t;催化剂B质量稳定,活性最高,达24 882 g/g,制备的粉料的细粉含量最少,粒径分布更有利于反应器长周期运行,但响应时间较长;催化剂C质量不稳定,制备的粉料堆积密度最高,但下料能力不稳定,无法满足装置高负荷平稳运行要求,并且催化剂消耗成本较催化剂B高4.58元/t。 相似文献
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本文介绍了全密度聚乙烯装置采用Unipol气相流化床工艺,使用铬系B型催化剂,生产小中空容器树脂高密度聚乙烯DMDA-6200的过程。其中UCAT-B和UCAT-G系列的铬系催化剂产品是目前装置的主要生产牌号,DMDA-6200是B型催化剂系列的主要生产牌号。生产的产品卫生性能满足GB 9691,产品加工性好、能够一次成型,可以代替现有低压小中空树脂HDPE 5500B和HDPE 5502的混配料,在娃哈哈乳品有限公司黑龙江双城分公司、大庆汇仁塑料制品厂生产小中空容器满足用户需要。 相似文献
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配制了THG型高效催化剂,并在高密度聚乙烯(HDPE)装置上进行了应用试验。THG型高效催化剂的活性为600~850 kg/g,是装置正使用的THB型催化剂的10倍左右,粒径分布接近THB型催化剂;通过调整生产方案,使用THG型高效催化剂时生产周期逐渐延长;用THG型催化剂生产不同牌号HDPE产品的熔体流动速率、密度、粒径分布等与用THB型催化剂生产的HDPE相当,蜡含量和钛含量明显低于用THB型催化剂生产的HDPE,白度和堆密度好于用THB型催化剂生产的HDPE。 相似文献
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综述了钛改性铬系催化剂的国内外研发现状、制备方法、性能以及对乙烯聚合性能的影响。与用表面浸渍法制备的钛改性铬系催化剂相比,用共凝胶法制备的钛改性铬系催化剂可以缩短诱导期,提高聚乙烯(PE)的熔体流动速率。钛改性铬系催化剂中的钛可阻止α-烯烃在PE的低相对分子质量部分插入,有效降低了含支链低相对分子质量PE的含量。随着钛的加入,低相对分子质量部分的共聚支链减少,从而可改变PE的支链分布。钛改性铬系催化剂的聚合性能明显改善,制备的聚乙烯性能优异。 相似文献
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LLDPE装置粉料输送系统安全性论证 总被引:3,自引:0,他引:3
对中国石油大庆石化分公司线性低密度聚乙烯装置粉末输送系统进行了安全性论证。通过模拟装置的试验和现场测试,考察了粉末输送了粉末输送管线、粉末储仓在正常生产过程和模拟装置试验过程中产生的静电量、测试分析了粉料仓中电场强度、电位、可燃气体含量,对粉料输送管道内的最大电场强度和料仓内混合物的最小点火能进行了计算,并对危险性进行了理论和实际分析,对危险部位提出了改进意见和建议。 相似文献
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Jingjing Zhang Chul B. Park Ghaus M. Rizvi Hanxiong Huang Qingping Guo 《应用聚合物科学杂志》2009,113(4):2081-2089
Uniform dispersion of wood fiber in high‐density polyethylene can improve the mechanical properties and surface finish of the wood plastic composites. However, it is difficult to achieve uniform dispersion when the wood content is high, due to its low thermal stability, incompatibility with polymer, and affinity for agglomeration. This work was undertaken to improve the uniformity of high‐density polyethylene/wood composites by designing screw configurations, optimizing screw speed, and altering material compositions. The rheological properties and scanning electron microscope micrograph were used to characterize the uniformity. The results showed that the medium dispersive and distributive mixing, medium screw speed, and lubricant were all beneficial in improving uniformity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
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LDPE管式法工艺粘壁的原因分析及对策 总被引:1,自引:0,他引:1
低密度聚乙烯(LDPE)装置生产中多次出现反应粘壁现象,使装置的平均产量比设计值低6~8 t/h。通过分析,找出适合装置的脉冲阀工艺控制参数,调整链转移剂的注入量,并清洗反应器,最大限度地降低了产生粘壁的几率,保证了装置的正常运行。 相似文献
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低密度聚乙烯(LDPE)装置在生产中多次出现二次压缩机出口至反应预热器之间管线结垢聚合物堵塞现象,造成二次压缩机出口与反应器入口压力差增大,影响装置安全运行。通过分析,找出二次压缩机出口结垢的原因,通过工艺参数调整,消除管线结垢的影响,确保装置长周期安稳运行。 相似文献
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To satisfy the diverse product quality specifications required by the broad range of polyethylene applications, polymerization plants are forced to operate under frequent grade transition policies. During the grade transition, the reactor temperature must be kept within the narrow range between the gas dew point and the polymer melting point, otherwise the particles melt or agglomerate inside the reactor. In the present study, a dynamic well‐mixed reactor model is used to develop a grade transition strategy to prevent melting and agglomeration of particles in an ethylene polymerization reactor. The model predicts the conditions under which the temperature of the reactor is outside the allowable range in continuous grade transition. Manipulation of feed flow and cooling water flow rates has shown that the reactor temperature cannot be maintained within the allowable range. Hence, a semi‐continuous grade transition strategy is used for this case so that the temperature is maintained within the allowable range. In addition, several continuous and semi‐continuous grade transition strategies for the production of linear low‐density polyethylene (LLDPE), medium density polyethylene (MDPE), and high‐density polyethylene (HDPE) are compared. 相似文献
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总结了煤基气相流化床聚乙烯装置从线型低密度聚乙烯(LLDPE)DFDA-7042转产LLDPE DNDA-8320的工业化过程,重点在于反应器和挤压造粒机的工况变化,出现的故障和生产难点,并对DNDA-8320的性能和应用进行了评价。结果表明:转产实施时,反应器流化松密度和床重下降,催化剂活性从21740 g/g降至14490 g/g,DNDA-8320的熔体流动速率为19.2 g/10 min,密度为0.9260 g/cm3,拉伸屈服应力为10.4 MPa,拉伸断裂应力为12.2 MPa,断裂标称应变为581%,可满足下游客户的塑料改性要求。 相似文献
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分析了气相法聚乙烯装置中反应器结块的各种原因,针对反应器扩大段处的结块、反应器内静电引起的结块、因催化剂活性太高导致的爆米花料以及反应器分布板下部的结块等提出了有效的预防措施。以确保气相法聚乙烯装置能够安全、稳定、长周期运行。 相似文献
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Tao Wei Xiaofei Hou Jiatao Yu Jian Zhang Ziyuan Wang Qiang Xu Jinsong Zhao Tong Qiu 《化学工程与技术》2014,37(4):605-610
Shutdown operations in olefin plants generate extensive flare emissions, which cause adverse environmental and societal impacts as well as large amounts of raw material and energy losses that could supposedly be unitized to generate much more needed products. Consequently, shutdown optimization for flare minimization is crucially important to all stake holders. However, the current practice for shutdown flare minimization almost exclusively depends on experienced operators, engineers, and plant administration. There is still a lack of systematic studies on how to cost‐effectively identify and examine shutdown flare minimization strategies through plant‐wide modeling and simulations. A novel process retrofit and shutdown operation strategy for flare minimization in an olefin plant is introduced. Plant‐wide dynamic simulations are employed to examine the operational feasibility and critical information during the plant shutdown operation. The proposed shutdown strategy could virtually reduce the flare emission significantly compared to historical records. 相似文献