氢气对钒系聚乙烯催化剂性能的影响

用复合载体负载钒化合物,同时加入邻苯二甲酸二丁酯,制得钒系聚乙烯催化剂,并通过淤浆聚合得到聚乙烯。用GPC和13C NMR等方法研究H2对催化剂聚合活性及聚乙烯性能的影响。实验结果表明,催化剂的活性中心分两类:一类受H2影响较大,一类受H2影响很小;H2是有效的链转移剂。随加氢量的增大,聚合活性逐渐降低,当H2分压为0.08 MPa时,聚合活性衰减趋于平稳。聚合物的表观密度随加氢量的增大呈先升高后降低的趋势。不加氢时聚合物粒径分布相对较分散,而加氢后聚合物粒径分布较集中。随加氢量的增大,聚合物的熔体流动速率增大、相对分子质量减小、相对分子质量分布也逐渐变宽、聚合物的甲基支化度逐渐增大,有利于提高聚合物的加工性能。     

铬系聚乙烯催化剂研究进展

高密度聚乙烯世界产量的40%~50%是采用Cr/SiO2催化剂来生产的。其重要的工业价值吸引了大量学术和工业研发的投入。文章结合Cr/SiO2催化剂的聚合行为,介绍该催化剂的一些基本特性,并对乙烯聚合用铬系催化剂的发展进行了展望。     

生产乙烯共聚体的方法和由此制备的共聚体，含有这样的共聚体的组合物和电装置

本发明涉及一种用于制备乙烯与丙烯和/或1-丁烯的无规共聚体的连续聚合方法，该方法包括：（A）在连续的无规聚合条件下，[第一段]     

氢气对铬系催化剂催化乙烯四聚制1-辛烯的影响

以Ph2PN(i-Pr)PPh2/Cr Cl3(THF)3(THF为四氢呋喃)为催化剂进行了乙烯四聚制1-辛烯反应,用GC,GPC,1H NMR,13C NMR等方法研究了H2对聚合活性和选择性、聚合物的生成量和相对分子质量及其分布的影响,推测了乙烯四聚反应过程中H2可能的作用机理。表征结果显示,随H2分压的增大,聚合活性先升高后降低,1-辛烯和1-己烯的总体选择性略降低;当H2分压为1.0 MPa时,只有微量的丝状聚合物生成。在保证较高催化活性和1-辛烯选择性的前提下,H2的加入可有效减少丝状聚合物的生成,有利于乙烯四聚制1-辛烯反应的连续长周期稳定运行。乙烯四聚制1-辛烯反应中得到的丝状聚合物主要为线型聚乙烯,蜡状聚合物主要为线型α-烯烃。前者反应原理为"Cossee"增长反应机理,后者反应原理为成环机理。     

三组分共聚高性能聚乙烯的质量预测模型

以Unipol聚乙烯气相流化床为研究对象,基于铬系催化剂多活性中心聚合机理,建立了乙烯-1-丁烯-1-己烯三组分共聚制备高性能聚乙烯的熔体流动指数和密度的预测模型,并采用生产过程中的动态响应数据进行了模型参数的优化求解。实验结果表明,熔体流动指数和密度的计算值与测量值的最大相对误差分别为4.37%和0.86%,精度满足工业要求,可结合先进控制策略用于聚乙烯质量的在线测控。     

新型催化剂催化乙烯-丙烯共聚合研究

用新型催化剂在5 L聚合釜上进行了乙烯-丙烯共聚合模试研究,对催化剂加入量、H2量、气体配比、主催化剂与助催化剂的比例和工艺条件进行了研究.确定了新型催化剂乙丙共聚较佳的聚合配方和工艺条件,合成的试样的各项指标与装置同类产品4045水平相当,为其在20 kt/a EPDM装置上进行工业化应用奠定了基础.     

新型高性能气相法聚乙烯Ziegler-Natta催化剂

通过简化的合成方法,制备了新型高性能MgCl2-SiO2复合载体型气相法聚乙烯Ziegler-Natta催化剂(NGE),通过BET,SEM,XRD等方法对催化剂进行了表征,采用淤浆聚合的方法评价了催化剂的乙烯/1-己烯共聚性能,考察了催化剂的形态、结构与聚合活性之间的关系。实验结果表明,NGE催化剂的聚合活性达到4 510⁷ 526 g/g(以单位质量催化剂上共聚物的产量计),当共聚单体1-己烯的加入量为2 mL时,催化剂的性能较好,共聚物产品的堆密度达0.382 g/cm3,熔体流动指数(10 min)为0.45 g,粒径为757 526 g/g(以单位质量催化剂上共聚物的产量计),当共聚单体1-己烯的加入量为2 mL时,催化剂的性能较好,共聚物产品的堆密度达0.382 g/cm3,熔体流动指数(10 min)为0.45 g,粒径为75⁷50μm的颗粒含量为99.32%(w);NGE催化剂是传统M催化剂的聚合活性7倍左右,共聚物产品的堆密度提高了10%左右,NGE催化剂的共聚能力优于M催化剂。     

共聚单体对无规共聚聚丙烯性能的影响

采用本体聚合法,以丙烯为原料,乙烯和1-丁烯为共聚单体,北化院NG为主催化剂,三乙基铝为助催化剂,二异丙基二甲氧基硅烷为外给电子体,在反应温度为66.0℃,反应压力为2.2 MPa,H_2/丙烯(摩尔比)为0.02,乙烯/丙烯(摩尔比)为0.01～0.04,丁烯/丙烯(摩尔比)为0.02～0.15的条件下,制备了无规共聚聚丙烯(乙丙共聚物和丙丁共聚物)。结果表明:通过调节共聚单体的质量分数,共聚物的熔体流动速率均控制在0.500～0.700 g/min;在共聚单体质量分数相当的条件下,乙丙共聚物的二甲苯可溶物质量分数高于丙丁共聚物;随着共聚单体质量分数的增加,与丙丁共聚物相比,乙丙共聚物的弯曲强度和热变形温度降幅较大,冲击强度增幅较为显著。     

Ziegler-Natta高效催化剂共聚性能研究

以正庚烷为溶剂进行淤浆聚合,研究了BJC01催化剂和BJC02催化剂分别与甲基环己基二甲氧基硅烷(CHMMS)和二环戊基二甲氧基硅烷(DCPMS)配合用于乙烯-丙烯共聚合的特征,发现不同催化剂体系所得乙烯-丙烯共聚物的相对分子质量和组成不同。BJC01+DCPMS催化体系所得聚合物的相对分子质量最大,聚合物的组成也最单一,主要由乙丙橡胶和长链段聚乙烯夹杂少量丙烯共聚物组成;BJC02+CHMMS体系所得共聚物的相对分子质量最小,组成也最复杂,共聚物由乙丙橡胶和不同链段长度的聚乙烯夹杂少量丙烯的共聚物组成。     

乙烯二聚共聚双功能均相催化体系的研究

研究了由二聚催化剂Ｔｉ（ＯＢｕ）４／ＡｌＥｔ３和共聚催化剂组成的双功能均相催化体系。这些催化体系能二聚乙烯，并同催化体系能二聚乙烯，并同时使生成的１丁烯与乙烯就地共聚，可以直接合成线型低密度聚乙烯。     

新型高效UHMWPE催化剂QTE-1的研究

利用过程强化技术制备了UHMWPE催化剂QTE-1,并进行了小试聚合评价,重点考察了过程强化技术以及聚合温度、聚合压力等工艺条件对其性能的影响。研究结果表明,QTE-1催化剂具有聚合活性高、反应动力学曲线平稳、活性衰减缓慢等特点,聚合所得树脂性能优异。     

LS-941硫化氢选择性氧化超级克劳斯催化剂的研究

介绍了用于超级克劳斯工艺的LS-941 H2S选择性氧化催化剂的实验室研制及活性评价结果。该催化剂以惰性氧化铝为载体，以Fe／Cr为活性组分并添加专有助剂制备而成。在反应温度270℃、常压、空速为2500h^-1，φ(H2s)=1．0％，φ(O2)-0．6％及φ(H2O)-20％的反应条件下，连续反应1000h后，LS-941催化剂脱除H2S的平均转化率和选择性一直保持在90％以上，表明具有较高的活性和稳定性，已达到设计要求，可替代同类进口催化剂使用。     

宽峰或双峰聚乙烯金属茂催化剂的研究

为提高茂金属聚乙烯的加工性能，选择两种茂金属催化剂APE-1和SP-2在实验室混合使用，由于它们催化乙烯聚合的活性相似，动力学行为也相似，适于复配进行乙烯均聚和共聚。在两种催化剂SP-2和APE-1复配的摩尔比为20时，随1-己烯加入量的提高．所得聚合物的相对分子质量分布有所加宽，且出现了双峰分布。     

茂金属催化剂与钛系催化剂聚乙烯滚塑料结构与性能研究

采用GPC、13C NMR、SSA、落锤冲击试验、耐环境应力开裂试验分析研究茂金属催化剂和钛系催化剂PE滚塑料的结构与性能.结果 表明:相对钛系催化剂滚塑料PE-2,茂金属催化剂滚塑料mPE-1的PD较窄、分子链支化点少,易形成较厚片晶,片晶厚度分布均匀,力学性能佳;优异的结构性能,使茂金属催化剂滚塑料mPE-1具有优...     

环氧乙烷环氧丙烷共聚中的分子结构设计研究

非离子型化合物环氧乙烷环氧丙烷共聚醚在助剂行业具有广泛的应用和较好的开发、研究的前景。本文结合共聚反应机理 ,从分子结构设计出发 ,对共聚过程中影响产品性能的各个因素进行了分析和讨论 ,并对醚化封端在聚醚端基结构设计中的应用进行了研究。对该领域的生产、科研有一定的参考价值。     

A STUDY ON THE EFFECT OF PREPARATION PARAMETERS ON THE CATALYTIC PERFORMANCE AND ACTIVE COMPONENTS OF A NEW TYPE HYDRODESULFURIZATION CATALYST

The effects of the impregnating conditions on the contents of the active components of a new type hydrodesulfurization (HDS) catalyst have been studied by ICP technique in this paper. Meanwhile, the effects of the activation temperature, the activation time and the calcining temperature on the catalytic properties of the CoMo/(TiO₂ + Al₂O₃) catalyst have also been studied. The results show that at the given hygroscopicity of the support, the contents of the Co and the Mo, both of which are the active components of the catalyst, change linearly with the changes of the concentrations of the solvents in the impregnant. When the catalyst is impregnated at 40°C for 2 h, the contents of the active components reach the maximum values. The calcining temperature sharply affects the dispersed state of the active components on the surface of the support. When calcined at 500°C for 2 h, this HDS catalyst obtains the best catalytic activity. Even when the catalyst has been calcined at 600°C for 3 h, its activity is still good, which indicates that the heat resistance of this new type catalyst is satisfactory.     

A STUDY ON THE EFFECT OF PREPARATION PARAMETERS ON THE CATALYTIC PERFORMANCE AND ACTIVE COMPONENTS OF A NEW TYPE HYDRODESULFURIZATION CATALYST

ABSTRACT

The effects of the impregnating conditions on the contents of the active components of a new type hydrodesulfurization (HDS) catalyst have been studied by ICP technique in this paper. Meanwhile, the effects of the activation temperature, the activation time and the calcining temperature on the catalytic properties of the CoMo/(TiO₂ + Al₂O₃) catalyst have also been studied. The results show that at the given hygroscopicity of the support, the contents of the Co and the Mo, both of which are the active components of the catalyst, change linearly with the changes of the concentrations of the solvents in the impregnant. When the catalyst is impregnated at 40°C for 2 h, the contents of the active components reach the maximum values. The calcining temperature sharply affects the dispersed state of the active components on the surface of the support. When calcined at 500°C for 2 h, this HDS catalyst obtains the best catalytic activity. Even when the catalyst has been calcined at 600°C for 3 h, its activity is still good, which indicates that the heat resistance of this new type catalyst is satisfactory.     

PREPARATION OF NEW TYPE CATALYST WITH GOOD PROPERTIES FOR HYDRODESULFURIZATION

ABSTRACT

The CoMo/TiA catalyst for hydrodesulfurization (HDS) and its composite support TiA with industrial scale had been produced through the certain process and the studied range of ratio of TiO₂/(TiO₂ + Al₂O₃) was enlarged. The good properties of the support TiA were attributed to its special pore structure. When the ratio of TiA/(TiA + Al₂O₃) was 0.80, the specific surface area of the support and its pore volume reached their maximum respectively. The range of atom ratio of Co/(Co + Mo) of the catalyst CoMo/TiA from 0.25–0.31 proved best, during which activity of the catalyst reached the maximum. The disperse state of TiO₂ on the surface of TiA and effect of the promoter Co content on the surface structure of the catalyst had been studied by XRD, LRS and XPS. The analytic results showed that 0.47 g TiO₂/g γ-Al₂O₃ was the schwellenwert for the coverage of TiO₂ on the surface of TiA. Beyond this, TiO₂ lies on the surface of TiA with a single layer; otherwise, it existed in the form of TiO₂ crystal phase (anatase phase). When adding a few promoters Co into the catalyst, the dispersity of MoO₃ on the surface of the support TiA increased remarkably and activity of this catalyst was also improved.