TiCl4-Mg(OC2H5)2催化乙烯聚合和形态学研究Ⅱ.预聚合对聚合物颗粒形态的修正

在较低的温度和乙烯分压下进行预聚合 ,然后提高温度和压力进行后续的聚合实验 ,考察了预聚合条件对催化剂聚合动力学和聚合物颗粒形态的影响。发现预聚合可以提高催化剂的活性 ,预聚合时间越长 ,催化剂活性提高越多。通过SEM分析发现 ,预聚合显著改善了聚合物的颗粒形态。由于聚合物颗粒中的线团状形态结构消失 ,聚合物粉体的堆密度显著上升。证明预聚合可以成功解决聚合速率提高与聚合物堆密度下降的矛盾     

TiCl_4-Mg(OC_2H_5)_2催化乙烯聚合和形态学研究Ⅰ.聚合过程及聚合物颗粒形态学表征

通过控制催化剂制备过程中的反应结晶条件 ,制备了 5种具有不同微观特征形态结构的催化剂。考察了催化剂微观物理形态对聚合活性、动力学衰减规律、聚合物颗粒形态的影响。发现催化剂的比表面积或孔隙率与聚合活性及活性衰减模式有关 ,利用SEM分析总结了三种典型的聚合物颗粒特征形态结构。其中线团状形态结构属首次发现 ,并剖析了其形成原因。     

预络合对TiCl_4/SiO_2-MgCl_2催化剂活性及聚丙烯颗粒形态的影响

采用MgCl2-SiO2复合载体,制备了TiCl4/SiO2-MgCl2催化剂,并将该催化剂用于丙烯聚合,研究了预络合对TiCl4/SiO2-MgCl2催化剂的活性及聚丙烯颗粒形态的影响。实验结果表明,预络合有助于提高TiCl4/SiO2-MgCl2催化剂的活性,可有效控制聚丙烯颗粒形态,防止聚丙烯颗粒破碎。预络合后,TiCl4/SiO2-MgCl2催化剂的活性从29kg/(g.h)提高至41kg/(g.h),聚丙烯的表观密度从0.38g/mL提高到0.45g/mL。在乙烯-丙烯共聚物的制备中,预络合有助于提高乙烯-丙烯共聚物的抗冲性能,常温冲击强度(25℃)由4.9kJ/m2增至12.8kJ/m2,低温冲击强度(-20℃)由2.2kJ/m2增至9.6kJ/m2。     

SiCl4、PPh3促进的TiCl4/Ni(acac)2复合催化剂的乙烯聚合研究

制备了SiCl4、PPh3促进的MgCl2-SiO2-ZnCl2为载体,TiCh/Ni(acac)2为主催化剂的A、B型乙烯聚合高效催化剂.研究了SiCCl4、PPh3对乙烯气相聚合的影响,发现SiCl4能大幅度提高催化效率,PPH3使催化效率出现峰值.用DSC、IR、13CNMR对聚合产物进行结构性能的分析和表征.结果表明,TiCl4/Ni(acac)2组成的复合催化剂较单一Ti系催化剂的聚合产物熔点、结晶度、密度、相对分子质量明显降低.添加PPh3的B型催化剂获得了支化度为3～5的支化聚乙烯,表明B型催化剂具有一定的低聚和原位共聚功能.     

粘土矿物用于乙烯聚合催化剂的研究 Ⅱ.凹凸棒石粘土微球负载MgCl_2 /THF/TiCl_4制备乙烯聚合催化剂

采用高比表面积、高孔隙率的凹凸棒石粘土微球作为MgCl2/THF/TiCl4活性组分的载体,制备了高效球形催化剂。研究了这种新型催化剂的制备规律和催化剂结构,结果表明,催化剂的聚合活性随焙烧温度的提高呈上升趋势,但过高的焙烧温度也会导致粘土晶体结构的彻底破坏而不利于活化粘土活性的提高。同时研究了该新型催化剂对乙烯均聚和乙烯-己烯共聚的反应性能。     

钛硅沸石催化C3H6和H2O2合成丙二醇单甲醚反应条件的研究

在加压固定床反应器上,将钛硅沸石和SiO2混合制备的TS-1/SiO2催化剂,用于H2O2、C3H6及甲醇反应制备丙二醇单甲醚(MME).考察了反应温度、操作压力、原料中H2O2浓度、H2O2与C3H6的摩尔比、进料总空速、空塔线速等反应参数对该催化剂催化性能的影响,找到了较佳的操作条件.实验结果表明,当反应温度60℃,操作压力3.0MPa,H2O2浓度0.85mol/l,H2O2与C3H6的摩尔比14.17,液相进料总质量空速3.36h-1,空塔线速43.74×10-2m/h时,MME的选择性达到91.35%,H2O2有效利用率达94.37%,H2O2转化率达98.26%,C3H6实际转化率达22.24%(此时C3H6理论转化率为23.98%).     

茂金属化合物[(C_(13)H_8)Si(CH_3)_2(C_5H_4)]ZrCl_2的制备及其乙烯、丙烯共聚的催化研究

实验以芴基锂、二氯二甲基硅烷和环戊二烯基钠为原料,在四氢呋喃溶剂中合成了茂锆催化剂[(C_(13)H_8)Si(CH_3)_2(C_5H_5)]ZrCl_2,总收率51%。经核磁共振氢谱和碳谱分析,确定了化合物的结构。经甲基铝氧烷活化,该化合物催化乙烯、丙烯共聚反应显示出较高的催化活性,其催化活性(每1 mol Zr)常压下可以达到10~3g/h,聚合物的相对分子质量约1.0×10~4。     

Ni-Nb2O5/γ-Al2O3催化1,5-双-(四氢呋喃基)-3-戊酮加氢脱氧制备长链烷烃的研究

设计了以γ-Al₂O₃为酸性载体、非贵金属Ni和Nb₂O₅为活性中心的催化剂x%Ni-y%Nb₂O₅/γ-Al₂O₃(x%为Ni质量分数,x=1,2,3,4,5;y%为Nb₂O₅质量分数,y=10,20),考察催化剂中Ni、Nb₂O₅含量和反应工艺条件对该催化剂催化生物燃料含氧中间体1,5-双-(四氢呋喃基)-3-戊酮加氢脱氧反应的影响。结果表明：在反应温度为260℃、H₂压力为3MPa、反应时间为24h的条件下,4%Ni-20%Nb₂O₅/γ-Al₂O₃催化1,5-双-(四氢呋喃基)-3-戊酮加氢脱氧制备长链烷烃的碳摩尔收率总和达89.6%,其中C₁₁烷烃、C₁₂烷烃和C<...     

TiCl_4-Mg(OC_2H_5)_2乙烯聚合催化剂制备及改性Ⅱ.载体的形成及结构对催化性能的影响

研究了TiCl_4-Mg(OC_2H_5)_2乙烯聚合催化剂制备条件对所得催化剂载体结构和性能的影响。用X-射线衍射分析等方法比较了由Mg(OC_2H_5)_2转化形成的β-MgCl_2与其它类型的MgCl_2在结构和性能上的异同。探讨了催化剂制备中热分解现象及机理。     

SiO2负载磷钨酸(盐)催化剂对乙酰乙酸乙酯与乙二醇缩合反应的催化性能

用浸渍法制备了一系列SiO2负载的磷钨酸(PW12)及其铯盐(Cs2.5H0.5PW12)和钾盐(K2.5H0.5PW12)催化剂,考察了这些催化剂对乙酰乙酸乙酯与乙二醇缩合制苹果酯反应的催化性能,并以X射线衍射、N2吸附-脱附和Hammett指示剂等方法表征了催化剂的物化性能.用水处理实验考察了催化剂的稳定性,溶脱到水中的杂多化合物浓度用紫外可见分光光度法测试.实验结果表明,在合成苹果酯的反应中,随磷钨酸(盐)负载量的增加,催化剂的活性有不同程度的增加,在负载量(质量分数)达到30%时,催化活性已基本不变,PW12/SiO2,Cs2.5H0.5PW12/SiO2,K2.5H0.5PW12/SiO2催化剂上,乙酰乙酸乙酯的转化率分别为69.8%,68.6%,68.4%,产物选择性为97%.催化剂的稳定性实验结果表明,催化剂失活与活性组分的流失有关,催化剂的稳定性顺序为30%Cs2.5H0.5PW12/SiO2≈30%K2.5H0.5 PW12/SiO2>30%PW12/SiO2.     

Vapor-hydrate phases equilibrium of （CH4＋C2H6） and （CH4＋C2H4） systems

Separation of the (C₁ + C₂) hydrocarbon system is of importance in natural gas processing and ethylene production. However it is the bottleneck because of its high refrigeration energy consumption, and needs to be urgently addressed. The technology of separating gas mixtures by forming hydrate could be used to separate (C₁ + C₂) gas mixtures at around 0 °C and has attracted increasing attention worldwide. In this paper, investigation of vapor-hydrate two-phase equilibrium was carried out for (C₁ + C₂) systems with and without tetrahydrofuran (THF). The compositions of vapor and hydrate phases under phase equilibrium were studied with model algorithm when structure I and structure II hydrates coexisted for the (methane + ethane) system. The average deviation between the modeled and actual mole fractions of ethane in hydrate and vapor phases was 0.55%, and that of ethylene was 5.7% when THF was not added. The average deviation of the mole fraction of ethane in vapor phase was 11.46% and ethylene was 7.38% when THF was added. The test results showed that the proposed algorithm is practicable.     

Catalytic oxidative desulfurization of fuels in acidic deep eutectic solvents with [(C6H13)3P(C14H29)]3PMo12O40 as a catalyst

Deep eutectic solvents (DESs) are a new class of green solvents analogous to ionic liquids due to their biodegradable capacity and low cost. However, the direct extractive desulfurization of diesel oil by DESs cannot meet the government’s standard. In this work, amphiphilic polyoxometalates were synthesized and characterized by FT-IR and mass spectrometry. The oxidative desulfurization results showed that benzothiophene (BT) could be completely removed by employing a [(C₆H₁₃)₃P(C₁₄H₂₉)]₃PMo₁₂O₄₀, DES (ChCl/2Ac) and H₂O₂ system. It was also found that the organic cation of catalysts played a positive role in oxidative desulfurization. The reaction conditions, such as reaction temperature and time, the amount of catalyst and DES and H₂O₂/S (O/S) molar ratio, were optimized. Different sulfides were tested to determine the desulfurization selectivity of the optimal reaction system, and it was found that 97.2% of dibenzothiophene (DBT) could be removed followed by 80.7% of 4-MDBT and 76.0% of 4,6-DMDBT. After reaction, the IR spectra showed that the catalyst [(C₆H₁₃)₃P(C₁₄H₂₉)]₃PMo₁₂O₄₀ was stable during the reaction process and the oxidative product was dibenzothiophene sulfone (DBTO₂). Furthermore, the catalyst can be regenerated and recycled for four runs with little loss of activity.     

硫酸亚铁、硫酸高铁分离法及干酪根与黄铁矿结合形式的研究

对于干酪根样品的制备,目前方法较多,制备的纯度各不相同,甚至差异很大,直接影响了各项参数的测定。我们在制备干酪根过程中主要采用如下步骤:①有机溶剂除去可溶性有机质;②盐酸处理碳酸盐;③氢氟酸处理硅酸盐;④稀盐酸处理不溶性硅氟化物;⑤氯仿抽提进一步除净可溶性有机质;③溴化锌重液超声离心除去黄铁矿及其他杂质。     

水对硫酸钡颗粒-气制油悬浮液的影响

针对加重材料的分散状态对油基钻井液的流变性能有较大影响,以脂肪醇聚氧乙烯醚羧酸（C₁₂E₉Ac）为分散剂,BaSO₄颗粒为分散相,气制油为分散介质,探讨了水对悬浮体系中颗粒沉降稳定性和体系黏度的影响。结果表明,随着水加量的增加,可以使分散颗粒间由以排斥力为主导转化为以吸引力为主导,当水加量小于0.5%（占BaSO₄颗粒质量的百分数）时,悬浮液体系的沉降稳定性和黏度几乎不受影响,且再分散性提高;当加量为0.5%～2.5%时,水不仅可以使悬浮液体系中颗粒发生聚集,并且聚集形成的“大颗粒”也在水桥作用下连接在一起,形成复杂的网络结构;当加量大于25%时,悬浮液体系中部分颗粒已处于水相中,使颗粒的网络结构减少,导致悬浮液的黏度降低。因此,向C₁₂E₉Ac稳定的悬浮液中引入适量水,能够实现在分散稳定性和黏度几乎不发生变化的前提下,提高沉积物的再分散性,为调控油基钻井液中颗粒沉降稳定性提供了研究方法。      

NH4Ca(NO3)3内相油基钻井液性能探讨

分别以CaCl₂、HCOOK、HCOONa和NH₄Ca(NO₃)₃为内相,配制具有相同活度（0.9）、相同密度（1.8 g/cm³）的油基钻井液体系,油水体积比为80∶20。比较了4 种钻井液的流变性、动态/静态沉降性能、黏弹性、触变性,考察了NH₄Ca(NO₃)₃钻井液的抗污染能力。结果表明,150℃滚动老化16 h 后,相同剪切速率下,NH₄Ca(NO₃)₃内相油基钻井液体系剪切应力最小,黏度最低。在50℃、170.3 s^-1下,该体系密度降低了0.255 g/cm3,其他3 种钻井液的密度降低值⊿ρ为0.513～0.545 g/cm³;相同剪切应力下,NH₄Ca(NO₃)₃钻井液弹性模量和黏性模量的比值（G'/G'）最大,体系动态沉降稳定性能最好。在10000 r/min 下搅拌30 min 后在50℃静置16 h,NH4Ca(NO3)3钻井液体系的表面张力为27.744 mN/m²,上层分离油体积为1.37 mL,剩余溶液的上下层密度差为0.038 g/cm³;该体系的凝胶尖峰为3.47 Pa,静态沉降稳定性和触变性最好。NH4Ca(NO3)3钻井液体系抗污染能力较强,可以抗10%劣土污染和15%盐水侵入污染     

Activity of Co(Ni)MoS/Al2O3 catalysts, derived from cobalt(nickel) salts of H6[Co2Mo10O38H4], in hydrogenolysis of thiophene and hydrogen treatment of diesel fraction

Co(Ni)MoS/Al₂O₃ catalysts have been prepared from ammonium 10-dodecamolybdodicobaltate (NH₄)₆[Co₂Mo₁₀O₃₈H₄] (further, Co₂Mo₁₀HPC) and cobalt(nickel) salts of 10-dodecamolybdodicobaltic acid H₆[Co₂Mo₁₀O₃₈H₄] (hereinafter, Co₂Mo₁₀HPA). It has been found that a high activity of the Co(Ni)₃-Co₂Mo₁₀HPA/Al₂O₃ catalysts in the hydrodesulfurization and hydrogenation reactions is due to the formation of a nanostructured type II CoMoS phase via the contact of the metals (Mo and Co(Ni)) at the molecular level. The use of Ni as a copromoter in the Ni₃-Co₂Mo₁₀HPA/Al₂O₃ catalyst leads to a simultaneous increase, compared with Co₃-Co₂Mo₁₀HPA/Al₂O₃, in the linear size of nanoparticles and the number of MoS₂ layers in the packing of active phase. The nature of the promoter X has a substantial effect on the properties of X₃Co₂Mo₁₀HPC/Al₂O₃ catalysts. It has been found that the catalysts with X = Co exhibit the highest activity in the hydrodesulfurization reactions and those with X = Ni, in hydrogenation reactions.     

SiCl_4、PPh_3促进的TiCl_4/Ni(acac)_2复合催化剂的乙烯聚合研究

制备了SiCl4、PPh3促进的MgCl2 -SiO2 -ZnCl2 为载体 ,TiCl4/Ni(acac) 2 为主催化剂的A、B型乙烯聚合高效催化剂。研究了SiCl4、PPh3对乙烯气相聚合的影响 ,发现SiCl4能大幅度提高催化效率 ,PPh3使催化效率出现峰值。用DSC、IR、1 3CNMR对聚合产物进行结构性能的分析和表征。结果表明 ,TiCl4/Ni(acac) 2 组成的复合催化剂较单一Ti系催化剂的聚合产物熔点、结晶度、密度、相对分子质量明显降低。添加PPh3的B型催化剂获得了支化度为 3～ 5的支化聚乙烯 ,表明B型催化剂具有一定的低聚和原位共聚功能。