丙烯醛水合加氢制1，3—丙二醇

考察了丙烯醛水合及3-羟基丙醛加氢制1，3-丙二醇的工艺条件。在装有阳离子交换树脂催化剂的固定床层反应中，当水合温度40～55℃，空速3～5h^-1、丙烯醛质量分数13%～17%，并加入少量对苯二酚阻聚剂时，丙烯醛单程转化率可达到85%，选择性大于90%，在高压釜内进行3-羟基丙醛加氢时，催化剂投料量1.5%～2.0%，一段加氢温度30～50℃，二段加氢温度110～130℃，氢气压力6.0MPa，搅拌速度500r/min，使用细颗粒Raney镍催化剂，可使3-羟基丙醛加氢转化率达到100%，1，3-丙二醇的选择性也在99%以上，在产品中醛基含量小于300μg/g。     

酸性树脂催化剂上丙烯醛水合动力学研究

以阳离子交换树脂为催化剂，对丙烯醛水合本征动力学进行了研究，通过热力学和动力学分析建立了丙烯醛水合反应动力学模型。实验结果表明，丙烯醛的水合具有一级串联不可逆的特征。根据实验数据，用最小二乘法，得到了本征动力学模型参数。统计检验结果表明，建立的丙烯醛水合反应动力学模型是可行的。     

COMPOSITE ZEOLITES SYNTHESIZED FROM (TEA)2O-Na2O- Al2O3-SiO2-H2O SYSTEM : STRUCTURAL CHARACTERISTICS AND HYDRATION ACTIVITY

ABSTRACT

Several catalysts of composite zeolites were synthesized from (TEA) ₂O-Na₂O-Al₂O₃-SiO₂-H₂O system adopting different conditions of the preparation. The prepared zeolites, in the hydrogen-exchanged form were characterized by EDS and XRD. The obtained catalysts consisted of ß-zeolite composited with different amounts of other zeolites such as morderute and/or analcime. Acidic properties of these composite zeolites were measured potentiometrically in an aqueous medium. The hydration of butene-1 over the H-exchanged composite zeolites was carried out at 250°C and 180 atm, and with a water/olefin ratio of 3.86. The hydration activity was discussed in terms of structural characteristics and acidic properties of the prepared catalysts.     

The Microwave-Synthesized β-Zeolite and the Use in Etherization

H β-zeolite was synthesized using tetraethyl ammonium hydroxide as the template pharmaceutical and microwave radiation as the heat source. The synthesized samples were characterized by x-ray diffraction, BET, and NH₃-TPD. The effects of the sol composition and the radiation temperature on the relative crystallinity were studied. The results showed that the relative crystallinity, special surface area, pore volume, and surface acidity of the H β-zeolite microwave synthesized were higher than the industrial product with synthesized with the conventional hydrothermal synthesis method. Etherification activities were evaluated in the minitype fix-bed reactor, and the yields of etherification production were higher than that of industrial samples.     

Effects of Impregnation Solvents on Catalytic Performance of Co-Ru-ZrO2/γ-Al2O3 Catalyst for Fischer-Tropsch Synthesis

Used ZrO₂ modified γ-Al₂O₃ as support, Co-Ru catalysts were prepared by incipient impregnation method. The effects of impregnation solvents on the performances of catalysts were examined. The catalyst was prepared with ethanol solution and high Co dispersion was obtained, exhibiting highest activity of CO hydrogenation, very low methane selectivity, and high heavy hydrocarbon C₅⁺ selectivity. The catalysts were prepared with aqueous solution and methanol solution, and the reaction behaviors were similar. The solvent isopropanol caused the lowest catalytic activity and highest methane selectivity. Increasing the reaction temperature enhanced the CO hydrogenation rate, and the CO conversion slightly increased the CO₂ selectivity and favored the formation methane and light hydrocarbons, while the chain growth probability decreased. For the catalyst prepared with ethanol, the CO conversion, the CH₄ selectivity, and the C₅⁺ selectivity were 94.16%, 5.65%, and 88.2%, respectively, and the chain growth probability was 0.87 at 493 K, 1.5 MPa, 800 h^-1, and n(H₂):n(CO) = 2.0 in feed.     

HPWA/SiO2催化剂催化合成十二烷基苯

采用溶胶-凝胶法,将不同含量的杂多酸负载在硅基上制得HPWA／SiO2催化剂,并用苯和十二碳烯烷基化反应评价了该催化剂的催化性能,考察了催化剂组成、焙烧温度、反应温度、空速对烷基化反应性能的影响,得到催化剂的最佳组成：杂多酸的含量30％(ω)。找出最佳操作条件：焙烧温度450℃,反应温度220℃,空速1h^-1(WHSV),同时对该催化剂的稳定性和再生性进行了研究。试验结果表明,该催化剂活性高、稳定性好且易于再生,可替代液体强酸用于烷基化反应,是环境友好的催化剂。     

丁烯异构化探针反应结合IR及CO_2-STD法研究K_2CO_3/Al_2O_3和KNO_3/Al_2O_3的碱性

采用丁烯异构化探针反应结合IR及CO_2-STD等方法,考察了K_2CO_3负载量、焙烧及活化温度、载体和钾盐中阴离子的性质对于钾盐负载型固体碱碱性的影响,并研究了K_2CO_3/AI_2O_3和KNO_3/Al_2O_3的最佳制备/活化条件.实验表明在523K以上,尤其是在673K以上依然吸附CO_2的强碱位才是顺-2-丁烯异构化反应的主要活性位.经773K焙烧和活化的KNO_3/A1_2O_3在顺-2-丁烯异构化反应中具有数倍于K_2CO_3/Al_2O_3的活性,因为其碱性活性位仅仅在反应前的原位活化过程中才产生,未受到大气中CO_2污染而保持着高效率.     

不同形貌薄水铝石制备γ-Al2O3及负载Pt稳定性的研究进展

γ-Al2O3是应用极为广泛的非均相催化剂载体之一,近年来,研究者发现其晶粒微观形貌对表面性质、活性金属Pt等的稳定性具有较大影响。综述了γ-Al2O3前体薄水铝石晶粒形貌的调控、表征技术,及γ-Al2O3晶粒暴露晶面对其表面性质、Pt原子稳定性的影响,对现有研究结果存在的问题进行了探讨,并展望了未来的研究方向。     

Mo/γ-Al2O3催化剂中金属-载体相互作用位点的研究

载体表面性质直接影响金属-载体相互作用的强弱,进而对加氢催化剂的结构和性能产生重要影响。为深入认识载体表面性质对金属-载体相互作用的影响机制,以工业加氢催化剂RS-2100的载体为研究对象,首先通过对其进行不同温度（20~180 ℃）的水热处理,调变了其表面各种位点（碱性、中性、酸性羟基及Al-CUS）的相对浓度,然后借助IR-OH和Py-IR表征手段对这些位点相对浓度的变化进行了分析,并采用Mo平衡吸附法对金属-载体相互作用强弱进行了量化分析。IR-OH和Py-IR分析结果表明,随水热处理温度的升高,载体表面碱性羟基和酸性羟基的浓度均先增加后减少,且均在100 ℃水热处理时浓度最大,但后者的浓度在水热处理温度大于100 ℃时减少幅度较小;中性羟基浓度和Al-CUS浓度则随水热处理温度的升高逐渐降低。Mo平衡吸附量分析结果表明,随水热处理温度的升高,金属-载体相互作用先增强后减弱。对上述两方面结果进行关联可以推测,碱性羟基是Mo金属-载体相互作用的关键位点。     

NiW/Al2O3上喹啉对二苯并噻吩 加氢脱硫的抑制作用及反应动力学

 以二苯并噻吩(DBT)为含硫模型化合物，在中压滴流床反应装置中研究了工业NiW/Al₂O₃催化剂(RN-10)上喹啉对DBT加氢脱硫(HDS)的抑制作用，考察了喹啉质量分数(0.5%~1.5%)、反应温度(290~380℃)、反应压力(4.0~5.6MPa)对DBT的HDS的影响。结果表明，喹啉的存在对于DBT的HDS反应有很强的抑制作用，且喹啉浓度越高，抑制作用越大；对DBT的先加氢饱和再脱硫路径(HYD)的抑制作用比对直接脱硫路径(DDS)更大；提高反应温度对DDS和HYD路径的脱硫活性均有提升，但由DDS路径生成联苯的选择性降低；较高反应压力有利于提高HYD路径产物的选择性。采用带有氮化物吸附(中毒项)的拟一级反应动力学模型对实验数据进行拟合，得到不同喹啉质量分数下DBT的HDS表观反应速率常数。经检验，模型计算结果与实验结果吻合。     

Pd/Al2O3催化过氧化氢异丙苯的液相加氢反应

 分别以K₂[PdCl₄]和K₂[PdCl₄]与草酸的混合液为Pd前驱体,采用浸渍沉淀法制备了Pd/Al₂O₃催化剂。采用等离子体耦合发射原子吸收光谱(ICP-AES)、透射电镜(TEM)、程序升温还原(TPR)等手段对Pd/Al₂O₃催化剂进行了表征。考察了Pd/Al₂O₃催化剂在过氧化氢异丙苯(CHP)固定床加氢反应中的催化活性。结果表明,金属Pd在载体Al₂O₃上呈不均匀分布,并发生团聚,其颗粒直径为5～10nm;催化剂在煅烧及还原过程中,活性金属Pd与载体Al₂O₃发生强烈相互作用,产生了Pd-Al合金。以K₂[PdCl₄]为前驱体制备的Al₂O₃催化剂在过氧化氢异丙苯(CHP)固定床加氢反应中显示了较高的二甲基苄醇(CA)选择性,而且在240 h 连续反应过程中,CHP的转化率始终维持在100%,目标产物CA的平均选择性也达到了97.7%。通过对比反应前后反应体系的组成,探讨了CHP液相催化加氢制备CA的反应途径。     

钛硅沸石催化C_3H_6和H_2O_2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 Si O2 混合制备的 TS-1 /Si O2 催化剂 ,用于 H2 O2 、 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 H2 O2 浓度、H2 O2 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 .0 MPa,H2 O2 浓度 0 .85mol/l,H2 O2 与 C3H6 的摩尔比 1∶ 4 .1 7,液相进料总质量空速 3 .3 6h- 1 ,空塔线速 4 3 .74× 1 0 - 2 m/h时 ,MME的选择性达到 91 .3 5% ,H2 O2 有效利用率达 94 .3 7% ,H2 O2 转化率达 98.2 6% ,C3H6 实际转化率达 2 2 .2 4 % (此时 C3H6 理论转化率为 2 3 .98% )     

PARTITION BETWEEN α-METHYL AND α-METHYLENE PROTONS IN 1H NMR SPECTRA OF COAL TARS

Cut-off points between protons in a-methyl and or-methylene groups were proposed for the evaluation of 'H NMR spectra of coal tars. The position of the cut-off points depended on the proton aromaticity and related structural features of the samples. Equations for the calculation of the cut-off points as a function of proton and carbon aromaticity, and atomic H/C ratio were proposed for the range of proton aromaticity between 0.2 and 0.6.