共聚法负载茂钛催化剂的合成及催化苯乙烯配位聚合

通过将带有不饱和双键的茂化合物(对-(1-环戊二烯甲基)-苯乙烯)与苯乙烯、二乙烯基苯共聚,再与乙基锂反应,最后与钛酸四丁酯络合的方法合成负载茂钛催化剂。将此催化剂与格氏试剂(RMgBr)组成催化体系,考察了催化反应温度、催化体系的组成,催化剂浓度和Mg/Ti摩尔比等因素对苯乙烯聚合的影响。结果表明,负载化可减少活性中心的偶联衰减,提高催化活性。催化活性与负载催化剂的结构、反应条件等因素密切相关。

吉林石化分子筛催化剂中试技术打破国外垄断

2017年6月30日，吉林石化研究院自主开发的新一代高性能MCM-22分子筛催化剂中试成功。经检测，这种催化剂均为纯相，没有杂晶，重复合成率达100％，催化性能优异，与进口催化剂水平相当。与进口催化剂相比，MCM-22分子筛催化剂的苯转化率提高2．7％，乙苯选择性提高5．7％，性能也更稳定。同时，催化反应温度可降低15℃，苯烯比可降低0．45，减少了苯循环量和产生的多乙苯，降低了物耗能耗和生产成本。MCM-22分子筛具有纳米薄层和MWW型骨架结构，拥有两套互不直接相通的孔道体系。独特的结构和物理化学性能，使其在烃类转化反应方面得到广泛应用。以MCM-22分子筛为活性组元的催化剂，已成功应用于乙苯、异内苯、重整汽油降苯和重整油脱烯烃等工业过程。

锅炉SCR脱硝改造中反应温度的保证

催化剂反应温度是锅炉SCR脱硝改造中需要考虑的关键因素。保证全负荷反应温度的前提下,锅炉改造分4种情况:小容量无再热汽包煤粉锅炉,调整高低温省煤器面积,反应器置于高温空预器之后;小容量一次再热汽包煤粉锅炉,省煤器分级布置,反应器置于前部省煤器之后;循环流化床锅炉,省煤器分级布置,反应器置于前部省煤器之后;300 MW及以上大容量锅炉,反应器置于回转式空预器之前。

Research on Ethylene and Propylene Formation during Catalytic Pyrolysis of Methylcyclohexane

The influence of operating parameters and type of zeolite catalysts on formation of ethylene and propylene during catalytic pyrolysis of methylcyclohexane (MCH) was studied in a laboratory fixed fluidized bed reactor. The results indicated that higher reaction temperature and lower WHSV tended to produce more ethylene and propylene, among which the reaction temperature was an important factor influencing the ethylene formation. Compared with the FAU and BEA type zeolites, the MFI structured zeolite catalyst, thanks to more acid sites and smaller pore diameter of the catalyst, was conducive to the formation of ethylene and propylene. The protonation occurred on different C—C bonds and C—H bonds in the carbon chain of MCH led to different product slates, and the protonation on C—C bonds located at naphthenic ring was favorable to the formation of ethylene and propylene.

Preparation of Exo-tetrahydrodicyclopentadiene Using SiW/Hβ Catalyst

Exo-tetrahydrodicyclopentadiene （exo-TCD） is an important high-energy fuel. Silicotungstic acid （SiW） immobilized on H-type β zeolite （Hβ） at room temperature were used to prepare the Hβ zeolite catalysts with different SiW contents. Catalytic performances of the catalysts were investigated during the preparation of exo-TCD via isomerization of endo-tetrahydrodicyclopentadiene （endo-TCD）. The properties of catalysts were characterized by XRD, temperature pro- grammed desorption of ammonia （NHa-TPD）, FT-IR, and N2-adsorption techniques. SiW was highly dispersed on the surface of Hβ zeolite, and the 10% SiW/Hβ zeolite catalyst had the highest amount of weak acidity among all SiW/Hβ zeolite catalysts. The influence of different factors on isomerization reaction was investigated. At a reaction temperature of 240 ℃, a n（cyclohexane） / n（endo-TCD） ratio of 10, a m（catalyst）/m（endo-TCD） ratio of 0.3, an initial pressure of 1.0 MPa, and a reaction time of 1.5 h in the presence of 10% SiW/Hβ catalyst calcined at 400 ℃, the conversion of endo-TCD reached up to 92.0%, with the yield of exo-TCD equating to 51.0%.

Bi-metallic catalysts of mesoporous Al_2O_3 supported on Fe, Ni and Mn for methane decomposition: Effect of activation temperature

Methane decomposition reaction has been studied at three different activation temperatures（500℃,800℃ and950℃）over mesoporous alumina supported Ni–Fe and Mn–Fe based bimetallic catalysts.On co-impregnation of Ni on Fe/Al2O3the activity of the catalyst was retained even at the high activation temperature at 950℃ and up to180 min.The Ni promotion enhanced the reducibility of Fe/Al2O3oxides showing higher catalytic activity with a hydrogen yield of 69%.The reactivity of bimetallic Mn and Fe over Al2O3catalyst decreased at 800℃ and 950℃ activation temperatures.Regeneration studies revealed that the catalyst could be effectively recycled up to 9times.The addition of O2（1 ml,2 ml,4 ml）in the feed enhanced substantially CH4conversion,the yield of hydrogen and the stability of the catalyst.

Kinetics of 2-Methyl-6-acetyl-naphthalene Liquid Phase Catalytic Oxidation

In this paper, a kinetics model for the liquid-phase oxidation of 2-methyl-6-acetyl-naphthalene to 2,6-naphthalene dicarboxylic acid catalyzed by cobalt-manganese-bromide is proposed. The effects of the reaction temperature, catalyst concentration and ratio of catalyst on the lime evolution of the experimental concentration for the constituents including raw material, intermediates and product are investigated. The model parameters are determined in a nonlinear optimization, minimizing the difference between the simulated and experimental time evolution of the product composition obtained in a semi-batch oxidation reactor where the gas and liquid phase were well nuxed. The kinetics data demonstrate that the model is suitable to the liquid-phase oxidation of 2-methyl-6-acetyl-naphthalene to 2,6-naphthalene dicarboxylic acid.

Preparation of Sodium Cobalt Tetracarbonyl and Optimization of Process Conditions for Hydroesterification of Ethylene Oxide

In this paper, sodium cobalt tetracarbonyl （NaCo（CO）4） was synthesized by using sodium dithionite and zinc powder as the reduction system and cobalt hexahydrate acetate as the precursor in the presence of methanol solvent. Methyl 3-hydroxypropionate was synthesized via hydroesterification of ethylene oxide （EO） catalyzed by NaCo（CO）4. The influencing factors on the reaction results were discussed, including the different ligands, the molar ratio of solvent and ethylene oxide, the reaction temperature, the reaction time, and the reaction pressure. An optimal catalytic system was obtained by using 3-hydroxypyridine as the ligoad under reaction conditions covering a reaction temperature 65 ℃, a reaction time of 7 h, a reaction pressure of 6 MPa, and a methoaol/EO molar ratio of 3：2. Under the optimal conditions, the conversion of ethylene oxide was equal to 97.86%, while the selectivity and yield of methyl 3-hydroxypropionate reached 88.19% and 86.30%, respectively. Finally, the reaction mechanism of hydroesterification of ethylene oxide catalyzed by NaCo（CO）4 was proposed.

Modeling and Optimization of Catalytic Dehydration of Ethanol to Ethylene Using Central Composite Design

The central composite design in the modeling and optimization of catalytic dehydration of ethanol to ethylene was performed to improve the ethylene yield.A total of 20 experiments at random were conducted to investigate the effect of reaction temperature,Si/Al ratios of H-ZSM-5 catalyst and liquid hourly space velocity(LHSV) on the ethylene yield.The results show that the relationship between ethylene yield and the three significant independent variables can be approximated by a nonlinear polynomial model,with R-squared of 99.9%and adjusted R-squared of 99.8%.The maximal response for ethylene yield is 93.4%under the optimal condition of 328 ℃,Si/Al ratio 85,and LHSV 3.8 h-1.

Kinetics of esterification of methanol and acetic acid with mineral homogeneous acid catalyst

In this work, esterification of acetic acid and methanol to synthesize methyl acetate in a batch stirred reactor is studied in the temperature range of 305.15–333.15 K. Sulfuric acid is used as the homogeneous catalyst with concentrations ranging from 0.0633 mol·L-1to 0.3268 mol·L-1. The feed molar ratio of acetic acid to methanol is varied from 1:1 to 1:4. The influences of temperature, catalyst concentration and reactant concentration on the reaction rate are investigated. A second order kinetic rate equation is used to correlate the experimental data. The forward and backward reaction rate constants and activation energies are determined from the Arrhenius plot.The developed kinetic model is compared with the models in literature. The developed kinetic equation is useful for the simulation of reactive distillation column for the synthesis of methyl acetate.

Effect of Sulfurization Temperature on Thioetherification Performance of Mo-Ni/Al_2O_3 Catalyst

The Mo modified Ni/Al_2O_3 catalysts were prepared and sulfided at different temperatures, and their catalytic activity for thioetherification of mercaptans and olefins(or dienes), hydrogenation of dienes and olefins in the thioetherification process using fluidized catalytic cracking(FCC) naphtha as the feedstock was investigated. In order to disclose the correlation between the physicochemical characteristics of catalysts and their catalytic activity, the surface structures and properties of the catalysts sulfided at different temperatures were characterized by the high resolution transmission electronic microscopy(HRTEM), X-ray photoelectron spectroscopy(XPS) and H2-temperature programmed reduction(H_2-TPR) technique. The results showed that an increase of sulfurization temperature not only could promote the sulfurization degree of active metals on the catalysts, but also could adjust the micro-morphology of active species. These changes could improve the catalytic performance of thioetherification, and hydrogenation of dienes and olefins. However, an excess sulfurization temperature was more easily to upgrade the ability of the catalyst for hydrogenation of olefins, which could lead to a decrease of the octane number of the product. It was also showed that a moderate sulfurization temperature not only could improve the catalytic performance of thioetherification and hydrogenation of dienes but also could control hydrogenation of olefins.

Synthesis of Methyl 3-Hydroxypropanoate by Hydroesterification of Ethylene Oxide over Dicobalt Octacarbonyl Catalyst

Methyl 3-hydroxypropanoate was synthesized via hydroesterification of ethylene oxide with CO in the presence of dicobalt octacarbonyl catalyst and methanol solvent. The catalyst exhibited high catalytic activity. The effect of reaction temperature, CO pressure, methanol dosage, catalyst dosage and reaction time on catalytic reaction was investigated. The test results revealed that this reaction was greatly affected by reaction temperature, but it was not significantly affected by the CO pressure, the methanol dosage, the catalyst dosage and the reaction time. Under the optimal conditions, the conversion of ethylene oxide was equal to 92.24%, while the selectivity and yield of methyl 3-hydroxypropanoate reached 88.99% and 84.35%, respectively.

Sn-1,3-specific Interesterification of Soybean Oil with Medium-chain Triacylglycerol Catalyzed by Lipozyme TL IM

The structured lipids are produced through sn-l,3-specific interesterification of soybean oil with medium-chain triacylglycerol （MCT） in continuous reactions catalyzed by Thermomyces lanuginose lipase （Lipozyme TL IM）. Cheap Lipozyme TL IM presents similar interesterification degree （ID）, sn-l,3-specificity and residual activity as expensive Rhizomucor miehei in batch reactions. In packed-bed interesterification of soybean oil with Mcr cat- alyzed by Lipozyme TL IM, the residence time has a significant effect on ID, while temperature has a small effect at 45-70 ℃. The sn-l,3-specificity of Lipozyme TI. IM is not satisfactory when reaction temperature is higher than 60 ℃. The optimal residence time and temperature are 30-40 min and 55 ℃, respectively. Among the solvents, including acetone, isopropanol, tert-butanol, and isobutanol, used to recover the activity of the used Lipozyme TL IM, acetone is the most suitable one than the other solvents.

Effects of Light Olefins Formation during Catalytic Pyrolysis of n-Heptane

The influence of zeolite structure and process parameters (including reaction temperature and catalyst/oil ratio) on rules for formation of ethylene and propylene in the course of catalytic pyrolysis of n-heptane was studied in a small- scale fixed fluid catalytic cracking unit. Test results have revealed that compared to the USY zeolite and Beta zeolite, the catalytic pyrolysis of n-heptane in the presence of the ZRP zeolite catalyst can result in higher yield and selectivity of ethyl- ene and propylene, while a higher reaction temperature and a higher catalyst/oil ratio can promote the formation of ethylene and propylene during catalytic pyrolysis of n-heptane. The ethylene formation reaction is more sensitive to the changes in reaction temperature, whereas the changes in catalyst/oil ratio are more influential to the propylene formation reaction. This paper has made a preliminary exploration into the different reaction pathways for formation of ethylene and propylene on zeolites with different structures.

空气中汞的滴定分析方法研究

[目的]建立空气中汞的滴定分析方法。[方法]以碘化钾作滴定剂，I^-与Hg^2＋形成稳定的[HgI4]^2-，当滴定到终点时，微过量的I^-迅速催化三氧化二砷和硫酸铈的氧化还原反应而放出热量。根据能斯特方程，利用离子选择电极对温度敏感的特点，当溶液温度突然升高时电位迅速下降，从而指示了滴定反应的终点。[结果]以0．5～5．0μgHg^2＋作标准曲线，相关系数为0．998；精密度实验结果，其变异系数在3．57％～6．89％之间；回收率实验，结果在93．4％～103．5％之间。[结论]该方法原理新颖，操作简单，重现性好，准确度高。

Experimental Study of Isopropanol Dehydrogenation over Amorphous Alloy Raney Nickel Catalysts

The dehydrogenation reaction of isopropanol occurring at low temperature is of great industrial importance. It is a key procedure in isopropanol/acetone/hydrogen chemical heat pump system. An experimental investigation was performed to study the behavior of the liquid phase dehydrogenation of isopropanol over amorphous alloy Raney nickel catalysts. Un-promoted and promoted catalysts were used and their performances were compared under various catalyst amounts, acetone content in the reactant and reaction temperature ranging from 348 K to 355 K.It is found that there exists an optimum catalyst concentration which is about 0.34 g in 300 ml isopropanol. The temperature has evident effect on the reaction. The presence of activities of Fe-promoted catalyst decrease slightly compared to the un-promoted catalyst when the temperature are 348 K and 351 K. Besides, the reaction rate decreases almost linearly with the increase of acetone volume fraction in the reactant.

Sequential protocol for C(sp)-H carboxylation with CO_2:KO^tBu-catalyzed C(sp)-H silylation and KO^tBu-mediated carboxylation

CO_2 incorporation into C-H bonds is an important and interesting topic. Herein a sequential protocol for C(sp)-H carboxylation by employing a metal-free C-H activation/catalytic silylation reaction in conjunction with KO^tBu-mediated carboxylation with CO_2 was established, in which KO^t Bu catalyzes silylation of terminal alkynes to form alkynylsilanes at low temperature, and simultaneously mediates carboxylation of the alkynesilanes with atmospheric CO_2. Importantly, the carboxylation further promotes the silylation, which makes the whole reaction proceed very rapidly. Moreover, this methodology is simple and scalable, which is characterized by short reaction time, wide substrate scope, excellent functional-group tolerance and mild reaction conditions,affording a range of corresponding propiolic acid products in excellent yields in most cases. In addition, it also allows for a convenient ^(13)C-labeling through the use of ^(13)CO_2.