“DMC新型催化剂的研究开发”项目在京通过鉴定验收

8月2日,中国科学院在京组织专家对中科院成都有机化学研究所承担的国家“九五”科技攻关专题“DMC新型催化剂的研究开发”进行了验收。该专题开发的用于碳酸二甲酯(DMC)生产的CUMP催化剂具有腐蚀性小、选择性好、寿命长的特点,并根据催化剂的特点,研究开发了新的工艺流程(包括新型共沸精馏工艺),在西南化工研究院70L反应釜进行了中试和催化剂的应用研究。结果表明,在1010h内催化剂性能稳定,平均生产1t DMC消耗催化剂约1kg。     

DMC催化剂诱导工艺研究

以自制的DMC(双金属氰化物)为催化剂合成环氧化物聚合物,研究了催化剂、起始剂、助催化剂、工艺条件对DMC催化剂诱导期的影响。结果表明:DMC催化剂诱导期受到催化剂用量及其储存期,起始剂水含量及其钾、钠含量,环氧丙烷用量及其水含量,助催化剂等影响,并且各因素之间存在交互影响。     

苯氨基甲酸酯催化合成研究进展

综述了国内外苯氨基甲酸酯合成方法和催化剂的研究进展,重点阐述了近年来以苯胺和碳酸二甲酯(DMC)为原料,合成苯氨基甲酸甲酯(MPC)催化剂的研究进展.同时对今后催化合成路线的研究和发展进行了讨论和分析,由苯胺和DMC合成MPC,副产物甲醇回收合成DMC,是零排放绿色工艺,其研究方向是开发出活性和选择性高的负载型催化剂.     

微波条件优化合成DMC催化剂的研究进展

碳酸酯类化合物是21世纪最重要的绿色化学品,最典型的碳酸酯化合物碳酸二甲酯(DMC)是工业上广泛应用于溶剂、燃料添加剂以及化学试剂方向的重要化学品。由于DMC毒性很小,可以替代一些剧毒的化学品,如取代硫酸二甲酯和甲基卤化物用于甲基化反应。由于其高电介质常数、低黏度、低毒性以及优秀的溶解能力等性质,DMC被用作锂离子电池的电解液。微波技术能有效地提高催化剂活性组分的分散度,改善催化剂表面的晶体类型,提高催化剂的活性,在催化领域具有广阔的应用前景。介绍了微波技术应用于合成DMC反应中的催化剂制备,探究了微波技术对不同合成路径、不同催化剂合成DMC反应的影响,最后对微波技术对目前非均相催化剂合成DMC存在的问题以及今后的发展方向进行了总结与展望。     

CuBrnLm配合催化剂液相氧化羰化合成碳酸二甲酯

研究了CuBrnLm配合催化剂对甲醇液相氧化羰化合成碳酸二甲酯(DMC)反应的催化活性及其稳定性,并采用XPS和EPR等对催化剂进行表征。结果发现,配位剂L的添加有助于形成甲醇选择性氧化羰基合成DMC的活性物种Cu（I）。采用正交设计对工艺条件进行优化,当温度100～110 ℃、压力3.0～3.5 MPa、时间4～6 h、催化剂浓度(以甲醇的体积) 0.15～0.20 g/mL时,甲醇转化率可达到23%,DMC选择性大于95%。     

双金属氰化物络合物催化剂的制备、表征与催化性能研究

分别以PEG-1000、β-环糊精和吐温-60等为助络合剂,采用不同工艺方法制备了具有不同结构的双金属氰化物络合物(DMC)催化剂,研究了不同助络合剂和不同制备方法对DMC催化剂的形貌、粒径、晶型结构和催化活性的影响.结果表明以PEG-1000、β-环糊精和吐温-60等为助络合剂,利用传统制备方法可以获得晶态与非晶态组分混合物的DMC催化剂.而将助络合剂提前加入到钾盐和锌盐溶液中,可制备出高度分散的非晶态的DMC.这种非晶态的DMC催化剂活性高,反应速度快,其催化性能明显优于利用传统制备方法制备的DMC.     

制备低不饱和度聚醚多元醇用DMC催化剂的研究进展

介绍了近年来聚醚多元醇的产能与需求,综述了双金属氰化络合物（DMC）催化剂的研究进展,总结了现有技术中DMC制备技术的共同点,并展望了进一步提高DMC催化剂性能和改善聚醚多元醇性能的研究方向。     

尿素醇解法绿色合成碳酸二甲酯催化剂的研究进展

尿素醇解法合成碳酸二甲酯(DMC)是一条绿色、廉价、可循环的生产工艺,引起了人们的广泛关注。本文综述了近年来可用于催化合成DMC的有机锡、金属盐、离子液体、锌基固体催化剂和固体碱等五种催化体系的研究现状。同时,对上述催化体系的催化行为进行了总结,并对它们的工业化应用前景进行了讨论。在此基础上,展望了尿素醇解法高效稳定合成DMC催化剂的发展方向。     

起始剂中杂质对DMC催化聚合反应制备聚醚的影响

研究了在双金属络合催化剂(DMC)用于合成聚醚过程中,起始剂N305所含水分、丙三醇及酸对聚合反应的影响。结果表明,起始剂中的水分及一定量的丙三醇会使催化剂失活,影响聚合反应,DMC催化剂在偏酸性条件下,活性则更高。     

二氧化碳和甲醇直接合成碳酸二甲酯的催化剂的研究进展

本文介绍了以CO₂和CH₃OH为原料直接合成DMC的绿色化学反应的主要合成方法、热力学和反应机理,对金属氧化物催化剂、有机金属催化剂、金属有机骨架(MOFs)、离子液体及杂多酸催化剂的特点、适用范围及应用效果等进行了总结,并对二氧化碳和甲醇直接合成碳酸二甲酯以提高DMC产率的策略进行了展望,以期为二氧化碳和甲醇直接合成碳酸二甲酯的相关研究提供一些参考。     

Optimization of the reactor–regenerator system with catalytic parallel–consecutive reactions

The system with moving deactivating catalyst, composed of a cocurrent tubular reactor and a catalyst regenerator with an additional flux of a fresh catalyst, has been investigated. For the temperature dependent catalyst deactivation, the optimization problem has been formulated in which a maximum of a process profit flux is achieved by a best choice of temperature profile along tubular reactor, best catalyst recycle ratio and best catalyst activity after regeneration. The set of parallel–consecutive reactions, A+B→R and R+B→S, with desired product R has been taken into account. A relatively unknown, powerful discrete algorithm in which a suitably defined Hamiltonian is constant along the optimal path, has been applied for optimization. The optimal solutions have been discussed. In particular, it has been shown that an increase of the unit cost of catalyst regeneration or an increase of the catalyst recycle ratio causes such optimal temperatures in reactor which save the catalyst, as the optimal temperature profiles are then shifted towards lower temperatures. Finally these profiles reach isothermal shape at the level of minimum allowable temperature and then there is no further possibility to control the reactor process by the temperature profile. Thus the catalyst activity after regeneration, as well as an average catalyst activity in the reactor do decrease when the unit catalyst regeneration cost increases. This is a new form of catalyst saving, as the catalyst deactivation rate becomes reduced when an average catalyst activity is allowed to decrease. It is important that this form of catalyst saving appears in the region where any saving of the catalyst by an optimal choice of temperature profile is impossible. It has been also shown that for small values of the catalyst recycle ratio, the catalyst regenerator should be removed from the system. In such a case, the renewal of catalyst takes place due to a fresh catalyst input, exclusively.     

Simple and green oxidation of cyclohexene to adipic acid with an efficient and durable silica-functionalized ammonium tungstate catalyst

A novel silica-functionalized ammonium tungstate interphase catalyst has been reported as a non-nitric acid route for adipic acid production from one-pot oxidative cleavage of 30% hydrogen peroxide and catalytic amounts of p-toluenesulfonic acid (PTSA). The catalyst has been simply prepared by commercially available starting material. The structure of the catalyst has been investigated using FT-IR spectroscopy, atomic absorption, TEM, SEM and XRD analysis. The catalyst has shown good to high activity even up to 10 runs of reaction. Simple preparation of the catalyst, avoids using harmful phase transfer catalyst (PTC) and/or chlorinated additives are among the other benefits of this work.     

镁在有机合成中的应用研究进展

综述了镁在有机合成中的应用研究,从镁在元素周期表的位置和电子构型详细讲述了镁作为催化剂和格氏试剂对有机合成的影响。催化剂从催化活性物质,催化剂载体,助催化剂的角度进行论述,格氏试剂主要论述了典型的反应类型,最后对镁在有机合成中的应用进行了展望。     

Environmentally Friendly Photocatalytic Oxidation of Aromatic Alcohol to Aldehyde in Aqueous Suspension of Brookite TiO2

X-ray photoelectron spectroscopy (XPS) has been applied to the study pertaining to preparation and characterization of catalysts used in propylene polymerization. The analysis has indicated support/donor interaction in active support (adduct) and active support/TiCl₄ interaction during catalyst preparation process. A systematic study has been made to identify suitable adduct from a set of three adducts for catalyst synthesis. Precise binding energy of Titanium species on catalyst surface has been measured and its dispersion on support has been evaluated to correlate catalyst performance with the surface spectroscopic parameters.     

Effect of the mechanical failure of catalyst pellets on the pressure drop of a reactor

The effect of the mechanical failure of catalyst pellets on the pressure drop across a laboratory-scale catalyst packing has been examined by experiment. Results reveal that, along with the mechanical failure of the pellets, there exists a point of maximum curvature around which the slope of pressure drop increases rapidly. This rapid increase is attributed to a mutation of the packing structure, occurring as the amount of failed pellets reaches a certain critical value. The secondary breakage of the pellets contributes much to the mutation of the packing and to the pressure drop. It has been observed that a trilobite catalyst is more susceptible to a mechanical stress than a cylindrical catalyst, and that a catalyst with a smaller diameter is much easier to result in an increase in the pressure drop. The measurement of the pressure drop across a laboratory-scale catalyst packing as the failure of pellets under a mechanical stress has a satisfactory reproducibility, and has a close meaning to the mechanical reliability of a fixed bed converter, and hence is recommended as a method for catalyst assessment. The multi-scale and multi-disciplinary nature of catalyst mechanical reliability is also discussed.     

3824中油型加氢裂化催化剂的工业应用

叙述了国产3824中油型加氢裂化催化剂在茂名80万t/a高压加氢裂化装置上的应用,两年多的工业运转证实,该催化剂活性、选择性、稳定性、氢耗及能耗等方面均已全面达到国外同类催化剂的水平,预计第一周期可运转三年后方进行再生,比原设计使用效果好。该催化剂尚可用于中压加氢裂化和缓和加氢裂化。1988年起已用于荆门25万t/a中压加氢裂化装置并取得成功。     

A Study of Hydrophobic Pd/SDB Catalyst for Ethylene Partial Oxidation to Acetic Acid

The performance of 0.2 wt% Pd/SDB catalyst used for partial oxidation of ethylene to acetic acid has been evaluated in a fixed-bed reactor. The catalyst has high activity and selectivity toward acetic acid, but it starts to deactivate after running 84 h at 120 °C and 1200 kPa. BET, XRD, FTIR and XPS have been employed to the characterization of the catalyst. It has been found that the deactivation of the catalyst is mainly due to the partial oxidative degradation of the SDB framework during reaction, particularly, in the presence of oxygen, which results in a decrease in surface area and an increase in hydrophilicity of the catalyst.     

高效载体催化剂下改性HDPE的合成

研究了TiCl_4/SiO_2—MgCl_2载体高效催化剂作用下的乙烯/己烯共聚,发现共聚合的催化效率高于乙烯均聚,从非均相Ziegler—Natta催化聚合的非稳态扩散动力学观点解释了这一现象。研究了所合成的改性HDPE范围的共聚物样品的热性能和拉伸性能,结果表明其性能与商品牌号样品性能相近。     

PET钛系催化剂的研究进展、发展趋势及应用策略

回顾了PET用钛系催化剂的发展历史,通过对技术发展脉络的梳理,提出未来钛系催化剂发展的技术趋势,并结合我国PET装置的特点,分析了在我国使用钛系催化剂生产PET的策略和前景.     

Effect of the Porous Structure of a Catalyst on the Rate of Its Deactivation in the Claus Reaction

The effect produced by the content of different size pores and the diameter of a catalyst grain on the deactivation rate has been estimated based on the experimental data on the conversion of H₂S in the Claus reaction. Catalysts with different pore size distributions have been used for analysis. Deactivation has been shown to occur in different fashions for a fine catalyst fraction and catalyst grains. A mathematical model that describes the process of deactivation has been proposed.