氨氧化法合成邻苯二甲腈

气相氨氧化邻二甲苯合成邻苯二甲腈是目前最简单、最经济的合成工艺。作者针对邻二甲苯的特 点,研制出了选择性高、寿命长、氨与邻二甲苯物质的量之比较小的V—Cr-Mo-O催化剂。经在φ330mm流化床中试 生产结果证明:邻苯二甲腈收率可达60％以上,产品纯度≥99.0％,达到了国际先进水平。     

Single micro-bubble generation by pressure pulse technique

A new method for generation of gas bubbles from a micropipette has been developed. In this method, step pulses of gas pressure are used to inject micro-volumes of gas into a liquid. Both the size and number of gas bubbles produced can be controlled through pressure regulation, pressure variation, orifice diameter and pipette position. A theoretical model derived to predict the size of bubbles generated from a non-vertical micropipette agrees well with the experimental results.     

Rate constants of elementary steps by pulse technique

Two methods for measuring the rate constants of the elementary steps by the pulse technique are proposed. The first gives the adsorption and the desorption rate constants from the retention time and the half width of the chromatographic peak, and was applied to the adsorption of benzene on HY and CaY zeolites. The second gives the surface reaction rate constant and the desorption rate constant of the reactant from the peak of the product which is not adsorbed on the catalyst surface. The method was applied to the cracking of cumene on HY and CaY.     

催化氨氧化法制备2-氰基吡嗪的研究

开发了一种由VMoOP四元素组成的氨氧化催化剂(V-II型)，用该催化剂在固定床反应器内由2-甲基吡嗪为原料进行气固相接触氨氧化反应制备了2-氰基吡嗪。V-II型催化剂组分中矾、磷的比例是影响催化剂反应活性及选择性的主要因素，矾磷比为1．9时，催化活性最好。探讨了氨氧化反应机理，认为2-甲基吡嗪经过氧化、脱水分别生成了吡嗪羧酸和吡嗪酰胺中间体后最终生成2-氰基吡嗪。正交实验确定了反应的影响因素和最佳条件，结果表明：反应温度是影响产品收率的最主要因素，当2-甲基吡嗪、氨气、空气的投料量分别为0．05mL．min-1，200mL．min-1,1000mL．min-1，反应温度430℃时，2-氰基吡嗪选择性大于90％，单程收率大于87％，产品纯度大于99％。按小试工艺条件放大l00倍中试，结果与小试吻合。     

丙烯环氧化反应的研究新进展

综述了不同氧源与丙烯环氧化反应的研究新进展。主要包括:氢氧原位制备过氧化氢丙烯环氧化,直接以分子氧为氧化剂的光诱导环氧化反应以及以臭氧和一氧化二氮为氧化剂的研究。指出开发活性高、选择性好的催化剂是解决问题的关键,并对其应用前景进行了讨论。     

氨氧化制邻甲苯腈新工艺

简要介绍了邻甲苯腈的用途及生产方法，探讨了氨氧化反应的工艺条件，重点考察了反应温度、空气比和氨比对反应结果的影响。试验结果表明：在最佳反应温度420℃，空气比20，氨比8的条件下，反应转化率为36．6％、收率为36．3％，选择性为99．2％；所得产品纯度高于99．O％，几乎无三废排放o，     

Carbon dioxide/propylene oxide coupling reaction catalyzed by chromium salen complexes

A series of chromium/Schiff base complexes N,N′-bis(salicylidene)-1,2-phenylenediamino chromium^III X were prepared and employed for the alternating copolymerization of carbon dioxide with racemic propylene oxide in the presence of (4-dimethylamino)pyridine. The effect of the complex structure and reaction conditions on the catalytic activity, the poly(propylene carbonate)/cyclic carbonate (PPC/PC) selectivity, and the polymer head-to-tail linkages was examined. The experiments indicated that N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-phenylenediamino chromium^III (NO₃) exhibited the highest PPC/PC selectivity as well as polymer head-to-tail linkages and N,N′-bis(3,5-dichlorosalicylidene)-1,2-phenylenediimino chromium^III (NO₃) possessed the highest catalytic activity among these chromium/Schiff base complexes. The structure of the produced copolymer was characterized by the IR, ¹H NMR, and ¹³C NMR measurements. Almost 100% carbonate content of the resulting polycarbonate were obtained with the help of these effective catalyst systems under facile conditions.     

过氧化氢直接氧化法制备环氧丙烷技术进展

概述了过氧化氢直接氧化法(HPPO法)制备环氧丙烷的工业生产现状,从生产工艺和装置设备等方面概述了我国HPPO法制备环氧丙烷的技术进展,提出了今后的发展建议。     

3,4-二氯甲苯氨氧化法制备3,4-二氯苯腈

采用气相氨氧化法,在DN120号催化剂作用下,由3,4-二氯甲苯制备了3,4-二氯苯腈(DCBN).考察了反应温度、物料摩尔比和进料量Qv对反应的转化率、摩尔产率和选择性的影响.确定最佳反应条件为:反应温度400℃、物料摩尔比nDCT∶nNH3∶nair=1∶7∶30、进料量Qv=0.6 mL·h-1.在此条件下,使用DN120号催化剂连续反应300 h,DCBN平均摩尔产率为85.3%.     

乙丙橡胶生产技术及应用进展

介绍了国内外乙丙橡胶的开发现状、生产技术及应用进展,对我国乙丙橡胶的发展提出了建议。     

Synthesis of propylene glycol methyl ether over amine modified porous silica by ultrasonic technique

Amine modified porous silica were synthesized by ultrasonic technique under mild conditions. The samples, which were characterized by BET, ²⁹Si NMR spectra, element analysis and indicator dye adsorption, exhibited promising catalytic properties towards the synthesis of propylene glycol methyl ether from methanol and propylene oxide. They had both high yields and reusability in the reaction, indicating that ultrasonic technique was effective for the preparation of organically modified silica catalysts. Furthermore, the possible reaction mechanism was proposed for the synthesis of propylene glycol methyl ether over such type of catalysts.     

丙烯氧化制环氧丙烷研究进展

环氧丙烷 (PO)是重要的有机化工原料和中间体 ,目前工业采用氯醇法和间接氧化法生产。这两种方法均存在严重缺陷 ,有待于改进。本文主要介绍丙烯直接氧化法制取PO的近期进展 ,指出了丙烯直接氧化法研究的难点和今后研究的方向。     

3,4-二氯甲苯氨氧化制3,4-二氯苯甲腈的工艺研究

介绍了运用湍流流化床反应器工艺氨氧化合成3,4-二氯苯甲腈(3,4-dichlorochlorotoluene)的方法,考察了其反应温度、反应线速、催化剂负荷、原料配比(氧比和氨比)等工艺条件对反应结果的影响.结果表明,在反应温度395℃,原料中3,4-二氯苯甲腈、氨气和氧气的物质量比为1:4:4,反应线速度为0.2 m/s,催化剂负荷(WWH)为0.050 h-1的条件下,3,4-二氯甲苯转化率达98.5％,3,4-二氯苯甲腈的摩尔收率大于90.0％,且催化剂具有较好的稳定性.     

改性TS-1催化甲乙酮氨氧化反应

将酸碱盐改性的TS-1分子筛用于甲乙酮(MEK)氨氧化反应中,考察了改性物质、反应温度、原料摩尔比、催化剂用量和后续反应时间对反应的影响及催化剂的重复使用与再生性能.结果表明: Zn(NO3)2改性的TS-1为适宜催化剂,较优的工艺条件是反应温度为70 ℃,n(NH3)∶ n(MEK)∶ n(H2O2)=3.5∶ 1∶...     

氨氧化催化合成氰基吡嗪的研究

研究2-甲基吡嗪氨氧化催化合成2-氰基吡嗪的催化反应机理后,可知2-甲基吡嗪是通过一系列的脱氢、氧化生成甲醛吡嗪和羧酸吡嗪然后氰化生成产物的,因此优良的催化剂必须由活性及数目合适的脱氢、供[O]及氰化中心组成.分析了各种氨氧化催化剂后,研制了Sb2O3-V2O5-TiO2/SiO2型催化剂,通过实验分别考察反应温度,进料空速,原料配比的影响.确认在空速0.3h-1,反应温度380℃,配料比为2-甲基吡嗪：氧气：氨气=1：8.5：3（摩尔比）时,2-甲基吡嗪的转化率为70%以上,2-氰基吡嗪的收率为55%以上.与同类催化剂相比,具有反应温度低,空速大等优点,更适合工业化;同时也验证了催化反应机理的合理性.     

Ammoxidation of propane to acrylonitrile on V---Sb---O catalysts. Role of ammonia in the reaction pathways

Transient experiments in the vacuum on the ammoxidation of propane over VSb₅O_x- and VSb₅O_x(30 wt%)/Al₂O₃ catalysts were performed. Additionally, the interaction of ammonia with the catalysts was investigated by means of TPD and DRIFT spectroscopic studies. The reported results reveal that short lived NH_x.-species, most probably NH_3,ads or NH⁺₄, are active species in the formation of acrylonitrile from propane. These species are also involved in the formation of the non-selective side-product N₂, which is formed via the intermediates NO and N₂O.     

Mechanism of Selective Paraffin Ammoxidation

Selective ammoxidation of paraffins into corresponding nitriles is of a prime practical significance as it could add to the sources for synthesis of a number of valuable organic products currently produced from oil. On the whole these processes seem to be more promising for commercial synthesis than partial oxidation of paraffins, as nitriles are more stable than corresponding oxy products and a higher yield of the desirable product may potentially be achieved.     

Oxidation and Ammoxidation of Aromatics

An overview of the state of the art in the direct oxygen or nitrogen insertion to aromatic rings and side‐chains by hydroxylation, acetoxylation, partial oxidation and ammoxidation is presented. The influence of a variety of catalysts and oxidants on the yields of hydroxylated products of aromatic species is discussed in more detail. The survey is also focussed on the usage of H₂O₂ as an effective oxidising agent for hydroxylation reactions. Acetoxylation of methyl‐substituted aromatic compounds to their corresponding esters in a single step is indeed an interesting area from an industrial point of view. Hence, the topics covering benzylic acetoxylation, although they are under a developmental stage for commercial exploitation, are also reviewed. The present contribution also covers the main directions of selective oxidation/ammoxidation of aromatic compounds to useful products, surveys recent developments and provides an updated discussion of the state of the art in the field of oxidation and ammoxidation of aromatics. Additionally, a comparative study of the vapour phase oxidation and ammoxidation of different alkyl aromatics to their corresponding aldehydes and nitriles using various heterogeneous catalysts is presented. Besides, the achievements and limitations of the catalysts/processes are emphasised. Furthermore, the present article includes a discussion of common features and differences in mechanistic steps of oxidation and ammoxidation reactions investigated by in situ FITR spectroscopy. The influence of acid‐base properties of catalyst surfaces in connection with electronic effects of the substituents on the performance of the catalysts is also described.     

Mechanism of Selective Paraffin Ammoxidation

Selective ammoxidation of paraffins into corresponding nitriles is of a prime practical significance as it could add to the sources for synthesis of a number of valuable organic products currently produced from oil. On the whole these processes seem to be more promising for commercial synthesis than partial oxidation of paraffins, as nitriles are more stable than corresponding oxy products and a higher yield of the desirable product may potentially be achieved.     

TS-1催化丙烯环氧化反应及动力学研究

研究了丙烯环氧化反应条件,系统考察了反应压力、溶剂中水质量分数、TS-1质量分数以及反应温度对过氧化氢转化率以及环氧丙烷选择性的影响,采用非机理速率方程确定了主反应动力学参数。并采用该反应动力学模型对TS-1质量分数、溶剂中水质量分数对在不同温度下的双氧水转化速率常数进行了关联。为今后建立复杂动力学模型以及该工艺的工业化打下了良好的基础。