甘油直接制备丙烯醇的催化剂和反应工艺研究进展

丙烯醇是一种十分重要的中间体和化学原料。近年来,以甘油为原料直接制备丙烯醇的研究引起了许多科学家的关注。本文参考了最近十年来发表的文献,详细介绍了均相甲酸诱导的甘油脱氧脱水反应、催化剂作用下的甘油脱氧脱水反应、液固相甘油氢解反应和气固相甘油氢转移反应等过程制备丙烯醇的相关工艺、反应机理和催化剂的研究进展及发展趋势,并对比了上述工艺的优缺点。其中,均相甲酸诱导的甘油脱氧脱水工艺比较成熟,已经在实验室中得到验证和应用,但是甲酸的消耗量大,整个过程的原子经济性很差。 甘油脱氧脱水反应和液固相甘油氢解反应不仅需要采用价格昂贵的铼基催化剂,而且丙烯醇的选择性较低。 铁基催化剂作用下的气固相甘油氢转移反应制备丙烯醇,由于催化剂的价格低廉、制备工艺简单、产品分离容易等优势而备受关注,是最近五年的研究热点。在文献基础上,认为今后研究应该重点关注催化剂的酸碱性、氢转移能力及其与速率控制步骤的匹配,并有针对性地对催化剂进行优化和改进。     

KINETIC STUDIES ON OXIDATION OF ALLYL ALCOHOL BY YEAST ALCOHOL DEHYDROGENASE

The kinetics of the oxidation of allyl alcohol by yeast alcohol dehydrogenase (YADH) was studied with stopped-flow technique. The experimental results showed that the specific activity of YADH remained constant within theYADH concentration range ofO-16.4mg/dm₃ and YADH exhibited maximum activity at pH 7.9 and a phosphate buffer concentration of 0.25 mol/dm₃ The oxidation rate of allyl alcohol by YADH followed the Arrhenius equation within the temperature range of 10 to 40°C The YADH was denatured irreversibly at the temperatures above 40°C. The rate equation for the YADH-catalyzed oxidation of allyl alcohol was obtained. A mixed-type substrate inhibition occurred when the concentration of allyl alcohol was higher than 200 mmol/dm₃ The presence of LiCl, NaCl and KG could enhance the activity of YADH. The YADH lost activity significantly in the presence of organic solvents, particularly benzene and its derivatives.     

丙烯醇催化氨化合成3-甲基吡啶催化剂的制备及性能

采用浸渍法制备了一系列H-ZSM-5分子筛负载过渡金属锌催化剂,在固定床反应器上考察了这些催化剂对丙烯醇催化氨化合成3-甲基吡啶的催化性能。通过对H-ZSM-5的硅铝比、锌负载量对催化剂催化性能影响的考察,发现硅铝比为80、锌负载量为12%时得到的催化剂Zn₁₂/H-ZSM-5（80）的催化性能最佳。在常压、反应温度420℃、氨醇摩尔比3：1、空速300 h^-1条件下,丙烯醇在该催化剂上的转化率和3-甲基吡啶的选择性分别达到97.8%和37.9%。利用X射线衍射（XRD）、X射线光电子能谱（XPS）以及吡啶吸附红外对催化剂进行了表征,结果表明,Zn₁₂/H-ZSM-5（80）上负载的Zn²⁺为L酸;在丙烯醇生成3-甲基吡啶的反应过程中催化剂的脱氢活性物种为氧化锌,而加成和环合反应则主要是由催化剂中的L酸催化实现的。     

二步法催化合成烯丙基无规聚醚的研究

以烯丙醇、环氧乙烷、环氧丙烷为原料，通过烯丙基低聚物的制备和烯丙基大分子量聚醚的制备两步反应，合成了烯丙基无规聚醚，并考察了适宜的合成条件。烯丙基低聚物制备阶段，反应温度为90～110℃，加环氧乙烷／环氧丙烷（EO／PO）时间为2．0～2．5h，氢氧化钾用量为烯丙醇质量的1％。烯丙基大分子量聚醚制备阶段，烯丙基低聚物为起始剂，多金属氰化物（MMC）催化刺添加量为产品的0．225％o，脱水时间为60min，脱水温度为110℃，反应温度为110℃左右，加EO／PO时间为3．5h。制得的烯丙基无规聚醚外观为无色透明液体，色泽小于20，不饱和度大于2．23％。     

新型单官能度高分子量聚醚多元醇的研究

介绍了一种丙烯醇聚醚多元醇的合成方法。采用了丙烯醇作为起始剂、环氧丙烷作为聚合单体、氢氧化钾和双金属催化剂作为双催化剂,采用二次聚合方式,通过选择适合的聚合反应条件,从而制得一种性能优异的新型单官能度高分子量丙烯醇聚醚多元醇。并对其反应条件及使用性能进行了研究。     

烯丙基聚醚合成方法的改进

以烯丙醇和固体KOH为原料制得烯丙醇钾,再在常压下与环氧乙烷反应制得高纯度的烯丙基聚醚,讨论了反应时间、反应温度、原料配比、投料方式等因素对反应的影响。当KOH与烯丙基的摩尔比为1：1.25时,加热回流下可以得到高收率的烯丙醇钾,开环反应依据所需的聚醚分子量调节环氧乙烷的用量,产品收率达到98%以上。     

菠萝酯的合成研究

以苯酚和氯乙酸为原料,四丁基碘化铵为催化剂合成了苯氧乙酸,收率达96．2％。并以苯氧乙酸和烯丙醇为原料,强酸性阳离子交换树脂为催化剂合成了菠萝酯,收率达84．5％。考察了两个反应的主要影响因素。     

不同结构聚醚改性硅油的制备与表征

以含氢硅油、（α-烯丙氧基,ω-羟基）聚氧乙烯聚氧丙烯醚（F-6）和（α-烯丙氧基,ω-甲氧基）聚氧乙烯聚氧丙烯醚（AEPM-1500）为原料,在氯铂酸催化剂作用下,通过硅氢加成反应,合成了一种聚醚改性硅油（AAMS）,并用红外光谱和核磁共振氢谱对其结构进行了表征。考察了反应时间、温度以及催化剂用量对Si—H转化率的影响,较佳合成工艺为：反应时间为6h、反应温度为105℃,氯铂酸用量为20μg/g,此时,Si—H的转化率可达94．6％;随着F-6与AEPM-1500的量之比的增大,产物AAMS水溶液的表面张力先降后升,浊点升高;当F-6与AEPM-1500量之比为4：1时,AAMS水溶液的表面张力可降至28．6mN／m,浊点为24℃。     

Epoxidation of allyl alcohol to glycidol using titanium silicalite TS-1: effect of the method of preparation

The epoxidation of allyl alcohol with hydrogen peroxide catalysed by the microporous titanium silicalite TS-1 has been investigated with respect to the effect of the method of catalyst preparation. Three methods of TS-1 synthesis have been studied using the standard tetrapropyl-ammonium cation as template (i) using tetraethyl orthosilicate, tetraethyl orthotitanate as reagents, (ii) using a fluoride method and (iii) using tetrabutyl orthotitanate as the titanium source. The TS-1 samples were characterised by electron microscopy, X-ray diffraction and infrared spectroscopy. The method of preparation controlled the morphology of the TS-1 crystals and in particular the crystallisation time was found to be an important parameter. Data are presented that correlate the activity for the epoxidation of allyl alcohol with the morphology of TS-1. In addition it is found that the catalytic activity of TS-1 for this reaction is not related to the intensity or presence of the infrared absorption band at ca. 960 cm^–1.     

Propenoxide isomerization in a fluidized bed reactor

Propenoxide isomerization, over lithium orthophosphate as a catalyst, was investigated in a fluidized bed reactor. A mathematical model of the process was developed and its kinetic parameters identified. There is a high degree of selectivity for allyl alcohol.     

Optimization of the technological parameters of epoxidation of allyl alcohol by hydrogen peroxide over Ti–BETA catalyst

The influence of the technological parameters on the epoxidation of allyl alcohol by a 30 wt% hydrogen peroxide in the medium of methanol over the Ti–BETA catalyst in the direction of glycidol has been presented. The experimental conditions were established on the basis of preliminary experiments and through the applications of statistical experimental design methods (rotatable uniform design). The results of the particular experiments were described by the following functions: the yield of glycidol in relation to allyl alcohol introduced into the reactor, the selectivity of transformation to glycidol in relation to allyl alcohol and hydrogen peroxide reacted, and the degree of conversion of allyl alcohol and H₂O₂. The optimal values of each function were established. The courses of functions corresponding to the parameters were plotted in the system of two variable parameters. The optimum parameters of the epoxidation process were established after the analysis of the layer drawings. The obtained results were confirmed by a series of verifying syntheses. Copyright © 2004 Society of Chemical Industry     

过渡金属催化下醛的烯丙基化反应研究进展

烯丙基醇在有机合成中是一类重要中间体,醛的烯丙基化反应是制备烯丙基醇的一类重要方法,其中过渡金属作为催化剂,在该领域获得了突飞猛进的发展。文章综述了近两、三年来在过渡金属催化下金属烯丙基试剂及其替代品与醛的烯丙基化反应研究进展。     

糠醇加氢制四氢糠醇催化剂的研究

制备了负载型镍催化剂 ,并加入碱性和过渡金属氧化物助剂 ,各种氧化物总负载量低于催化剂质量的 30 %。在 393～ 413K、0 .2 5～ 0 .4h-1、2 .0～ 4.0MPa条件下 ,用上述催化剂加氢还原糠醇制备四氢糠醇。对于含少量助剂的镍催化剂Ⅱ ,在 393K、4.0MPa和空速 0 .2 5h-1时 ,糠醇转化率可达 99%以上 ,四氢糠醇收率和选择性都达到或接近 97%。在相同反应条件和糠醇转化率条件下 ,四氢糠醇收率和选择性均比没有助剂的镍催化剂Ⅰ高 2 .0 % ,比骨架镍催化剂高3.0 %     

Epoxidation of allyl alcohol with hydrogen peroxide over titanium silicalite TS‐2 catalyst

The influence of the technological parameters on the course of the epoxidation of allyl alcohol with 30% H₂O₂ in the presence of titanium silicalite TS‐2 catalyst and methanol as a solvent was studied. The process was performed in an autoclave at the autogenic pressure. The influence of temperature in the range 20–120 °C, molar ratio of allyl alcohol/H₂O₂ (1:1–10:1), methanol concentration in the reaction mixture (10–80% w/w), catalyst TS‐2 concentration (0.1–2.0% w/w) and reaction time (1–8 h) were investigated. The functions describing the process were: selectivity of transformation to glycidocidol in relation to allyl alcohol consumed, selectivity of transformation to organic compounds in relation to hydrogen peroxide consumed, conversions of allyl alcohol and hydrogen peroxide. Copyright © 2007 Society of Chemical Industry     

D-酒石酸丙烯酯的合成研究

以D-酒石酸和丙烯醇为原料合成了酒石酸丙烯酯。考察研究了催化剂用量、反应温度和时间等因素对产物产率的影响。结果表明：酒石酸和丙烯醇摩尔比为1.0∶2.5,1.0%对甲苯磺酸,1.0%对苯二酚,反应温度80℃,反应时间为8 h,酒石酸丙烯酯的产率达到96.6%;并对产品结构进行了红外光谱表征。     

三种不稳定化合物临界温度和临界压力的测定

用独特的毛细管流动法装置测定物质的临界温度和临界压力,该法具有体积小、升温迅速和受热均匀等特点,适于测定不稳定化合物的临界性质。以正己烷、1 庚烯为标准试剂,对该装置进行了考核。测定了溴乙烷、丙烯酸丁酯、烯丙醇3种物质的临界温度及临界压力。首次提供了丙烯酸丁酯、烯丙醇的临界数据,并且校正了溴乙烷临界温度和临界压力值。     

A combined MAS nuclear magnetic resonance spectroscopy,in situ FT infrared spectroscopy and catalytic study of the conversion of allyl alcohol over zeolite catalysts

A combined study of allyl alcohol conversion over zeolite catalysts using catalytic measurements in a flow microreactor, in situ FTIR and MAS NMR spectroscopy is reported. Rate constants for the conversion in the flow reactor and the static in situ reactor used in the FTIR studies are in broad agreement, emphasising the viability of the experimental approach. In the flow microreactor allyl alcohol conversion over the zeolite catalyst is shown to form diallyl ether, hydrocarbons and acrolein. The in situ study successfully models the formation of diallyl ether and hydrocarbon as initial reaction products, but unfortunately acrolein is found to be rapidly converted to hydrocarbons under the condition used in the in situ cells. The studies are combined to provide a model for the reaction which involves two parallel pathways for the formation of the hydrocarbons and acrolein.     

Gas-phase hydrogen-transfer reduction of acrolein using 2-propanol over MgO/B2O3 and SiO2/AlPO4 catalysts

Two MgO/B2O3 and SiO2/AlPO4 catalysts designated BM50 and PM2, respectively, were used in the gas-phase hydrogen transfer between acrolein and 2-propanol to obtain allyl alcohol and propanal. The acid-base properties and catalytic activity of the two systems were found to be rather different. Thus, the MgO/B2O3 catalyst is more selective towards allyl alcohol than is the SiO2/ AlPO4 catalyst (conversion to the alcohol was 28% with the former and 0% with the latter). This special selectivity is discussed in terms of the different ways in which acrolein can be adsorbed on the catalytic surface as revealed by temperature-programmed desorption profiles and DRIFT spectra for pre-adsorbed acrolein. This revised version was published online in July 2006 with corrections to the Cover Date.     

2-环己氧基乙酸烯丙酯的合成

以摩尔比为１∶１．１５的环己醇钠和氯乙酸钠为原料,在１３５～１４５℃下反应合成了环己氧基乙酸钠,反应时间为２．５ｈ,收率约为８１％,再将环己氧基乙酸钠用盐酸酸化制得中间体环己氧基乙酸。后者在对甲苯磺酸催化下与烯丙醇经酯化反应制得标题化合物,收率为８７．１％。最佳工艺条件是：环己氧基乙酸∶烯丙醇＝１∶５．５（摩尔比）,催化剂加入量为０．１８ｍｏｌ／ｍｏｌ酸,反应温度为１１５～１２０℃,反应时间为６ｈ。     

Ethoxylation of detergent-range oxo alcohols derived from fischer-tropsch α-olefins

Detergent-range alcohols currently are produced from a variety of basic raw materials including natural fats and oils, natural gas, and petroleum. Joining this list of basic raw materials is coal. Olefins are formed in the conversion from coal via the Fischer-Tropsch (F-T) process and are then converted to alcohol via the oxo process. This paper describes the characteristics of Fischer-Tropsch oxo alcohol and its ethoxylation properties in comparison with other common detergentrange alcohols. This work shows that oxo 1213 alcohol (i.e., a mixture of primary fatty alcohols containing both 12 and 13 carbons in their hydrocarbon backbone) reacts with ethylene oxide similarly to linear alcohol, yielding low levels of unethoxylated alcohol. Substitution at the C₂ position has more impact on the ethoxylation of an alcohol than the degree of linearity.