甲苯定向氯化催化剂的研究

对甲苯定向氯化的催化剂进行了研究,找到了一种新型助催化剂,对助催化剂合成的主要影响因素进行了探讨,得到了最佳合成工艺条件,这种助催化剂与SbCl3共同作用,催化甲苯氯化反应时,对氯甲苯的选择性由原来的46%提高到60%。     

苯并硫氮杂卓化合物助催化下甲苯定向氯化

甲苯氯化反应在L酸催化下,加入助催化剂可以调节邻氯甲苯和对氯甲苯比率。合成了三种不同结构杂环苯并硫氮杂卓化合物助催化剂。以SbCl3为催化剂,分别用三种不同结构苯并硫氮杂卓化合物为助催化剂,考察了甲苯定向氯化对氯甲苯选择性的影响;得出最高选择性助催化剂后,找出温度和催化剂用量等工艺条件,使甲苯定向氯化对氯甲苯与邻氯甲苯物质的量之比达到1.29。     

甲苯选择性氯化合成对氯甲苯

综述了国内外甲苯选择性氯化合成对氯甲苯的研究情况,介绍了用氯气、含氯有机化合物和无机氯化物作氯化剂氯化的各种氯化方法,重点介绍了路易斯酸催化剂和含硫助催化剂的催化体系和沸石分子筛催化剂体系,并评价了有关的方法。     

甲苯选择性氯化合成对氯甲苯

综述了国内外甲苯选择性氯化合成对氯甲苯的研究情况，介绍了用氯气、含氯有机化合物和无机氯化物作氯化剂氯化的各种氯化方法，重点介绍了路易斯酸催化剂和含硫助催化剂的催化体系和沸石分子筛催化剂体系，并评价了有关的方法。     

高分子负载铁催化剂的制备及其甲苯选择性氯化反应性能

通过金属铁离子与高分子载体进行螯合反应,制备高分子负载铁催化剂,用原子吸收光谱法测定催化剂中Fe3+含量,并利用傅里叶变换红外光谱仪、扫描电子显微镜、热重分析对制备的催化剂分子结构、微球形貌和热稳定性进行表征,并研究有机硫助催化剂的添加对高分子负载铁催化剂催化甲苯选择性氯化性能的影响。结果表明,铁离子与乙酰丙酮基的两个氧原子形成了六元螯合环的强相互作用,使Cl2分子更易极化,提高了催化反应速率;有机硫助催化剂不仅改变Cl—Cl键的强度,而且增大了亲电试剂的空间位阻,从而显著提高对位选择性和稳定性。1%(占甲苯的质量分数)高分子负载铁催化剂/0.05%(占甲苯的质量分数)有机硫助催化剂催化甲苯选择性氯化反应表现出最佳的催化性能,氯化反应2 h,甲苯转化率超过90%,对氯甲苯选择性55.74%,多氯甲苯质量分数低于1%。催化剂可重复使用。     

甲苯定向氯化合成对氯甲苯

在一种天然沸石催化剂上加以助催化剂,进行甲苯氯化反应,甲苯转化率达到99%,一氯甲苯产物中55%的对氯甲苯,在实验条件下考查了一些因素的变化对一氯甲苯中对位选择性的影响。     

对氯甲苯的合成研究

在溶剂和催化剂下,三氯化铁间接氯化甲苯合成对氯甲苯,探讨了催化剂用量、溶剂用量、反应温度和时间等对氯化反应的影响。结果表明,在反应温度80℃,六氯丁二烯、三氯化铁为氯化剂,反应3 h后,甲苯转化率可达56. 6%,对氯甲苯选择性达86. 0%。     

菲咯啉基铁催化剂催化乙烯齐聚

合成了配合物氯化2-乙酰基-1,10-菲咯啉缩2,6-二乙基苯胺合铁(Ⅱ),以甲苯为溶剂,甲基铝氧烷为助催化剂,催化乙烯齐聚制备线型α-烯烃.催化剂表现出高活性和对α-烯烃的高选择性.考察了反应温度、n(Al)/n(Fe)、反应压力和催化剂浓度等对催化剂活性和齐聚产物分布的影响.     

间氯三氟甲苯的合成

催化剂FeCl3／I2与催化剂FeCl3／Fe催化氯化三氟甲苯合成了间氯三氟甲苯，比较了两种催化剂的活性，并研究了反应温度、转化率对间氯三氟甲苯选择性的影响。     

氯化2-乙酰基-1,10-菲咯啉缩2,6-二异丙基苯胺合铁(Ⅱ)/MAO催化乙烯齐聚的研究

合成了配合物氯化2-乙酰基-1,10-菲咯啉缩2,6-二异丙基苯胺合铁(Ⅱ),以甲苯为溶剂,甲基铝氧烷(MAO)为助催化剂,催化乙烯齐聚制备线型α-烯烃。催化剂表现出高活性和对α-烯烃的高选择性。考察了反应温度、n(Al)/n(Fe)和反应压力等对催化剂活性和齐聚产物分布的影响。     

双戊烯脱氢裂解同步反应与异步反应对比研究

双戊烯脱氢裂解的同步反应和异步反应对比研究显示,双戊烯脱氢裂解的同步反应产物比较混杂,反应产物中甲苯的相对含量仅为24.03%,双戊烯相对于甲苯的料耗比为5.34,甲苯的得率为30.79%,中间产物对伞花烃的得率为2.49%;双戊烯脱氢裂解的异步反应产物混杂程度相对较低,反应产物中甲苯的相对含量为40.74%,对伞花烃的相对含量为18.31%,双戊烯相对于甲苯的料耗比为3.33,甲苯的得率为49.26%,中间产物对伞花烃的得率为16.92%。总体上看,双戊烯脱氢裂解的异步反应优于同步反应。     

Photocatalytic degradation of toluene in a staged fluidized bed reactor using TiO<Subscript>2</Subscript>/silica gel

Relatively high concentration toluene is photocatalytically degraded in a multi-stage fluidized bed reactor continuously. The fluidizing media are titanium dioxide deposited silica gel particles, which are prepared by the doping sol-gel method. The effects of the Ti/Si atomic ratio, the inlet gas flow rates, and the number of the stages on the toluene removal efficiency were evaluated. The highest toluene removal efficiency is obtained when the fluidizing media are with the Ti/Si atomic ratio of 1.25. The apparent reaction orders are 0.4-0.5 for the single-stage system and 0.7 for the two-stage system, respectively. With an inlet toluene concentration of 1,000 ppm, a relative humidity of 30% and a volumetric flow rate of 10 L/min, the removal efficiency of toluene at the steady state is as high as 80% and is maintained in the 6-hr experimental time.     

Exergy and exergoeconomic analyses for integration of aromatics separation with aromatics upgrading

Methanol to aromatics produces multiple products, resulting in a limited selectivity of xylene. Aromatics upgrading is an effective way to produce more valuable xylene product, and different feed ratios generate discrepant product distributions. This work integrates the aromatics separation with toluene disproportionation, transalkylation of toluene and trimethylbenzene, and isomerization of xylene and trimethylbenzene. Exergy and exergoeconomic analyses are conducted to give insights in the splitting ratios of benzene, toluene and heavy aromatics for aromatics upgrading. First, a detailed simulation model is developed in Aspen HYSYS. Then, 300 splitting ratio sets of benzene and toluene for conversion are studied to investigate the process performances. The results indicate that there are different preferences for the splitting ratios of benzene and toluene in terms of exergy and exergoeconomic performances. The process generates lower total exergy destruction when the splitting ratio of toluene varies between 0.07 and 0.18, and that of benzene fluctuates between 0.55 and 0.6. Nevertheless, the process presents lower total product unit cost with the splitting ratio of toluene less than 0.18 and that of benzene fluctuating between 0.44 and 0.89. Besides, it is found that distillation is the biggest contributor to the total exergy destruction, accounting for 94.97%.     

焦化甲苯的加氢精制

对焦化甲苯原料首先进行加氢处理,之后采用连续精馏的方法进行分离与提纯,以得到纯度较高的甲苯产品。加氢阶段有效去除并转化了焦化甲苯中的噻吩、吡啶和烯烃类杂质。精馏阶段采用2塔连续精馏的实验流程,并对流程进行了模拟,分别对2塔的操作参数进行了优化。通过连续精馏实验对模拟结果进行了验证,结果表明,对加氢处理之后的焦化甲苯原料采用NRTL热力学方法得到的精馏模拟结果可得到纯度为99.39%的甲苯产品,证明实验结果与模拟结果吻合较好。     

Effects of Oxygen Transfer Limitation and Kinetic Control on Biomimetic Catalytic Oxidation of Toluene

Under oxygen transfer limitation and kinetic control, liquid-phase catalytic oxidation of toluene over metalloporphyrin was studied. An improved technique of measuring dissolved oxygen levels for gas-liquid reaction at the elevated temperature and pressure was used to take the sequential data in the oxidation of toluene catalyzed by metalloporphyrin. By this technique the corresponding control step of toluene oxidation could be obtained by varying reaction conditions. When the partial pressure of oxygen in the feed is lower than or equal to 0.070 MPa at 463 K, the oxidation of toluene would be controlled by oxygen transfer, otherwise the reaction would be controlled by kinetics. The effects of both oxygen transfer and kinetic control on the toluene conversion and the selectivity of benzaldehyde and benzyl alcohol in biomimetic catalytic oxidation of toluene were systematically investigated. Three conclusions have been made from the experimental results. Firstly, under the oxygen transfer limitation the toluene conversion is lower than that under kinetic control at the same oxidation conditions. Secondly, under the oxygen transfer limitation the total selectivity of benzaldehyde and benzyl alcohol is lower than that under kinetic control with the same conversion of toluene. Finally, under the kinetics control the oxidation rate of toluene is zero-order with respect to oxygen. The experimental results are identical with the biomimetic catalytic mechanism of toluene oxidation over metalloporphyrins.     

酸、碱改性活性炭对甲醇、甲苯吸附性能

分别采用硝酸和氢氧化钠对活性炭进行改性,利用比表面积及孔径分析仪（BET）、扫描电镜（SEM）、Boehm滴定法对活性炭物化性质进行表征,测试改性活性炭对甲醇、甲苯吸附性能。结果表明,经过酸、碱改性后的活性炭比表面积、总孔容、微孔孔容均有所增大。酸改性表面酸性基团增加,碱改性后活性炭酸性基团减少。酸改性后的活性炭对甲醇、甲苯吸附能力有所下降,后经碱改性的活性炭吸附能力均有不同程度的提高。单组分吸附实验时,甲醇穿透曲线斜率要大于甲苯,穿透时间早于甲苯。在多组分吸附过程中会出现甲苯取代甲醇的吸附现象,使得已经被吸附的甲醇发生脱附,此时甲醇的出口浓度大于进口浓度,形成峰值效应。     

甲苯二异氰酸酯的生产和应用

介绍了甲苯二异氰酸酯的性质、用途、国内外生产概况和生产方法,并对目前广泛采用的胺光气化法做了详细介绍。     

Two phase nitration of toluene—III

Initial nitration rates of toluene have been measured at sulphuric acid strengths between 76 and 79 per cent in a stirred cell with pure toluene, and also in a stirred batch reactor with a dilute solution of toluene in an inert solvent.The results are consistent with the rates in both cases occurring within the transition from the slow to the fast reaction diffusional regime. With the stirred reactor and diluted toluene reasonable values of 44·cm^?1 and 1·03×10^?3 cm sec^?1 are obtained for the interfacial area per unit volume of the acid phase and the overall mass transfer coefficient, respectively.However, when the organic phase is pure toluene, both stirred cell and stirred reactor rates are lower than expected. The conclusion is drawn that the formation of nitronium ions, rather than their attack on the toluene, is the rate limiting kinetic step under these conditions. The rate constants for the formation of nitronium ions from nitric acid in 78·45 per cent sulphuric acid is estimated to have the value 0·40 sec^?1 at 25°C.     

Preparation of carbon foams with supercritical toluene

Carbon foams with pore sizes of 10–50 μm were prepared with mesophase pitch and toluene as the carbonaceous precursor and supercritical agent, respectively. Results revealed that the light pitch components and dissolved toluene in pitch significantly affected the pore structures of resultant carbon foams. The amount of toluene dissolved in molten pitch is greatly dependent on the foaming conditions, such as the ratio of toluene to pitch, foaming temperature, foaming pressure and saturation time. Carbon foams with hierarchical porous structures are obtained by controlling the amount of light pitch components.     

Normal coordinate analysis of isotactic polystyrene: 1. A force field for monosubstituted alkyl benzenes

The normal modes for toluene, toluene D8, and ethyl benzene are calculated starting from a revised force field for benzene. A good agreement is obtained between calculated and observed frequencies.