三氧化硫气相磺化甲苯制高纯度对甲苯磺酸的实验研究

进行了用三氧化硫气相磺化甲苯制对甲苯磺酸的实验室研究，以提高产品纯度。磺化反应温度为８－１０℃，加入１％的有机酸作定位剂，ＳＯ３气浓８％左右，产品中对甲苯磺酸含量达９８％左右。     

气相SO3磺化甲苯工艺研究进展

本文综述了气相三氧化硫磺化甲苯制取对甲苯磺酸的反应机理及工艺条件,阐述了设备及工艺条件等诸多因素对反应的影响。指出气相SO3磺化甲苯具有反应速度快,强放热,反应体系粘度大的特点,为了得到高质量的对甲苯磺酸,减少副产物的生成,需要在设备和工艺两方面做研究。一方面,反应器是磺化反应的核心,应具有快速均匀混合和良好的质热传递性能;另一方面,工艺条件应根据反应的特点进一步优化。     

甲苯磺化技术新进展

对甲苯磺化技术的最新进展进行评述,探讨了几种重要磺化反应器的的优劣,并介绍了作者最近开发的甲苯气相三氧化硫磺化工艺。     

甲苯磺化制对甲酚的生产工艺路线

本文对甲苯磺化／碱熔法制对甲酚的硫酸磺化工艺、三氧化硫磺化工艺的特点，反应器的最新进展作了系统的综述。     

对甲苯磺酸合成工艺的研究进展

从液-液和气-液反应两方面综述了甲苯磺化合成对甲苯磺酸的磺化工艺,介绍了过量硫酸、氯磺酸、液相三氧化硫(SO3)、气相甲苯和气相SO3等磺化工艺,并探讨了气相SO3磺化工艺中釜式反应器、降膜反应器和喷射环流反应器的优缺点。最后就甲苯磺化合成对甲苯磺酸的磺化工艺进行了展望。     

气相三氧化硫甲苯磺化工艺及喷射环流反应器

主要介绍了气相三氧化硫甲苯磺化新工艺及喷射环流磺化反应器的结构。     

我国三氧化硫磺化装置现状及发展趋势

对我国三氧化硫磺化技术的研究开发进行了回顾。从引进三氧化硫磺化装置和国产三氧化硫磺化装置两方面论述了我国三氧化硫磺化装置的现状，提出了我国三氧化硫磺化装置发展的趋势。     

浅谈烷基苯磺酸磺化工艺安全性

介绍了三氧化硫磺化反应工艺的技术发展概况,参照意大利BALLESTRA公司的磺化器设计数据,将三氧化硫和十二烷基苯制备十二烷基苯磺酸的安全性,与安监总管三〔2009〕116号文《关于公布首批重点监管的危险化工工艺目录的通知》中对磺化工艺危险性定性进行了对比研究.结果表明三氧化硫和十二烷基苯制备十二烷基苯磺酸的危险性与安...     

对甲苯磺酸的合成

本文论述了合成对甲苯磺酸的四种方法，分别采用硫酸、三氧化硫、氯磺酸等三种不同的磺化剂，并对这四种方法进行了比较，认为采用三氧化硫磺化法生产对甲苯磺酸具有一定的优势。同时简述了对甲苯磺酸的精制和分析方法。     

喷射环流反应器中甲苯气相三氧化硫磺化

<正>对甲苯磺酸是制备对甲酚的重要中间体。目前,工业上主要采用甲苯浓硫酸磺化的方法生产,该方法硫酸利用率低,生产过程产生大量废酸,造成环境污染严重;同时,由于磺化产物中,间甲苯磺酸含量高达4%以上,以此为原料生产高纯对甲酚的收率低、成本高、工艺复杂,以SO_3为磺化剂能克服以上不足。对于大相对分子质量的烷基苯（如十二烷基苯）的SO_3磺化早已工业化,关于小相对分子质量烷基苯（如甲苯）的磺化,1983年,Sohrabi建立了气液传质模型,Davidsohn提出了多釜串联生产对甲苯磺酸的专利技术,但至今未见有工业化报道,针对SO_3磺化甲苯具有反应速度快,放热量大等特点,本文首次将用于生化反应过程的喷射环流反应器用于气相SO_3磺化甲苯的反应过程,克服了釜式磺化反应器传质比表面积小、体积大及降膜磺化反应器内易出现局部过热、结构复杂等不足。通过实验,对反应产物的物性变化情况、反应器内的气含率特性及工艺条件进行了初步研究,为工程放大提供了合理的依据。     

Production of p‐toluenesulfonic acid by sulfonating toluene with gaseous sulfur trioxide

Toluene was sulfonated by gaseous sulfur trioxide to prepare p‐toluenesulfonic acid. The effects of reaction temperature and toluene conversion on the isomer selectivities and the dynamic viscosity of the reaction mixture in a well‐stirred tubular glass reactor of 4 cm diameter and 16 cm height were investigated. Lower selectivity to the m‐isomer was obtained at lower reaction temperature and lower conversion of toluene, whereas the selectivity to the p‐isomer seemed to be less affected by these parameters. With the increase in toluene conversion a sharp increase in viscosity of the reaction mixture was observed, which was attributed to the saturation of the toluenesulfonic acids dissolved in toluene. A pilot‐scale stainless steel jet loop reactor (JLR) of 0.3 m diameter and 4 m height with an external cooler was constructed and used for the continuous sulfonation of toluene. It was found that the JLR was very effective for the fast removal of the large amount of reaction heat, and selectivities to the p‐isomer around 85% and to the m‐isomer below 1.2% were obtained. © 2001 Society of Chemical Industry     

凹凸棒石镍基催化剂对污泥气化焦油催化裂解的特性分析

以凹凸棒石为催化剂载体,采用等体积浸渍法制备了多种镍基催化剂,并对催化剂进行了XRD、SEM、BET、EDS等特性分析。在固定床反应器中对催化剂催化裂解污泥气化焦油模型化合物的特性进行了实验研究。考察了反应温度、水碳比（S/C）、气相停留时间、助剂等因素对模型化合物催化裂解特性的影响。结果表明,提高反应温度、增加S/C、延长停留时间、添加助剂均能提高催化剂的催化活性,模型化合物转化率明显增加。但是助剂含量过高反而导致催化剂催化裂解的能力减弱,模型化合物转化率下降。对比Fe、Ce、Cu、Ca 4种助剂发现,在实验范围内,增加Fe的含量,模型化合物转化率上升。当Ce、Cu、Ca助剂质量分数达到3%及以上时,转化率下降明显,甚至低于未添加助剂时的转化率。     

氧化氯化法提高甲苯氯化的对位选择性

我们以氧化氯化的间接方法对甲苯进行氯化,发现这种体系较传统的直接氯化法有更好的对位选择性。通过筛选不同的金属氯化物、氧化剂,及各种溶剂、反应温度和反应时间,发现氯化锂/过硫酸氢钾体系在10℃反应12 h,可以得到100%的甲苯转化率和75%的对氯甲苯,反应条件温和简单。     

米格列奈钙的合成新工艺

(S)-2-苄基丁二酸脱水生成酸酐后与顺式全氢异吲哚反应生成米格列奈酸及其异构体副产物酸。将副产物酸分离出并异构化为米格列奈酸;米格列奈酸经成盐得产品米格列奈钙。考察了工艺条件对反应的影响,结果表明：以10mL甲苯为溶剂,5mL乙酸酐为脱水剂,0.03mol (S)-2-苄基丁二酸在110℃下脱水反应1h,酸酐收率可达90.49%;酸酐与顺式全氢异吲哚反应产物收率可达97.60%;用乙酸乙酯对产物米格列奈酸及其异构体副产物酸进行分离后,二者HPLC含量均高于98%;以甲苯为溶剂,回流反应3h,异构体副产物酸异构化为米格列奈酸,转化率达到57.65%;产品米格列奈钙总收率可达67.49%,HPLC含量高达99.25%。中间体和产物结构用¹H NMR进行表征确认。     

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.     

Enhancing p-xylene productivity for disproportionation of toluene in microstructured reactors

Microstructured monolith reactors washcoated with ZSM5 and La₂O₃-loaded ZSM5 (LaZSM5) were used for disproportionation of toluene for studying the effect of washcoat thickness on reactor productivity and yield of the commercially important p-xylene isomer. The toluene conversion and p-xylene yield in the ZSM5 washcoated monolith reactor was superior to that in a packed bed reactor using ZSM5 pellets. Modification of the surface properties of ZSM5 due to addition of La₂O₃ reduced the toluene conversion but resulted in a substantial enhancement in p-xylene yield. The decrease in catalytic activity and p-xylene yield with increase in washcoat thickness was attributed to the lengthening of the diffusional path length. The reactor productivity was highest with thin washcoats and low conversion on La₂O₃-loaded ZSM5 washcoated monoliths. The advantage of higher p-xylene productivity using monoliths is offset by the increase in the cost of recycling unreacted toluene.     

己内酰胺苯磺酸类离子液体催化甲苯选择性硝化反应的研究

制备了己内酰胺对甲基苯磺酸和苯磺酸离子液体作为催化剂和溶剂,用于催化甲苯与等摩尔67%(m/m)硝酸的硝化反应,并用1H NMR进行了表征。研究了不同的反应温度、时间和离子液体用量及不同的离子液体等因素对甲苯硝化反应的影响。结果表明:该离子液体对甲苯的硝化有较好的对位选择性,产物中邻、对异构体质量比为1.2,较硝硫混酸硝化(邻、对异构体质量比约2.0)显著降低,收率可达37.1%,且可重复使用。     

ZSM-22分子筛催化甲苯甲醇烷基化反应的研究

通过浸渍法对ZSM-22分子筛进行SiO₂和La₂O₃改性,制备了一系列催化剂。采用固定床微型连续流反应器对催化剂的反应性能进行了评价。考察了ZSM-22、SiO₂和La₂O₃改性ZSM-22对甲苯甲醇烷基化反应性能的影响。实验发现,ZSM-22催化甲苯甲醇烷基化反应的产物中,对二甲苯的选择性远高于间位和邻位异构体的选择性,而改性后的催化剂上目标产物对二甲苯的选择性得到提高,但反应活性下降。随SiO₂和La₂O₃负载量的增加,甲苯的转化率逐渐降低,对二甲苯选择性逐渐提高,其中,以La₂O₃改性后对二甲苯选择性提高较明显。SiO₂和La₂O₃复合改性后,甲苯的转化率高于La₂O₃单独改性的结果,而对二甲苯选择性与La₂O₃单独改性结果相近,并且,二甲苯的选择性略有提高。     

The Synthesis of Cresol from Toluene and N2O on H[Al]ZSM-5: Minimizing the Product Diffusion Limitation by the Use of Small Crystals

The direct hydroxylation of toluene with nitrous oxide to cresol has been studied on two different H[Al]ZSM-5 zeolites with an Si/Al ratio of around 25 and different crystal sizes (30-70 nm and 1-3 m). The samples were activated by calcination and characterized by X-ray diffraction, temperature programmed desorption of ammonia, adsorption of nitrogen and transmission electron microscopy. For the two different crystal sizes, different macroscopic cresol yields and time on stream behaviours are observed. The sample having larger crystals shows a decrease in toluene conversion with increasing reaction temperature. For the smaller crystals an increase in toluene conversion, selectivity to cresol and amount of para-cresol in the cresol fraction with increasing reaction temperature is observed. The para-cresol selectivity is lower on the sample with the longer diffusion path. The findings are explained by product diffusion limitation caused by high reactivity and strong adsorption of the polar product cresol on H[Al]ZSM-5, resulting in a rapid deactivation of the larger crystals.