One Pot Synthesis of Methyl N-Phenyl Carbamate from Aniline, Urea and Methanol

Methyl N-phenyl carbamate (MPC) was synthesized from aniline, urea and methanol. The effects of catalysts, loading amounts, preparation condition of catalyst and reaction condition on the synthesis of MPC were investigated. It was shown that KNO₃ modified zeolite HY gave the best performance to MPC formation among the evaluated catalysts, over which 93.1% aniline conversion and 82.6% MPC selectivity were obtained under the optimum reaction condition. Additionally, a possible catalytic mechanism to the formation of MPC in this reaction was proposed.     

A New Process for Synthesis of γ‐Butyrolactone and Cyclohexanone

A new process through the coupling of maleic anhydride hydrogenation and cyclohexanol dehydrogenation has been studied for the simultaneous synthesis of γ‐butyrolactone and cyclohexanone. The possibility of the coupling process has been investigated thermodynamically. The separated hydrogenation of maleic anhydride, the dehydrogenation of cyclohexanol, and the coupling process over the same Cu‐Zn‐Al catalyst have been carried out in a fixed‐bed reactor. Compared to conventional processes, the coupling process has several advantages, e.g., improved γ‐butyrolactone and cyclohexanone yields, good energy efficiency, and optimal hydrogen utilization. The effects of reaction temperature, n(H₂)/n (reactants) and liquid hourly space velocity on the coupling process are investigated. One thousand hours of stability testing shows that the Cu‐based catalyst has relatively high activity and good stability in the coupling process.     

Synthesis of Dimethyl Carbonate from Methyl Carbamate and Methanol Using a Fixed‐Bed Reactor

Several mixed oxide catalysts were prepared by coprecipitation for dimethyl carbonate (DMC) synthesis from methyl carbamate and methanol. During the batch process, the DMC yield was below 35 %. In order to minimize the unfavorable thermodynamic equilibrium and side reactions for the DMC synthesis, a fixed‐bed reactor was designed. A maximum DMC yield of ～ 73 % could be realized over a ZnO‐Al₂O₃ catalyst. The effects of reaction conditions for this type of reactor were investigated in detail.     

尿素法合成氨基甲酸甲酯及其应用进展

氨基甲酸甲酯具有广泛的用途，可用作农药、医药和有机合成的中间体等。本文对尿素法制氨基甲酸甲酯的几种工艺进行了介绍和比较，认为在合理的温度和压力、无催化下的反应精馏工艺是一种较好的氨基甲酸甲酯生产工艺。同时对氨基甲酸甲酯的应用也进行了述评。     

苯胺、尿素、甲醇一步法合成苯氨基甲酸甲酯

用苯胺、尿素和甲醇一步法合成了苯氨基甲酸甲酯(MPC)。考察了不同类型催化剂对MPC生成的影响。对性能最好的HY分子筛催化剂着重考察了催化剂用量,反应温度,反应时间和原料摩尔比对反应的影响。结果表明,n(C6H5NH2)∶n(NH2CONH2)∶n(CH3OH)=1∶5∶15,反应温度453 K,反应时间5 h为适宜工艺条件。在该工艺条件下,苯胺转化率和苯氨基甲酸甲酯选择性分别达到90.5%和73.5%。     

Kinetic and Technological Analysis of Dimethyl Toluene‐2,4‐Dicarbamate Synthesis

The synthesis of dimethyl toluene‐2,4‐dicarbamate from 2,4‐toluene diamine and dimethyl carbonate is a complex reaction system. First, the reaction enthalpies, the Gibbs function changes, and the equilibrium constants of the reactions were calculated by several methods of group contribution. Secondly, the kinetics of the synthesis reaction over a zinc acetate catalyst was investigated in a batch autoclave. The kinetic model equations were established by parameter estimation based on experimental data, and the model met the requirements of the statistical test. The calculated results based on the model agreed well with the experimental data. According to the results of both thermodynamic calculation and kinetic analysis, the influence of some technological parameters, such as content of methanol in the feed and reaction temperature, on the synthesis reaction was discussed.     

Syngas Production Process Development and Economic Evaluation for Gas‐to‐Liquid Applications

The range of syngas composition produced by autothermal reforming of natural gas makes it suitable and in compliance with the gas‐to‐liquid technology for subsequent conversion to synthetic crude oil. A modified and improvised design for this reforming technique is proposed in which oxygen consumption is reduced as compared to the conventional process. Simulative optimization helps in optimal designing of the new process subject to a set of constraints applied to both the processes for uniform and homogeneous comparison. Aspen HYSYS is used for simulation and optimization of the process and the economics are evaluated by an Aspen Process Economic Analyzer.     

羟基乙腈合成工艺研究与设计要点

介绍羟基乙腈性质、制备方法和主要应用情况。叙述了间歇式羟基乙腈工艺的主要影响因素，并且从工艺设计原理的角度上讨论了生产中要注意事项和解决措施。     

Fischer‐Tropsch Synthesis: Modeling and Performance Study for Fe‐HZSM5 Bifunctional Catalyst

A water‐cooled fixed bed Fischer‐Tropsch reactor packed with Fe‐HZSM5 catalyst has been modeled in two dimensions (radial and axial) using the intrinsic reaction rates previously developed at RIPI. The reactor is used for production of high‐octane gasoline from synthesis gas. The Fischer‐Tropsch synthesis reactor was a shell and tube type with high pressure boiling water circulating on the shell side. By the use of a two‐dimensional model, the effects of some important operating parameters such as cooling temperature, H₂/CO ratio in syngas and reactor tube diameter on the performance capability of the reactor were investigated. Based on these results, the optimum operating conditions and the tube specification were determined. The model has been used to estimate the optimum operating conditions for the pilot plant to be operated in RIPI.     

三相床甲醇合成新工艺开发研究

三相床甲醇合成，可提高反应出口气体中的甲醇浓和单程转化率，提高反应选择性与产品质量。是一项正在开发过程中的新工艺。     

氨基甲酸甲酯的尿素醇解法制备及其应用研究进展

氨基甲酸甲酯作为一种重要的精细化学品,在众多领域中有着广泛的应用,当前已成为尿素下游领域竞相开发的重点。概述了常温常压催化合成、中温中压催化合成及无催化剂高压合成尿素醇解法生产氨基甲酸甲酯工艺研究进展,同时展望其在有机合成、医药、农药等领域的应用,以期对氨基甲酸甲酯行业的发展有较为深入的了解。     

Analysis of TBA‐Based ETBE Production by Means of an Optimization‐Based Process‐Synthesis Approach

The current article presents the extension of a recently developed optimization‐based approach to process synthesis for process intensification. It generates phenomena‐based flowsheet options using superstructure optimization and provides a dedicated translation into equipment‐based flowsheets. The considered case‐study illustrates the application of the method for the analysis of ethyl tert‐butyl ether production, based on the conversion of tert‐butyl alcohol, under consideration of variable configurations of a rector network and a newly introduced pervaporation‐based membrane‐reactor block.     

Influence of Solvent on Reaction Path to Synthesis of Methyl N-Phenyl Carbamate from Aniline,CO2 and Methanol

Methyl N-phenyl carbamate （MPC）, an important organic chemical, can be synthesized from aniline, CO2 and methanol. Catalyst Cu-Fe/ZrO2-SiO2 was first prepared and its catalytic performance for MPC synthesis was evaluated. Then the influence of solvent on the reaction path of MPC synthesis was investigated. It is found that the reaction intermediate is different with acetonitrile or methanol as a solvent. With acetonitrile as a solvent, the synthesis of MPC follows the reaction path with diphenyl urea as the intermediate, while with methanol as a solvent the reaction occurs via the reaction path with dimethyl carbonate as the intermediate. The catalytic mecha-nism of cooperative catalysis comprising metal sites, Lewis acid sites and Lewis base sites is proposed according to different reaction intermediates.     

Macrokinetic Study of the Electrochemical Synthesis Process of Sodium Dichromate

In order to address the problems existing in the traditional production techniques for sodium dichromate, a new green technology for producing sodium dichromate using an electrochemical synthesis method was studied. Using a self‐made electrosynthesis reactor composed of pure titanium and stainless steel, with a multiple‐unit metal oxide combination anode, a stainless steel cathode, and a reinforcing combination cation exchange membrane, the kinetic experiments were carried out on the direct electrochemical synthesis reaction of sodium dichromate from sodium chromate. The kinetic data were experimentally measured at different temperatures and different initial sodium chromate concentrations of anolyte. The results show that the electrochemical synthesis process presents complicated zero‐order reaction kinetic characteristics, with the reaction rate constant depending on the initial sodium chromate concentration. The macrokinetic equation of the electrochemical synthesis reaction was established, and some kinetic parameters were calculated. The apparent activation energy is less than that of the ordinary chemical reaction, and this shows that the electrochemical synthesis of sodium dichromate has great development potential.     

A Semi‐Batch Process for Nitroxide Mediated Radical Polymerization

Summary: A semi‐batch process using nitroxide mediated polymerization, was explored for the design of low molecular weight solvent‐borne coatings, typical of those used in the automotive industry. While living radical polymerization (LRP) offers many advantages in the control of polymer chain microstructure that may confer important physical and chemical property benefits to coatings, adapting LRP to a semi‐batch process poses significant challenges in the design and operation of the process. Using styrene monomer, various two‐component initiating systems (free radical initiator, 4‐hydroxy‐TEMPO) were studied to understand the effects of different initiators on the course of polymerization. In addition, an alkoxyamine was synthesized and used as the initiating source. The initiators Luperox 7M75 and Luperox 231 give higher polymerization rates and reasonable control over polymerization, while benzoyl peroxide (BPO), Vazo 67, and the alkoxyamine are less effective. The number of polymer chains in the final product is always less than the theoretical value, reflecting poor initiation efficiency, probably resulting from undesirable termination reactions that become important due to the nature of the semi‐batch process. Adding camphorsulfonic acid (CSA) or charging initiator concurrently with monomer during semi‐batch feed, can increase the polymerization rate while maintaining the living character of the polymerization. The copolymerization of styrene and butyl acrylate is also shown to exhibit living character.

Schematic representation of the exchange reaction to produce N‐TEMPO capped polymer chains.     

煤制甲醇工艺甲醇合成塔的工艺设计探讨

以30万吨/年焦炉气制甲醇项目各工序的压力、温度、介质成分、流量等工艺条件,确定合成塔设备排热量及结构形式。甲醇合成塔又称甲醇合成反应器,是甲醇装置中的核心设备之一,也是合成工段中最关键的设备,合成塔为立式绝热管壳型反应器,管内装有C306型低压合成甲醇催化剂,本设计的目的是按照工艺要求设计甲醇合成工段甲醇合成塔,为压力容器设计提供理论依据。     

Synthesis of epichlorohydrin from 1,3-dichloropropanol using solid base

In this work the synthesis of epichlorohydrin (ECH) from 1,3-dichloropropanol (DCP) by using solid sodium hydroxide (NaOH) is carefully investigated.Inert organic solvent,l-octanol,is introduced to ensure reaction intensity under control.The reaction performances with respect to apparent kinetics and selectivity are determined to explore optimized reaction conditions and confirm potentials for enhancing productivity in one batch.The dissolution and liquid phase reaction mechanism and instant reaction assumption are proposed and verified through process analysis.A process design towards free additional water is schematically figured out to manipulate solid NaOH,by-product,and unreacted starting materials to realize a nearly closed circuit.This process allows high selectivity over 97％ and complete DCP conversion at 323.2 K within a reaction time less than 20 min.Other advantages include near-zerowastewater emission,economically possible NaOH regeneration from NaCl,and robust operating condition window.     

甲基叔丁基醚合成反应器工艺计算

用拟均相一维数学模型对甲基叔丁基醚合成反应器进行电算,并根据电算程序进行优化设计,计算结果与生产数据相吻合。     

新颖氨基甲酸酯类杀虫剂-茚虫威(indoxacarb)的合成与应用

介绍了一种高效,低毒,对环境十分安全的新颖杀虫剂茚虫威.较详细叙述了它的合成路线及应用.