Liquid phase methanol and dimethyl ether synthesis from syngas

The Liquid Phase Methanol Synthesis (LPMeOH^TM) process has been investigated in our laboratories since 1982The reaction chemistry of liquid phase methanol synthesis over commercial Cu/ZnO/Al₂O₃ catalysts, established for diverse feed gas conditions including H₂-rich, CO-rich, CO₂-rich, and CO-free environments, is predominantly based on the CO₂ hydrogenation reaction and the forward water-gas shift reactionImportant aspects of the liquid phase methanol synthesis investigated in this in-depth study include global kinetic rate expressions, external mass transfer mechanisms and rates, correlation for the overall gas-to-liquid mass transfer rate coefficient, computation of the multicomponent phase equilibrium and prediction of the ultimate and isolated chemical equilibrium compositions, thermal stability analysis of the liquid phase methanol synthesis reactor, investigation of pore diffusion in the methanol catalyst, and elucidation of catalyst deactivation/regenerationThese studies were conducted in a mechanically agitated slurry reactor as well as in a liquid entrained reactorA novel liquid phase process for co-production of dimethyl ether (DME) and methanol has also been developedThe process is based on dual-catalytic synthesis in a single reactor stage, where the methanol synthesis and water gas shift reactions takes place over Cu/ZnO/Al₂O₃ catalysts and the in-situ methanol dehydration reaction takes place over -Al₂O₃ catalystCo-production of DME and methanol can increase the single-stage reactor productivity by as much as 80%. By varying the mass ratios of methanol synthesis catalyst to methanol dehydration catalyst, it is possible to co-produce DME and methanol in any fixed proportion, from 5% DME to 95% DMEAlso, dual catalysts exhibit higher activity, and more importantly these activities are sustained for a longer catalyst on-stream life by alleviating catalyst deactivation.     

Kinetics of the reaction of olefin synthesis from methanol and dimethyl ether

The kinetics of the reaction of olefin synthesis from dimethyl ether and methanol is studied. A kinetic model of the nine-route reaction under study is constructed. The constants of the model are estimated using experimental data. The adequacy of the model to the results of experiments is shown     

Thermodynamic investigation of methanol and dimethyl ether synthesis from CO2 Hydrogenation

The thermodynamics involved in the catalytic hydrogenation of CO₂ have been examined extensively. By assuming that methanol and dimethyl ether (DME) are the main products, two reaction systems each consisting of two pararell reactions were analyzed and compared in terms of the equilibrium yield and selectivity of the useful products, methanol and DME. The calculation results demonstrated that the production of DME allows much higher oxygenate yield and selectivity than that of methanol.     

甲醇制二甲醚技术

简述了二甲醚的性质和主要的几种合成工艺,较详细介绍了西南化工研究设计院技术的工艺特点和工业化成果.     

Dehydration of methanol over Nordstrandite based catalysts for dimethyl ether synthesis

This study focused on the investigation of Nordstrandite as a catalyst for dehydration of methanol to dimethyl ether synthesis. The structure phase of Nordstrandite has been changed to boehmite and γ-Al₂O₃ in sequence via calcinations at various temperatures. Moreover, the properties of the samples have been varied significantly with heat treatment. The number of acid sites of Nordstrandite was much higher than the other aluminas. However, the catalytic activity of Nordstrandite was comparable to the other catalysts with fewer amounts of acid sites. This means that structure phase is one of the most important factors for catalytic performance in this reaction.     

CO2加氢制甲醇、二甲醚的研究进展

CO2催化加氢合成甲醇、二甲醚是解决CO2减排的有效途径之一,具有环保、经济等意义。本文从新的视角综述了CO2催化加氢合成甲醇、二甲醚催化剂的研究进展和研究特点,并从催化剂的制备方法、沉淀剂的选择、焙烧时间、催化剂载体、助剂等方面进行了系统综述。     

甲醇制二甲醚用全氟磺酸树脂催化剂的研究

采用溶胶-凝胶法制备了用于甲醇气相脱水制二甲醚的新型催化剂全氟磺酸树脂/二氧化硅,应用X射线衍射、红外光谱、热重-差示扫描量热、低温氮物理吸附和氨程序升温脱附法对所得催化剂进行了表征。考察了反应温度、甲醇液空速、全氟磺酸树脂含量对甲醇气相催化脱水制二甲醚反应性能和催化剂稳定性的影响。结果表明,催化剂比表面积达820m2/g,在全氟磺酸树脂负载量10.0%、甲醇液空速1h?1、反应温度184℃时,甲醇转化率92.0%,二甲醚选择性99.9%,经350h实验测试,活性和稳定性没有明显变化。     

Intrinsic reaction rate and the effects of operating conditions in dimethyl ether synthesis from methanol dehydration

The kinetic behavior of a commercial γ-Al₂O₃ catalyst for the methanol to dimethyl ether (DME) dehydration reaction has been investigated using a differential fixed bed reactor at the pressure range 1–16 barg within a temperature range of 260–380 °C. The experimental runs were performed in a wide range of feed to water ratios. The experiments were designed by general full factorial design (GEFD) and a novel rate equation has been developed which exhibited the best fitting with our experimental data. Based on the analysis of variance (ANOVA), the following order of importance for operating conditions was obtained when the objective function is the yield of DME: Temperature >Water % in feed >Pressure. In addition, the optimum operating conditions for the maximum yield of DME, were found at T= 380°C, P=16 barg and zero wt% of water in the feed.     

Thermodynamic equilibrium in the synthesis of dimethyl ether from synthesis gas

Chemical equilibrium in dimethyl ether synthesis from synthesis gas was studied thermodynamically over wide ranges of gas compositions and process parameters.     

Application of the thermodynamic method to developing the process of producing methanol and dimethyl ether from synthesis gas

A thermodynamic method intended for choosing the most efficient flowsheet in developing new technologies of processing the natural gas is proposed. The method was tested for the process of synthesizing methanol and used in designing a new process, dimethyl ether synthesis.     

甲醇气相脱水制二甲醚的催化剂

采用硝酸铝和氨水中和方法得到拟薄水铝石为原料,制备了甲醇制二甲醚催化剂。考察拟薄水铝石制备过程中的中和pH值、中和温度以及催化剂制备过程中的煅烧温度对甲醇气相脱水制二甲醚性能的影响。结果表明,当中和pH值在8.0±0.2、中和温度为50～60 ℃以及煅烧温度在550～600 ℃时得到的甲醇制二甲醚催化剂活性最高。通过在催化剂上添加SiO2、SO42?、PO43?等对甲醇脱水催化剂进行改性表明,改性后甲醇脱水催化剂活性有明显的提高。     

甲醇催化脱水制二甲醚

研究了甲醇在ZSM-5沸石分子筛上催化脱水制二甲醚反应条件的影响。并在等温积分反应器中进行了本征动力学测试,对动力学模型进行筛选和参数估值,获得反应速率方程。     

二甲醚与合成气反应制乙醇的热力学计算与分析

采用Benson基团贡献法估算得到二甲醚（DME）和乙酸甲酯（MA）的标准生成焓和标准生成吉布斯自由能,在298～1000K时计算了DME与合成气制乙醇（DME羰基化反应、MA加氢反应以及二者组成的总反应）过程中的反应焓变、反应熵变、反应吉布斯自由能变和化学反应的平衡常数。在此基础上,分析了反应压力、反应温度和原料比对DME转化率的影响。在413K、1×105Pa、CO∶DME=1条件下考察了不同H2浓度情况下合成乙醇反应中两个反应的协同效应。分析结果表明,在低于493K、3MPa、n(CO)∶n(DME)=1的条件下有利于合成反应的进行,由于两反应的协同效应,使MA加氢反应的平衡转化率有大幅度提高。     

合成气一步法制二甲醚工艺及催化剂研究进展

二甲醚在车用燃料和民用燃料方面具有良好发展前景。合成气一步法制二甲醚工艺分气相法和浆态床法。综述了合成气一步法制取二甲醚的工艺和催化剂的研究进展以及工业化前景。     

Development of catalysts based on pentasil-type zeolites for selective synthesis of lower olefins from methanol and dimethyl ether

Using an integrated physicochemical approach to the study of zeolites and catalysts, scientific foundations for the targeted synthesis of catalysts based on ZSM-5 type zeolites for selective production of lower olefins from methanol and dimethyl ether have been developed. The selective synthesis of the C₂₌ and C₃₌ olefins takes place on medium-strength acid sites. The domination of strong acid sites increases the extent of the secondary oligomerization, aromatization, and cracking reactions and intensifies the deactivation of the catalyst. The effects of reaction conditions (feed partial pressure and temperature) on the outcomes of the process have been investigated. High-efficiency Zn-containing catalysts based on modified pentasils and promoted with magnesium and phosphorus have been developed for C₂₌–C₄₌ olefin synthesis. These catalysts compare well with the industrial catalyst used in the Lurgi process.     

低温甲醇合成研究进展

日本学者Tsubaki等开创了一种全新的低温甲醇合成反应路径。该路径以含有二氧化碳的合成气为反应原料,使用单一低碳醇(包括甲醇)同时作为催化剂和溶剂,实现了反应原料一氧化碳在低温(443 K)条件下,一步转化率达到70%～100%。原位红外和多种表征手段证明,该反应能够在低温条件下进行,是由于催化剂上吸附的甲酸盐物种可以和多种低碳醇溶剂在低温条件发生酯化反应,生成相对应的甲酸酯。而生成的甲酸酯很容易在低温条件下,铜基催化剂表面,发生加氢反应,生成甲醇和相应的溶剂醇。该种全新的甲醇合成路径克服了常规甲醇合成过程中,甲酸盐必须在高温条件下才能发生加氢反应的关键步骤。同时,还介绍了适用于低温甲醇合成反应的金属Cu/ZnO催化剂制备方法的研究进展。全新的溶胶-凝胶-燃烧法、固相研磨-燃烧法以及甲酸辅助燃烧法直接制备高活性、纳米尺度、高分散的金属Cu/ZnO催化剂,而不需要额外的还原流程。     

合成气一步法制二甲醚过程的热力学模拟研究

使用Aspen plus软件对合成气一步法制二甲醚过程进行热力学模拟计算。考察了温度、压力、合成气组成及CO2体积分数对CO转化率、二甲醚选择性和产率的影响。模拟结果与文献实验结果相比对,具有较好的一致性。     

甲醇和甲醛催化合成聚甲氧基二甲醚

聚甲氧基二甲醚作为柴油添加剂,可以提高柴油的十六烷值(CN),提高燃油的利用率,作为甲醇大宗下游产品具有广阔的应用前景。在固定床管式反应器中,以改性大孔阳离子交换树脂为催化剂,在温度40～100℃、液相空速1.32～16.37 h^-1、甲醛/甲醇摩尔比1～4和反应压力0.1～3.0 MPa下,以单因素实验和正交实验相结合的方式,系统地研究了甲醛与甲醇缩醛化工艺条件,获得了较佳的工艺条件,在温度70℃、甲醛/甲醇摩尔比3:1、液相空速1.32 h^-1、反应压力2.0 MPa的条件下,甲醇的转化率为69.72%,DMM_3-8选择性为62.08%。     

生物质合成气一步法合成二甲醚的研究

用共沉淀沉积法制备了生物质合成气直接合成二甲醚(DME)的催化剂,考察了固定床中温度、压力、空速等工艺条件对二甲醚合成性能的影响,同时基于Gibbs自由能最小法对合成DIME反应的化学平衡进行模拟计算,并与实际测试结果相比较.结果表明,模拟结果与测试结果吻合较好.