一种甲醇脱水制二甲醚的方法

<正>本发明涉及一种甲醇脱水制二甲醚的方法,包括:甲醇经预热后,在催化剂作用下发生脱水反应,得到的反应混合物进行气液分离;得到的气相直接进入二甲醚精馏塔;得到的液相先脱除阴、阳离子后也进入二甲醚精馏塔;二甲醚精馏塔塔顶馏出物经冷凝后得到合格的二甲醚产品;二甲醚精馏塔塔釜得到含醇废水。本发明工艺流程简单,甲醇在液相状     

二甲醚系统粗甲醚冷凝器改造及应用

<正>1改造前二甲醚工艺流程河南龙宇煤化工有限公司(以下简称龙宇公司)一期工程装置年产500 kt甲醇和200 kt二甲醚,二甲醚装置是甲醇下游装置,进行甲醇产品深加工。甲醇制二甲醚生产工艺过程分为合成反应、精馏和汽提三大工序。经汽化塔汽化后的甲醇蒸气进反应器反应后,粗甲醚气体经气体换热器与原料甲醇蒸气换热,然后去精馏塔再沸器Ⅱ与精馏塔釜液换热,再去甲醇预热器与原料甲醇换热,最后去粗甲醚预热器与粗甲醚换热,换热后     

一种由甲醇脱水制取二甲醚的方法

正本发明是化工领域的一种由甲醇脱水制取二甲醚的方法,其工艺流程包括:(1)将外界的原料甲醇送入甲醇缓冲罐与来自甲醇精馏塔塔顶的甲醇混合成甲醇原料;(2)甲醇原料经甲醇预热器预热后进入甲醇汽化罐汽化;(3)汽化后的甲醇蒸汽经热反应进入反应器;反应后出来的反应气经进料出料换热器、甲醇换热器、甲醇塔气体再沸器、二甲醚塔进料冷却器     

一种变压热耦合精馏分离甲缩醛与甲醇的工艺

正一种变压热耦合精馏分离甲缩醛与甲醇的工艺是甲醇与甲缩醛混合溶液从低压精馏塔上部进入进入塔内,循环物流从塔下部进入,甲缩醛甲醇共沸物蒸汽从塔顶流出,经冷凝后一部分回流至塔内作为回流液,另一部分作为高压精馏塔进料采出,塔釜得到纯净甲醇;在高压精馏塔塔顶得到甲缩醛甲醇共沸物蒸汽,该蒸汽去低压精馏塔再沸器冷凝后一部分回流至高压精馏塔作为回流液,另一部分作为循环物流返回至低压精馏塔,高压精馏塔塔釜得到纯净甲缩醛。本发明具有分离过程简单,成本低,分离     

高纯二甲醚气的制取

在以锌铬系触媒生产甲醇的工艺过程中,约有相当于甲醇重量3%的二甲醚产生。在粗甲醇精制过程中,这部份二甲醚被放空,如何回收利用这部份放空的二甲醚,首先遇到的问题就是二甲醚纯度的分析,各厂一般采用色谱法,但在标定二甲醚的色谱系数时需高纯度二甲醚。目前一些广采用硫酸氢甲酯同甲醇共热或甲醇浓硫酸脱水法制得二甲醚,但这些方法制取的二甲醚杂质含量较高,给标定带来麻烦和误差。还有些厂用乙醚或丙酮代替二甲醚标定二甲醚的色谱系数,误差就更大了。为寻求较理想的制备高纯二甲醚的方法,我们采用浓硫酸吸收予精馏塔放空气中二甲醚,经水解后冷凝分离,其纯度可达99.7％以上。其余主要为空气,几乎不含其它有机物质。     

一种甲醇钠和二甲醚联产装置及方法

正一种甲醇钠和二甲醚联产装置及方法,联产装置包括精甲醇精馏塔、甲醇钠合成塔、水甲醇精馏塔、甲醇脱水反应器和二甲醚精馏塔,为了与二甲醚脱水反应的高温高压相接合,甲醇钠生产也在高温高压下进行,由此而得到的甲醇钠甲醇溶液产品的主要品质指标卡氏水远低于普通厂家的0.16~0.35,而在0.12以下,甚至低至0.07,不亚于以金属钠为原料的甲醇钠甲醇溶液产品,且联产的甲醇钠甲醇     

一种二甲醚生产系统中的醇油采出装置及醇油采出方法

正一种二甲醚生产系统中的醇油采出装置及醇油采出方法,以粗甲醇为原料制取二甲醚所得的反应产物进入二甲醚精馏塔,精馏塔釜液至甲醇汽化塔流程中设置釜液缓冲槽,阀门控制釜液流量,在精馏塔的液位计上部接采出口至缓冲槽,缓冲槽顶端接     

合成气一步法制备二甲醚的工艺流程模拟与优化

二甲醚作为燃料的替代品,其生产开发在化学工程领域受到了广泛关注。本文对合成气一步法制备二甲醚过程进行了模拟分析,提出了用水作为吸收剂并采用多效精馏的二甲醚生产新工艺。利用Aspen Plus化工模拟软件对吸收塔进行模拟比较了甲醇和水作为吸收剂的能耗,模拟结果表明,用水吸收较甲醇吸收总热负荷降低23.54％,总冷负荷降低35.97％,更为节能。从节能降耗角度出发,根据不同的分离任务,提出了采用两塔分离甲醇-水及三塔分离甲醇-水的两项工艺改进措施。结果表明,采用两塔分离甲醇-水工艺比原工艺二甲醚产量增加了11.50%,能量消耗无明显变化。进一步采用三塔精馏工艺总冷负荷比原工艺减少45.07％,总热负荷减少19.27%,且二甲醚产量增加11.15％,节能效果显著。     

一种二甲醚生产过程中催化剂循环升温装置

正一种二甲醚生产过程中催化剂循环升温装置,包括二甲醚精馏塔,在二甲醚精馏塔进口管道与甲醇汽化塔出口管道之间设有专用升温管道,在二甲醚精馏塔进口与甲醇汽化塔出口之间安装有萝茨     

一种渗透汽化-加压精馏集成分离碳酸二甲酯和甲醇的工艺

正本发明提供了一种渗透汽化-加压精馏集成分离碳酸二甲酯和甲醇的工艺,其特征在于反应精馏塔得到的碳酸二甲酯和甲醇的共沸液经过渗透汽化膜系统时,渗透汽化膜有效突破了甲醇-碳酸二甲酯共沸瓶颈,碳酸二甲酯低浓度侧料液返回至反应精馏塔进行循环分离,碳酸二甲酯高浓度侧料液输送至加压精馏塔,经加压精馏塔分离后塔釜得到质量纯度为99.6%以上的碳酸二甲酯产品,塔顶得到甲醇含量较高的碳酸二甲酯和甲醇混合液,也返回到反应精馏塔中,进入下一次循环分离。本发明工艺     

Performance enhancement of thermally coupling of methanol synthesis,DME synthesis and cyclohexane dehydrogenation processes: Employment of water and hydrogen perm-selective membranes via different recycle streams

In this research, effect of water and hydrogen perm-selective membranes via different recycle cases in a thermally double-coupled two-membrane reactor (TDCTMR) has been investigated. Methanol and direct dimethyl ether (DME) synthesis from natural gas as exothermic reactions have been thermally coupled with cyclohexane dehydrogenation as an endothermic reaction. Hydroxy sodalite (H-SOD) and Pd/Ag membranes have been employed for removing water from methanol side and injection of hydrogen to DME side respectively. Three different recycle stream cases have been studied for the performance enhancement of TDCTMR. In the first case, the outlet stream from DME reactor is recycled to itself. Also, in the second case, the outlet stream from methanol side is recycled to DME side and finally, the third case is that the mixture of methanol and DME outlet streams are recycled to DME side. The results of these three cases are compared with thermally double coupled reactor (TDCR). Results show that hydrogen production in cyclohexane side of TDCTMR increases 8.32%, 22.89% and 23.88% for cases 1, 2 and 3 in comparison to TDCR respectively. Also, DME and methanol production enhances 38.38% and 13.3% for case 3 (best case) in comparison to TDCR respectively.     

二甲醚精馏塔实验研究与模拟计算

建立了用于二甲醚精制的精馏塔实验流程,实验测定了在操作工艺条件下的精馏结果。以平衡级理论为依据建立二甲醚精馏过程的数学模型,根据研究体系在通常情况下沸点相差较大、液相非理想性的特点,建立序贯收敛的循环嵌套迭代计算方法对模型进行求解,模拟计算结果与实验数据结果吻合较好。对二甲醚精馏塔的模拟分析结果表明：塔顶要得到含量不小于99 %(mol)二甲醚产品,维持操作压力1 MPa、在精馏塔中部进料的情况下,进料量不超过22 mol·h^-1为宜;回流比要根据进料液中二甲醚组分含量控制在一定范围内;进料液中二氧化碳含量高低对产品二甲醚纯度和收率影响显著,在进入精馏塔之前尽可能地将二氧化碳除去是必要的。     

完全液相法催化剂上甲醇脱水合成二甲醚的动力学及DFT研究

采用完全液相法制备AlOOH催化剂并进行了浆态床反应器中甲醇脱水制备二甲醚的反应动力学和DFT的研究。在3种甲醇脱水制备二甲醚的反应机理中,以表面反应即两个同时吸附的甲醇反应生成二甲醚作为速控步骤,所建立动力学模型的计算值和实验值吻合较好。采用DFT计算了液体石蜡环境中AlOOH(100)面的脱水反应,其反应过程和活化能结果与动力学模型结果基本一致,进一步表明采用该模型可以合理描述完全液相法制备的AlOOH催化剂表面甲醇脱水反应过程。     

Sorption-enhanced dimethyl ether synthesis—Multiscale reactor modeling

As an opportunity for the attenuation of atmospheric CO₂ emissions, conversion of carbon dioxide into valuable oxygenates as fuel additives or fuel surrogates was explored conceptually in terms of a potentially feasible dimethyl ether (DME) conversion process. Incentives for application of conventional CO₂–DME conversion process are insufficient due to low CO₂ conversion, and DME yield and selectivity. In-situ H₂O removal by adsorption (sorption-enhanced reaction process) can lead to the displacement of the water gas shift equilibrium and therefore, the enhancement of CO₂ conversion into methanol and the improvement of DME productivity. A two-scale, isothermal, unsteady-state model has been developed to evaluate the performance of a sorption-enhanced DME synthesis reactor. Modeling results show that under H₂O removal conditions, methanol and DME yields and DME selectivity are favoured and the methanol selectivity decreases. The increase of methanol and DME yields and DME selectivity becomes more important at higher CO₂ feed concentration because a relatively large amount of water is produced followed by a large quantity of water removed from the system. Also, the drop in the fraction of unconverted methanol becomes more important when CO₂ feed concentration is higher and the dehydration reaction is favoured. Therefore, application of the sorption-enhanced reaction concept allows the use of CO₂ as a constituent of the synthesis gas as the in-situ H₂O removal accelerates the reverse water gas shift reaction.     

Design framework for dimethyl ether (DME) production from coal and biomass-derived syngas via simulation approach

A comprehensive thermodynamic study was conducted to evaluate the comparative efficacy of methanol and dimethyl ether (DME) synthesis using CO₂ rich syngas feed. The first part of our study included assessing the relative performances of the methanol synthesis system, two step DME synthesis system, and one step DME synthesis system in terms of the CO_x conversion and product yield (methanol/DME) based on the Gibbs free energy minimization approach. The wide range of composition of CO₂-enriched syngas feed produced by the coal and biomass gasification was simulated using Aspen Plus and the following evaluation parameters were analyzed for a broad parameter range: reaction temperature (180–280°C), reaction pressure (10–80 bar), stoichiometry number (SN) (0–11), and CO₂/(CO₂ + CO) molar feed ratio (0–1) for isothermal as well as adiabatic conditions. Based on the equilibrium yield, one-step DME synthesis was discovered as the most viable process to utilize the co-gasification derived syngas effectively. In the second part of our study, the overall process efficiency was inspected through the process design of 1 tonnes per day (TPD) DME plant inclusive of heat integration, resulting in significant CO₂ abatement and DME production with high product purity and minimum energy consumption. Consequently, one-step DME production via CO₂-enriched syngas obtained through the coal or biomass gasification process is identified as the leading technology based on energy utilization and CO₂ abatement.     

An innovative reaction heat offset operation for a multiphase fixed bed reactor dealing with volatile compounds

Hydrogenation of benzene to cyclohexane was conducted in an adiabatic fixed-bed reactor under a phase transitional condition. In which process, a mixture of benzene and cyclohexane was fed into the reactor at the bottom under the liquid condition, however, the liquid phase disappeared and turned into gas phase at the reactor outlet through vaporization. It follows from this novel idea that the problems associated with reaction heat removal and low catalyst efficiency of the liquid-filled catalyst could be solved simultaneously with emptying of the liquid from the catalyst. However, the benzene concentration in the mixture should not exceed 14% if simple phase transition is employed, since the reaction heat is seven times the liquid vaporization heat. To optimize this primitive operation, a side stream quenching operation was proposed and attempted experimentally, and it was found that the side stream quenching with double injection points could be an acceptable operating strategy.     

完全液相制备催化剂上合成二甲醚动力学研究

采用浆态床反应器,研究了用完全液相法制备的Cu-Zn-A l双功能催化剂上CO加氢直接合成二甲醚(DME)的反应动力学。按CO加氢先合成CH3OH,再由CH3OH脱水生成DME二步串联的反应机理,根据不同的中间产物及控制步骤分别建立了动力学模型,以反应物的平衡浓度代替逸度进行计算,最终选取的模型计算值和实验值吻合较好,说明采用L-H型动力学模型可以合理地描述催化剂表面的反应过程,模型参数计算结果表明,催化剂表面对CO2的弱吸附是该催化剂在浆态床中稳定性较好的主要原因之一。     

Dehydration of Methanol to Dimethyl Ether by Catalytic Distillation

The kinetics of liquid catalytic dehydration of methanol over an ion exchange resin (Amberlyst 35) has been determined for the temperature range 343 to 403 K using a batch reactor. The experimental data are described well by an Eley‐Rideal type kinetic expression, for which the surface reaction is the rate‐determining step. A catalytic distillation process for methanol dehydration to dimethyl ether (DME) has been modeled using the experimentally determined kinetic data. The results were incorporated into the rate‐controlled reaction mode for RadFrac, a part of the commercial simulation program Aspen Plus. It was shown that synthesis of high purity DME can be achieved using a single catalytic distillation column. Thus there is significant potential for reduction of overall capital cost for a plant for methanol dehydration to DME when compared to conventional production facilities that involve separate reaction and distillation processes.     

煤基合成气一步制备高纯度二甲醚的全流程建模与模拟

As a result of shortage supply of oil resources, the process for the alternative coal-based fuel, dimethyl ether (DME), has emerged as an important process in chemical engineering field. With the laboratory experiment data about DME synthesis and separation, the production process for DME with high purity is proposed when one-step synthesis of DME in slurry bed reactor from syngas is adopted. On the basis of experimental research and process analysis, the proper unit modules and thermophysical calculation methods for the simulation process are selected. Incorporated the experimentally determined parameters of reaction dynamic model for DME synthesis, regression constants of parameters in non-random two-liquid equation (NRTL) model for binary component in DME separation system with built-in properties model, the process flowsheet is developed and simulated on the Aspen Plus platform. The simulation results coincide well with data obtained in laboratory experiment. Accordingly, the accurate simulation results offer useful references to similar equipment design and process operation optimization.     

能源化工与催化固定床一步法制二甲醚催化剂性能

采用固定床反应装置,以共沉淀法制备甲醇催化剂和一步法合成二甲醚催化剂,采用BET、XRD和SEM对催化剂进行表征。在反应压力2.5 MPa、反应温度260 ℃和空速(500~900) h^-1条件下,催化剂催化活性最好,其中,CO转化率≥90%,二甲醚收率≥60%,二甲醚选择性≥65%。