MTBE装置的全流程模拟与优化

采用Aspen Plus软件,对MTBE(甲基叔丁基醚)装置进行了全流程模拟,模拟结果与实际值吻合良好。在此基础上,考察了工艺参数对催化精馏塔、萃取塔和甲醇回收塔影响,得到了优化的工艺参数:醇烯比为1.5,催化精馏塔回流比为1.05,萃取塔溶剂比为0.21,甲醇回收塔塔顶采出率为0.107,甲醇回收塔回流比为5。通过工艺参数优化,MTBE产品质量分数达98.8%,MTBE回收率达99.71%,异丁烯转化率达98.52%,催化精馏塔和甲醇回收塔的总热负荷可降低7.4%。     

乙酸异丙酯回收工艺模拟与优化

分析回收物系特性和实际生产任务要求,建立回收乙酸异丙酯的预精馏-萃取精馏-闪蒸工艺流程,采用Aspen Plus流程模拟软件对所建立流程进行过程模拟。以理论板数、回流比、原料进料位置、溶剂比、溶剂进料位置为操纵变量,以乙酸异丙酯和甲醇质量分数、回收率及萃取精馏塔再沸器热负荷为采集变量,采用Design Specs和Sensitivity工具,对预精馏塔、萃取精馏塔和闪蒸设备进行灵敏度分析。在满足生产工艺要求的优化工艺条件下,产品乙酸异丙酯质量分数为99.6%,回收率为99.7%,甲醇质量分数为95.6%,回收率为95.5%,实现了资源再利用,降低了生产成本。     

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     

三塔精馏精甲醇的酸度控制

分析了三塔精馏过程中精甲醇酸值高的原因,提出了精甲醇酸度的控制方法:预精馏塔pH值的控制、预精馏塔不凝气温度的控制、甲醇合成反应的控制、常压塔侧线采出量的控制以及控制加压塔和常压塔的操作等,通过优化控制,精甲醇优等品率可达到90%以上。     

萃取精馏法回收制药废液中四氢呋喃和甲醇

采用装有1.5 m高θ丝网填料的玻璃精馏塔对含有四氢呋喃、甲醇和水的制药废液进行了萃取精馏分离研究。以乙二醇为萃取剂,溶剂比为1.75∶1、精馏段高度为1.0 m、回流比为1.5时,四氢呋喃回收率可达99.5%。精馏回收萃取剂乙二醇时,所需填料高度为60 cm,回流比为1.0时乙二醇回收率达99.6%。回收甲醇所需填料高度为0.7 m,回流比为3.0时甲醇回收率为99.7%,甲醇摩尔分数为0.988。研究表明,乙二醇是分离含四氢呋喃、甲醇和水的制药废液的适宜的苹取剂。     

低温甲醇洗富硫气深冷回收硫化氢工艺

开发了一种与低温甲醇洗联产、采用热耦合精馏塔深冷精馏回收浓度99.9%以上的H_2S产品气的工艺,其回收率达到77%以上。该流程采用Aspen Plus模拟软件进行设计,使用增压透平膨胀机制冷并回收部分能量。以原料气处理量200 kmol/h为例,详细分析了膨胀端分配率对产品流量和浓度的影响、塔内组分分布状况和产品单耗。最终确定膨胀端的分配率为0.35时,浓度满足要求,回收率较高,硫化氢单耗为211.61 k Wh/t。     

三塔精馏精甲醇的酸度控制

分析了三塔精馏甲醇的过程中精馏甲醇酸度值偏高的原因,提出了精甲醇酸度的控制方法：预精馏塔pH值的控制、预精馏塔不凝气温度的控制、甲醇合成反应的控制、常压塔侧线采用量的控制以及控制加压塔和常压塔的操作等,通过优化控制,精甲醇优等品率可达到90％以上。     

三塔甲醇精馏装置改造情况

<正>山西晋煤天源化工有限公司装置年生产能力为360 kt合成氨、600 kt尿素、40 kt甲醇。合成工段净化气精制采用甲醇化、甲烷化工艺,生产出的粗甲醇中甲醇质量分数一般在52%~59%,通过精馏的办法除去杂质获得高纯度甲醇。甲醇精馏采用三塔精馏工艺,预精馏塔、加压精馏塔、常压精馏塔均为填料塔,采用规整填料。开车运行后,甲醇产品不能达到优等品的要求且蒸汽消耗较高,通过对甲醇精馏塔填料及内件进行更换和改造,甲醇产品达到了优等品(质量分数99.9%)     

一种分离甲醇-水混合物的方法

正本发明提供一种分离甲醇-水混合物的方法,将甲醇-水混合物首先经过精馏塔浓缩至质量分数90%以上,再通过高吸水树脂脱水,最终得到质量分数99.95%以上的甲醇产品。将吸水后的高吸水树脂再生后循环使用。本发明的新方法工艺简单,操作时间短,能有效     

甲醇双塔精馏中萃取水对产品水溶性的影响

影响甲醇水溶性的有机杂质有2类:①一类杂质来源于预精馏塔的釜液,一些沸点较精甲醇高的高级醇类,主要集中在预精馏塔塔釜,并经主精馏塔入料泵进入主精馏塔内,可通过加大主精馏塔侧线杂醇油采出量的方式去除这类杂质;②一类杂质能与产品甲醇形成共沸的C5以上高级烷烃类物质,其沸点大多数都比甲醇高,并且能与甲醇形成低沸点共沸物,该共沸物沸点要比甲醇低,导致粗甲醇精馏中有机杂质浓度增大,精馏过程中加入萃取水可很好地脱除这类杂质。     

Heterogeneous extractive batch distillation of chloroform-methanol-water: Feasibility and experiments

A novel heterogeneous extractive distillation process is considered for separating the azeotropic mixture chloroform-methanol in a batch rectifying column, including for the first time an experimental validation of the process. Heterogeneous heavy entrainer water is selected inducing an unstable ternary heteroazeotrope and a saddle binary heteroazeotrope with chloroform (ternary diagram class 2.1-2b). Unlike the well-known heterogeneous azeotropic distillation process and thanks to continuous water feeding at the column top, the saddle binary heteroazeotrope chloroform-water is obtained at the column top, condensed and further split into the liquid-liquid decanter where the chloroform-rich phase is drawn as distillate. First, feasibility analysis is carried out by using a simplified differential model in the extractive section for determining the proper range of the entrainer flowrate and the reflux ratio. The operating conditions and reflux policy are validated by rigorous simulation with ProSim Batch Column^® where technical features of a bench scale distillation column have been described. Six reproducible experiments are run in the bench scale column matching the simulated operating conditions with two sequentially increasing reflux ratio values. Simulation and experiments agree well. With an average molar purity higher than 99%, more than 85% of recovery yield was obtained for chloroform and methanol.     

多杀菌素A的纯化方法研究

采用柱层析的方法从多杀菌素原料药中提取多杀菌素A和D的混合物(85∶15),然后采用重结晶的方法从多杀菌素A和D的混合物中提取多杀菌素A。多杀菌素A提取的优化条件为:甲醇为重结晶溶剂,多杀菌素A和D混合物质量与甲醇体积比为0.1 g/mL。在该条件下多杀菌素A的重结晶收率为64%,纯度为98.7%。     

Optimization of Methanol Yield from a Lurgi Reactor

Methanol is an important chemical with the potential to become an alternative fuel. An optimization study was performed for a Lurgi methanol synthesis reactor using the commercial process simulator Aspen Plus. The optimization routine is coupled with a steady‐state model of the methanol synthesis reactor. Syngas inlet temperature, steam drum pressure, and cooling water volumetric flow rate were optimized so that methanol production in the reactor outlet was maximized. The methanol yield increased by 7.04 %.     

高性能溶剂N-甲酰吗啉的合成

以吗啉和甲酸为原料,利用带水剂A通过共沸精馏的方法脱水,合成了高性能溶剂N-甲酰吗啉(NFM)。其最佳反应条件为:n(吗啉)∶n(甲酸)=1∶1.10,反应温度为85~95℃,反应时间为4 h,带水剂A的用量为吗啉体积分数的50%,产品收率为94.3%,纯度为99.6%。在同等条件下,保温反应后进行分水和分水装置中安装精馏柱,NFM收率分别可以提高约15%和8%。     

Fuel cell grade hydrogen from methanol on a commercial Cu/ZnO/Al2O3 catalyst

This paper presents the results of experiments of the methanol decomposition reaction catalyzed by a commercial Cu/ZnO/Al₂O₃ in the absence and presence of water. Methanol decomposition of 100% in the absence of water was obtained at 290 °C and a space velocity of 2 cm³/h g cat. At these conditions, the hydrogen yield was 1.9–2.0. Water addition to the feed increased the yield of hydrogen and reduced the formation of: dimethyl ether; methyl formate and methane. The variation of the catalyst’s activity and selectivity with time, temperature and feed composition was consistent with previous studies of methanol–steam reforming and water–gas shift reaction, however, this appears to be the first study over the same catalyst of methanol decomposition and methanol–steam reforming. XPS analysis of used catalyst samples and time on-stream data showed that the Cu²⁺ oxidation state of copper favors methanol decomposition, and we propose that the deactivation of the catalyst is mainly caused by the change in the oxidation state of copper.     

甲醇-水体系中碱式氯化镁纤维的制备工艺研究

在甲醇-水的复合溶剂中,以MgCl2·6H2O和NH3·H2O为原料制备碱式氯化镁纤维。研究了甲醇浓度、氯化镁与NH3·H2O物质的量比、氯化镁浓度、反应温度、陈化温度等对碱式氯化镁产率及形貌的影响规律,以正交实验进行优化,并采用XRD、SEM、TG/DTG等对产品进行分析。实验结果表明,甲醇体积分数为25.0%、n（氯化镁）∶ n（NH3·H2O）=3.0∶1、氯化镁浓度为4.0 mol/L、反应温度为25 ℃、陈化温度为50 ℃时,碱式氯化镁一次产率为13.13%,长径比大于100,XRD和TG/DTG结果证实产品组成为Mg2（OH）3Cl·4H2O。产率比水相中产率提高了近 1倍,表明甲醇-水体系是制备高产率碱式氯化镁的有效方法之一。     

Separation of ethyl acetate–isooctane mixture by heteroazeotropic batch distillation

This paper studies the separation of an ethyl acetate–isooctane mixture by heterogeneous azeotropic distillation in a batch rectifying column. An initial list of 60 candidates was studied but only methanol and acetonitrile were obtained as potential heterogeneous entrainers. These entrainers form a low boiling heterogeneous azeotrope with isooctane. Experimental verification of the miscibility gap with isooctane was performed at 25 °C for each entrainer giving a smaller region for methanol than for acetonitrile. Feasibility of the heterogeneous azeotropic batch distillation was carried out experimentally in a laboratory batch distillation column having 44 theoretical equilibrium stages and using a high reflux ratio. Several distillate fractions were taken as a function of the temperature at the top of the column. For both methanol and acetonitrile, the main fraction was defined by the condensed vapor providing a liquid–liquid split of the isooctane/entrainer heteroazeotrope into the decanter. Ethyl acetate impurity was detected in both decanted phases, but in much lower amount when using acetonitrile as entrainer. The process with acetonitrile also resulted in a shorter operating time and higher purity and recovery yield of isooctane as the main distillate product. Pure ethyl acetate remained into the boiler at the end of each process.     

低温低压二步法合成甲醇

二步法合成甲醇,其第一步是甲醇羰基化合成甲酸甲酯;第二步是甲酸甲酯氢解合成甲醇。二步法反应的优点是使反应温度和压力降低、选择性提高、产物甲醇不含水,使提纯容易。从而低能耗、高产率地合成甲醇。     

垂直管式反应器中超临界甲醇连续制备生物柴油I:相含率及反应中间产物的轴向分布(英文)

Production of biodiesel with supercritical methanol is a green synthesis process.A study was carried out in a vertical tubular reactor with a length of 3700 mm and a diameter of 20 mm at 275-375°C,15 MPa,and molar ratio of methanol to soybean oil of 40︰1.The phase holdup,intermediate product,yield and axial distribution of methyl ester(ME) were investigated.Methanol and oil were mixed non-uniformly due to the formation of biodiesel and difference in their densities,even when the reaction system was in the supercritical state.From top to bottom,the phase holdup of methanol increased and that of oil decreased.As temperature increased,the concentrations of monoglyceride and diglyceride decreased gradually and the ME yield increased.When the temperature reached 300°C,the critical temperature of the system,the ME yield was 50%.Further increase in temperature led to a sharp in-crease of ME yield.However,at 375°C after 1200 s of reaction time,the decomposition rate of ME was greater than its formation rate,reducing the ME yield.