毕业设计(论文)外文资料翻译附件1：外文资料翻译译文通过反应精馏合成乙酸乙酯的柱结构的研究摘要采用不同的催化填料研究反应精馏合成乙酸乙酯的理论和实验。
实验室研究采用直径为50mm，高为3m的精馏塔；中试试验研究采用直径为162mm，高为12m的精馏塔。
两种实验研究有相似的结论。
本实验研究了几种不同的商业填料，它们分别是KATAP AK® -S和两个MULTIPAK不同品种。
模拟采用的模型为一级反应速率模型。
并采用ASPEN进行了计算机模拟。
计算机模拟结果与实验结果基本吻合。
此外还研究了反应的适宜操作条件，催化机理和提高产品纯度。
根据每种填料的特性，将研究模型从实验室研究应用到工业规模。
关键词：乙酸乙酯的合成，反应精馏；催化机理；塔结构，工程扩大1 简介反应精馏已成功地应用于一些重要的工业过程并且其应用领域正在扩大。
然而，反应精馏设计过程仍然是一个挑战，因为这是很难获得可靠的过程模型描述一些复杂和相互关联包括同步反应与分离的能力的现象。
因此，安全的从实验室到工业的规模扩大极具挑战性。
反应分离过程中固体催化剂的使用，导致了内部的柱子依赖于托盘，随机和规则装填的新设计。
我们要考虑反应精馏塔内部反应和分离情况，并保持它们之间的良好平衡。
因此，内部催化柱结构的选择以及作为在列催化和非催化区的放置位置对柱子的整体性能是非常关键的。
本实验采用乙醇和乙酸反应生成乙酸乙酯和水的反应，我们不同类型的催化剂进行反应精馏。
我们进行了两个不同装置的实验，分别在直径50mm和直径162mm。
对于这个系统，对速率建模和模拟应用与实验结果进行了比较。
对经营状况和所选择的催化列影响内部对整体性能进行了研究。
此外，催化反应精馏柱的结构化装备柱扩大内部能力的考虑。
2 反应精馏的内部催化柱反应精馏的基本概念在20世纪20年代已经被引入。
然而，直到最近，这个过程并没有发现重要的应用。
在建模与模拟研究进展，以及令人印象深刻的工业实践，如通过反应精馏醋酸甲酯的生产，已经引发了在这些过程中的兴趣。
反应和蒸馏装置的结合可以节约大量的资本和运营成本，尤其是在有限的平衡反应，例如把酯化反应与酯化反应结合起来。
由于产品从反应区继续去除，转化率和选择性都得到提高。
另一个好处是，对于放热反应，反应热是直接用于蒸发的液体成分，从而有助于节约能源。
此外，在某些情况下，反应精馏，可用于实际或接近沸点共沸混合物分离，例如，元和对二甲苯分离。
然而，反应精馏是不是极端的反应条件，如反应压力远远高于10bar，温度远高于400℃，因为增加的业务和设备成本。
这种设计与依然，由于其复杂性，集成过程的控制是一个挑战性任务。
在过去十年间在这一领域的研究多集中在固体催化剂反应精馏使用。
这个过程也称为催化蒸馏。
无催化剂的分离是必要的，如果被固定在包装物上盘或在催化涂层，有利于较均匀催化反应精馏的形式。
一些调查也取得了作为以托盘浆料分散固体催化剂。
固定化催化剂的使用促进了反应和分离区的确切定义。
然而，催化蒸馏的主要缺点之一是催化剂失活的情况交流，由于催化剂的支持有需要更换或新的催化剂填充。
在下降管中的容器和托盘放置催化剂也已进行了研究。
在结构化和散堆填料的基础上，两种不同的技术已经确立。
第一种技术是包装催化涂层，甚至从催化活性材料来制造。
第二种方法是在包装袋颗粒催化剂。
对于后者的技术，传统的颗粒状催化剂可用于包装生产，同时为涂料的程序，这在许多情况下是相当复杂，催化剂的供应商的支持成为一种必要。
在固定化颗粒催化剂催化结构中是包结构和规整填料，比如KATAPAK和MULTIPAK。
在这项工作中，两种不同类型的包装已被选定调查，KATAPAK和MULTIPAK，他们每个在两个变种。
这两种类型的结合现代包装规整填料，如低压降和高吞吐量等好处以及多相催化的优点。
图1 KATAPAK®-S的实验室包装（左），KATAPAK®-S的250.Y（右）6 实验和理论成果6.1 实验结果在两者的柱范围，一系列的实验已完成的。
所提出的结果集中在实验室规模柱设置。
为实验室规模柱选定的实验结果以及相应的工作条件列于表4。
柱中的转换是有限的催化剂安装量，因此是由截面高度的催化和催化剂的应用内部体积分数。
在进料比例接近化学计量比的实验与高达78％乙醇KATAPAK®-S的显示转换。
正如预期的那样，随着转化率馏分对饲料的比例。
通过实验说明了这一点3,7和10，其中既有摩尔投料比和总进给速度可媲美，而回流比略比实验三高。
然而，对于与KATAPAK®-S的，选择的操作条件不液液相分离是观察，因为在这些情况中的乙醇含量蒸馏防止相分离，如图所示。
4只在乙醇浓度很低时，被调查预测系统的热力学描述显示出相容性差距。
MULTIPAK®-1与KATAPAK®-S实验的结果是相似的。
对于一些实验，已观测滗水器中的两个液相，而在实验15，醋酸的过量导致乙醇转化率的增加。
此外，在实验中在质量分数约2.9％的水已经在乙醇饲料正在为分相有利，而对所有其他实验室规模表4乙醇给予约99.9重量纯度实验等被使用。
额外的分离步骤提高了产品质量。
关于MULTIPAK® -2实验表明提高转化率以及增加产品的纯度，这是造成较高的分数作为催化剂，与其他在实验室规模的研究下，内部进行了比较。
在很多次实验中，都证明了随着反应精馏后期液液两相的分离，乙醇的转化率很高，基本上达到了等摩尔的转化。
反应的转化率也很高（高达89％）。
虽然实验室的装置只是一个1m高的填料塔，三个实验都表明了产品的转化率和纯度都高于传统的化学反应器。
6.2 模型验证为了保证开发的模式可预测性，在实验室和中试实验均用于模型验证。
仿真和实验之间的协议，一般是非常好的方面转化和偏差，产品纯度一般小于5％。
在图8，计算的温度和浓度分布与相应的实验数据进行了比较，实验的操作条件为10（见表4）。
在这个实验中，KATAPAK®-S被应用。
浓度分布表明，醋酸条浓度非常高这是有利的反应过程，因为反应速度显示了指数为1.5倍酸浓度依赖性。
实验和理论之间的统一是非常好的结果，不仅为馏分油和底浓度，但也为沿柱温度分布。
在高纯度醋酸得到列，可再回收利用的饲料，而馏分油中的醋酸乙酯部分约为72%重量底部。
图2液相气相浓度和温度的实验室栏：空符号，计算线;实心符号，实验6．3 操作条件的影响主要操作条件的影响已经在模拟反应器中进行了详细的研究。
Fig10 展示了热负荷和饲料率对转化率的影响。
已进行模拟与实验室规模设置和MULTIPAK®-1作为催化剂应用于包装。
在醋酸和乙醇的摩尔投料比为1.03，而回流比为5.3，总进给速度为0.7kg/h该进程的行为是高度非线性的，与被调查地区的热负荷可分为三个部分细分。
在第一个制度，乙醇是主要积累在列的催化部分，如市场预期，都与再沸器热负荷增加，饲料转化率和增加。
在第二个制度，水，中间锅炉，大大积聚在列的结果在一个陡峭的倒下双方的转换和馏分油对饲料的比例，因为只有较少的乙酸乙酯（低沸点组分催化节）形成。
在第三个制度，乙酸积累的催化部分，更迅速地转化率与热负荷由于指数1.5醋酸浓度依赖性的动力学表现。
最后政权无疑是最适合在高柱馏到进料比例。
7 结论在本工作中，主要研究了采用不同的催化填料，以乙醇和乙酸为原料反应精馏合成乙酸乙酯。
反应精馏塔内部催化填料的选择分布与没有填料的区域相比，有很大的区别。
我们在实验和理论上研究了不同的配置对反应的影响。
本次工艺的模拟是采用的一级反应速率模型。
我们进行了两个不同的装置进行实验，分别是直径50mm和直径162mm的反应精馏塔，并采用了四种不同的催化填料。
两个反应精馏塔的实验结果和模拟结果高度一致。
该模拟结果可以很好的表述反应过程内部的机理，有助于我们更好的了解反应精馏的工艺过程。
理论研究表明，填料KATAPAK®-S和MULTIPAK®-1在实验室模拟中非常相似，而因为填料MULTIPAK®-2的催化效率跟高，所以其转化率和产品纯度较其他填料高。
模拟结果可以更好的从实验室研究扩大到半工业研究。
通过反应精馏合成乙酸乙酯和传统反应器相比，可以显著地提高反应的转化率。
只要精馏塔的高度合适，不经过预反应器乙醇就可以完全转化。
过量的乙酸是必要地，因此塔顶完全没有乙醇。
此外，过量的乙酸提高了反应的转化率。
附件2：外文原文Investigation of different column configurations for the ethyl acetate synthesis via reactivedistillationAbstractThe ethyl acetate synthesis via reactive distillation is studied theoretically and experimentally using different catalytic packings. Experiments are carried out at laboratory scale in a 50 mm diameter column with a packing height of 3 m, and at semi-industrial scale in a 162 mm diameter column with a packing height of 12 m. The experimental set-up is similar for both cases. The commercially available packings studied are KATAPAK®-S and two different variants of MULTIPAK®. Modelling is performed with a rate-based stage model. The simulation environment ASPEN Custom ModelerTM is used for the implementation and solution of the model equations. The results of therate-based simulations agree well with the corresponding experimental results. In addition, suitable operating conditions and the influence of the selected catalytic internal onconversion and product purity are investigated. The developed model enables the scale-up from laboratory to industrial size columns, based on the respective packing characteristics. Keywords: Ethyl acetate synthesis; Reactive distillation; Catalytic internals; Column configuration; Scale-up1. IntroductionReactive distillation has been successfully used in several important industrial processes and its field of application is expanding. However, the design of reactive distillation processes still remains a challenge, since it is difficult to obtain process models capable of reliably describing several complex and interrelated phenomena including simultaneous reaction and separation. As a result, safe scale-up from laboratory experiments to industrial plants is quite challenging.The use of solid catalysts in reactive separation processes has led to a new design of column internals on the basis of trays, random and structured packings. The internals for reactive separations have to enhance both separation and reaction and maintain a sound balance between them. There-fore the choice of catalytic column internals as well as the placement of catalytic and non-catalytic zones in the column are crucial for the overallperformance of the column.This study deals with the heterogeneously catalysed esterification of ethanol and acetic acid to ethyl acetate and water by reactive distillation. Experiments are performed at two different scales, in a 50 and 162 mm diameter column.For this system, rate-based modelling is applied and the simulations are compared with experimental results.The influence of operating conditions and of the selected catalytic column internals on the overall performance is investigated. Moreover, the scale-up ability of reactive distillation columns equipped with structured catalytic column internals is considered.2. Catalytic column internals for reactive distillationThe basic concept of reactive distillation has already been introduced in the 1920s. However, until recent times, this process has not found significant application. The progressin modelling and simulation, as well as impressive examples realised in industrial practice, such as methyl acetate production via reactive distillation , have led to increasing interest in such processes.The integration of both reaction and distillation in oneapparatus can result in significant capital and operational cost savings, especially in the case of equilibrium limited reactions, such as esterifications and etherifications. Due to the continuous removal of products from the reaction zone,both conversion and selectivity are increased. Another benefit is that, for exothermal reactions, the heat of reaction is directly used for the evaporation of liquid components and thus contributing to energy savings. Furthermore, insomecases reactive distillation can be applied for the separation of azeotropic or close boiling mixtures, e.g. the separation of meta- and para-xylene. However, reactive distillation is not suitable for extreme reaction conditions,such as reaction pressure far above 10 bar or temperature far above 400 ◦C, because of increased operating and equipment costs. Design and control of such integrated processes still remain—due to theircomplexity—challenging tasks.In the past decade much of the research in this field has focused on the use of solid catalysts for reactive distillation.This process is also known as catalytic distillation. No separation of the catalyst is necessary, if the solids are immobilized in packings, on trays or in form of a catalytic coating, which is advantageous as compared with homogeneouslycatalysed reactive distillation. Some investigationshave also been made onsolid catalysts distributed as slurry on trays.The use of immobilised catalyst facilitates the exact definition of reaction and separation zones. However, one of the major disadvantages of catalytic distillation is the catalyst exchange in case of deactivation, since the catalyst support has to be replaced or refilled with new catalyst. The placement of catalyst containers in the downcomers and on trayshas also been investigated.On the basis of structured and random packings, two different techniques have beenestablished. The first technique is the catalytic coating of packings or even the manufacturing from catalytically active material. The second method is the immobilisation of granular catalyst in bags as part of these internals. For the latter technique, conventional granular catalyst can be used by the packing manufacturer,while for the coating procedure, which is in many cases rather complex, the support of the catalyst supplier becomesnecessary. Among the constructions with immobilised granular catalyst are catalytic bales] and structured packings such as KATAPAK® and MULTIPAK®.In this work, two different types of packings have been selected for investigation, KATAPAK®-S and MULTIPAK®,ach of them in two variants. Both packing types combine the benefits of modern structured packings, such as lowpressure drop and high throughput and offer the advantages of heterogeneous catalysis.Fig. 1. KATAPAK®-S laboratory packing (left), KATAPAK®-S 250.Y(right).6. Experimental and theoretical results6.1. Experimental resultsA series of experiments has been performed at both column scales. The presented results focus on the laboratory scale column set-up.Selected experimental results for the laboratory scale column are summarised in Table 4 together with the corresponding operating conditions. The conversion in the column is limited by the catalyst amount installed, and thus by the height of the catalytic section and the catalyst volume fractionof the applied internals. Experiments with KATAPAK®-S show conversions of up to 78% for ethanol at feed ratios close to stoichiometric ratio. As expected,conversion increases with increasingdistillate-to-feed ratio.This is illustrated by experiments 3, 7 and10, in whichboth molar feed ratio and total feed rate are comparable,while the reflux ratio is slightly higher in experiment 3. However, for the selected operating conditionswith KATAPAK®-S, no liquid–liquid phase separation is observed,because in these cases the ethanol content in the distillate prevents phase splitting as illustrated in Fig. 4.Thethermo dynamic description of the investigated system predictsthe occurrence of miscibility gaps only at low ethanolconcentrations.The results of the experiments with MULTIPAK®-1 aresimilar to those witKATAPAK®-S. For some experiments,two liquid phases in the decanter have been observed, whereas in experiment 15, a strong excess of acetic acid is fed resulting in an increased conversion of ethanol. Moreover,in this experiment about 2.9 wt.% water is already present in the ethanol feed being advantageous for the phase splitting, while for all other laboratory scale experiments given in Table 4 ethanol with a purity of about 99.9wt.% is used. The product quality is increased by the additional separation step in thedecanter.Experiments with MULTIPAK®-2 showed a significant increase in conversion and thus product purity, which is caused by the higher catalyst fraction as compared with that of other internals under study at laboratory scale. In most of the experiments, ethanol conversion proved to be high enough for the subsequent liquid–liquid phase separation.Even for nearly equimolar feed composition, very high conversionsare obtained (up to 89%).Although the laboratory set-up is only equipped with 1 mof catalytic packing, experiments for all three internals showthat both conversion and product purity can be increased at compared with conventional chemical reactors.6.2. Model validationTo ensure the predictability of the developed model, both laboratory and pilot scaleexperiments are used for the model validation. The agreement between simulations and experiments is in general very good and deviations regarding conversion and product purity are typically smaller than 5%.In Fig. 8, the calculated temperature and concentration profiles are compared with the corresponding experimental data, for the operatingconditions in experiment 10 (see Table 4). In this experiment, KATAPAK®-S is applied. Concentration profiles show a very high concentration of acetic acid in the reactive section in the middle, which is favourable for the processes, since the reaction rate shows an exponent1.5 dependence of the acid concentration. The conversionis about 78% for ethanol for a nearly equimolar feed.Fig. 2 Liquid phase concentrations and vapour phase temperature in laboratory column: lines with empty symbols, calculations; solid symbols, experiment.6.3. Influence of the operating conditionsFig. 10 shows the influence of the heat duty on the conversion and distillate-to-feedratio. Simulations have been performed with the laboratory scale set-up and MULTIPAK®-1 as the applied catalytic packing. The molar feed ratio of acetic acid and ethanolis 1.03, whereas the reflux ratio is 5.3 and the total feed rate is 0.7 kg/h. The process behaviour is highlynon-linear, and the investigated heat duty region can be subdivided into three parts. Inthe first regime (I), ethanol is mainly accumulated in the catalyticsection of the column, and, as expected, both distillateto-feed ratio and conversion increase with increasing reboiler heat duty. In the second regime (II), water, the intermediate boiler, significantlyaccumulates in the catalytic section of the column which resultsin a steep fall down of both the conversion and distillate-to-feed ratio,because less ethyl acetate (low boiling component) is formed. In the third regime (III), acetic acid accumulates in the catalytic section, and conversion increases more rapidly with the heat duty due to the exponent 1.5 dependence of the acetic acid concentration in the kinetic expression.Thelast regime is undoubtedly the most suitable for the column at highdistillate-to-feed ratios.7. ConclusionsIn this work, the synthesis of ethyl acetate from ethanol and acetic acid by heterogeneously catalysed reactive distillation is investigated. Since the choice of column internals and arrangement of catalytic and non-catalytic zones have significant influence onthe overall performance, different configurations are experimentally and theoretically studied.Modelling of this process is accomplished with a rate-basedstage model.Experiments are performed at two different scales, in a 50mm and in a 162 mm diameter column, with four differentcatalytic internals. The simulations are in a very satisfactory agreement with the results obtained at both column scales.The models are able to describe the process behaviour inan entire range of operating conditions and contribute to a better understanding of the process.Theoretical investigations show that the performance ofKATAPAK®-S andMULTIPAK®-1 is very similar at laboratoryscale, while conversion and product purity are higherwith MULTIPAK®-2 because of the greater catalyst content.The simulations arefurther applied for investigations of the scale-up from the laboratory to the semi-industrial set-up.The production of ethyl acetate via reactive distillation can significantly increase conversion as compared with conventional reactors. Almost total conversion of ethanol can be obtained with moderate column heights and even without using a pre-reactor. Anexcess of acetic acid is necessary to achieve nearly complete conversion of ethanol, and therefore,nearly ethanol-free top product. Furthermore, a high acetic acid concentration in the catalytic section of the column increases the reaction rate.。
