20100909 化工专业英语练习题 题目 1 8

1、 仅供个人参考 物质的混合物发生物理变化或化学变化的操作或一系列操作。进入过程的过程指引起一种物质和(多种)1) 物料称之为对该过程的输入或进料，而离开的物料称之为输出或产品。 A process is any operation or series of operations that causes a physical or chemical change in a substance or a mixture of substances . The material that enters a process is referred to as input or feed the pro

2、cess, and that which leaves is called output or product. 年，从一个生产医药产品的小生产厂家不断发展，以成为一个跨国公司，现经营1839 B.Braun 成立于 2) Founded in 1839 from a small production firm for pharmaceutical 医药产品、医疗技术、药物及生物技术products, B. Braun has grown steadily into a multinational company dealing with medical products, medical t

3、echnology, pharmaceutical and biotechnology. In the same way that a complex plant can be divided into basic unit operations, so chemical reactions involved 1） in the process industries can be classified into certain groups, or unit processes (e.g., polymerizations, 过程工etherifications, and nitrations

4、), have common characteristics.复杂的工厂可划分为基本的操作单元一样， 业中涉及的化学反应也可划分为一定的单元过程（如聚合、酯化、和硝化），它们具有共同的特性。The notion of a processing plant encompassing a number of operations, such as mixing, evaporation, and 2） filtration, and of these operations being essentially similar, whatever the product, led to the con

5、cept of unit 包括的一系列操作，如混合、蒸发、过滤，无论产物是什么，这些操作都基本相同，从而导致了operations. 单元操作的概念。 The chemical engineer must work closely with the chemist in order to understand thoroughly the chemistry 3）involved in the process and to make sure that the chemist gets the reaction kinetic data and the physical property 化学

6、工程师必须与化学家紧密合作，以完全了解过程data needed to design, operate, and optimize the process 操作及优化所需的化学动力学数据及物性数据。中涉及的化学知识，并要弄清化学家是否得到了过程设计、- even water - their density will change as pressure changes. Under steady compressible All fluids are 4） conditions, and provided that the changes in pressure are small, it i

7、s usually possible to simplify analysis of the 所有的液体是可压缩的甚至水他们的flow by assuming it is incompressible and has constant density.通常可以简化假设流量分析是不可压缩并给出在压力很小,密度变化是压力的变化。稳定的条件下的变化, 的和有一定的密度。 In a region such as outer space, which is virtually void of gases, the pressure is essentially zero. Such a 5）condit

8、ion can be approached very nearly in a laboratory when a vacuum pump is used to evacuate a bottle. The pressure in a vacuum is called absolute zero, and all pressures referenced with respect to this zero pressure are 能压力本质上是零。这样的条件下,这几乎是无用的气体termed absolute pressures. 在某一区域内如太空, 所有的压力参考关于这够到达几乎在实验室里

9、当真空泵是用来撤离一个瓶子里。在真空压力称为绝对零,Many pressure-measuring devices like the manometer measure not absolute pressure but 个零压称为绝对压力。only difference in pressure. The reference pressure is actually the atmospheric pressure. Whenever atmospheric pressure is used as a reference, the possibility exists that the pre

10、ssure thus measured can be either positive or 许多压力的测量设negative. When this difference is positive, this type of pressure reading is called gage pressure. 有可能存在但是不是绝对压力唯一的不同。参考压力实际上是大气压力。每当气压作为参考,备如压力,着压力从而测量可以积极还是消极的。当这种差异是积极的,这类型的压力阅读被称为规的压力。 不得用于商业用途 仅供个人参考所示的一个基本实例，是石油化工某部分的一个完整设计（主要是单元操作，换热网络和控制回

11、图 7 1) ，其转化率在几个。系统包括反应和分离部分。反应属于催化反应，由于催化剂的失活（deactivation）路）月的操作周期内是变化的。当催化剂活性较低时，反应转化率下降，相应地精馏塔的进料发生变化。精馏组成保持稳定。塔顶组分（循环）组成是，以保证塔底产物(bottom product)塔有自己的控制系统（未画出）Figure 7 shows the base case, a complete design (main to accommodate）催化剂失活的影响。可变的，以抵消（unit operations, heat exchanger network, and contro

12、l loops) for part of a petrochemicals process. The system involves reaction and separation. The reaction is catalytic and conversion is variable over periods of several months due to catalyst deactivation. During times od low catalyst activity, conversion falls off and consequently the composition o

13、f the distillation feed stream changes. The distillation column has its own control system (not shown), which is used to ensure that the composition of the bottom product is kept constant. The top product composition (recycle) is variable to accommodate the effect of catalyst deactivation. 化学工程师必须能对

14、全流程以及所用的化学工程是处理那些原材料变化或分离成有用产品的工业过程。2) 设备进行开发、设计和操作；选择合适的原料；高效、安全、经济地操作工厂，同时确保生产的产品能满Chemical engineer has to deal with industrial processes in which raw materials are changed or 足顾客的要求separated into useful products. Chemical engineers must develop, design, and engineer both the complete process and

15、 the equipment used; choose the proper raw materials, operate the plants efficiently, safely, and economically; and see to it that products meet the requirements set by customers 1) The above examples teach us an important lesson, although it is the chemists who make and discover the new chemicals w

16、hich may have special properties, a considerable input from engineers and technologists may be 上述这required before the chemical can be processed and converted into a suitable form in which it can be used.些实例给我们一个主要的启示：虽然化学家制备并开发了具有特性性质的新的化学物质，但是要将这些化 学物质加工并转化为可实用的合适形态， 还需要工程师和技术人员投入大量的工作。-scale manuf

17、acture of commodity products. 2) “Unit operations” evolved in meeting the need of economic largeThe concept of unit operations held that any chemical manufacturing process could be resolved into a coordinated series of operations such as pulverizing, drying, roasting, crystallizing, filtering, evapo

18、rating, distilling, 单元操作已发展成为满足商品大规模生产的需要，其概念认为：任何化学生产过程electrolyzing, and so on. 可分解为一系列同等的操作，如粉碎、干燥、焙烧、结晶、过滤、蒸发、蒸馏、电解等。 professional concern 3) The term “chemical engineer” implies that the person is primarily an engineer whose first making something, or making some process work. The adjective is

19、with manufacturing processes“chemical”implies a particular interest in processes which involve chemical changes.术语“化学工程师”意味着人主要是一个工程师的第一个专业的关心的是制造过程做活儿,或做一些过程的工作。这个形容词“化学”意味着一个特定的兴趣涉及的化学变化过程。 1）除对恒定平均值(mean values)可能的微小涨落外，如果一个过程的所有变量(variables)（即：所有温度、压力、体积、流速等）的值都不随时间变化，该过程可认为是处于稳定操作。如有任何过程变量随时间变化

20、，则可称为处于过度态或非稳态。将其本质而言，间歇过程和半间歇过程是非稳定态，而连续过程是稳态或过度态。If the values of all the variables in a process (e.g. all temperatures, pressures, volumes, flow rates, etc.) do not change with time, except possibly for minor fluctuations about constant mean values, the process is said to be operating at steady s

21、tate. If any of the process variables change with time, transient or unsteady-state operation is said to exist. By their nature, batch and semi batch process are unsteady-state operations, whereas continuous processes may be either steady state or transient 不得用于商业用途仅供个人参考 2）合成有机化合物可定义为从天然存在的原料（如石油、天

22、然气、煤）中衍生出的产品，这些原料至少 要经过一种化学反应过程（如氧化反应、加氢反应、卤化反应 halogenations、磺化反应 sulfonation,或烷基化反应）。Synthetic organic chemicals can be defined as derivative products of naturally occurring materials (petroleum, natural gas and coal), which have undergone at least one chemical reaction, such as oxidation, hydroge

23、nation, halogenation, sulfonation, or alkylation. 1） A pilot plant is a collection of equipment designed and constructed to investigate some critical aspects of a process operation or perform basic research. It is a tool rather than an in itself. A pilot plant can range in size from a laboratory ben

24、ch-top unit to a facility only marginally smaller than a commercial unit. The purposes for its construction and operation can vary widely: confirming feasibility of a proposed process; providing design data; determining the economic feasibility of a new process; determining optimum materials of cons

25、truction; testing operability of a control scheme; determining the extent of plant maintenance; producing sufficient qualities of product for market evaluation; obtaining kinetic data; screening catalysts; providing areas of advanced technology; providing data for solutions to scale-up problems; pro

26、viding technical support to an existing process or product assessing process hazards; determining operating costs; optimizing an existing process; and performing basic process research.中试工厂是用于研究过程操作中某些关键问题或进行基础研究的一整套设备。它是研究手段而不是研究目的。中式工厂的规模，可从实验室小型实验设备直 至比工业装置的外形略小一点的装置。建立并进行中试操作的目的很多：检验所设想过程的可行性；提供

27、设计数据；确定新过程在经济上的可行性；确定最佳的施工材料；检验控制系统的可操作性；确定工厂的维护范围；生产足够量的产品以供市场评价；获取动力学数据；为先进技术提供试验基地；提供解决放大问题的数据；为以有过程或产品提供技术支持；评定过程的危险程度；确定操作费用；优化现有工艺；进行基础过程研究。 2) A batch reactor is used for small-scale operation, for testing new processes that have not been fully developed, for the manufacture of expensive prod

28、ucts, and for processes that are difficult to convert to continuous operations. The reactor can be charged through the holes at the top. The batch reactor has the advantage of high conversions that can be obtained by leaving the reactant in the reactor for long periods of time, but it also has the d

29、isadvantages of high labor costs per batch and the difficulty of large-scale production.间歇反应器用于小于小规模生产，用于试验尚未完全开发成功的新过程，还用于生产昂贵的产品，以及那些难于实现连续化操作的过程。间歇反应器可以从顶部加料。延长反应物在反应器的停留时间可以获得较高的转化率，这是间歇反应器的优点，而其缺点在于每个周期的劳动成本高及难以进行大规模生产。 1）异庚烷由丁烯和异丁烷在浓硫酸的乳化液(emulsion)中反应生产。过程的新鲜进料以 40,000kg/h 的速率加入。其中含25.00mole%

30、的异丁烷、25.00mole%丁烯和 50.00mole%的正丁烷，后者在过程中是化学惰性的。部分反应器的出料（effluent）循环至反应器的进口。其余部分流入分层槽（settler）在槽中水相（硫酸）和烃相得以分离。酸循环至反应器，烃则进入精馏塔。塔顶馏出物含正丁烷和异庚烷，而塔底产物全为异丁烷循环至反应器。 Isooctane is produced by the reaction of butylenes and isobutene in an emulsion the concentrated sulfuric acid. The fresh feed to the process

31、flows at a rate of 40000 kg/h, and contains 25mole% isobutene, 25% butylenes, and 50% n-butane, which is chemically inert in this process. A portion of the reactor effluent is recycled to the reactor the inlet, and the remainder passes to a settler, in which the aqueous (sulfuric acid) and hydrocarb

32、on phases are allowed to separate. The acid is recycled to the reactor, and the hydrocarbons pass to a distillation column. The overhead from the column contains isooctane and n-butane, and the bottoms product, which is recycled to reactor, contains only isobutene. 不得用于商业用途 仅供个人参考，一个vessel） 15。装置的特征

33、是有两个巨大的容器（2) 流化床催化裂化装置（cracker）的典型简图见图）newer）催化剂再生。新型（用于使进料在热催化剂上进行反应，另一个用空气烧去碳以使用过的（spent分子筛催化剂的活性如此之高，使得物料和催化剂之间的接触时间必须急剧减少，否则石油就会过度裂解 而得到不希望得到的气体和焦碳。(overcrack)A typical diagram of a fluid catalytic cracker is shown in Fig. 15. The unit is characterized by two huge vessels, one to read the feed w

34、ith hot catalyst and the other to regenerate the spent catalyst by burning off carbon with air. The activity of newer molecular-sieve catalysts is to great that the contact time between feed and catalyst is reduced drastically. If not, the oil will overcrack to give unwanted gases and coke. While te

35、chnical advances and efficiency improvements in specific unit operations are occurring the time, the 1)big story is the hybridization of processes. Combining individual unit operations, such as reaction, and heat exchange, into larger, concurrent operations will be major trend om upcoming years. Tec

36、hnologies such as reactive distillation, catalytic membranes, and phase-transfer catalysts all represent examples of hybridized processes where reaction and separation are combined. 当技术进步和提升效率发生在特定单元操作,大的故事是有关杂交过程。结合个人单元操作,如反应,与换热,成规模更大、并行操作将主要趋势即将到来的市的年。技术,如反应蒸馏、催化膜、相转移催化剂的例子都表现化过程中,反应和分离的总和。 2) Th

37、e formulation of the thermodynamic equilibrium problem and the methodologies used for its solution are presented in this chapter. The resulting equations need a number of pure component and mixture equilibrium properties, which, whenever not experimentally available at the conditions of interest, mu

38、st be estimated.本章给出了对热力学平衡问题的描述及其解决方法。所导出的方程需要大量纯组分的平衡性质及混合物的平衡性质，如果在要求的条件下，以实验方式得不到这些平衡数据，就必须估算这些数据。 Most of the problems in chemical engineering, however, are multivariable and nonlinear, with constraints, and often require the use of discrete valued variables. Also, while optimization is a conce

39、ptually powerful framework, its impact has been somewhat limited in practice due to the lack of tools that facilitate the formulation and solution of these problems. 然而，化学工程中大多数问题都是多变量、非线性、有约束条件的问题还常常需要利用离散变量。此外，虽然优化概念上很有效的构想，但由于缺乏描述问题和求解问题的简便工具，使得优化的效果在实用上有一定的局限性。 1)因为产物氨的分子的体积比反应物的体积小，所以提高压力会提高氨的平

40、衡转化率。提高温度对平衡产生相反的效应，但会明显（greatly）提高反应速率。温度对平衡的负效应又兼具对反应速率很强的正效应，对其他许多反应也是常见的，为此，需要对各种条件精致地权衡以确保得到令人满意（good）的操作条件，获得可能的利润。较快的反应速率意味着减小设备尺寸，因而相应地降低设备成本。Because the product molecule, ammonia, has a lower volume than the reactant molecules, the equilibrium yield of ammonia is increased by increasing pre

41、ssure. Temperature increase produces the opposite effect on the equilibrium, but increases the rate of reaction greatly. This negative temperature effect on equilibrium combined with a strong positive effect on rate is common to many other reactions and requires a nice balance of assure good operati

42、ng conditions and to make profits possible. Greater rate means reduced equipment and consequent equipment cost. 2)硝酸广泛用于生产无机硝酸盐和有机硝酸酯、用于各种金属处理，以及用于光刻（photoengraving）。硝酸生产是铂-铑（platinum-rhodium）催化剂上将氨氧化成一氧化氮（nitric oxide），一氧化氮氧化成二氧化氮，然后将二氧化氮溶解于水。降低产品速率的副反应是氨氧化成氮气和水蒸气。Nitric acid is used extensively fo

43、r the production of inorganic and organic nitrates, for metal treatment of various kinds, and for photoengraving. It is produced by oxidizing ammonia to nitric oxide over a platinum-rhodium catalyst, oxidizing the nitric oxide to nitrogen dioxide, and dissolving the NOin water. A side reaction that

44、lowers the product yield 2 is the oxidation of ammonia to nitrogen and water vapor. 不得用于商业用途 仅供个人参考 ）许多石油化工产品从木材制得，首先将木材转化为合成气，合成气然后转化为甲醇或者氨，通过进一3归纳了一些能够以甲醇和氨这两种基本中间体生产的化工产品衍步的加工就能够获得所需的产品。图 1 A wide variety of petrochemicals can be produced from wood by first converting the wood to synthesis gas, 生

45、物。which can then be converted to either methanol or ammonia and further processed to produce the desired chemical products. Fig.1 summarizes some of the chemical derivatives that can be produced from the two basic intermediate products. 1) Much equipment for the separation of liquids and finely divi

46、ded solids was invented independently in a number of industries and is of diverse character. These developments have occurred without benefit of any but the most general theoretical considerations. Even at present, the selection of equipment for specific solid-liquid separation 在许多工业applications is

47、largely a process of scale-up based on direct experimentation with the process material.部门独立开发出许多用于分离液体和细微固体颗粒的设备，它们各具特性。这些开发只是依据一些最基本液分离过程的设备选型主要还是一个以工艺物料直接实验结果为基础的放-的理论。即使在目前，为特定固 大过程。The unit operations are largely used to conduct the primarily physical steps of preparing of reactants, separating

48、 2）and purifying the products, recycling unconverted reactants, and controlling the energy transfer into or out of the chemical reactor. We also can say that, the unit operations deal mainly with the transfer and change of energy and 设备操作the transfer and change of materials primarily by physical mea

49、ns but also by physical-chemical means.在很大程度上是用来进行主要物理步反应物料配比、准备分组分离纯化回收得救产品反应物料配比、和控设备操作应对主要是由于转会和改变的能量和转移和改变的制能量传递进、出化学反应器。我们也能说, 材料主要由物理方法还理化手段。 Unlike many products whose structure and reactions were well known before their industrial application, some 1和许多的产品polymers were produced on an industr

50、ial scale long before their chemistry or physics were studied.一些聚合物工业生产规模生产化学或物理他们之前的很长一,结构和反应是非常熟悉的在他们的工业应用 段时间进行了研究。Configurational isomerism is then due to the presence in the molecule of one or more dissymmetric centers, in 2the simplest case asymmetric carbon atoms each of which can have (R) an

51、d (S) absolute configuration; and, or, to 然后构型正异构由于存在一个the presence of double bonds which can give cis- and trans-geometrical isomers.或;(S)绝对的配置在最简单的情况下不对称碳原子其中的每一个都可以有或多个分子不对称中心,(R)和 者双联系的存在能给顺和转化几何异构体。The homologes of benzene are those containing an alky group or alkyl groups in place of one or mo

52、te hydrogen 3 atoms.那些含有烷基团体或烷基官能团的同分异构体的苯必须代替一个尘粒氢原子构成。 Objectionable hydrogen sulfide is removed from such a gas or from naturally occurring hydrocarbon gases by 4washing with various alkaline solutions in which it is absorbed. 这是吸收。讨厌的硫化氢将这些气体或自然发生的碳氢化合物气体从用各种碱液中,Gas absorption is an operation in

53、 which a gas mixture is contacted with a liquid for the purposes of 5preferentially dissolving one or more components of the gas and to provide and to give a solution of these in the liquid.气体吸收的一种操作联系的混合气体与液体溶解优先为目的的一个或多个组件提供的气体,把解决这些处在液体里。 不得用于商业用途 仅供个人参考 6.The continuous process although requirin

54、g more carefully designed equipment than the batch process, can ordinarily be handled in less space, fits in with other continuous steps more smoothly, and can be conducted at any 适用于其它连续过程虽然需要更多精心设计的设备比批量生产、通常能处理较少的空prevailing pressure. 可进行任何流行的压力。连续舞步顺利,Normally, in evaporation the thick liquid is

55、 the valuable product and the vapor is condensed and discarded. 7 Mineral-bearing water is often evaporated to give a solid-free product for boiler feed, for special process requirements, or for human consumption. This technique is often called water distillation, but technically it is evaporation.

56、In one specific situation, however, the reverse is true. 在蒸发浆是有价值的产品和蒸汽被压缩并且丢弃。含矿物质的水是经常蒸发给无固相产品对于一般来说,但技术上讲是蒸发。在某一情,或给人食用。这一技术是经常被称为“水蒸馏锅炉,为特别的工艺的要求, 刚好相反。况下,然而, 将甲烷转化成石油化工产品的最重要的工艺路线是借助于氢气，或借助于氢气和一氧化碳的混合气， 1）to establish 。以煤来生产氢气和一氧化碳混合物最初实现工业化（后者称之为“合成气”(synthesis gas) 。industrially）是通过著名的水煤气反应（w

57、ater-gas reaction）Will the methane into petrochemical products is the most important process route by hydrogen, or by hydrogen and carbon monoxide richer mixture, the latter called syngas. With coal to produce hydrogen and carbon monoxide mixture first realization industrialization is through the fa

58、mous serni-water gas reactions. When two objects at different temperatures are brought into thermal contact, heat flows from the object at the ）1high temperature to that at the lower temperature. The net flow is always in the direction of the temperature 当两个物decrease. The mechanisms by which the heat may flow are three: conduction, convention, and radiation.热源自于物体的高温温度较低的物体。网络流的方向一直在温度降低。所体在不同的温度被带至接触热, :办理、会议展览、和辐射等。采用的机制流热可以有三个To understand the contributions which are feasible and desirable from the two understanding of the individual ） 2kno