《化学工程与工艺专业英语》全本
Unit 1 Chemical Industry
化学工业
Although the use of chemicals dates back to the ancient civilizations, the evolution of what we know as the modern chemical industry started much more recently. It may be considered to have begun during the Industrial Revolution, about 1800, and developed to provide chemicals roe use by other industries. Examples are alkali for soapmaking, bleaching powder for cotton, and silica and sodium carbonate for glassmaking. It will be noted that these are all inorganic chemicals. The organic chemicals industry started in the 1860s with the exploitation of William Henry Perkin’s discovery if the first synthetic dyestuff—mauve. At the start of the twentieth century the emphasis on research on the applied aspects of chemistry in Germany had paid off handsomely, and by 1914 had resulted in the German chemical industry having 75% of the world market in chemicals. This was based on the discovery of new dyestuffs plus the development of both the contact process for sulphuric acid and the Haber process for ammonia. The later required a major technological breakthrough that of being able to carry out chemical reactions under conditions of very high pressure for the first time. The experience gained with this was to stand Germany in good stead, particularly with the rapidly increased demand for nitrogen-based compounds (ammonium salts for fertilizers and nitric acid for explosives manufacture) with the outbreak of world warⅠin 1914. This initiated profound changes which continued during the inter-war years (1918-1939).
1．化学工业的起源
尽管化学品的使用可以追溯到古代文明时代，我们所谓的现代化学工业的发展却是非常近代（才开始的）。可以认为它起源于工业革命其间，大约在1800年，并发展成为为其它工业部门提供化学原料的产业。比如制肥皂所用的碱，棉布生产所用的漂白粉，玻璃制造业所用的硅及Na2CO3. 我们会注意到所有这些都是无机物。有机化学工业的开始是在十九世纪六十年代以William Henry Perkin 发现第一种合成染料—苯胺紫并加以开发利用为标志的。20世纪初，德国花费大量资金用于实用化学方面的重点研究，到1914年，德国的化学工业在世界化学产品市场上占有75%的份额。这要归因于新染料的发现以及硫酸的接触法生产和氨的哈伯生产工艺的发展。而后者需要较大的技术突破使得化学反应第一次可以在非常高的压力条件下进行。这方面所取得的成绩对德国很有帮助。特别是由于1914年第一次世界大仗的爆发，对以氮为基础的化合物的需求飞速增长。这种深刻的改变一直持续到战后（1918-1939）。
date bake to/from: 回溯到
dated: 过时的，陈旧的
stand sb. in good stead: 对。。。很有帮助
Since 1940 the chemical industry has grown at a remarkable rate, although this has slowed significantly in recent years. The lion’s share of this growth has been in the organic chemicals sector due to the development and growth of the petrochemicals area since 1950s. The explosives growth in petrochemicals in the 1960s and 1970s was largely due to the enormous increase in demand for synthetic polymers such as polyethylene, polypropylene, nylon, polyesters and epoxy resins.
1940年以来，化学工业一直以引人注目的速度飞速发展。尽管这种发展的速度近年来已大大减慢。化学工业的发展由于1950年以来石油化学领域的研究和开发大部分在有机化学方面取得。石油化工在60年代和70年代的迅猛发展主要是由于人们对于合成高聚物如聚乙烯、聚丙烯、尼龙、聚脂和环氧树脂的需求巨大增加。
The chemical industry today is a very diverse sector of manufacturing industry, within which it plays a central role. It makes thousands of different chemicals which the general public only usually encounter as end or consumer products. These products are purchased because they have the required properties which make them suitable for some particular application, e.g. a non-stick coating
品，而人们通常只接触到终端产品或消费品。这些产品被购买是因为他们具有某些性质适合（人们）的一些特别的用途，例如，用于盆的不粘涂层或一种杀虫剂。这些化学产品归根到底是由于它们能产生的作用而被购买的。
2. Definition of the Chemical Industry
At the turn of the century there would have been little difficulty in defining what constituted the chemical industry since only a very limited range of products was manufactured and these were clearly chemicals, e.g., alkali, sulphuric acid. At present, however, many intermediates to products produced, from raw materials like crude oil through (in some cases) many intermediates to products which may be used directly as consumer goods, or readily converted into them. The difficulty cones in deciding at which point in this sequence the particular operation ceases to be part of the chemical industry’s sphere of activities. To consider a specific e xample to illustrate this dilemma, emulsion paints may contain poly (vinyl chloride) / poly (vinyl acetate). Clearly, synthesis of vinyl chloride (or acetate) and its polymerization are chemical activities. However, if formulation and mixing of the paint, including the polymer, is carried out by a branch of the multinational chemical company which manufactured the ingredients, is this still part of the chemical industry of does it mow belong in the decorating industry?
2．化学工业的定义
在本世纪初，要定义什么是化学工业是不太困难的，因为那时所生产的化学品是很有限的，而且是非常清楚的化学品，例如，烧碱，硫酸。然而现在有数千种化学产品被生产，从一些原料物质像用于制备许多的半成品的石油，到可以直接作为消费品或很容易转化为消费品的商品。困难在于如何决定在一些特殊的生产过程中哪一个环节不再属于化学工业的活动范畴。举一个特殊的例子来描述一下这种困境。乳剂漆含有聚氯乙烯/聚醋酸乙烯。显然，氯乙烯（或醋酸乙烯）的合成以及聚合是化学活动。然而，如果这种漆，包括高聚物，它的配制和混合是由一家制造配料的跨国化学公司完成的话，那它仍然是属于化学工业呢还是应当归属于装饰工业中去呢？
It is therefore apparent that, because of its diversity of operations and close links in many areas with other industries, there is no simple definition of the chemical industry. Instead each official body which collects and publishes statistics on manufacturing industry will have its definition as to which operations are classified as the chemical industry. It is important to bear this in mind when comparing statistical information which is derived from several sources.
因此，很明显，由于化学工业经营的种类很多并在很多领域与其它工业有密切的联系，所以不能对它下一个简单的定义。相反的每一个收集和出版制造工业统计数据的官方机构都会对如何届定哪一类操作为化学工业有自己的定义。当比较来自不同途径的统计资料时，记住这点是很重要的。
3. The Need for Chemical Industry
The chemical industry is concerned with converting raw materials, such as crude oil, firstly into chemical intermediates and then into a tremendous variety of other chemicals. These are then used to produce consumer products, which make our lives more comfortable or, in some cases such as pharmaceutical produces, help to maintain our well-being or even life itself. At each stage of these operations value is added to the produce and provided this added exceeds the raw material plus processing costs then a profit will be made on the operation. It is the aim of chemical industry to achieve this.
3．对化学工业的需要
化学工业涉及到原材料的转化，如石油首先转化为化学中间体，然后转化为数量众多的其它化学产品。这些产品再被用来生产消费品，这些消费品可以使我们的生活更为舒适或者作药物维持人类的健康或生命。在生产过程的每一个阶段，都有价值加到产品上面，只要这些附加的价值超过原材料和加工成本之和，这个加工就产生了利润。而这正是化学工业要达到的目的。
It may seem strange in textbook this one to pose the question “do we need a chemical industry?” However trying to answer this question will provide(ⅰ) an indication of the range of the chemical industry’s activities, (ⅱ) its influence on our lives in everyday terms, and (ⅲ) how great is society’s need for a chemical industry. Our approach in answering the question will be to consider the indus try’s contribution to meeting and satisfying our major needs. What are these? Clearly food (and drink) and health are paramou nt. Other which we shall consider in their turn are clothing and (briefly) shelter, leisure and transport.
在这样的一本教科书中提出：“我们需要化学工业吗？”这样一个问题是不是有点奇怪呢？然而，先回答下面几个问题将
然，食物和健康是放在第一位的。其它我们要考虑的按顺序是衣物、住所、休闲和旅行。
(1) Food. The chemical industry makes a major contribution to food production in at least three ways. Firstly, by making available large quantities of artificial fertilizers which are used to replace the elements (mainly nitrogen, phosphorus and potassium) which are removed as nutrients by the growing crops during modern intensive farming. Secondly, by manufacturing crop protection chemicals, i.e., pesticides, which markedly reduce the proportion of the crops consumed by pests. Thirdly, by producing veterinary products which protect livestock from disease or cure their infections.
(1)食物。化学工业对粮食生产所做的巨大贡献至少有三个方面。第一，提供大量可以获得的肥料以补充由于密集耕作被农作物生长时所带走的营养成分。（主要是氮、磷和钾）。第二，生产农作物保护产品，如杀虫剂，它可以显著减少害虫所消耗的粮食数量。第三，生产兽药保护家禽免遭疾病或其它感染的侵害。
(2) Health. We are all aware of the major contribution which the pharmaceutical sector of the industry has made to help keep us all healthy, e.g. by curing bacterial infections with antibiotics, and even extending life itself, e.g. ?–blockers to lower blood pressure.
（2）健康。我们都很了解化学工业中制药这一块在维护我们的身体健康甚至延长寿命方面所做出的巨大贡献，例如，用抗生素治疗细菌感染，用β-抗血栓降低血压。
(3) Clothing. The improvement in properties of modern synthetic fibers over the traditional clothing materials (e.g. cotton and wool) has been quite remarkable. Thus shirts, dresses and suits made from polyesters like Terylene and polyamides like Nylon are crease-resistant, machine-washable, and drip-dry or non-iron. They are also cheaper than natural materials.
衣物。在传统的衣服面料上，现代合成纤维性质的改善也是非常显著的。用聚脂如涤纶或聚酰胺如尼龙所制作的T恤、上衣、衬衫抗皱、可机洗，晒干自挺或免烫，也比天然面料便宜。
Parallel developments in the discovery of modern synthetic dyes and the technology to “bond” them to the fiber has resulted in a tremendous increase in the variety of colors available to the fashion designer. Indeed they now span almost every color and hue of the visible spectrum. Indeed if a suitable shade is not available, structural modification of an existing dye to achieve this can readily be carried out, provided there is a satisfactory market for the product.
与此同时，现代合成染料开发和染色技术的改善使得时装设计师们有大量的色彩可以利用。的确他们几乎利用了可见光谱中所有的色调和色素。事实上如果某种颜色没有现成的，只要这种产品确有市场，就可以很容易地通过对现有的色彩进行结构调整而获得。
Other major advances in this sphere have been in color-fastness, i.e., resistance to the dye being washed out when the garment is cleaned.
这一领域中另一些重要进展是不褪色，即在洗涤衣物时染料不会被洗掉。
(4) Shelter, leisure and transport. In terms of shelter the contribution of modern synthetic polymers has been substantial. Plastics are tending to replace traditional building materials like wood because they are lighter, maintenance-free (i.e. they are resistant to weathering and do not need painting). Other polymers, e.g. urea-formaldehyde and polyurethanes, are important insulating materials for reducing heat losses and hence reducing energy usage.
（4）住所，休闲和旅游。讲到住所方面现代合成高聚物的贡献是巨大的。塑料正在取代像木材一类的传统建筑材料，因为它们更轻，免维护（即它们可以抵抗风化，不需油漆）。另一些高聚物，比如，脲甲醛和聚脲，是非常重要的绝缘材料可以减少热量损失因而减少能量损耗。
Plastics and polymers have made a considerable impact on leisure activities with applications ranging from all-weather artificial surfaces for athletic tracks, football pitches and tennis courts to nylon strings for racquets and items like golf balls and footballs made entirely from synthetic materials.
Likewise the chemical industry’s contribution to transport over the years has led to major improvements. Thus development of improved additives like anti-oxidants and viscosity index improves for engine oil has enabled routine servicing intervals to increase from 3000 to 6000 to 12000 miles. Research and development work has also resulted in improved lubricating oils and greases, and better brake fluids. Yet again the contribution of polymers and plastics has been very striking with the proportion of the total automobile derived from these materials—dashboard, steering wheel, seat padding and covering etc.—now exceeding 40%.
多年来化学工业对旅游方面所作的贡献也有很大的提高。一些添加剂如抗氧化剂的开发和发动机油粘度指数改进使汽车日产维修期限从3000英里延长到6000英里再到12000英里。研发工作还改进了润滑油和油脂的性能，并得到了更好的刹车油。塑料和高聚物对整个汽车业的贡献的比例是惊人的，源于这些材料—挡板，轮胎，坐垫和涂层等等—超过40%。
So it is quite apparent even from a brief look at the chemical industry’s contribution to meeting our major needs that life i n the world would be very different without the products of the industry. Indeed the level of a country’s development may be judged by the production level and sophistication of its chemical industry.
很显然简单地看一下化学工业在满足我们的主要需求方面所做的贡献就可以知道，没有化工产品人类社会的生活将会多么困难。事实上，一个国家的发展水平可以通过其化学工业的生产水平和精细程度来加以判断。
4. Research and Development (R&D) in Chemical Industries
One of the main reasons for the rapid growth of the chemical industry in the developed world has been its great commitment to, and investment in research and development (R&D). A typical figure is 5% of sales income, with this figure being almost doubled for the most research intensive sector, pharmaceuticals. It is important to emphasize that we are quoting percentages here not of profits but of sales income, i.e. the total money received, which has to pay for raw materials, overheads, staff salaries, etc. as well. In the past this tremendous investment has paid off well, leading to many useful and valuable products being introduced to the market. Examples include synthetic polymers like nylons and polyesters, and drugs and pesticides. Although the number of new products introduced to the market has declined significantly in recent years, and in times of recession the research department is usually one of the first to suffer cutbacks, the commitment to R&D remains at a very high level.
4．化学工业的研究和开发。
发达国家化学工业飞速发展的一个重要原因就是它在研究和开发方面的投入和投资。通常是销售收入的5%，而研究密集型分支如制药，投入则加倍。要强调这里我们所提出的百分数不是指利润而是指销售收入，也就是说全部回收的钱，其中包括要付出原材料费，企业管理费，员工工资等等。过去这笔巨大的投资支付得很好，使得许多有用的和有价值的产品被投放市场，包括一些合成高聚物如尼龙和聚脂，药品和杀虫剂。尽管近年来进入市场的新产品大为减少，而且在衰退时期研究部门通常是最先被裁减的部门，在研究和开发方面的投资仍然保持在较高的水平。
The chemical industry is a very high technology industry which takes full advantage of the latest advances in electronics and engineering. Computers are very widely used for all sorts of applications, from automatic control of chemical plants, to molecular modeling of structures of new compounds, to the control of analytical instruments in the laboratory.
化学工业是高技术工业，它需要利用电子学和工程学的最新成果。计算机被广泛应用，从化工厂的自动控制，到新化合物结构的分子模拟，再到实验室分析仪器的控制。
Individual manufacturing plants have capacities ranging from just a few tones per year in the fine chemicals area to the real giants in the fertilizer and petrochemical sectors which range up to 500,000 tonnes. The latter requires enormous capital investment, since a single plant of this size can now cost $520 million! This, coupled with the widespread use of automatic control equipment, helps to explain why the chemical industry is capital-rather than labor-intensive.
一个制造厂的生产量很不一样，精细化工领域每年只有几吨，而巨型企业如化肥厂和石油化工厂有可能高达500,000吨。后者需要巨大的资金投入，因为一个这样规模的工厂要花费2亿5千万美元，再加上自动控制设备的普遍应用，就不难解释为什么化工厂是资金密集型企业而不是劳动力密集型企业。
the world, and they also have manufacturing units in a number of countries. This international outlook for operations, or globalization, is a growing trend within the chemical industry, with companies expanding their activities either by erecting manufacturing units in other countries or by taking over companies which are already operating there.
大部分化学公司是真正的跨国公司，他们在世界上的许多国家进行销售和开发市场，他们在许多国家都有制造厂。这种国际间的合作理念，或全球一体化，是化学工业中发展的趋势。大公司通过在别的国家建造制造厂或者是收购已有的工厂进行扩张。
Unit 2 Research and Development
研究和开发
Research and development, or R&D as it is commonly referred to, is an activity which is carried out by all sectors of manufacturing industry but its extent varies considerably, as we will see shortly. Let us first understand, or at least get a feel for, what the terms mean. Although the distinction between research and development is not always clear-cut, and there is often considerable overlap, we will attempt to separate them. In simple terms research can be thought of as the activity which produces new ideas and knowledge whereas development is putting those ideas into practice as new process and products. To illustrate this with an example, predicting the structure of a new molecule which would have a specific biological activity and synthesizing it could be seen as research whereas testing it and developing it to the point where it could be marketed as a new drug could be described as the development part.
研究和开发，或通常所称R&D是制造业各个部门都要进行的一项活动。我们马上可以看到，它的内容变化很大。我们首先了解或先感觉一下这个词的含义。尽管研究和开发的定义总是分得不很清楚，而且有许多重叠的部分，我们还是要试着把它们区分开来。简单说来，研究是产生新思想和新知识的活动，而开发则是把这些思想贯彻到实践中得到新工艺和新产品的行为。可以用一个例子来描述这一点，预测一个有特殊生物活性的分子结构并合成它可以看成是研究而测试它并把它发展到可以作为一种新药推向市场这一阶段则看作开发部分。
1.Fundamental Research and Applied Research
In industry the primary reason for carting out R&D is economic and is to strengthen and im prove the company’s position and profitability. The purpose of R&D is to generate and provide information and knowledge to reduce uncertainty, solve problems and to provide better data on which management can base decisions. Specific projects cover a wide range of activities and time scales, from
a few months to 20 years.
1．基础研究和应用研究
在工业上进行研究和开发最主要的原因是经济利益方面，是为了加强公司的地位，提高公司的利润。R&D的目的是做出并提供信息和知识以减低不确定性，解决问题，以及向管理层提供更好的数据以便他们能据此做出决定。特别的项目涵盖很大的活动范围和时间范围，从几个月到20年。
spring to the mind of the academic, rather than the industrial, chemist then these would be basic, fundamental (background) or exploratory research and the synthesis of new comp ounds. This is also labeled “blue skies” research.
我们可以在后面的段落里举出大量的R&D活动。但是如果我们举出的点子来源于研究院而不是工业化学家的头脑，这就是基础的或探索性的研究
Fundamental research is typically associated with university research. It may be carried out for its own intrinsic interest and it will add to the total knowledge base but no immediate applications of it in the “real world” well be apparent. Note that it will provi de
a valuable training in defining and solving problems, i.e. research methodology for the research student who carries it out under
supervision. However, later “spin offs” from such work can lead to useful applications. Thus physicists claim that but for th e study and development of quantum theory we might not have had computers and nuclear power. However, to take a specifically chemical example, general studies on a broad area such as hydrocarbon oxidation might provide information which would be useful in more specific areas such as cyclohexane oxidation for the production of nylon intermediates.
基础研究通常与大学研究联系在一起，它可能是由于对其内在的兴趣而进行研究并且这种研究能够拓宽知识范围，但在现实世界中的直接应用可能性是很小的。请注意，这种以内就在提出和解决问题方面提供了极有价值的训练，比如，在指导下完成研究工作的学生所接受的研究方法学（的训练）。而且，从这些工作中产生的“有用的副产品”随后也能带来可观的使用价值。因此，物理学家宣称要不是量子理论的研究和发展我们可能仍然没有计算机和核能量。不管怎样，举一个特殊的化学方面的例子吧，在各个领域如烃的氧化方面所做的广泛的研究将为一些特殊的领域如环己烯氧化生成尼龙中间产物提供有用的信息。
Aspects of synthesis could involve either developing new, more specific reagents for controlling particular functional group interconversions, i.e. developing synthetic methodology or complete synthesis of an entirely new molecule which is biologically active. Although t he former is clearly fundamental the latter encompasses both this and applied aspects. This term ‘applied’ has traditionally been more associated with research out in industrial laboratories, since this is more focused or targeted. It is a consequence of the work being business driven.
通过合成可以生产出一些新的、更特殊的试剂以控制特殊的官能团转换，即发展合成方法或完成一些具有生物活性的新分子的合成。尽管前者显然属于基础性研究而后者则包括基础研究和实用性研究两部分。所谓“实用性”习惯上是指与在工业实验室完成的研究联系在一起的，因为它更具目的性，它是商业行为驱动的结果。
Note, however, that there has been a major change in recent years as academic institutions have increasingly turned to industry for research funding, with the result that much more of their research effort is mow devoted to more applied research. Even so, in academia the emphasis generally is very much on the research rather than the development.
然而，请注意。近几年有很大的变化，大学研究机构正越来越多地转向工业界寻求研究经费，其结果就是他们的研究工作越来越多地是致力于实用研究。即使这样，学院工作的重点通常还是在于研究而不是开发。
2.Types of Industrial Research and Development
The applied or more targeted type of research and development commonly carried out in industry can be of several types and we will briefly consider each. They are: (ⅰ)product development, (ⅱ) process development, (ⅲ) process improvement and (ⅳ) applications development. Even under these headings there are a multitude of aspects so only a typical example can be quoted in each case. The emphasis on each of these will vary considerably within the different sectors of the chemical industry.
2．工业研究和开发的类型
通常在生产中完成的实用型的或有目的性的研究和开发可以分为好几类，我们对此加以简述。它们是：（1）产品开发；（2）工艺开发；（3）工艺改进；（4）应用开发；每一类下还有许多分支。我们.对每一类举一个典型的例子来加以说明。在化学工业的不同部门内每类的工作重点有很大的不同。
(1)Product development. Product development includes not only the discovery and development of a new drug but also, for
chemicals acquire them for the effects that they produce i.e. a specific use. Teflon, or polytetrafluoroethylene (PTFE), may be purchased because it imparts a non-stick surface to cooking pots and pans, thereby making them easier to clean.
(1)产品开发。产品开发不仅包括一种新药的发明和生产，还包括，比如说，给一种汽车发动机提供更长时效的抗氧化添加剂。这种开发的产品已经使（发动机）的服务期限在最近的十年中从3000英里提高到6000、9000现在已提高到12000英里。请注意，大部分的买家所需要的是化工产品能创造出来的效果，亦即某种特殊的用途。Tdflon，或称聚四氟乙烯（PTFE）被购买是因为它能使炒菜锅、盆表面不粘，易于清洗。
(2) Process development. Process development covers not only developing a manufacturing process for an entirely new product but also a new process or route for an existing product. The push for the latter may originate for one or more of the following reasons: availability of new technology, change in the availability and/or cost of raw materials. Manufacture of vinyl chloride monomer is an example of this. Its manufacturing route has changed several times owing to changing economics, technology and raw materials. Another stimulus is a marked increase in demand and hence sales volume which can have a major effect on the economics of the process. The early days of penicillin manufacture afford a good example of this.
（2）工艺开发。工业开发不仅包括为一种全新的产品设计一套制造工艺，还包括为现有的产品设计新的工艺或方案。而要进行后者时可能源于下面的一个或几个原因：新技术的利用、原材料的获得或价格发生了变化。氯乙烯单聚物的制造就是这样的一个例子。它的制造方法随着经济、技术和原材料的变化改变了好几次。另一个刺激因素是需求的显著增加。因而销售量对生产流程的经济效益有很大影响。Penicillin早期的制造就为此提供了一个很好的例子。
The ability of penicillin to prevent the onset of septicemia in battle wounds during the Second World War (1939～1945) resulted in an enormous demand for it to be produced in quantity. Up until then it had only been produced in small amounts on the surface of the fermentation broth in milk bottles! An enormous R&D effort jointly in the U.S. and the U.K. resulted in two major improvements to the process. Firstly a different stain of the mould gave much better yields than the original Penicillium notatum. Secondly the major process development was the introduction of the deep submerged fermentation process. Here the fermentation takes place throughout the broth, provided sterile air is constantly, and vigorously, blown through it. This has enabled the process to be scaled up enormously to modern stainless steel fermenters having a capacity in excess of 50000 liters. It is salutary to note that in the first world war (1914～1919) more soldiers died from septicemia of their wounds than were actually killed outright on the battlefield!
Penicillin能预防战争中因伤口感染引发的败血症，因而在第二次世界大战（1939-1945）中，penicillin的需求量非常大，需要大量生产。而在那时，penicillin只能用在瓶装牛奶表面发酵的方法小量的生产。英国和美国投入了巨大的人力物力联合进行研制和开发，对生产流程做出了两个重大的改进。首先用一个不同的菌株—黄霉菌代替普通的青霉，它的产量要比后者高得多。第二个重大的流程开发是引进了深层发酵过程。只要在培养液中持续通入大量纯化空气，发酵就能在所有部位进行。这使生产能力大大地增加，达到现代容量超过5000升的不锈钢发酵器。而在第一次世界大战中，死于伤口感染的士兵比直接死于战场上的人还要多。注意到这一点不能不让我们心存感激。
Process development for a new product depends on things such as the scale on which it is to be manufactured, the by-products formed and their removal/recovery, and required purity. Data will be acquired during this development stage using semi-technical plant (up to 100 liters capacity) which will be invaluable in the design of the actual manufacturing plant. If the plant is to be a very large capacity, continuously operating one, e.g. petrochemical or ammonia, then a pilot plant will first be built and operated to test out the process and acquire more data, these semi-technical or pilot plants will be required for testing, e.g., a pesticide, or customer evaluation, e.g., a new polymer.
对一个新产品进行开发要考虑产品生产的规模、产生的副产品以及分离/回收，产品所要求的纯度。在开发阶段利用中试车间（最大容量可达100升）获得的数据设计实际的制造厂是非常宝贵的，例如石油化工或氨的生产。要先建立一个中试车间，运转并测试流程以获得更多的数据。他们需要测试产品的性质，如杀虫剂，或进行消费评估，如一种新的聚合物。
Note that by-products can has a major influence on the economics of a chemical process. Phenol manufacture provides a striking example of this. The original route, the benzenesulphonic acid route, has become obsolete because demand for its by-produce sodium
demand for the by-product acetone (0.6 tons/l ton phenol).The sale of this therefore reduces the net cost of the phenol.
注意，副产品对于化学过程的经济效益也有很大的影响。酚的生产就是一个有代表性的例子。早期的方法，苯磺酸方法，由于它的副产品亚硫酸钠需求枯竭而变的过时。亚硫酸钠需回收和废置成为生产过程附加的费用，增加了生产酚的成本。相反，异丙基苯方法，在经济效益方面优于所有其他方法就在于市场对于它的副产品丙酮的迫切需求。丙酮的销售所得降低了酚的生产成本。
A major part of the process development activity for a mew plant is to minimize, or ideally prevent by designing out, waste production and hence possible pollution. The economic and environmental advantages of this are obvious.
对一个新产品进行工艺开发的一个重要部分是通过设计把废品减到最低，或尽可能地防止可能的污染，这样做带来的经济利益和对环境的益处是显而易见的。
Finally it should be noted that process development requires a big team effort between chemists, chemical engineers, and electrical and mechanical engineers to be successful.
最后要注意，工业开发需要包括化学家、化学工程师、电子和机械工程师这样一支庞大队伍的协同合作才能取得成功。
（3) Process improvement. Process improvement relates to processes which are already operating. It may be a problem that has arisen and stopped production. In this situation there is a lot of pressure to find a solution as soon as possible so that production can restart, since ‘down time’ costs money.
（3）工艺改进。工艺改进与正在进行的工艺有关。它可能出现了某个问题使生产停止。在这种情形下，就面临着很大的压力要尽快地解决问题以便生产重新开始，因为故障期耗费资财。
down time: 故障期
More commonly, however, process improvement will be directed at improving the profitability of the process. This might be achieved in a number of ways. For example, improving the yield by optimizing the process, increasing the capacity by introducing a new catalyst, or lowering the energy requirements of the process. An example of the latter was the introduction of turbo compressors in the production of ammonia by the Haber process. This reduced utility costs (mainly electricity) from $6.66 to %0.56 per ton of ammonia produced. Improving the quality of the product, by process modification, may lead to new markets for the product.
然而，更为常见的，工艺改进是为了提高生产过程的利润。这可以通过很多途径实现。例如通过优化流程提高产量，引进新的催化剂提高效能，或降低生产过程所需要的能量。可说明后者的一个例子是在生产氨的过程中涡轮压缩机的引进。这使生产氨的成本（主要是电）从每吨6.66美元下降到0.56美元。通过工艺的改善提高产品质量也会为产品打开新的市场。
In recent years, however, the most important process improvement activity has been to reduce the environmental impact of the process, i.e., to prevent the process causing any pollution. Clearly there have been two interlinked driving forces for this. Firstly, the public’s concern about the safety of chemicals and their effect on the environment, and the legislation which has followed as a result of this. Secondly the cost to the manufacturer of having to treat waste (i.e., material which cannot be recovered and used r sold) so that it can be safely disposed of, say by pumping into a river. This obviously represents a charge on the process which will increase the cost of the chemical being made. The potential for improvement by reducing the amount of waste is self-evident.
然而，近年来，最重要的工艺改进行为主要是减少生产过程对环境的影响，亦即防止生产过程所引起的污染。很明显，有两个相关连的因素推动这样做。第一，公众对化学产品的安全性及其对环境所产生影响的关注以及由此而制订出来的法律；第二，生产者必须花钱对废物进行处理以便它能安全地清除，比如说，排放到河水中。显然这是生产过程的又一笔费用，它将增加所生产化学产品的成本。通过减少废物数量提高效益其潜能是不言而喻的。
Note, however, with a plant which has already been built and is operating there are usually only very limited physical changes which can be made to the plant to achieve the above aims. Hence the importance, already mentioned, of eliminating waste production at the design stage of a new plant. Conserving energy and thus reducing energy cost has been another major preoccupation in recent years.
然而，请注意，对于一个已经建好并正在运行的工厂来说，只能做一些有限的改变来达到上述目的。因此，上面所提到
(4) Applications development. Clearly the discovery of new applications or uses for a product can increase or prolong its profitability. Not only does this generate more income but the resulting increased scale of production can lead to lower unit costs and increased profit. An example is PVC whose early uses included records and plastic raincoats. Applications which came later included plastic bags and particularly engineering uses in pipes and guttering.
（4）应用开发。显然发掘一个产品新的用处或新的用途能拓宽它的获利渠道。这不仅能创造更多的收入，而且由于产量的增加使单元生产成本降低，从而使利润提高。举例来说，PVC早期是用来制造唱片和塑料雨衣的，后来的用途扩展到塑料薄膜，特别是工程上所使用的管子和排水槽。
Emphasis has already been placed on the fact that chemicals are usually purchased for the effect, or particular use, or application which they have. This often means that there will be close liaison between the chemical companies’ technical sales representa tives and the customer, and the level of technical support for the customer can be a major factor in winning sales. Research and development chemists provide the support for these applications developments. An example is CF3CH3F. This is the first of the CFC replacements and has been developed as a extracting natural products from plant materials. In no way was this envisaged when the compound was first being made for use as a refrigerant gas, but it clearly is an example of applications development.
我们已经强调了化学产品是由于它们的效果，或特殊的用途、用处而得以售出这个事实。这就意味着化工产品公司的技术销售代表与顾客之间应有密切的联系。对顾客的技术支持水平往往是赢得销售的一个重要的因素。进行研究和开发的化学家们为这些应用开发提供了帮助。CH3CH3F的制造就是一个例子。它最开始是用来做含氟氯烃的替代物作冷冻剂的。然而近来发现它还可以用作从植物中萃取出来的天然物质的溶解剂。当它作为制冷剂被制造时，固然没有预计到这一点，但它显然也是应用开发的一个例子。
3.Variations in R&D Activities across the Chemical Industry
Both the nature and amount of R&D carried out varies significantly across the various sectors of the chemical industry. In sectors which involve largescale production of basic chemicals and where the chemistry, products and technology change only slowly because the process are mature, R&D expenditure is at the lower end of the range for the chemical industry. Most of this will be devoted to process improvement and effluent treatment. Examples include ammonia, fertilizers and chloralkali production from the inorganic side, and basic petrochemical intermediates such a ethylene from the organic side.
3．化工行业中研究与开发活动的变化
化学工业的不同部门所进行的R&D的性质与数量都有很大的变化。与大规模生产的基础化工产品有关的部门中，化学产品和技术变化都很慢，因为流程已很成熟。R&D经费支出属于化工行业中低的一端，而且大部分的费用是用于过程改进和废水处理。无机方面的例子有氨、肥料和氯碱的生产，有机方面的如乙烯等一些基础石油化学的中间产物。
At the other end of the scale lie pharmaceuticals and pesticides (or plant protection products). Here there are immense and continuous efforts to synthesize new molecules which exert the desired, specific biological effect. A single company may generate 10,000 new compounds for screening eac h year. Little wonder that some individual pharmaceutical company’s annual R&D expenditure is now approaching $1000 million! Expressing this in a different way they spend in excess of 14% of sales income (note not profits) on R&D.
不一样规模生产的是药品和除草剂。人们付出了巨大而持续的努力以合成能产生所希望的、特殊的生物作用的新分子。一家公司每年可能要合成10,000新化合物以供筛选。可以想象一些医药公司其每年的R&D经费支出高达100亿美元。换句话说，他们把超过14%的销售收入投入在R&D上。
Unit 3 Typical Activities of Chemical Engineers
化学工程师的例行工作
The classical role of the chemical engineer is to take the discoveries made by the chemist in the laboratory and develop them into money--making, commercial-scale chemical processes. The chemist works in test tubes and Parr bombs with very small quantities of reactants and products (e.g., 100 ml), usually running “batch”, constant-temperature experiments. Reactants are placed in a small container in a constant temperature bath. A catalyst is added and the reactions proceed with time. Samples are taken at appropriate intervals to follow the consumption of the reactants and the production of products as time progresses.
化学工程师经典的角色是把化学家在实验室里的发现拿来并发展成为能赚钱的、商业规模的化学过程。化学家用少量的反应物在试管和派式氧弹中反应相应得到少量的生成物，所进行的通常是间歇性的恒温下的实验，反应物放在很小的置于恒温水槽的容器中，加点催化剂，反应继续进行，随时间推移，反应物被消耗，并有生成物产生，产物在合适的间歇时间获得。
By contrast, the chemical engineer typically works with much larger quantities of material and with very large (and expensive) equipment. Reactors can hold 1,000 gallons to 10,000 gallons or more. Distillation columns can be over 100 feet high and 10 to 30 feet in diameter. The capital investment for one process unit in a chemical plant may exceed $100 million!
与之相比，化学工程师通常面对的是数量多得多的物质和庞大的（昂贵的）设备。反应器可以容纳1000 到10,000加仑甚至更多。蒸馏塔有100英尺多高，直径10到30英尺。化工厂一个单元流程的投资可能超过1亿美元。
large commercial plant. The chemical engineer must work closely with the chemist in order to understand thoroughly the chemistry involved in the process and to make sure that the chemist gets the reaction kinetic data and the physical property data needed to design, operate, and optimize the process. This is why the chemical engineering curriculum contains so many chemistry courses.
在把化学家研制的小型反应器及分离系统“放大”到很大的商业化车间时，通常需要化学工程师的参与。为了彻底了解过程中的化学反应，化学工程师必须与化学家密切合作以确保能得到所需要的反应的动力学性质和物理性质参数以进行设计、运转和优选流程。这就是为什么化工课程要包括那么多的化学类课程的原因。
The chemical engineer must also work closely with mechanical, electrical, civil, and metallurgical engineers in order to design and operate the physical equipment in a plant--the reactors, tanks, distillation columns, heat exchangers, pumps, compressors, Control and instrumentation devices, and so on. One big item that is always on such an equipment list is piping. One of the most impressive features f a typical chemical plant is the tremendous number of pipes running all over the site, literally hundreds of miles in many plants. These pipes transfer process materials (gases and liquids) into and out of the plant. They also carry utilities (steam, cooling water, air, nitrogen, and refrigerant) to the process units.
化学工程师还必须与机械、电子、土木建筑和冶金工程师密切协作以设计和操作工厂的机械设备—反应器、槽、蒸馏塔、热交换器、泵、压缩机、控制器和仪器设备等等。在这张设备单上还有一大类是管子。化工厂最典型的特征之一就是数目庞大的管道贯穿所有生产间。可以毫不夸张地说，在许多车间都有几百英里长的管道。这些管道输入和输出车间的反应物质进行传递，同时还可携带有用的东西（水蒸气、冷却水、空气、氧、冷却剂）进入操作单元。
To commercialize the laboratory chemistry, the chemical engineer is involved in development, design, construction, operation, sales, and research. The terminology used to label these functions is by no means uniform from company to company, but a rose by any other name is still a rose. Let us describe each of these functions briefly. It should be emphasized that the jobs we shall discuss are “typical” and “classical”, but are by no means the only things that chemical engineers do. The chemical engineer has a broad background in mathematics, chemistry, and physics. Therefore, he or she can, and does, fill a rich variety of jobs in industry, government, and academia.
要把实验室研究商业化，化学工程师要参与进行开发、设计、建筑、操作、销售和研究工作。各个公司用来表示这些工作的名词不完全一样，但万变不离其宗。让我们简单地把每个工作描述一下。应该强调的是，我们所讨论的工作是“典型的”和“经典的”，但并不意味着化学工程师只能做这些事。化学工程师在数学、化学和物理学方面都有很好的知识基础，因此，他或她能够而且确实适应工业、政府部门、大专院校等非常广泛的职业要求。
1.Development
Development is the intermediate step required in passing from a laboratory-size process to a commercial-size process. The “pilot-plant” process involved in deve lopment might involve reactors that are five gallons in capacity and distillation columns that are three inches in diameter. Development is usually part of the commercialization of a chemical process because the scale-up problem is a very difficult one. Jumping directly from test tubes to 10,000-gallon reactors can be a tricky and sometimes dangerous endeavor. Some of the subtle problems involved which are not at all obvious to the uninitiated include mixing imperfections, increasing radial temperature gradients, and decreasing ratios of heat transfer areas to heat generation rates.
1. 开发
开发工作是从实验室规模向商业化规模转化所必需的中间阶段。开发阶段所涉及的“中试”流程所使用的反应器容量为5加仑，蒸馏塔直径为3英寸。开发通常是化学流程商业化的一部分。因为“放大”规模是一个非常困难的问题。直接从试管研制跳到在10.000加仑反应器里生产是非常棘手的有时甚至是危险的工作。一些（在实验室研究阶段）根本不明显的未加以考虑的细微问题，如混合不均匀，温度梯度辐射状升高，热交换面积逐渐降低以及热交换速度下降等（在后一阶段变得影响很大）。
The chemical engineer works with the chemist and a team of other engineers to design, construct, and operate the pilot plant. The design aspect involves specifying equipment sizes, configuration, and materials of construction. Usually pilot plants are designed to be quite flexible, so that a wide variety of conditions and configurations can be evaluated.
Once the pilot plant is operational, performance and optimization data can be obtained in order to evaluate the process from an economic point of view. The profitability is assessed at each stage of the development of the process. If it appears that not enough money will be made to justify the capital investment, the project will be stopped.
中试车间一旦开始运转，就能获得性能数据和选定最佳数值以便从经济学角度对流程进行评价。对生产过程的每一个阶段可能获得的利润进行评定。如果结果显示投入的资金不能有足够的回报，这项计划将被停止。
The pilot plant offers the opportunity to evaluate materials of construction, measurement techniques, and process control strategies. The experimental findings in the pilot plant can be used to improve the design of the full-scale plant.
中师车间还提供了评价设备制造材料、测量方法、流程控制技术的机会。中试车间的这些实验数据对于工业装置设计的改善能提供有用的帮助。
2.Design
Based on the experience and data obtained in the laboratory and the pilot plant, a team of engineers is assembled to design the commercial plant. The chemical engineer’s job is to specify all process flow rates and conditions, equipment types and sizes, materials of construction, process configurations, control systems, safety systems, environmental protection systems, and other relevant specifications. It is an enormous responsibility.
2．设计
根据在实验室和中试车间获得的经验和数据，一组工程师集中起来设计工业化的车间。化学工程师的职责就是详细说明所有过程中的流速和条件，设备类型和尺寸，制造材料，流程构造，控制系统，环境保护系统以及其它相关技术参数。这是一个责任重大的工作。
The design stage is really where the big bucks are spent. One typical chemical process might require a capital investment of $50 to $100 million. That’s a lot of bread! And the chemical engineer is the one who has to make many of the decisions. When you find yourself in that position, you will be glad that you studied as hard as you did (we hope) so that you can bring the best possible tools and minds to bear on the problems.
设计阶段是大把金钱花进去的时候。一个常规的化工流程可能需要五千万到一亿美元的资金投入，有许多的事情要做。化学工程师是做出很多决定的人之一。当你身处其位时，你会对自己曾经努力学习而能运用自己的方法和智慧处理这些问题感到欣慰。
The product of the design stage is a lot of paper:
(1) Flow sheets are diagrams showing all the equipment schematically, with all streams labeled and their conditions specified (flow rate, temperature, pressure, composition, viscosity, density, etc.)
设计阶段的产物是很多图纸：
（1）工艺流程图。是显示所有设备的图纸。要标出所有的流线和规定的条件（流速、温度、压力、构造、粘度、密度等）。
(2) P and I (Piping and Instrumentation) Drawings are drawings showing all pieces of equipment (including sizes, nozzle locations, and materials), all piping (including sizes, materials, and valves), all instrumentation (including locations and types of sensors, control valves, and controllers), and all safety systems (including safety valve and rupture disk locations and sizes, flare lines, and safe operating conditions).
（2）管道及设备图。标明所有设备（包括尺寸、喷嘴位置和材料）、所有管道（包括大小、控制阀、控制器）以及所有安全系统（包括安全阀、安全膜位置和大小、火舌管、安全操作规则）。
(3) Equipment specification Sheets are sheets of detailed information on all the equipment precise dimensions, performance criteria, materials of construction, corrosion allowances, operating temperatures, and pressures, maximum and minimum flow rates, and
最小流速以及诸如此类等等。这些规格说明书应交给中标的设备制造厂以进行设备生产。
3.Construction
After the equipment manufacturers (vendors) have built the individual pieces of equipment, the pieces are shipped to the plant site (sometimes a challenging job of logistics, particularly for large vessels like distillation columns). The construction phase is the assembling of all the components into a complete plant. It starts with digging holes in the ground and pouring concrete for foundations for large equipment and buildings (e.g., the control room, process analytical laboratory, and maintenance shops).
3．建造
当设备制造把设备的所有部分都做好了以后，这些东西要运到工厂所在地（有时这是后勤部门颇具挑战性的任务，尤其对象运输分馏塔这样大型的船只来说）。建造阶段要把所有的部件装配成完整的工厂，首先要做的就是在地面打洞并倾入混凝土，为大型设备及建筑物打下基础（比如控制室、流程分析实验室、维修车间）。
After these initial activities, the major pieces of equipment and the steel superstructure are erected. Heat exchangers, pumps, compressors, piping, instrument sensors, and automatic control valves are installed. Control system wiring and tubing are run between the control room and the plant. Electrical wiring, switches, and transformers are installed for motors to drive pumps and compressors. As the process equipment is being installed, it is the chemical engineer’s job to check that it is all hooked together pro perly and that each piece works correctly.
完成了第一步，就开始安装设备的主要部分以及钢铁上层建筑。要装配热交换器、泵、压缩机、管道、测量元件、自动控制阀。控制系统的线路和管道连接在控制室和操作间之间。电线、开关、变换器需装备在马达上以驱动泵和压缩机。生产设备安装完毕后，化学工程师的职责就是检查它们是否连接完好，每部分是否正常工作。
This is usually a very exciting and rewarding time for most engineers. You are seeing your ideas being translated from paper into reality. Steel and concrete replace sketches and diagrams. Construction is the culmination of years of work by many people. You are finally on the launch pad, and the plant is going to fly or fizzle! The moment of truth is at hand.
对大部分工程师来说这通常是一个令人激动、享受成功的时候。你将看到自己的创意由图纸变为现实。钢铁和混凝土代替了示意图和表格。建筑是许多人多年辛劳的结果。你终于站到了发射台上，工厂将要起飞还是最后失败。揭晓的那一刻即将到来。
Once the check-out phase is complete, “startup” begins. Startup is the initial commissioning of the plan t. It is a time of great excitement and round-the-clock activity. It is one of the best learning grounds for the chemical engineer. Now you find out how good your ideas and calculations really are. The engineers who have worked on the pilot plant and on the design are usually part of the startup team.
测试阶段一旦完成，“运转阶段”就开始了。启动是工厂的首项任务，是令人兴奋的时刻和日夜不停的工作。这是化学工程师最好的学习机会之一。现在你可以了解你的构思和计算究竟有些什么好。参与中试车间和设计工作的工程师通常也是启动队伍中的人员。
The startup period can require a few days or a few moths, depending on the newness of the technology, the complexity of the process, and quality of the engineering that has gone into the design. Problems are frequently encountered that require equipment modifications. This is time consuming and expensive: just the lost production from a plant can amount to thousands of dollars per day. Indeed, there have been some plants that have never operated, because of unexpected problems with control, corrosion, or impurities, or because of economic problem.
启动阶段需要几天或几个月，根据设计所涉及工艺技术的新颖、流程的复杂程度以及工程的质量而定。中间经常会遇到要求设备完善的问题。这是耗时耗财的阶段：仅仅每天从车间出来的废品会高达数千美金。确实，曾经有些车间因为没有预计到的问题如控制、腐蚀、杂质或因为经济方面的问题而从来没有运转过。
of products.
在启动阶段，工程师们通常需轮流值班。在很短的时间里有很多的东西需要学习。一旦车间按照设定程序成功运转，它就转变为产品的常规生产或制造部门。
4.Manufacturing
Chemical engineers occupy a central position in ma nufacturing. (or “operations” or “production,” as it is called in some companies). Plant technical service group are responsible for the technical aspects of running an efficient and safe plant. They run capacity and performance tests on the plant to determine where the bottlenecks are in the equipment, and then design modifications and additions to remove these bottlenecks.
4．制造
化学工程师在制造阶段占据中心的位置。车间技术服务部门负责车间有效而安全地运转的技术方面。他们进行生产量和性能测试以找出设备的瓶颈在哪，然后设计一些修正或附加的东西以解决这些瓶颈。
Chemical engineers study ways to reduce operating costs by saving energy, cutting raw material consumption, and reducing production of off-specification products that require reprocessing. They study ways to improve product quality and reduce environmental pollution of both air and water.
化学工程师研究一些方法节省能源，降低原材料消耗、减少不合要求的需进行处理的产品的生产，以降低生产成本。他们还研究一些提高产品质量、减少空气和水中环境污染的措施。
In addition to serving in plant technical service, many engineers have jobs as operating supervisors. These supervisors are responsible for all aspects of the day-to-day operation of the plant, including supervising the plant operators who run the plant round the clock on a three-shift basis, meeting quality specifications, delivering products at agreed-upon times and in agreed-upon quantities, developing and maintaining inventories of equipment spare parts, keeping the plant well maintained, making sure safe practices are followed, avoiding excessive emissions into the local environment, and serving as spokespersons for the plant to the local community.
除了提供技术服务外，许多工程师还负责生产监督。这些监督保证工厂日常生产的各个方面正常进行。包括管理换班工作的操作工，满足质量要求，按期按量发出产品，生产并保持设备备件的存储量，为车间设备维修，保证安全规则被遵守，避免过多排出废物污染环境，并且做工厂对当地社会的代言人。
5.Technical sales
Many chemical engineers find stimulating and profitable careers in technical sales. As with other sales positions, the work involves calling on customers, making recommendations on particular products to fill customer’s needs, and being sure that orders are handled smoothly. The sales engineer is the company’s representative and must know the company’s product line well. The sales engin eer’s ability to sell can greatly affect the progress and profitability of the company.
5．技术销售
许多化学工程师发现在技术销售中充满了刺激性的、有利可图的机会。与其它的销售业务一样，这项业务包括拜访客户，推荐一些特别的商品以满足客户的需要，并确保订单能顺利完成。销售工程师是公司的代表，必须十分清楚公司的产品生产情况。销售工程师的销售能力极大地影响公司的发展和利润。
The marketing of many chemicals requires a considerable amount of interaction between engineers in the company producing the chemical and engineers in the company using the chemical. This interaction can take the form of advising on how to use a chemical or developing a new chemical in order to solve a specific problem of a customer.
许多化工产品的市场开发需要制造化工产品公司的工程师与使用化工产品公司的工程师密切合作。这种合作所采取的方式可以是对如何使用一种化学产品提出建议，或者是生产出一种新的化学产品以解决客户的某个特殊的困难。
When the sales engineer discovers problems that cannot be handled with confidence, he or she must be able to call on the expertise
当销售工程师碰到他自己没有把握解决的问题时，他或她必须要请教专家。有时销售工程师还需组织来自不同公司的研究人员共同努力来解决某个问题。
6.Research
Chemical engineers are engaged in many types of research. They work with the chemist in developing new or improved products. They develop new and improved engineering methods (e.g., better computer programs to simulate chemical processes, better laboratory analysis methods for characterizing chemicals, and new types of reactors ad separation systems). They work on improved sensors for on-line physical property measurements. They study alternative process configurations and equipment.
6．研究
化学工程师能从事多种类型的研究工作。他们与化学家联合开发新的或革新的产品。他们探索新的和改良的工程技术（比如更好的计算机程序以模拟化工工艺，更好的实验室分析方法分析有代表性的化学产品，新型的反应和分离系统。）他们研究改进的传感器以进行物理性质的在线检测，他们还研究单个流程结构和设备。
Research engineers are likely to be found in laboratories or at desks working on problems. They usually work as members of a team of scientists and engineers. Knowledge of the process and common types of process equipment helps the chemical engineer make special contributions to the research effort. The chemical engineer’s daily activities may sometimes closely resembl e those of the chemist or physicist working on the same team.
研究工程师可能是在实验室或办公桌前钻研难题。他们通常是一组科学家或工程师中的一员。了解生产流程以及通常流程所使用的设备使化学工程师能在研究工作中做出突出的贡献。化学工程师的日常工作有时颇似那些化学家和物理学家。
Unit 4 Sources of chemicals
化学物质的来源
化学物质的数量多得惊人，其差异很大：所知道的化学物质的数量就达上千万种。如此的数量与理论
上可能形成的含碳化合物的数量相比，相形见绌。含碳化合物的数量之大是耦合的结果：即相对较强的碳
碳共价键的碳原子长链和异构体的形成。大部分这些化合物只是满足实验室好奇心或学术兴趣。然而，其
1. 无机化学品
Table1-1 无机化学品的主要来源
因为“无机化学品”这个词（术语）涉及到（cover，包括、涵盖）的是除碳以外所有元素构成的化合物。
其来源的多样性并不很大（见表1-1）。一些较重要的来源是金属矿（包括重要的金属铁和铝）以及盐和海
水（用于生产氯、钠、氢氧化钠和碳酸钠）。在这些情况下，至少两种不同的元素化合以一种稳定的化合
物在一起。因此，如果要得到单个元素（也就是金属），那么提取过程除了纯物理的分离方法以外，还必
须涉及到化学处理（过程）。金属矿或无机矿很少以纯物质的形式存在，因此，处理过程的第一步通常是：
（将无机矿中）从不要的固体如粘土或沙石中分离出来。固体筛分后经压碎和研磨，利用颗粒尺寸差异可
以完成一些物理分离。下一步骤则取决于所需矿物的本质及其特征。例如，铁矿常在磁分离器利用他们的
磁性加以分离。泡沫浮选是另一种广泛应用的分离技术。在该技术中，所需要的矿物，以细小颗粒形式存
在，借助被水溶液润湿能力的差异而与其他矿物加以分离。常加入表面活性剂（抗润湿剂），这些典型的
分子，一头为非极性部分（如长碳氢链），另一头为极性部分（如-NH2）。该极性基团与矿物相吸，形成不
牢固的键；而碳氢基团与水相斥而阻止矿物被润湿，因而矿物能浮选。相反，其他固体物质很容易被润湿
而沉在水溶液中。搅拌溶液或液体中鼓泡以产生泡沫能大大促进表面活性剂包裹的矿物的漂浮，这些矿物
从容器中溢出到收集容器中，在收集容器，矿物得到回收。显然，该过程成功的关键在于，为所处理矿物
选择一种高选择的特定的表面活性剂。
2 有机化合物
相比于无机化学品来自于众多不同的资源（这一点我们已经明白了），商业上的一些重要的有机化合
物基本上来源单一。如今，所有有机化合物的99%以上，可以通过石化工艺过程从原油（石油）和天然气
得到。这是一种有趣的情形——该情形一直在改变，而且将来也会变化，因为从技术上讲，相同的化学品
可以从其他原料得到。尤其是脂肪族化合物，可以通过由碳水化合物的发酵所得的乙醇加以生产，另一方
面，芳香族化合物可以从煤焦油中分离得到。煤焦油是煤炭化工过程的副产物。动植物油脂，是为数不多
的脂肪族化合物的特定的资源，这些脂肪族化合物包括长链脂肪酸（如正十八酸）和长链醇（如正十二烷
醇）。
化石燃料（即石油、天然气和煤）的形成要花上百万年，一旦用掉就不能被替换，因此，它们称之为
不可再生的资源。这与来自于植物的碳水化合物恰恰相反，碳水化合物能够较快被更新。一种较为普遍应
用的资源为蔗糖——一旦作物被收割和土地被清理，又可以种植和收割新的作物，通常少于一年。因此，碳氢化合物可称为可再生资源。据估计，植物原料（干重）的总的年产量为1*1011 吨。化石燃料－天然气、原油和煤，主要用作为能源，而不是作为有机化合物的资源。例如，各种石油分馏物的气体，用于家用烹调和取暖、用作为汽车用的汽油、加热建筑物重燃油，或用于在工业处理以产生
的蒸汽。通常，一桶原油的8%用于化学品的生产。下列数据可以说明，为什么化学工业在原油的使用方
面与燃料或能源消耗的工业展开着竞争。
显然，若我们愿意使用可代替化石燃料的其他能源，那么这些可替代能源可以利用的，同时，我们自
信地预料到在不久的将来，可以用上其他的可替代能源。因此，有必要要去保存宝贵的石油供应以用于化
学品的生产。“处理石油的最后一件事情是将之燃烧”该说法是有根据的。注意到这件事很有趣且有益的：
早在1894 年门捷列夫（发现元素周期表之俄国科学家）就向当局报道，“石油是太宝贵的资源而不能将之
燃烧掉，应该将之以化学品资源加以保存。”
来自于碳水化合物（植物茎杆）的有机化学物质，职务的主要成分是碳水化合物，碳水化合物组成职
务的结构。它们为多糖（如纤维素和淀粉），大量的淀粉存在于食物（如谷类、大米和马铃薯）之中，纤
维素是组成细胞壁的主要物质，因而广泛存在，可以从木材、棉花等中得到。因此，来自于碳水化合物的
化学品的潜力是相当大的，而且该原料可再生。
从碳水化合物得到化学物质的主要途径是通过发酵过程。然而发酵过程不能利用多糖（如维素和淀
粉），因此，淀粉必须先收到酸性或酶水解反应生成更简单的糖类（单糖或二糖（如蔗糖），这些较为简单
的糖是发酵过程中的）合适的起始原料。
发酵过程是利用单细胞的微生物（一般有酵母菌、真菌、细菌或霉菌）生产特殊化学品。有些发酵农
间体。尽管用此方法生产的化学品有所减少，但是用这种方法生产汽车燃料方面存在大量的兴趣。
反映在发酵过程的缺点可分为两方面（1）原料（2）发酵过程。因为植物茎杆是一种农业原料，其生
产和收割均为劳动力密集型的过程，所以相比之，它的原料费用高于原油的费用。同时，物料的运输更困
难，费用更高。与石化处理过程相比，发酵过程的主要缺点是：其一，时间通常要好几天，相比有些催化
石油反应只要几秒；其二，所得的产物通常是以稀的水溶液（浓度<10%）存在，因此，分离和纯化费用
较高。因为微生物是活的体系，过程的条件几乎不容许改变。为了增加反应速度，即使相对于小的温升，独有可能会导致微生物的死亡和发酵过程终止。
另一方面，发酵方法的独特优点是，其选择性高，一些结构复杂而很难以合成或者需要多步合成的化合物，通过发酵很容易制得。著名的实例有多种多样的抗生素的生产。如青霉素，头孢菌素和链霉素。
如果也基因工程中快速发展的过程中大量的实际问题得到解决，那么发酵方面的兴趣存在很大的兴趣。在基因工程中。微生物（如细菌）能定制地生产成所需的化学品。然而，因为发酵反应速度慢和产物
分离费用高，在不久的将来要实现用发酵方法生产大众化学品（即需求量极大的化学品如依稀，笨。）看来是不可能。
来自于动植物油和脂肪的有机化学品，动植物油脂（常指类肪）是由甘油脂组成，甘油酯为三羟基醇，甘油（丙烷-1，2，3-三醇，丙三醇）。有多种不同的种植物油资源，较为普通的有，大豆，谷物，棕树核，油菜籽，橄榄油，动物脂肪和巨鲸。这些油类可通过溶剂萃取分离得到。有相当大的部分，烹调油脂的形式用食品工业中，用于生产黄油，人选黄油和其他食品（如冰激凌）。这些食品的烷基对人的健康的影响，
尤其对血液中的胆固醇的影响，存在着争议。血液中的高胆固醇的含量会引起高血压和心脏病。目前的观点似乎赞成高含量不饱和的基因在降低胆固醇的水平和降低心脏病（发病率）危险是有利的。这引起如下趋势。不用烹调脂类和普通黄油或人造黄油（这些物质中饱和烷基含量丰富），而转向用烹调油和不饱和烷基的含量高的人造黄油。
类脂属于脂类（物质），用于生产化学物质时，以水解反应开始，虽然水解反应可以用酸或碱催化，
但碱催化效果更好，因为碱催化反应不可逆。碱性条件下的水解反应叫做皂化反应。
注意到这样事实很重要—皂化反应，水解反应（脂肪分解）一级氢解反应不会利用单一甘油酯（或甲
基醇，实际上，所用植物油是各种甘油酯的混合物，因此（水解）产物也是混合物，需要分离。
Unit 5 Basic Chemicals
基本化学品
我们将化学工业部门分成两类，生产量较大的部门和产量较低的部门。在产量高的部门中，各种化学品的年产量达上万吨至几十万吨。结果这样所用的工厂专门生产某一个单个产品。这些工厂的连续方式进行操作，自动化程度高（计算机控制）归类于产量高的部门有硫酸，含磷化合物，含氮化合物，氯碱及其相关化合物，加上石油化学品和商品聚合物（如聚乙烯）（生产部门）。除商品聚合物外，其它的均为重要的中间体，或基本化学品。这些基本化学品是其他许多化学品的生产原料，其他许多基本化学品的需求量很大。
相反，产量低的部门主要从事精细化学品的生产。单个化学品的年产量只有几十吨到几千吨。然而，与高产量的产品相比，这些产品单位重量具有很高的价值。通常，精细化斜坡的生产与间歇方式操作在工厂中，而且这些工厂常进行多种产品的生产。低产量生产部门生产农用化学品，染料，药品和特种聚合物（如聚醚醚酮）。
基础化学品在化学工业中得不到支持，它们不那么引人注意（如药品），有时候利润不很高。其利润来自于经济盛衰时难以预测的周期。
这些基本化学品不被公众注意到和直接使用，因此其重要性常得不到理解。即使在化学工业中，其重要性也得不到足够的重视。然而，如果没有这些基本化学品，其他工业就不复存在。
基本化学品处于原料（及那些从地下通过采矿、开采或用泵抽出来的物质）和最终产品的中间位置。
基本化学品的一个显著的特征就是它们的生产规模，每一种（基本化学品）的生产规模都相当大。图2-1表示在1993 年美国市场上的25 中化学品。（为了使我们了解化学品的分类与生产量有关。）通常，基本化学品生产于那些年产量上万吨的工厂。年产量10 万吨的工厂每小时要生产1.25 吨。基本化学品的另一显著重要的特征是其价格。大多数价格相当便宜。
基本化学品工业所作的工作（或任务）是找到经济的途径将原来转变为有用的中间体。生产厂家要对它们的产品收取较高的价格几乎没有余地，因此，那些最低费用生产产品的厂家可能获得的利润最高。这就意味着，厂家就必须不断准备寻求新的，更
总之，这些产品和石化工业的基本产物两者结合起来可生产无数重要的化学物质，这些重要的化学物质可作为其余化学工业的原料。
基本化学工业现在面临着其历史上中最大的挑战之一，该工业中的产品消费部门---农业以停止增长。同时大大减小了对肥料的需求。西方的农场主生产了大多的食物，政府减小了对农业部门的津贴，结果导致了更少的土地用于耕种和所需的肥料减少。过量肥料的流失而引起的环境的关注也减少了对肥料的需求。
诸如含氯化合物之类的产品，已收到了来自环境学家的压力。根据《关于消耗臭氧层物质的蒙特利尔白皮书》，一些产品将受到禁止。而其它的物质，可以受得住环境学家的压力。基本化学品工业再也不会依靠在需求量方面的长期增长。
为了实现更好的规模经济和某一特殊产品更好的市场地位，厂家相互交换工厂（车间），该工业注重不断合并联合。这使从事某一工业的人员减少，使该工业达到更好的供需平衡和更好的利润。基本化学品工业正逐渐转向为其他化学工业服务，而越来越小地为农业服务。
基本化学品受到的压力是许多大规模过程引起的（觉察得到的）较大的环境污染。尽管许多大厂家的生产效率较高，但是该工业要实现最好的环境标准还有很长的路要走。增加重复利用的驱动力和理想化的无排放的工厂，是影响接下来十年该工业发展的主要因素。
技术的进步不会停止，我们将日益重视无污染的工厂和过程。厂家将在效率上展开竞争。那些能以最低的成本生产最高质量产品的厂家将繁荣昌盛。这需要厂家在技术改进方面保持投资。基本化学品的合成有用的中间体的新颖方法将不断被人们发现。在基本化学品工业中，仍然还有许多工作有待去做。
Unit 6 Chlor-Alkali and Related Processes
氯碱及其相关过程
纵观历史，大众化学品工业在氯碱及其相关过程之上。该部分通常包括氯气、苛性苏打（氢氧化钠）
无水碳酸钠（以各种形式存在的碳酸钠的衍生物），以及以石灰为基础的产品。
自从无水碳酸钠和氢氧化钠的各种制备工艺发现以来，两者在作为碱为主要原料方面相互竞争。电解过程的特殊经济性意味着不管对氯气和氢氧化钠这两种不同类型的产品的相对需求量如何，你只有以固定的比例同时制备氯气和氢氧化钠。这引起了氢氧化钠的价格的摇摆不定，从而使得纯碱作为一种碱或多或
少有利。
氯气苛性苏打和纯碱的生产都取决于廉价易得的原料供应，前者的生产需要廉价的海水和电力的供应，而纯碱的生产需要海水、石灰和大量的能耗。纯碱厂只有在其原料不必要长距离的运输时才能赢利。
这些原料供应利用是影响化工企业位置分布的一个重要因素。
1. 石灰为基础的产品
一种关键（重要）原料是石灰石。石灰石主要是由CaCO3 组成，高质量的石灰石可直接用于下一步反应。石灰石通常在大型露天石矿中开采，许多采石矿也进行原料的一些处理。
从石灰石得到两种重要的产物：生石灰（CaO）和熟石灰水，生石灰是由石灰石根据该反应是热分解
（1200-1500℃）制备得到。
CaCO3 —— > CaO+ CO2
一般的，石灰石经过粉碎加入倾斜旋转窑的较高端，在此发生热分解反应，生石灰在另一端回收。
然而，通常生石灰用于进一步反应而分离，而加入其它化合物，与生石灰在窑的较低口处生成最低产品。
例如，加入铝矿、铁矿和沙石可生成硅酸盐水泥。纯碱的生产，通常要向生石灰加入焦炭，焦炭燃烧生成纯碱所需的CO2，熟石灰由生石灰和水的反应制造，较生石灰更加方便。
大约40%的石灰工业的产品用于钢铁制造业。在钢铁制造业中，纯碱用来与铁矿石中难溶解的硅酸盐反应，生成流态矿渣，矿渣漂浮于表面上，很容易从液态金属中分离，叫少量但重要的石灰工业的产品用于化学品的制造，污染控制和水处理。从石灰石得到的最重要的化学茶品是纯碱。
2. 纯碱
索尔维工艺，该工艺发现于1965 年由ES 优化：工艺是以当含氮的盐溶液经来自于石灰窑中焦炭燃烧产物CO2 碳酸盐反应时，NaHCO3 沉淀析出为基础。NaHCO3 经过滤、干燥、煅烧生成CaCO3。过滤后NH4Cl溶液和熟石灰反应后（溶液体呈碱性）。蒸馏出NH3 在该过程中循环利用，生成物CaCl2 是废弃物或副产物。
对于某一简单的基本产物来说，索尔维法看起来十分复杂。该反应的基本原理是，以NaCl2 和CaCO3为原料生成产物CaCl2 和Na2CO3.然而发生于原料和产物之间的反应并不明显，需要利用NH3 和Ca(OH)2作为中间化合物。
该过程的基本原理为：利用准确的控制组分（尤其是NH3 和NaCl）的浓度，NaHCO3 能够从含NaCl、CO2 和NH3 的溶液里沉淀析出。该过程的关键是控制溶液的酸碱强度和结晶的速度，该工艺的基本路线如
下，NH3 气于氨气吸收器中吸收于事先经纯化的海水中，纯化的海水以减小Ca+、Mg+离子的量。（Ca+、Mg+在生产过程中易产生沉淀而阻塞管道）。含NaCl 和NH4HCO3 的溶液经吸收了CO2 的吸收塔(CO2 气体量塔
底向上流) 开始时形成(NH4)2CO3 然后再生成NH4HCO3。
在工厂的下面步骤中，Nacl 和NH4HCO3 经复分解反应生成NaHCO3（以沉淀形式形成）和NH4Cl。
过滤将固体NaHCO3 从溶液中分离。将NaHCO3 送至旋转干燥器，在该干燥器中，NaHCO3 失去水和CO2后生成疏松的晶体块（即轻质纯碱）它的主要成分为Na2CO3 蓬松的晶体块很轻，是因为NaHCO3 失去CO2
后，留下很多空隙，而保留原来的晶体形状。通常要得到密度更大的物质很方便，加入水（水能引起咦密度较大的形式重结晶）进一步干燥即可实现。
值得争议的是，上述的化学知识是否为该过程的很好的描述，但这些只是肯定有助于理解过程。想要对此过程有详细的理解，必须要熟悉该组分体系中关于溶度积的很多知识。需要知道的重要知识是，该体
系是复杂体系，为了使该过程高效操作，需要对该过程每部分小心控制。
该过程的一个缺点是：产生的CaCl2 的量很大，其产生量比所需量大得多。因此，大部分CaCl2 只是简单的倒掉（CaCl2 毒性不大），如果能要该过程中的有的进料加以利用，那么该过程是有优势，例如，从该氯化物可产生HCl。
一类化学物质。硅酸是具有大表面积细小颗粒的Na2SO3，可用于催化剂、色谱之中，洗涤剂和肥皂中作为部分磷酸盐的替代品。
3. 生成Cl2/NaOH 的电解过程
简介，在化学工业法杖是的各个时期，Cl2 和NaOH 两者的需求量均很大，但是不幸的是，对于电化学工厂的操作人员来说，两者的需求量必总是相同。Cl2 可作为漂白粉或作为漂白粉的生产原料，水供应的消毒剂，以及作为塑料和溶解剂知道的原料。苛性钠用于生产纯碱、肥皂和纺织品，以及在多种化学过程中作为一种十分重要的原料。
所有的电解有着共同之处，盐的电解生成Cl2 和NaOH。大多数生产过程是电解（盐的）水溶液，但是有些重要的工厂，电解熔融盐生成Cl2 和液态钠。这些电解熔融盐的过程用用于重要液态Na 的工业。虽
然石油添加剂厂家多种多样，设会出现液态钠的其他用途，但是他的主要是用于生产四烷基铅石油添加剂。
实质上用于水溶液电解过程有三种不同的电解槽：水银槽、隔板槽和膜电解槽。膜电解槽只是用于此案在化工厂中新的生产过程，但是还存在着大量的旧生产过程，尽管说阴曹涉及到对环境的影响，但是许多生产厂家上位法此案膜片电解槽代替水印电解槽的经济性。
所有的电解反应都是以电子作为化学反应的试剂的观点为基础。设水电解过程的基本反应可写成下式：
阳极2Cl—— 2e-→ Cl2
阴极2H2O + 2e—→ H2 + 2OH—
总反应为2Na+ + 2Cl— + 2H2O→ NaOH + Cl2 + H2
该反应的自由能为正，因此，需要电驱使进行。
像其他许多化学品工艺一样，尽管该反应看起来似乎极其简单，但是有一些方面很复杂。首先，该反应的产物必须分开，如果H2 和Cl2 允许混合在一起，它们会剧烈反应。H2 和Cl2 反应生成HOCl 和氯化物
（两者均会浪费产物、生成副产物）。接着，HOCl 和次氯酸盐反应生成氯酸盐（ClO3
-）、质子和更多的氯化物。OH—在阳极区反应生成能污染Cl2 的O2。所有的这些反应可降低效率和（或）引起分解困难或污染
问题。因此，在产物销售之前，有必要对这些反应清理。理解各种用于电解过程的关键是各种类型的过程分离反应产物的方式。尽管不同的制造商所用的电解槽在细节方面有着多种改变，但是用于盐水的电解过程的电解槽基本可分为以上三类。
4、Cl2 和NaOH 的用途
NaOH 的用途之多，以致很难将它们方便地进行分类。最大的用途之一是用于造纸，造纸业中木材的处理需要强碱。有些国家造纸业中NaOH 的消耗占其产量的20%，另外的20%用于无机化学品（如，次氯酸钠、漂白粉和消毒剂）的生产。各种有机合成约消耗另外的15%，氧化铝和肥皂的生产需要少量的NaOH。
Cl2 广泛用于其它各种产品的生产。在全世界范围内大约有1/4 的Cl2 用于生产氯乙烯（生产PVC 的单体）。1/4 至1/2 的Cl2 用于水的纯化。尽管因为《关于消耗臭氧层物质的蒙特利议定书》多种溶剂正在被
逐步淘汰，但是仍有高达20%的氯气用于溶剂的生产（如甲基氯仿、三氯乙烯等）。全世界范围内，大约10%的Cl2 用于无机含氯的化合物的生产。尽管Cl2 用于漂白木材浆是来自环境压力的另一种途径，但是在一些国家Cl2 的十分重要的用途是用于木材浆的漂白。