化学工程与工艺专业英语_UNIT_1

化学工程与工艺专业英语授课班级： 化工05授课教师： 郎中敏学时： 32Unit 1 Chemical IndustryBefore reading the text below, try to answer following questions: 1。 When did the modern chemical industry start?  2 。 Can you give a definition for the chemical industry? 3 。 What are the contributions which the chemical industry has made to meet and satisfy our needs? 4 。 Is the chemical industry capital-or labor-intensive? Why?1。 Origins of the Chemical IndustryAlthough the use of chemicals dates back to the ancient civilizations, the evolution of what weknow as the modern chemical industry started much more recently。

It may be considered to havebegun during the Industrial Revolution, about 1800,and developed to provide chemicals for 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 of the first synthetic dyestuff—mauve。 At the start of the twentieth century the emphasis on research on the applied of chemistry in Germany had paid off handsomely, and by 1914 had resulted in the German chemical industry having75% 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 latter 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 War I in 1914。

This initiated profound changes which continued during the inter-war years(1918-1939)。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 chemicalssector due to the development and growth of the petrochemicals area since 1950。The explosivegrowth 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。

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。 Theses products are purchased because they have the required properties which make them suitable for some particular application, e。g。 a non-sick coating for pans or a weedkiller。 Thus chemicals are ultimately sold for the effects that they produce。2。 Definition of the Chemical IndustryAt the turn of the century there would have been little difficulty in defining what constitutedthe 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 thousands of chemicals are 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 convertedinto them。 The difficultly comes 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 example 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 or does it now belong in the decorating industry?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。3。 The Need for Chemical IndustryThe chemical industry is concerned with converting raw materials, such as crude oil, firstlyinto 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 products , help to maintain our well-being or even life itself。 At each stage of these operations value is added to the product and provided this added valueexceeds 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。It may seem strange in textbook like this one to pose the question “do we a chemical industry? ” However, trying to answer this question will provide (i) an indication f 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。