化工专业英语Lesson 6.doc

Lesson 6 AmmoniaAl Dinitrogen makes up more than three-quarters of the air we breathe , but it is not readily available for further chemical use.在我们呼吸的空气中，有超过3/4是氮气，但是要进一步的化学应用并不简单2 Biological transformation of nitrogen into useful chemicals is embarrassing for the chemical industry, since all the effort of all the industry's technologists has been unable to find an easy alternative to this. 对于化学工业来说，利用牛物转化法将氮气转化为有用的化学产品是很困难的，因为所有工厂的技 术专家做了很多努力也没有找到一个容易的方法3 Leguminous plants can take nitrogen from the air and convert it into ammonia and ammonium-containing products at atmosphere pressure and ambient temperature;豆科植物可以在大气压和常温下将空气中的氮转化为氨和含有钱基的物质。

4 despite a hundred years of effort ,the chemical industry still needs high temperatures and pressures of hundreds of atmospheres to do the same job.但是对于化学工业，尽管经过了一百多年的努力，要完成相同的工作，仍需要高温和高出大气压几 百倍的高压5 Indeed, until the invention of the Haber process, all nitrogen-containing chemicals came from mineral sources ultimately derived from biological activity.实际上，在哈伯博斯制氨法发明之前，所有含氮的化学产品是从矿物中提取出来的，最终通过牛物 方法得到Bl Essentially all the nitrogen in manufactured chemicals comes from ammonia derived from the Haber-based process.本质上而言，所有已制备的化学产品中的氮都来自于哈伯博斯制氨法制备的氨。

2 So much ammonia is made (more molecules than any other compound, though because it is a light molecule greater weights of other products are produced), and so energy-intensive is the process, that ammonia production alone was estimated to use 3% of the World's energy supply in the mid-1980s.制备大量的氨(由于氨分子较轻，因此尽管牛产的其它产品的量更大，但氨的分子数要多于其他任 何化合物)，需要在过程中消耗大量的能源，在20世纪80年代中期，牛产氨产品消耗的能源约占世 界能源供给的3%C The Haber Process For Ammonia Synthesis氨合成中的哈伯博斯制氨法1 Introduction. All methods for making ammonia are basically fine-tuned versions of the process developed by Haber, Nernst and Bosch in Germany just before the First War.介绍。

哈伯、能斯特和波希于一战前在德国开发出了哈伯工艺，现在所有的合成氨方法基本工艺都 是以该法为基础、再稍微加以改变的N2+3H2=2NH3DI In principle the reaction between hydrogen and nitrogen is easy; it is exothermic and the equilibrium lies to the right at low temperatures.从理论上来讲，氢气和氮气的反应很简单，反应是放热的，在低温吋，平衡向右移动2 Unfortunately, nature has bestowed dinitrogen with an inconveniently strong triple bond, enabling the molecule to thumb its nose at thermodynamics.不幸的是，自然赠与了氮分子强烈的三键结合，使该分子不易受热力学因素的影响3 In scientific terms the molecule is kinetically inert ,and rather severe reaction conditions are necessary to get reactions to proceed at a respectable rate.用科学术语来说，该分子是动力学惰性的，因此，要使该反应以一定的速度进行，需要相当苛刻的 反应条件。

4 A major source of “fixed" (meaning, paradoxically，“ usefully reactive^) nitrogen in nature is lightning, where the intense heat is sufficient to create nitrogen oxides from nitrogen and oxygen.自然界中“固定”(与“有效的活动性”相反)氮的一个主要的来源是闪电，巨大的热量使氮气和氧 气牛成氮的氧化物El To get a respectable yield of ammonia in a chemical plant we need to use a catalyst.在化工厂里，为了得到氨的可观的产量，我们需要使用催化剂2 What Haber discovered-and it won him a Noble prize-was that some iron compounds were acceptable catalysts.哈伯发现一些铁的化合物可以做催化剂，这使他获得了诺贝尔奖3 Even with such catalysts extreme pressures (up to 600 atmospheres in early processes) and temperatures (perhaps 400 °C) are necessary.但是，即使有这些催化剂，这个反应仍然需要很高的压力(在早期的工艺中高达600个大气压)和 高温(大约400°C)oFl Pressure drives the equilibrium forward, as four molecules of gas are being transformed into two. 由于四个气体分子转化为两个气体分子，所以增加压力使平衡向右移动。

2 Higher temperatures, however, drive the equilibrium the wrong way, though they do make the reaction faster, chosen conditions must be a compromise that gives an acceptable conversion at a reasonable speed. 虽然高温可以加快反应速度，但它使平衡向反向移动，因此，所选的条件必须要适当，从而使反应 在合理的速率下有令人满意的转化率3 The precise choice will depend on other economic factors and the details of the catalyst・ 反应条件的准确选择将取决于其他的经济因素和催化剂的具体情况4 Modern plants have tended to operate at lower pressures and higher temperatures (recycling unconverted material) than the nearer-ideal early plants, since the capital and energy casts have become more significant.现代工厂已倾向于在更低压和更高温下操作(回收没有转化的材料)，因为投资费用和能量费用已变 得更为重要。

G1 Biological fixation also uses a catalyst which contains molybdenum (or vanadium) and iron embedded in a very large protein, the detailed structure of which eluded chemists until late 1992.氮的牛物固定也要使用催化剂，催化剂是将钳(或这飢)和铁嵌入巨大的蛋白质中，细微的结构困 扰着化学家直到1992后期2 How it works is still not understood in detail.它是如何起作用的直到现在也没有完全弄明白Hl Raw Materials. The process requires several inputs: energy, nitrogen and hydrogen.原料过程中需要的原料有：能量、氮气和氢气2 Nitrogen is easy to extract from air, but hydrogen is another problem・氮气很容易从空气中提取，但氢气是一个问题。

3 Originally it was derived from coal via coke which can be used as a raw material (basically a source of carbon) in steam reforming, where steam is reacted with carbon to give hydrogen, carbon monoxide and carbon dioxide.最初，氢气是从煤中得到的，将焦炭作为一•种原材料(碳的一种基本的來源)在水蒸汽中转化，水 蒸气和碳反应牛成氢气、一氧化碳和二氧化碳4 Now natural gas (mainly methane) is used instead, though other hydrocarbons from oil can also be used. 现在由天然气代替(主要成分是甲烷)，也可以用石油中的其他碳氢化合物。