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mooncakesun木虫 (著名写手)
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[求助]
帮忙翻译几句话
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帮忙翻译几句话！谢谢！ （3）对于苯加氢，适宜温度范围为120-210摄氏度，又因加氢反应是一个体积缩小的反应。因此，提高压力对反应有力，但由于高压系统的设备投资费、动力消耗费及保养维修费高。因此，对苯加氢一般要求0.5-1.0Mpa。 对苯加氢而言，液苯空速为0.2-1.0h，考虑到传热、工艺、生产平衡等因素，在通常情况下，其空速在0.4h左右，对其它不饱和有机物的加氢空速范围变化很大，一般为0.05-40h，应视具体条件及要求选择。 氢空速一般控制氢液比，对于苯加氢而言氢与苯的摩尔比为4.0-10，在通常情况下为3.5-6.而对于其他有机物加氢而言，氢与有机物的摩尔比一般为1-40：1. （4）原料和气体中有毒杂质对催化剂的影响 1）硫 原料中的硫及硫化物（如：H2S、COS、噻吩等）很容易与催化剂中的主活性成分镍化合，最简单的H2S中毒反应式为：（略）。有机硫化合物的分子愈大，其锚链效应也愈严重，对活性影响愈严重。因此，要求氢气中不含硫、物料中硫含量小于3ppm。 2）氯 氯对催化剂的毒害比硫大得多，约为数倍至数十倍。要求氢气中不含氯，原料中含氯量应小于0.5ppm。 3）油 油的来源往往出自循环机或压缩机上的润滑油。润滑油覆盖于催化剂内外表面上，并在催化剂工作条件下会逐步发生聚合、碳化等反应。这样不但造成催化剂有效表面的不断减小，而且还会造成催化剂床层阻力的不断上涨。同时，油中所含的硫等杂质使催化剂中毒。因此，必须采取有效措施，严防油带入催化剂层中。 4）氨 氨能可逆地吸附在镍上，占据活性中心，对催化剂活性不利。 5）水 水也能可逆地吸附在镍上，占据活性中心，对催化剂活性不利。 6）粉尘 它们覆盖在催化剂表面上，造成不利的影响。尤其是铁粉之类，还会引起副反应，因此，都必须严格控制。 工业应用情况：QC-4型苯加氢催化剂应用于中石油大连石化万吨级己烷脱苯装置上，可将己烷中含有1.5%（wt）的苯脱除至10ppm以下。 |
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chengcj.2008
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mooncakesun(金币+50,VIP+0):xiexie
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(3) For the hydrogenation of benzene, the suitable temperature range is 120-210 oC. higher pressure will contribute to the reaction because hydrogenation is a volume-decreasing process. However, considering expensive investment, power, maintenance comsumption for high pressure systems, hydrogenation pressure of benzene is usually 0.5-1.0Mpa. In the case of benzene hydrogenation, the rate of liquid benzene is 0.2-1.0h, and the rate is usually kept at around 0.4h in consideration of the factors such as heat transfer, processing, production balance. For the hydrogenation of other unsaturated organic compunds, the rate should be chosen according to the conditions, which can range from 0.05 to 40h. Hydrogen space velocity is usually obtained by controlling hydrogen liquid ration, and the molar ratio of hydrogen and benzene is 4.0-10.0 for benzene hydrogenation, and 3.5-6 is preferred. While the ratio is 1-40：1 for the hydrogenation of other organic compounds. (4) Effect of poisonous impurities in materials and gases on the catalyt 1) Sulfur Sulfur and sulfides （eg. H2S、COS、thiophene, etc.）in materials can easily bonded to the main active component nickel of the catalyst. The simplest poisonous reaction equation by H2S is : (omitted). The larger the molecular weights of organic sulfides are, the more serious the anchor effects are. So, hydrogen should not contain sulfur, and sulfur content in materials should be lower than 3ppm. 2) Chlorides Chlorides have severl to dozens-fold effect on catalyst than sulfur. Hydrogen should not contain chlorides, and chlorides content in materials should be lower than 0.5ppm. 3) Oil Oil usually stems from lubricating oil in recirculating machines and compression machines. The lubricating oil will cover surface of the catalyst, and pomerization as well as carbonization will occur under the catalyst working conditions, which will not only reduce the effective catalyst surface area, but increase the catalyst bed resistance. Furthermore, sulfur and other impurities in the oil can poison the catalyst. Therefore, effective measures must be taken to strictly prevent catalyst contamination by the oil. 4) Ammonia Ammonia can be reversably adsorbed on nickel and occupies the active sites, which has negative effect on the catalyst. 5) Water Water can also be reversably adsorbed on nickel and occupies the active sites, which has negative effect on the catalyst. 6) Dusts They cover the catalyst surface to negatively affect the catalyst. Especially for iron impurities, side reactions can occur. Hence, all dusts must be strictly controlled. Application in industries: QC-4 type benzene hydrogenation catalyst has been applied on the 10000-ton scale hexane debenzene equipments of Dalian petroleum chemical engineering, Petro-China, and 1.5%（wt）contents of benzene in hexane can be removed to a content lower than 10ppm. 花了半个下午, 总算完成了.  |
3楼2008-10-02 18:19:10
