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小木虫论坛-学术科研互动平台 » 科研生活区 » 专业外语 » 计算模拟 » 化工专业英语考试求助
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chubin555

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[求助] 化工专业英语考试求助已有3人参与

2. Simultaneous absorption of H2S and CO2 from gaseous streams into an aqueous MEA solution using a packed bed pilot-scale contactor has been studied theoretically and experimentally. As a first conclusion, the packing size affects the relative absorption (selectivity) of CO2 and H2S in MEA solution as a new proposed structural parameter.
Smaller packing size leads to decrease in selectivity of H2S absorption. The results also show that, increasing of total pressure, which helps the diffusion steps in absorption, increases the H2S absorption selectivity and rate. It also could be seen that increasing L/G as a potential for liquid phase events, decreases the H2S absorption selectivity while increases the absolute rate of absorption. It is the same, when amine concentration is increased. Increasing the amine concentration, L/G and decreasing the packing size conceptually means the increase in absorption potential per bed volume which decreases the selectivity.（15 points）
3. Green Chemistry is the design, development, and implementation of chemical products and processes to reduce or eliminate the use and generation of substances hazardous to human health and the environment. Unlike regulatory requirements for pollution prevention, Green Chemistry is an innovative, non-regulatory, economically driven approach toward sustainability. Green Chemistry considers the entire life cycle of chemical processes as an opportunity for design innovation. Rather than regulatory restrictions for controlling hazards, Green Chemistry challenges innovators to design and
utilize matter and energy in a way that increases performance and value while protecting human health and the environment.（10points）
4. Diffusivity of chromate was taken from the literature. To test the effect of suspended solids on the rate of diffusion controlled corrosion of the impeller, porcelain particles were used. Particle size ranged from 0.3 to 0.7 mm while particle concentration ranged from 1% to 3% by volume. In order to test the effect of drag reducing polymers on the rate of diffusion controlled corrosion of the impeller, polyethylene oxide (polyox WSR-301) a product of Union Carbide was used in the form of suspension at concentrations of 200, 200, 400 and 500 ppm. The solid polymer powder has a density of
1.15±1.26 g/cm3, particle size ranged from less than 38 mm to larger than 500 mm. The polymer was used as received and no attempt was made to separate different sizes. The chemical stability of the polymer in acidified chromate was tested in separate experiments by adding polyox to acidified chromate solution (blank) for 1 h after which chromate concentration was determined, no change in chromate concentration was found to take place, i.e polyox is chemically stable in the solutions used in the present study. Rheological measurements showed that all polymer containing solutions were Newtonian; polymer addition in the form of solid particles to the blank solution was found to have a negligible effect on the physical properties of the solutions. Table 1 shows the physical properties of the solutions.（20points）
5. A common oxidative coupling reactor design has a fluidized bed, though many other designs are also being considered. In the reactor, methane (CH4) and oxygen react over a catalyst to form water and a methyl radical (CH3). This reaction is called partial oxidation of methane. The methyl radicals combine to form a higher alkane, mostly ethane (C2H6) which dehydrogenates into ethylene (C2H4). The function of the catalysts is to control the activity of oxygen ions so that reactions can be kept on the desired path. Complete oxidation (rapid formation of CO2 before the radicals link up to form ethane and ethylene) is an undesired reaction. The catalysts used are mostly oxides of alkali, alkaline earth and other rare earth metals. Hydrogen and steam are sometimes added to reduce coking on catalysts. After one pass, roughly 80% of the total oxygen feed by mass is consumed. Ideally, 100% is desired since oxygen is difficult to separate and can cause undesired combustion or even explosion. The per-pass ethylene yield on a mass basis of methane is about 30% due to low conversion and poor selectivity to ethylene. （15points）

Ⅱ. Translate the following paragraphs into English:
1. 从现代化工和高新技术发展的需求出发, 论述了化工分离技术的重要性、多样性和复杂性。分析了化工分离技术在新世纪所面临的新的机遇和挑战。并对当代化工分离技术的发展特点和我们的对策进行了探讨。（10points）
2. 对绿色化工催化剂的研究进展进行了综述, 主要介绍了固体酸催化剂、固体碱催化剂和金属催化剂的研究现状, 并对其应用和发展前景作了总结和评述。
关键词: 绿色化工催化剂; 固体酸催化剂; 固体碱催化剂; 金属催化剂（10points）
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liulion2008

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chubin555: 金币+20, ★★★★★最佳答案 2014-01-08 20:05:22
3.绿色化学是从设计、研发和生产等多角度同时考虑如何减少和消除能对人身健康和环境能造成危害的化学物质的产生和使用的工艺过程。与污染防治法律法规要求不同的是，绿色化学是一种创新性、经济利益驱动性和不带有法律强制性的可持续发展概念。绿色化学把化学品的整个生命周期作为设计革新的着眼点。与法律法规控制有害物质的目的不同，绿色化学在保护人身健康和环境的同时，就如何利用物质和能源创造更多效能和价值提出新型挑战。
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liulion2008

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hanches: 金币+2, 感谢应助，BB奖励~~~ 2014-01-09 08:50:52
2. Simultaneous absorption of H2S and CO2 from gaseous streams into an aqueous MEA solution using a packed bed pilot-scale contactor has been studied theoretically and experimentally. As a first conclusion, the packing size affects the relative absorption (selectivity) of CO2 and H2S in MEA solution as a new proposed structural parameter. 使用中试规模的带有填料床的吸收器，在MEA水溶液（作为填料）中同时从气态蒸气中吸收硫化氢和二氧化碳的工艺已经过理论和实践研究。第一个结论是填料床的大小会影响硫化氢和二氧化碳在MEA水溶液中的相对吸收（选择性）。因此填料床的大小就构成影响相对吸收的结构参数。
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2楼2014-01-08 14:01:04
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liulion2008

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chubin555: 金币+20 2014-01-08 20:05:29
Smaller packing size leads to decrease in selectivity of H2S absorption. The results also show that, increasing of total pressure, which helps the diffusion steps in absorption, increases the H2S absorption selectivity and rate. It also could be seen that increasing L/G as a potential for liquid phase events, decreases the H2S absorption selectivity while increases the absolute rate of absorption. It is the same, when amine concentration is increased. Increasing the amine concentration, L/G and decreasing the packing size conceptually means the increase in absorption potential per bed volume which decreases the selectivity.缩小填料床的大小会降低硫化氢吸收的选择性。试验结果还显示，增加气压可以改善气液结合，从而增加硫化氢的吸收选择性和速率。可以预见提升L/G（液气比）会使吸收选择性降低，但同时会提升吸收速率。提高MEA水溶液的浓度会产生相同的结果。因此，同时提高MEA水溶液的浓度、提升L/G（液气比）和缩小填料床的大小会提高填料床单位体积的吸收速率，也会降低吸收选择性。
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3楼2014-01-08 14:24:19
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chubin555: 金币+18 2014-01-08 20:05:34
5.通常氧化偶联反应釜都设计有一个流化床，虽然其他设计类型的反应釜也逐渐被认可。在这种反应釜内，甲烷和氧气在催化剂的作用下反应生成水和游离甲基。这种反应被称为甲烷的局部氧化反应。游离甲基相互结合生成更高等级烷烃，大多数乙烷脱氢生成乙烯。催化剂的作用就是控制氧离子的活动，使反应按照预期路线进行。完全氧化反应（在游离基团相互连接形成烷烃和烯烃之前，形成二氧化碳）不是预期的反应路线。常见的催化剂大多数是碱金属氧化物、碱土和其他稀土金属。反应过程中经常会通入氢气或水蒸气以减少催化剂焦化。一轮反应之后，按质量计算大约80%的氧气被反应消耗掉。理想状态是100%的氧气被消耗，因为残余氧气很难从最终产品中分离，还有可能造成燃烧或爆炸。粗略估计，按甲烷的质量分数计算，乙烯的收率是30%，主要原因是低转化率和（催化剂的）低选择性。
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