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首页> 外文学位 >THE STUDY OF THE METHANOL CONVERSION TO ETHYLENE AND PROPYLENE USING SMALL PORE SIZE ZEOLITES (DEHYDRATION, MIXING, KINETICS, COKING, DEACTIVATION).
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THE STUDY OF THE METHANOL CONVERSION TO ETHYLENE AND PROPYLENE USING SMALL PORE SIZE ZEOLITES (DEHYDRATION, MIXING, KINETICS, COKING, DEACTIVATION).

机译：用小孔径沸石（脱水，混合，动力学，焦化，失活）研究甲醇转化为乙烯和丙烯的方法。

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Olefins represent the starting point in the formation of the majority of the petrochemical products. The components can be polymerized, copolymerized, and selectively oxidized to a large number of useful products.; As crude oil and natural gas which are the conventional sources of olefins increase in price, unconventional sources such as coal and biomass become more attractive. Methanol can be readily produced from coal via synthesis gas, whereas coal represents a highly abundant and scarcely utilized raw material in the United States. In the short term a 60% carbon yield of methanol to olefins would allow methanol to displace naphtha feedstocks in Western Europe and Japan.; This project consisted of the study of the kinetics of the reaction of methanol to olefins. A combined selectivity to ethylene and propylene of 90% is readily achieved by selecting a proper set of operating conditions. The investigation encompassed the study of external and internal diffusion, adsorption and reaction.; Instantaneous and overall material balances were developed, and a minimization technique was used to calculate the rate of formation of coke, the amount of coke deposited on the catalyst, and the hydrogen to carbon ratio. This procedure allowed the adjustment of several parameters in order to satisfy the material balances. The results were used to calculate the rate constants of the proposed model.; The results indicated that the dehydration of methanol was inhibited by the adsorption of methanol. In general low methanol partial pressures, achieved by decreasing the total pressure in the case of pure methanol feeds, or by diluting methanol with water or nitrogen, increased the selectivity toward olefins.; All the catalysts studied showed deactivation due to the accumulation of aromatic compounds ("coke"), which had a hydrogen to carbon ration close to 1.1. The maximum amount of coke that can be deposited on the catalyst was about 0.16 grams coke/gram catalyst. The catalyst was regenerated by burning the coke with air.; Residence time distribution experiments using a step input change showed that perfect mixing could be obtained with 200 grams of powder catalyst of 30-100 microns particle size by using flow rates smaller than 5 cc/sec measured at reactor conditions, and impeller speeds higher than 12 rev/sec.
机译：烯烃代表大多数石化产品形成的起点。这些组分可以聚合，共聚和选择性氧化成大量有用的产物。随着作为常规烯烃来源的原油和天然气价格上涨，诸如煤炭和生物质之类的非常规来源变得更具吸引力。甲醇可以很容易地通过合成气从煤中生产，而煤在美国代表着高度丰富且很少使用的原材料。从短期来看，甲醇制烯烃的碳产率为60％，将使甲醇取代西欧和日本的石脑油原料。该项目包括对甲醇与烯烃反应动力学的研究。通过选择适当的一组操作条件，可以轻松实现对乙烯和丙烯的90％的组合选择性。该调查包括对内部和外部扩散，吸附和反应的研究。建立了瞬时的和整体的材料平衡，并使用最小化技术来计算焦炭的形成速率，沉积在催化剂上的焦炭量以及氢碳比。该程序允许调整几个参数以满足物料平衡。结果用于计算所提出模型的速率常数。结果表明甲醇的吸附抑制了甲醇的脱水。通常，通过降低纯甲醇进料中的总压力或通过用水或氮气稀释甲醇来实现较低的甲醇分压，会提高对烯烃的选择性。所有研究的催化剂均显示出由于芳族化合物（“焦炭”）的积聚而失活，该芳族化合物的氢与碳之比接近1.1。可以沉积在催化剂上的焦炭的最大量为约0.16克焦炭/克催化剂。通过用空气燃烧焦炭来再生催化剂。使用阶跃输入变化的停留时间分布实验表明，通过使用在反应器条件下测得的流速小于5 cc / sec的200克粒度为30-100微米的粉末催化剂，可以实现完美的混合转/秒

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