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丁烷选择氧化制顺酐VPO催化剂再氧化性能的研究
Reoxidation Performance of Vanadium Phosphorus Oxide Catalyst for Selective Oxidation of n-Butane to Maleic Anhydride
【作者】 潘向东;
【导师】 李成岳;
【作者基本信息】 北京化工大学 , 化学工艺, 2002, 硕士
【摘要】 VPO催化剂上丁烷选择氧化制顺酐是迄今唯一已经工业化的、非均相催化、低碳烷烃选择氧化制含氧化合物的反应,以丁烷选择氧化制顺酐体系为模型反应,采用热分析仪,固定床微型反应器、气相色谱、在线质谱等手段,对三种VPO催化剂,进行催化剂氧化再生动力学行为和定态反应特性研究,从中筛选出最适于非定态操作的催化剂,然后仔细研究其再氧化性能,优选人为非定态操作反应条件。 主要工作包括: 首先,建立了一种简单实用的气相色谱分析方法,改建一套适合定态反应性能评价的微型固定床反应器实验装置,对三种催化剂进行定态反应性能评价和比较。 其次,利用热分析仪,通过程序升温氧化(TPO)实验对催化剂氧化再生行为进行研究,结合定态性能评价结果,从中筛选出一种最适宜于人为非定态反应的催化剂。 第三,导出了VPO-1催化剂再氧化速率方程并用实验进行了判识,结果表明,氧化再生过程遵循相边界反应控制的收缩核模型, 北京化工大学硕士学位论文催化剂体相晶格氧扩散速率相对较快,对反应速率影响较小。 最后,通过进料组成周期性调变热分析实验和质谱在线动态响应检测,得到了催化剂质量和产物气组成周期性变化曲线,结果表明,REDOX循环是稳定的。
【Abstract】 The partial oxidation of n-butane to Maleic Anhydride (MA) over vanadium phosphorus oxide (VPO) catalyst is still the only heterogeneously catalyzed, alkane-selective oxidation reaction in commercial use.Three kinds of VPO catalysts, used to the model reaction system, n-butane oxidation to MA were investigated. By the means of thermogravimetric unit, fixed bed micro-reactor, on-line chromatographic and mass spectroscopy, oxidation regeneration kinetics and the performance of steady-state reaction were probed. The best catalyst suitable to forced unsteady-state reaction was distinguished.At first, a simple, and accurate GC analysis method and the method for processing experimental data were established for n-butane selective oxidation to MA. An experimental set-up was built for investigating the steady-state operation of fixed bed reactor. Under steady-state conditions, the performances of three kinds of the VPO catalysts were evaluated and compared each other.Secondly, the thermal oxidation regeneration process and its reaction kinetics were investigated by temperature-programmed-oxidation (TPO). The best catalyst suitable to forced unsteady-state reaction was distinguished, combining steady-state performance.Thirdly, re-oxidation rate equation was deduced and identified. The results show that the re-oxidation process of the catalyst obeys the contracted core model controlled by phase border, and the rate-controlling step is chemical reaction. A model of oxidation regeneration process for VPO catalyst is developed for simulation and prediction purposes.Finally, using TGA unit and on-line mass spectroscopy (MS) transient measurement in fixed bed micro-reactor, the modulation of feed composition transient response experiments were completed and the stability of REDOX cycle was also examined.
【Key words】 VPO catalyst; n-butane; oxidation regeneration; kinetics; forced unsteady state operation;
- 【网络出版投稿人】 北京化工大学 【网络出版年期】2005年 01期
- 【分类号】O643.3
- 【被引频次】1
- 【下载频次】195