论文部分内容阅读
研究了甲烷在ＬＣ和ＳＬＣ催化剂体系上氧化偶联反应过程的热效应现象和反应气中添加ＣＯ２对催化剂反应行为的影响．在不使用稀释气的情况下，当反应温度由８７３升至９２３Ｋ时，反应活性存在一个突变点．这主要是由ＣＨ４燃烧反应放出大量热使催化剂床层的局部温度很高，形成一个局部过热区，因此引发甲烷氧化偶联．此即所谓热点温度效应，它严重影响催化剂活性评价结果的可靠性和重复性．在反应气中添加ＣＯ２对ＬＣ几乎无影响；由于ＳＬＣ中各组分与ＣＯ２作用生成碳酸盐，使催化剂表面氧浓度显著减少，导致催化剂的反应活性大大降低和严重失活．
The thermal effect of methane on the oxidative coupling reaction of LC and SLC catalyst systems and the effect of CO2 addition on the reaction behavior were investigated. Without the use of diluent gas, when the reaction temperature is increased from 873 to 923K, there is a mutation point in the reactivity. This is mainly due to the fact that a large amount of heat is released from the CH4 combustion reaction so that the local temperature of the catalyst bed is high, forming a local overheating zone, thus initiating the oxidative coupling of methane. The so-called hot spot temperature effect, which seriously affect the reliability of the catalyst activity evaluation and repeatability. Adding CO2 to the reaction gas has almost no effect on the LC. Since all the components in the SLC react with CO2 to form carbonate, the oxygen concentration on the surface of the catalyst is significantly reduced, which leads to the greatly decreased reactivity and serious inactivation of the catalyst.