镍基催化剂甲烷水重整反应速率的一个近似普适模型

摘要

甲烷水重整(methane steam reforming,MSR)反应速率是影响以甲烷为燃料的固体氧化物燃料电池(solid oxide fuel cell,SOFC)性能的一个重要因素.SOFC中最常用的MSR催化剂是镍(Ni).根据不同实验而提出的Ni催化MSR反应速率表达式差异很大,且实验都是在较高水碳比条件下开展,不能满足使用低水甲烷燃料的SOFC研究需要.系统总结了已知主要速率模型,归纳了其共性与差异性特征,并基于最近发现的低水甲烷MSR反应速率结果,提出了一个适宜任意水汽含量的统一的MSR速率半经验表达式.该模型可以解释不同实验得出不同水反应级数的貌似矛盾的结果,并可合理地拟合不同条件如不同水汽组分和不同工作温度下获得的实验数据.%Methane steam reforming (MSR) reaction rate is an important factor affecting the performance of methane fueled solid oxide fuel cell (SOFC).Ni is the most common catalyst for MSR in SOFC.There are large discrepancies in the Ni catalyzed MSR kinetic models proposed by different experiments.Moreover,the experiments for all the MSR kinetic models use methane with relatively high steam content,rendering the kinetic models unsuitable for the study of low steam methane fueled SOFCs.The major MSR kinetic models are surveyed here with the analysis of their similarities and differences.Based on the analysis and a new MSR kinetic model found for methane with low steam content,a unifying MSR kinetic model applicable for any steam content was deduced.The model is capable of explaining the confusion phenomenon that different steam reaction orders are observed by different experiments.It also provides good fits to the experimental data obtained under conditions such as different steam compositions and different working temperatures.