Ceramic microreactors for on-site hydrogen production from high temperature steam reforming of propane.
Ceramic microreactors for on-site hydrogen production from high temperature steam reforming of propane.
复制标题
用于通过丙烷高温蒸汽重整现场制氢的陶瓷微反应器。
DOI：
10.1039/b607552e
复制
发表时间：
2006
期刊：
影响因子：
6.1
通讯作者：
P. Kenis
中科院分区：
文献类型：
--
作者：
M. Christian;P. Kenis
碳氢燃料的水蒸气重整制氢是一种很有前途的便携式电源氢气生产方法。然而，适用于这种应用的反应器必须与800摄氏度以上的温度兼容，以避免在重整过程中催化结构结焦。在这里，陶瓷微反应器由高比表面积、涂有Ru(Ru)催化剂的定制大孔碳化硅多孔整体组成，并集成在高密度氧化铝反应器外壳中，用于丙烷在800-1000℃之间的水蒸气重整制氢。我们通过研究C3H8转化率、H2选择性和产物流组成与总入口流量、汽碳比(S/C)和温度的函数来表征这些微反应器。当S/C为1.095，温度大于900℃时，从3.5sccm的C3H8进气中可得到18.2sccm H2，或3.3x104sccm H2/cm3的整体体积，在S/C接近1的条件下操作可以减少将多余蒸汽加热到反应温度所需的能量，并提高燃料处理器的整体热效率。动力学分析表明，丙烷和水蒸气的反应级数分别为0.50和-0.23，表明水蒸气重整反应的限速步骤是丙烷在Ru催化剂上的解离吸附。在高达1000℃的温度下进行15次以上的热循环后，微反应器的性能没有受到影响，在800℃下连续运行超过120h后，没有观察到催化剂失活，这使得这些陶瓷微反应器有望用于聚合物电解质膜(PEM)燃料电池的高效现场碳氢生产氢气。
The steam reforming of hydrocarbon fuels is a promising method for the production of hydrogen for portable electrical power sources. A suitable reactor for this application, however, must be compatible with temperatures above 800 degrees C to avoid coking of the catalytic structures during the reforming process. Here, ceramic microreactors comprising high surface area, tailored macroporous SiC porous monoliths coated with ruthenium (Ru) catalyst and integrated within high-density alumina reactor housings were used for the steam reforming of propane into hydrogen at temperatures between 800 and 1000 degrees C. We characterized these microreactors by studying C3H8 conversion, H2 selectivity, and product stream composition as a function of the total inlet flow rate, steam-to-carbon ratio (S/C), and temperature. As much as 18.2 sccm H2, or 3.3 x 104 sccm H2 per cm3 of monolith volume, was obtained from a 3.5 sccm entering stream of C3H8 at a S/C of 1.095 and temperatures greater than 900 degrees C. Operating at a S/C close to 1 reduces the energy required to heat excess steam to the reaction temperature and improves the overall thermal efficiency of the fuel processor. Kinetic analysis using a power law model showed reaction orders of 0.50 and -0.23 with respect to propane and steam, respectively, indicating that the rate limiting step in the steam reforming reaction is the dissociative adsorption of propane on the Ru catalyst. The performance of the microreactor was not affected after exposure to more than 15 thermal cycles at temperatures as high as 1000 degrees C, and no catalyst deactivation was observed after more than 120 h of continuous operation at 800 degrees C, making these ceramic microreactors promising for efficient on-site hydrogen production from hydrocarbons for use in polymer electrolyte membrane (PEM) fuel cells.