Hydrogen and syngas production from two-step steam reforming of methane using CeO2 as oxygen carrier

• 作 者: Xing Zhu Hua Wang Yonggang Wei
• 机 构: Engineering Research Center of Metallurgical Energy Conservation and Emission Reduction
• 出 处: 天然气化学（英文版）
• 发表日期: 2004年期
• 关键词: two-step steam reforming of methane CeO2 hydrogen syngas redox cycle
• 基金项目: This work was supported by the National Natural Science Foundation of China;云南省自然科学基金;The Research Foundation for the Doctoral Program of Higher Education of China;the Analysis and Test Foundation of

CeO2 oxygen carrier was prepared by precipitation method and tested by two-step steam reforming of methane (SRM). Two-step SRM for hydrogen and syngas generation is investigated in a fixed-bed reactor. Methane is directly converted to syngas at a H2/CO ratio close to 2: 1 at a high temperature (above 750 ℃) by the lattice oxygen of CeO2; methane cracking is found when the reduction degree of CeO2 was above 5.0% at 850 ℃ in methane isothermal reaction. CeO2-δ obtained from methane isothermal reaction can split water to generate CO-free hydrogen and renew its lattice oxygen at 700 ℃; simultaneously, deposited carbon is selectively oxidized to CO2 by steam following the reaction (C+2H2O→CO2+2H2). Slight deactivation in terms of amounts of desired products (syngas and hydrogen) is observed in ten repetitive two-step SRM process due to the carbon deposition on CeO2 surface as well as sintering of CeO2.