吸附强化甲烷水蒸气重整制氢在颗粒和反应器尺度上的研究

Sorption-enhanced steam methane reforming (SESMR) is a promising technology for hydrogen production, in which the thermodynamic equilibrium toward hydrogen is favored through in situ CO2 removal by sorbents. SESMR shows advantages over conventional SMR, including decreased reaction temperature and integration of reaction and separation into one unit which greatly reduces the number of installations. Based on reaction kinetics, sorption kinetics and reactor model, the proposed project connects the design and preparation of catalysts and sorbents on the particle scale with the optimization of operation conditions on the reactor scale, aiming at systematically investigating the SESMR process both experimentally and theoretically. The proposed project mainly consists of three parts: first, to prepare Ru-Ni/Mg(Al)O catalysts and CaO-CaxAlyOx+1.5y sorbents and to control their compositions and structures, as well as to determine the structure-performance relationship of the catalysts and sorbents; second, to prepare multifunctional catalysts which combine catalyst and sorbent into one particle, and to control their compositions and structures, as well as to evaluate their performance; and third, to establish mathematical models for reaction kinetics, sorption kinetics as well as the SESMR reactor, and to optimize operation conditions of the reactor. The results obtained in this project are believed to provide fundamental and technical support for industrial application of the SESMR process.

吸附强化的甲烷水蒸气重整制氢技术利用吸附剂原位移走反应产物CO2，打破热力学平衡限制，既降低了反应温度，又集成反应和分离工序，减少了设备数量，比传统的甲烷水蒸气重整制氢方法更具优势。本项目以反应动力学、吸附动力学和反应器数学模型为纽带，将颗粒尺度上的催化剂和吸附剂的设计与制备同反应器尺度上的操作条件优化相联系，从实验和理论两方面对吸附强化重整制氢过程展开系统和深入的研究。本项目的研究内容主要包括：（1）制备Ru-Ni/Mg(Al)O催化剂和CaO?CaxAlyOx+1.5y吸附剂，调控催化剂和吸附剂的组成与结构，揭示催化剂和吸附剂的结构与性能关系；（2）制备催化剂和吸附剂集成的复合催化剂，调控复合催化剂的组成与结构并对其性能进行评价；（3）建立反应动力学、吸附动力学和反应器数学模型，优化反应器操作条件。本项目的研究成果将为吸附强化的甲烷水蒸气重整制氢技术的工业应用提供理论基础和技术支撑。

本项目以吸附强化甲烷水蒸气重整制氢反应体系（Sorption-Enhanced Steam Methane Reforming，SESMR）为背景，研究其中涉及的关键科学问题与技术问题，目的是揭示这些关键科学问题的本质，解决其中的关键技术问题，为SESMR的工业应用提供理论和技术支撑。项目的主要研究内容包括：采用共沉淀法制备得到了一系列Ni基非均相催化剂，研究了催化剂的构效关系和甲烷水蒸气重整制氢反应动力学；采用湿法混合法、金属醇盐溶胶-凝胶法和柠檬酸溶胶-凝胶法制备了一系列CaO-Ca9Al6O18和CaO-CaZrO3吸附剂，探究了吸附剂的构效关系和CO2吸附动力学；采用溶胶-凝胶法制备了Ni/CaO-Ca5Al6O14和Ni/CaO-CaZrO3双功能催化剂（反应活性位和吸附活性位均匀分布），以及核（吸附剂）-壳（催化剂）型催化剂CaO-Ca9Al6O18@Ca5Al6O14/Ni，研究了双功能催化剂的构效关系；建立了用于描述甲烷水蒸气重整工业反应器的数学模型，研究了催化剂颗粒形貌和反应操作条件的影响。通过上述研究，我们掌握了催化剂的组成和结构对SESMR制氢性能的调控规律，获得了适合SESMR的高效催化剂；掌握了吸附剂的组成和结构对CO2吸附性能的调控规律，获得了适合SESMR的高性能吸附剂；认识了复合催化剂的组成和结构与SESMR制氢性能的关系，确定了最适合SESMR的催化剂/吸附剂的使用方式（核（吸附剂）-壳（催化剂）结构）；确定了最优的催化剂颗粒形状（环形）和适宜的工业反应器进口温度和压力（500 ˚C和3 MPa）。截止目前，本项目一共发表了SCI/EI收录的论文11篇，包括AIChE J. (1篇)、Chem. Eng. Sci. (2篇)、Ind. Eng. Chem. Res. (2篇)、Appl. Catal. B: Environ. (1篇)、Catal. Today (1篇)、Chin. J. Chem. Eng. (2篇)、化工学报（2篇）；获得授权国家发明专利2项；入选2015年上海市优秀硕士学位论文1篇。