Structured Catalytic Membrane Reactor for Sustainable Hydrogen Production

开发可持续的“蓝色氢”途径，即从化石资源中提取清洁燃烧的氢气，并与二氧化碳捕获和封存相结合，为主要以煤炭、石油和天然气为动力的世界与以太阳能和风能为动力的世界之间架起一座技术桥梁。这项研究将推进位于天然气井的模块化技术，从天然气（甲烷）中提取氢气，同时实现二氧化碳封存并提高天然气产量。这项技术经济有效地利用了国内大量的天然气资源，同时最大限度地减少了温室气体的排放，加强了国家的能源安全，并加强了经济。休斯顿大学是一所面向西班牙裔、亚裔和太平洋岛民的服务机构，旨在扩大来自代表性不足群体的学生在天然气分布式转化、化学和能源工业脱碳等新兴领域的参与，该项目主题与正在进行的活动相一致。参与该项目的学生将在能源转型期间为工业界和学术界的就业做好准备。该项目将解决在结构催化膜反应器（SCMR）中耦合生成、分离和纯化H2的基本膜、催化剂和反应器问题。该项目的目标是克服这一潜在突破性技术的两个基本障碍：(1)在升高的总压和温度下合成H2运输膜，该膜可靠地满足目标通量（0.01 mol H2/m2 s）和超选择性[H2/(CH4+CO2) 100];(2)设计和开发一种紧凑的结构催化膜反应器，该反应器满足各种进料组成和流速下的体积生产率（10 mol H2/m3 s）和纯度（90% H2）目标。多层催化膜反应器将催化层（Pt-Pd/Al2O3或Ni/Al2O3）与H2透选微孔膜（CoO-SiO2）结合在一起，涂覆在导电、坚固的整体衬底（SiC）的多孔壁上，进行甲烷的蒸汽重整，并进行原位H2分离和纯化。核心假设是，这样构建的催化膜反应器通过原位脱除H2，克服了蒸汽重整平衡约束和动力学抑制，产生了作为低碳能源载体的纯化H2渗透流和用于局部封存和增强产气的加压CO2截留流。该研究成果要求将膜聚合为一种可行的膜，该膜在应用相关条件下具有pero选择性、通量和弹性的组合，并且具有将天然气重整与H2去除耦合的设计属性。项目范围涵盖膜合成和表征，包括膜渗透测量和实验规模反应器性能实验，以及反应器分析和建模。项目结果将被纳入正在开发的氢过程和反应工程课程。提出的几个方面的研究具有更广泛的应用，包括：(i)耦合催化反应和膜运输；（ii）空间分辨浓度和温度测量；（iii）设计和控制具有吸热和放热耦合反应的反应器；（四）模块化反应堆的分析与设计。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Development of sustainable routes to “blue hydrogen,” clean burning H2 that is derived from fossil sources and is combined with CO2 capture and sequestration, provides a technological bridge between a world mostly powered by coal, petroleum, and natural gas to one powered by solar and wind. This research will advance modular technology located at the natural gas well, extracting hydrogen from the natural gas (methane), while enabling CO2 sequestration and boosting natural gas production. This technology cost effectively utilizes the vast domestic natural gas resources while minimizing emissions of greenhouse gases, fortifying the nation’s energy security, and strengthening its economy. The project subject aligns with ongoing activities for broadening participation of students from underrepresented groups at the University of Houston, a serving institution for Hispanic, Asian, and Pacific Islanders, in the emerging fields of distributed conversion of natural gas and decarbonization of the chemical and energy industries. Students working on this project will be well positioned for employment in industry and academe during the energy transition.The project will address fundamental membrane, catalyst and reactor issues during coupled generation, separation, and purification of H2 in a structured catalytic membrane reactor (SCMR). The project goal is to overcome two fundamental barriers of this potentially breakthrough technology: (1) Synthesis of a H2 transport membrane that reliably meets target flux ( 0.01 mole H2/m2 s) and permselectivity [H2/(CH4+CO2) 100] at elevated total pressure and temperature, and (2) Design and development of a compact, structured catalytic membrane reactor that meets the targets for volumetric productivity (10 mol H2/m3 s) and purity (90% H2) for a range of feed compositions and flow rates. The multi-layer catalytic membrane reactor combines a catalytic layer (Pt-Pd/Al2O3 or Ni/Al2O3) with a H2 permselective microporous membrane (CoO-SiO2), both coated onto the porous walls of a conductive, robust monolith substrate (SiC), to carry out steam reforming of methane with in situ H2 separation and purification. The central hypothesis is that the catalytic membrane reactor, so constituted, overcomes steam reforming equilibrium constraints and kinetic inhibition through in situ H2 removal, producing a purified H2 permeate stream that serves as a low-carbon energy carrier, and a pressurized CO2 retentate stream for localized sequestration and enhanced gas production. The research deliverable entails convergence to a membrane that has a feasible combination of permselectivity, flux, and resilience under application-relevant conditions and a membrane reactor that has the design attributes to couple natural gas reforming with H2 removal. The project scope spans membrane synthesis and characterization, including membrane permeation measurements and bench-scale reactor performance experiments, in parallel with reactor analysis and modeling. Project findings will be incorporated into a course under development on hydrogen process and reaction engineering. Several aspects of the proposed research has broader application, including: (i) coupled catalytic reaction and membrane transport; (ii) spatially-resolved concentration and temperature measurements; (iii) design and control of reactors with coupled endothermic and exothermic reactions; and (iv) analysis and design of modular reactors.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.