Structured Catalytic Membrane Reactor for Sustainable Hydrogen Production

“蓝氢”是一种清洁燃烧的氢气，来自化石资源，并与二氧化碳捕获和封存相结合，开发出可持续的途径，为世界提供了一座技术桥梁，连接了一个主要由煤炭、石油和天然气提供动力的世界，以及一个由太阳能和风能提供动力的世界。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和提高天然气产量。这一技术成本有效地利用了国内巨大的天然气资源，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。该项目的主题与休斯顿大学正在开展的活动相一致，这些活动旨在扩大休斯顿大学代表不足群体的学生在新兴领域的参与，这些领域包括天然气的分布式转换以及化工和能源行业的脱碳。休斯顿大学是一所为拉美裔、亚洲和太平洋岛民提供服务的机构。从事这一项目的学生将在能源转换期间在工业和学术界就业。该项目将解决在结构化催化膜反应器(SCMR)中耦合生成、分离和提纯氢气的基本膜、催化剂和反应器问题。该项目的目标是克服这项潜在突破性技术的两个基本障碍：(1)合成一种在较高的总压和温度下能够可靠地满足目标通量(0.01molH2/m2 S)和渗透选择性[H2/(CH4+CO2)100]的氢传输膜，以及(2)设计和开发一种紧凑的结构化催化膜反应器，它满足一系列进料成分和流速的体积生产率(10molH2/m3 S)和纯度(90%H2)的目标。多层催化膜反应器将催化层(Pt-Pd/Al_2O_3或Ni/Al_2O_3)与氢气选择微孔膜(CoO-SiO_2)相结合，两者都涂覆在导电、坚固的整体衬底(碳化硅)的多孔壁上，通过原位分离和提纯甲烷进行水蒸气重整。中心假设是，这样构成的催化膜反应器，通过原位脱氢，克服了水蒸气重整平衡的限制和动力学抑制，产生了作为低碳能量载体的纯氢渗透流，以及用于局部封存和提高产气量的加压CO2保留流。研究成果需要融合到一种在应用相关条件下具有渗透选择性、通量和弹性的可行组合的膜，以及一种具有将天然气重整与脱氢相结合的设计属性的膜反应器。该项目的范围包括膜合成和表征，包括膜渗透测量和实验室规模的反应器性能实验，同时还包括反应器分析和建模。项目成果将纳入正在开发的氢工艺和反应工程课程。拟议研究的几个方面有更广泛的应用，包括：(I)耦合催化反应和膜传输；(Ii)空间分辨浓度和温度测量；(Iii)具有吸热和放热耦合反应的反应堆的设计和控制；以及(Iv)模块化反应堆的分析和设计。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.