Stacked etched aluminum flow-through membranes for methanol steam reforming

Zhu

ACS Appl. Mater. Interfaces

et al. 2020

A catalytic membrane microreactor is a potential tool for the application in multiphase catalytic reactions. Currently, the installation of a permeable ultrathin membrane to separate the reactants with different phases and the grafting of a catalyst layer on the membrane in a microreactor remain challenging. In this work, a catalytic ultrathin membrane microreactor with an ultrathin freestanding supporting membrane was developed for nitrobenzene hydrogenation, which was formed by the interfacial polycondensation reaction with parallel laminar flow in a microchannel, followed by catalyst layer immobilization on one side of the ultrathin membrane surface using the layer-by-layer selfassembly technique and in situ reduction. The ultrathin freestanding membrane ensured a stable gas/liquid contact interface and good hydrogen permeability. The developed membrane microreactor could exhibit high catalytic performance under mild conditions, demonstrating its superior mass transport. In addition, the effects of the thickness of the ultrathin freestanding membrane, flow rates, and inlet nitrobenzene concentration were investigated to obtain the optimum operating conditions. The experimental results demonstrate that this newly developed membrane microreactor is a promising candidate for multiphase catalytic reactions.

Section: Introductionmentioning

confidence: 99%

Catalytic Membrane Microreactors with an Ultrathin Freestanding Membrane for Nitrobenzene Hydrogenation

Zhu

ACS Appl. Mater. Interfaces

et al. 2020

“…When the MP structured catalyst (MPC) is lled into a gas-solid catalytic reactor, it is expected that the reactivity will improve because the reactant uid would be disarranged. Our research group is studying the process of producing hydrogen by steam reforming of methanol (SRM) (Hiramatsu et al, 2016(Hiramatsu et al, , 2017.…”

Section: Introductionmentioning

confidence: 99%

Proposal of Index for Reaction Improvement Using Structured Catalyst

Sasaki

Sakurai

2020

J. Chem. Eng. Japan

Self Cite

Micro-partition (MP; supplied by Nano Cube Japan Co., Ltd.) which is commercially available as a heat sink for precision electronic parts (and generally not as a catalyst support), was adopted as a structured catalyst support. The MP was made from aluminum; it was converted into an alumite catalyst as structured catalyst and applied for a gas-solid catalytic reaction. The MP has micro ns and holes; therefore, the reactivity was expected to improve because the reactant uid would be disarranged. In this research, we linked the disarrangement of the uid with the reactivity, analyzed the ow state of the reactants in detail, and evaluated its e ect on the reactivity. Experiments and a three-dimensional simulation were carried out to investigate the relationship between the structure and reactivity. Steam reforming of methanol was adopted as the model reaction. When the structured catalyst was used, the conversion increased by 80% at 553 K compared with that of a non-characteristic structured catalyst plate, and it was implied that the improvement in reactivity was better at lower temperature. The characteristic structure of the MP, not only the ns but also the holes signi cantly improved the reactivity. An analysis of the reaction rate showed that the contact frequency between the reactants and the catalyst increased. Furthermore, an index to evaluate the promotion of mass transfer was introduced when analyzing the mass transfer around the catalyst using dynamics simulation. The simulation showed that the structure promoted the mass transfer by convection, and a similar trend as the experiments was observed; the e ect of the structured catalyst was larger at lower temperature condition. The factor of the reactivity improvement by the structured catalyst became clear from the results of the experiments and simulation.

International Journal of Hydrogen Energy

“…The main benefit of the integration of a palladium membrane directly in a steam reformer would be that the produced hydrogen is directly removed from the reaction zone at ultra-high purity, while additional purification steps are not required. Selective membranes can be made of several materials such as silica gel, zeolite, high temperature organic thermoplastic polymers and other metals such as aluminum [39][40][41][42], however here we focus on dense metal membranes made of Pd-Ag alloys, being the kind of technology most mature and the most suitable for our purposes.…”

Section: Introductionmentioning

confidence: 99%

“…Many studies focus on the single component development for membrane reactors using several experimental or modeling techniques [39][40][41][42][48][49][50][51][52][53][54][55], however here we are interested in retrieving the performance of the whole energy system.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical modeling of an automotive derivative polymer electrolyte membrane fuel cell cogeneration system with selective membranes

Loreti

Facci

Peters

et al. 2019

Cogeneration power plants based on fuel cells are a promising technology to produce electric and thermal energy with reduced costs and environmental impact. The most mature fuel cell technology for this kind of applications are polymer electrolyte membrane fuel cells, which require high-purity hydrogen. The most common and least expensive way to produce hydrogen within today's energy infrastructure is through steam reforming of natural gas. Such a process produces a syngas rich in hydrogen that has to be purified to be properly used in low temperature fuel cells. However, the hydrogen production and purification processes strongly affect the performance, the cost, and the complexity of the whole energy system. Purification is usually performed through pressure swing adsorption, which is a semi-batch process that increases the plant complexity and incorporates a substantial efficiency penalty. A promising alternative option for hydrogen purification is the use of selective metal membranes that can be integrated in the reactors of the fuel processing plant. Such a membrane separation may improve the thermo-chemical performance of the energy system, while reducing the power plant complexity, and potentially its cost. Herein, we perform a technical analysis, through thermo-chemical models, to evaluate the integration of Pd-based H 2-selective membranes in different sections of the fuel processing plant: (i) steam reforming reactor, (ii) water gas shift reactor, (iii) at the outlet of the fuel processor as a separator device. The results show that a drastic fuel processing plant simplification is achievable by integrating the Pd-membranes in the water gas shift and reforming reactors. Moreover, the natural gas reforming membrane reactor yields significant efficiency improvements.