Autothermal reforming of ethanol in dense oxygen permeation membrane reactor

Thermodynamic Assessment of a Solar-Driven Integrated Membrane Reactor for Ethanol Steam Reforming

To efficiently convert and utilize intermittent solar energy, a novel solar-driven ethanol steam reforming (ESR) system integrated with a membrane reactor is proposed. It has the potential to convert low-grade solar thermal energy into high energy level chemical energy. Driven by chemical potential, hydrogen permeation membranes (HPM) can separate the generated hydrogen and shift the ESR equilibrium forward to increase conversion and thermodynamic efficiency. The thermodynamic and environmental performances are analyzed via numerical simulation under a reaction temperature range of 100-400 °C with permeate pressures of 0.01-0.75 bar. The highest theoretical conversion rate is 98.3% at 100 °C and 0.01 bar, while the highest first-law efficiency, solar-to-fuel efficiency, and exergy efficiency are 82.3%, 45.3%, and 70.4% at 215 °C and 0.20 bar. The standard coal saving rate (SCSR) and carbon dioxide reduction rate (CDRR) are maximums of 101 g·m-2·h-1 and 247 g·m-2·h-1 at 200 °C and 0.20 bar with a hydrogen generation rate of 22.4 mol·m-2·h-1. This study illustrates the feasibility of solar-driven ESR integrated with a membrane reactor and distinguishes a novel approach for distributed hydrogen generation and solar energy utilization and upgradation.

Catalytic mixed conducting ceramic membrane reactors for methane conversion

Schematic of catalytic mixed conducting ceramic membrane reactors for various reactions: (a) O₂ permeable ceramic membrane reactor; (b) H₂ permeable ceramic membrane reactor; (c) CO₂ permeable ceramic membrane reactor.

Recent advances in membrane reactors for hydrogen production by steam reforming of ethanol as a renewable resource

During the last decade, hydrogen has attracted lots of interest due to its potential as an energy carrier. Ethanol is one of the renewable resources that can be considered as a sustainable candidate for hydrogen generation. In this regard, producing hydrogen from ethanol steam reforming (ESR) would be an environmentally friendly process. Commonly, ESR is performed in packed bed reactors; however, this process needs several stages for hydrogen separation with desired purity. Recently, the concept of a membrane reactor, an attractive device integrating catalytic reactions and separation processes in a single unit, has allowed obtaining a smaller reactor volume, higher conversion degrees, and higher hydrogen yield in comparison to conventional reactors. This paper deals with recent advances in ESR in terms of catalyst utilization and the fundamental of membranes. The main part of this paper discusses the performance of different membrane reactor configurations, mainly packed bed membrane reactors, fluidized bed membrane reactors, and micro-membrane reactors. In addition, a short overview is given about the impact of ESR via different catalysts such as noble metal, non-noble metal, and bi-metallic catalysts.