Recent Developments in Compact Membrane Reactors with Hydrogen Separation

Abstract

Hydrogen production and storage in small and medium scale, and chemical heat storage from renewable energy, are of great interest nowadays. Micro-membrane reactors for reforming of methane, as well as for the dehydrogenation of liquid organic hydrogen carriers (LOHCs), have been developed. The systems consist of stacked plates with integrated palladium (Pd) membranes. As an alternative to rolled and electroless plated (Pd) membranes, the development of a cost-effective method for the fabrication of Pd membranes by suspension plasma spraying is presented.

Pd-Based Membranes: Overview and Perspectives

“…Moreover, membrane repair and protection strategies are introduced. In addition, Wunsch et al present an alternative cost-effective technique for metal-layer deposition by suspension plasma spraying, using supports composed of porous sinter metallic supports made of Crofer-22 APU deposited with a YSZ diffusion-barrier layer [ 6 ]. Advantages lie in the short time requirements for deposition, substrates do not have to be activated as in the case of electroless plating, and no metal-loaded liquid waste is produced.…”

“…Advantages lie in the short time requirements for deposition, substrates do not have to be activated as in the case of electroless plating, and no metal-loaded liquid waste is produced. Initial results were not satisfactory, however, since deposited layers had remaining open porosity, but work is ongoing [ 6 ].…”

“…Here, micro-membrane reactors that enhance heat management, reduce gas phase diffusion limitations, and increase the membrane area to reactor volume ratio compared to traditional tubular reactors are introduced [ 14 , 15 ]. The papers dealing with this topic are those of Wunsch et al, which report a number of aspects related to micro-membrane reactors, ranging from reactor configuration development, feasible and low-cost fabrication techniques of micro-membranes, and optimal coupling and integration of reactive and separating processes in single compact modules [ 6 , 16 ]. Specifically, Dittmeyer and colleagues at the Institute for Micro Process Engineering at the Karlsruhe Institute of Technology (KIT) have developed micro-membrane reactors composed of stacks of sub-modules including multiple reactive and permeative stages.…”

Manufacture, Applications, and Opportunities of Thin Film Palladium-Silver (PdAg) Alloys: A Review

“…A summary of the developments in the most recent literature (within the 12 months preceding publication) of PdAg films is presented. While the primary focuses of research remain as previously outlined: hydrogen-permeable membranes, [216][217][218][219][220] and sensors. 221 Advanced analytical methods have also been used to explore the properties and reactions of PdAg film.…”

“…218 Advancements in preparative technologies have also been investigated, including high-powered magnetron sputtering-based PVD methods, 219 and plasma methods. 220 Long-term studies investigating the performance of PdAg membranes over time have also been undertaken under varying reaction conditions, determining the maximum operational temperature of the materials for optimal longevity is 450 o C. 225 Spun-cast PdAg film sensors have been demonstrated as sensitive for the detection of E-coli bacteria in liquid media. 221 The reaction of hydrogen with PdAg films has been mechanistically explored using state-of-the-art ambient-pressure XPS analysis, providing additional insight into permittivity processes, 222 and computational simulations of such processes undertaken.…”