Applications of Thermoelectric Generators To Improve Catalytic-Assisted Hydrogen Production Efficiency: Future Directions

Abstract

Current waste-heat recovery technologies (e.g., heat exchangers) for low-temperature reactor systems are not as efficient as they need to be for high-temperature industrial plants. However, thermoelectric generators (TEGs), enabling the capture of electricity from low-grade waste heat, are regarded as a potential solution. The current research aims to discuss the effectiveness of TEGs in enhancing the efficiency of catalyst-assisted methane conversion by boosting input electrical energy. By applying TEGs to a conventional methane cracking system, the catalytic reactions proceed more effectively as they employ the low-temperature waste heat byproduct of the system. Such an approach has not yet been investigated. The applications of TEGs are discussed and justified according to two mechanisms for activating the performance of catalysts: catalyst heat treatment and electroforming (i.e., the protonic effect). Accordingly, TEG-generated direct-current electrical heating not only reduces the preheating time but also activates the surfaces of catalysts. Furthermore, surface polarization caused by the applied electric field provides the proton conduction to facilitate methane cracking. This new and simple process may potentially capture low-grade waste heat and generate electricity for activating catalyst beds, thereby improving the efficiency of hydrogen production techniques.

Surface Chemistry and Band Engineering in AgSbSe2: Toward High Thermoelectric Performance

“…Thermoelectricity, providing direct interconversion between thermal and electrical energy, is a green technology with ample potential applications in the fields of self-powered devices for the Internet of Things (IoT), deep-space exploration, and solid-state refrigeration. , Besides, the use of medium-temperature thermoelectric (TE) devices has been also proposed for the recovery of heat from a plethora of sources, including combustion engine exhausts, , high temperature catalytic crackers, and furnaces, to cite just a few. However, to realize the mass-market potential applications of TE devices, their cost-effectiveness must be increased by improving the energy conversion efficiency and/or reducing production costs.…”

Thermocatalytic Decomposition of Methane: A Review on Carbon-Based Catalysts

“…Recent research results have been used to provide an insight into the catalytic capabilities of both commercial carbons (activated carbon, carbon black, carbon nanotubes, and metal-doped carbons) and noncommercial carbons (mesoporous carbons) toward the CDM reaction. − Carbon materials have proven advantageous as catalysts in energy conversion and storage technologies, such as electrochemical and photoelectrochemical conversions, conversions through biological routes, and pyrolysis of natural gas. − The use of carbon-based materials as catalysts has a long history, particularly to CDM in the recent past. Recently, various fascinating results in terms of the stability of catalyst and the yield of carbon nanomaterials have been reported in literature using carbon-based catalysts. − This Review thus lays emphasis on reaction conditions, sustained catalyst activity, product composition, and the nature of carbon formed over the carbonaceous materials. Compilation of the literature indicates the use of various carbon materials, such as activated carbon (AC), carbon black (CB), graphite, carbon nanotubes (CNTs), and ordered mesoporous carbons (OMCs) as potential catalysts for CDM.…”

“…The majority of literature on CDM focuses on the types of catalysts and reactors used for this reaction. ,, Often the published literature addresses different types of mono- and bimetallic catalysts on various templates, reporting the conversion and the types of carbon formed. − This Review, however, begins with discussing the reaction mechanism of CDM, followed by a summary of catalysts widely studied by researchers, with a specific focus on porous carbonaceous catalysts and templates. Recent research results have been used to provide an insight into the catalytic capabilities of both commercial carbons (activated carbon, carbon black, carbon nanotubes, and metal-doped carbons) and noncommercial carbons (mesoporous carbons) toward the CDM reaction. − Carbon materials have proven advantageous as catalysts in energy conversion and storage technologies, such as electrochemical and photoelectrochemical conversions, conversions through biological routes, and pyrolysis of natural gas. − The use of carbon-based materials as catalysts has a long history, particularly to CDM in the recent past. Recently, various fascinating results in terms of the stability of catalyst and the yield of carbon nanomaterials have been reported in literature using carbon-based catalysts. − This Review thus lays emphasis on reaction conditions, sustained catalyst activity, product composition, and the nature of carbon formed over the carbonaceous materials.…”

Numerical Investigation of the Transport Phenomena in Microchannel Steam Reforming Reactors for Hydrogen Production

“…In a steam reforming process, the factors influencing the choice of the fuel include the availability, cost, environmental footprint, existing infrastructure, and desired application. , Hydrogen production by steam reforming from alcohols is of great practical value. , Methanol is especially preferred, as the steam reforming reaction is preferably carried out at temperatures from 220 to 300 °C. , This enables excellent conversion into hydrogen at lower temperatures, thereby increasing the level of thermal efficiency. Additionally, the reaction can proceed over a broad range of pressures, therefore increasing the flexibility of reactor design. , Especially, very low levels of carbon monoxide are achievable, , which is of great importance in fuel cell applications.…”

“…In a steam reforming process, the factors influencing the choice of the fuel include the availability, cost, environmental footprint, existing infrastructure, and desired application. 15,16 Hydrogen production by steam reforming from alcohols is of great practical value. 17,18 Methanol is especially preferred, as the steam reforming reaction is preferably carried out at temperatures from 220 to 300 °C.…”