No 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.