Thermally Regenerative CO2-Induced pH-Gradient Cell for Waste-to-Energy Conversion

Abstract

Current primary energy generation systems produce a significant amount of waste CO2 and low-grade heat which consequently have a significant negative impact on the global climate and environment. In contrast to current carbon capture and storage (CCS) technologies which require external input energy or mass to extract and store the waste without efficient utilization, this study proposes a thermally regenerative CO2-induced pH-gradient cell (TRCPC) that simultaneously utilizes CO2 and low-grade heat for waste-to-electricity conversion. CO2 is absorbed in one side of the symmetric electrolyte and causes a change in pH of the cell to induce voltage generation, achieving a peak power density of 0.578 W m–2. After discharging, the system can be regenerated using low-grade heat while the CO2 can then be stored and transported. This research proposes a promising method with economic and environmental benefits that converts CO2 and waste heat into electricity before further CO2 storage.