Utilizations of reaction exothermic heat to compensate the cost of the permanent CO2 sequestration through the geological mineral CO2 carbonation

Abstract

Many climate change events drive global efforts on CO2 sequestration to reach carbon neutrality. With the help of chemical processes, the novel “geological mineral CO2 carbonation” procedure makes it possible to sequester CO2 quickly and then store it permanently as stable carbonates. The exothermic nature of the mineral carbonation reaction can potentially compensate for the energy consumption during CO2 sequestration. This study mainly addresses a two-dimensional model of the geological mineral CO2 carbonation (herein, the geological formation of peridotite), by which the effects of temperature conditions on the reaction rate and the quantity of the sequestrated CO2 and exothermic heat energy are discussed. Results reveal a typical case of the average temperature elevation of peridotite by over 55 °C (reaching 240 °C) after 2 years. Peridotite's average CO2 sequestration rate in this typical case can achieve 132.62 kg/(year·m³). By changing the injected fluid temperature and the initial peridotite temperature to 110–150 °C, the average CO2 sequestration rate can be increased by 33–43%, obtaining a temperature greater than 150 °C. This heat production from the geological mineral CO2 carbonation can profitably compensate for the energy consumption in the Carbon Capture, Utilization, and Storage projects via the geological mineral CO2 carbonation.