Optimized structural parameters and heat extraction capacity of a mixing device for constant pressure CO2 mineralization using alkaline waste.

Abstract

Alkaline waste such as calcium carbide slag is an ideal material for mineralizing CO2 and promoting atmospheric carbon reduction. In this study, the structural parameters of a mixing device and a thermal extraction method for the high-efficiency mineralization of CO2 using alkaline waste were optimized. First, the influence of structural parameters was studied by means of numerical simulation, and it was found that when the length-diameter ratio, blade angle, spacing, and diameter of the mixing device were 3, 15, 6 cm, and 14 cm respectively, 2.14 t CO2 can be mineralized within 1 h. The amount of heat extracted from mineralization of 1 t CO2 reached 189.60 MJ. In addition, the winding configuration of the heat pipe, which is beneficial for extracting more reaction heat, was optimal, and a model of the relationship between the heat pipe outlet water temperature and flow velocity at the outlet of the heat pipe was established. This study provides theoretical guidance for the field application of alkaline waste for high-efficiency mineralization of CO2, which can accelerate the realization of peak CO2 emissions and carbon neutrality.