Parametric investigation and scale testing on accelerated CO2 sequestration of cement-based materials by utilizing industrial waste heat

Abstract

The increasing CO2 emissions from heavy industries have presented a growing threat to the global environment. The critical solution is to develop CO2 sequestration technologies, especially the fast speed CO2 fixation methods. In this study, the CO2 uptake performances of hydrated cement paste under various environment parameters coupling with high temperature were evaluated through accelerated carbonation experiments. The results show that high temperature is an effective way to improve CO2 sequestration efficiency, in which the waste heat accompanied by the emitted CO2 can be used as the source of high temperature. Based on this, appropriate vapor and liquid water addition during carbonation can further improve the CO2 sequestration performance of powder samples. Moreover, the hydration and carbonation products and the porosity before and after carbonation were evaluated, high temperature and vapor acceleration method facilitated aragonite generation and higher porosity reduction. Scale-up test of recycled aggregates on CO2 sequestration under optimum carbonation conditions was evaluated, and the results show the CO2 sequestration performance of recycled aggregates was stable in different input scales, which could sustain the CO2 sequestration amount of 80kg/t-cem.