Performance evaluation of integrated air pollution control with alkaline waste valorization via high-gravity technology

Abstract

Abstract In this study, a high-gravity process using alkaline wastes, i.e., petroleum coke fly ash, was proposed for integrated air pollution control, including nitrogen oxides, carbon dioxide and particulate matters. After the control process, the reacted fly ash can be further utilized as supplementary cementitious materials in cement mortar to realize a circular economy. The performance of air pollution control using petroleum coke fly ash in a high-gravity process was evaluated by on-site operations. The results indicated that the removal ratios of nitrogen oxides, carbon dioxide and particulate matters in the flue gas were approximately 99% (in the presence of ozone), 95% and 80%, respectively. In addition, the kinetics of carbon dioxide removal in the high-gravity process was analyzed by a surface coverage model. A high reaction rate constant of 0.27 mol/min/m2 was reached under a liquid-to-solid of 20 mL/g and a rotating speed of 1000 rpm at 20 °C. Furthermore, the performance of reacted fly ash used in blended cement mortar was evaluated. Compared with the pure Portland cement mortar, the compressive strength of cement mortar with reacted fly ash can be increased by 26%. Lastly, a preliminary economic analysis was conducted to estimate the costs and benefits from the process.