An engineering-environmental-economic-energy assessment for integrated air pollutants reduction, CO2 capture and utilization exemplified by the high-gravity process

Abstract

In this study, a high-gravity (HiGee) process incorporating CO₂ and NO_x reduction from flue gas in a petrochemical plant coupled with petroleum coke fly ash (PCFA) treatment was established. The performance of HiGee was systematically evaluated from the engineering, environmental, economic, and energy aspects (a total of 15 key performance indicators) to establish the air pollution, energy efficiency, waste utilization nexus. The engineering performance was evaluated that lower energy consumption of 78 kWh/t-CO₂ can be achieved at a capture capacity of 600 kg CO₂/t-PCFA. A net emission reduction of 327.3 kg-CO₂/t-PCFA could be determined based on six environmental impact indicators. A cost-benefit analysis was conducted using operating cost, product sale, carbon credit, and savings in air pollution fees to present a better technological selection compared to existing carbon capture and storage plants. The waste heat recovery from the flue gas via the HiGee process could be measured via moisture condensation and attendant elimination of white smog emissions. Retrofitted heat recovery and energy intensity up to 131.8 kJ/t-PCFA and 0.21 kWh/t-PCFA were assessed. Finally, a comprehensive analysis of the HiGee process based on three daily load scenarios of CO₂ capture scale were conducted, suggesting an optimal operating condition of the HiGee for generating profitability.

Keywords: Comprehensive performance evaluation; Cost benefit analysis; Engineering performance; Environmental impacts; High-gravity process; Retrofit heat recovery.