Abstract: CO₂ generated from coke combustion in fluid catalytic cracking (FCC) is the major process emission source of the FCC unit. Accurate accounting of its emissions is of great significance for carbon emission reduction management and control, carbon market compliance, and environmental protection compliance in refineries. This paper systematically constructs four types of accounting methods for CO₂ emissions from FCC coke combustion, conducts case verification combined with actual industrial operation data, carries out a comprehensive comparative analysis from multiple dimensions, and proposes an optimal strategy for engineering application. The results show that the direct accounting method based on flue gas composition features high precision and is suitable for daily unit monitoring and accurate accounting for carbon compliance; the coke-combustion-related accounting method balances precision and accuracy, making it a relatively practical approach in industrial applications; the catalyst carbon difference correlation accounting method can be used as an auxiliary verification means; and the unit carbon balance accounting method is applicable to macro estimation and the design stage. This study can provide theoretical support and engineering reference for the scientific accounting, precise management and control of CO₂ emissions from FCC coke combustion, as well as industrial carbon emission reduction.

Key words: catalytic cracking, carbon emissions, accounting method, carbon market compliance, coke combustion