The fluid catalytic cracking (FCC) process is one of the most important oil refining processes, in which heavy oil is converted to light fractions. The FCC catalyst regeneration generates flue gas containing SO2, NOx and particulates, and treatment before discharge is required to meet the emission regulations. The integrated FCC flue gas treatment technology offered by JNEP seamlessly integrates state-of-the-art SO2, NOx and PM control technologies, and provides an efficient and cost-effective solution to FCC flue gas treatment requirements.
Flue gas from the FCC catalyst regeneration process recovers thermal energy through an expander and waste heat boiler before entering the SCR (Selective Catalytic Reduction) reactor at a specified temperature. In the presence of the SCR catalyst, NOx in the flue gas reacts with ammonia and produces N2 and H2O. After NOx removal the flue gas is fed into the pre-scrubber to remove particulates and then to the ammonia absorber to remove SO2. After the cooling, scrubbing, absorption and demising steps, the clean flue gas is discharged from the stack. Ammonium sulfite/bisulfite, the product from the reaction between SO2 and NH3, is further refined through oxidation, concentration, crystallization and solid-liquid separation to produce ammonium sulfate fertilizer.
The typical FCC flue gas treatment process is SCR for NOx removal and a caustic scrubbing process for SO2 and PM removal. Compared to the conventional process, JNEP’s IFGT technology saves 20% to 40% of the capital cost and more than 10% of the operating cost while achieving the same air pollutant control efficiency (NOx emissions ≤ 100 mg/Nm3, SO2 emissions ≤ 50 mg/Nm3, PM emissions ≤ 30 mg/Nm3). Besides, the system generates no waste water.
NOx emissions ≤ 100 mg/Nm3
SO2 emissions ≤ 50 mg/Nm3
PM emissions ≤ 30 mg/Nm3