CO-Selective Catalytic Reduction of NO x in Fluid Catalytic Cracking Units and Applications of the Generated Exhaust Gas for Enhanced Shale Gas Recovery and Sequestration

Nitrogenoxides (NO x ) in fluid catalyticcracking (FCC) units, which are major atmospheric pollutants, arehazardous to the human body and environment. In this work, the CuO-CeO2 catalyst prepared by the co-precipitation method (CuCe-CPM)is applied in the CO-selective catalytic reduction (CO-SCR) reaction.NO and CO can be completely converted to exhaust gas, CO2 and N-2, in the temperature range of 600-700 & DEG;C.Subsequently, we propose a new method of application of the generatedexhaust gas, where the exhaust gas is employed to enhance shale gasrecovery and achieve sequestration within the shale reservoir. A seriesof comparisons of CH4 displacement efficiency and sequestrationcapacity of reaction gas (CO + NO) and generated waste gas (CO2 + N-2) in kerogen slit nanopores were performed.It is found that the displacement efficiency of CO2 + N-2 as the driving gas is higher than that of CO + NO withinthe formation depth from 0.33 to 3 km. The displacement efficiencyof CO2 + N-2 reached 70 and 76% when the reservoirdepths reached 1 and 3 km, respectively, with a pressure increaseof 30 MPa and a temperature increase of 54.6 & DEG;C during this period.The displacement process is dominated by the interaction between kerogenand driving gas. The sequestration capacity of CO2 + N-2 is slightly weaker than that of CO + NO, but direct CO2 + N-2 sequestration has the advantages of beingharmless and less corrosive and with fewer operational safety hazards.The proposed scheme may provide a feasible guide to the NO x treatment process and the application of the generatedexhaust gas from FCC units.

Automated summary

By using the CuO-CeO2 catalyst, the CO-selective catalytic reduction reaction can convert NO and CO into exhaust gas, CO2, and N-2. The displacement efficiency of CO2 + N-2 is higher than that of CO + NO, suggesting potential application in enhancing shale gas recovery. The scheme provides a feasible guide to NO x treatment and the utilization of exhaust gas from FCC units.