Recent advances in heighten sulfur resistance of SCR catalysts: A review

Abstract

NOx removal by selective catalytic reduction (SCR) technology is a research hotspot in the field of environmental catalysis, and this method is dominated by catalysts. However, denitrification catalyst is easy to be polluted by the presence of SO2, which seriously restricts its practical industrial application. This review focuses on the latest domestic and foreign research results and advancement in improving sulfur resistance of deNOx catalysts, reveals the sulfur poisoning mechanism and regeneration process, as well as introduces the positive role of quantum chemistry in the field of sulfur resistance. In view of the questions set forth in this review, the future development direction of deNOx catalysts is prospected, which provides valuable scientific guidance for the design and development of efficient and practical sulfur resistant deNOx catalysts.

Effect of Ultrasound Irradiation on the Properties and Sulfur Contents of Blended Very Low-Sulfur Fuel Oil (VLSFO)

“…The reasons could be explained by the change in rheological characteristics of the asphaltenes contained in RMG. Asphaltenes, which have a highly complex molecular structure, readily dissolve in aromatic compounds but do not dissolve in paraffin [7]. As asphaltenes in fuel oil stabilize in micellar form upon adsorption by resin [37,38], the saturation rate of aromatics that can dissolve the micelles is the critical parameter for stabilizing the asphaltenes [39].…”

“…The demand for VLSFO is expected to continue over the long term, as the adoption possibility of future regulations governing scrubber wash-water cannot be ruled out. Moreover, using VLSFO may also be beneficial in improving the efficiency of selective catalytic reduction [6], the only method of NO X emission reduction recognized by the IMO, as denitrification catalysts can be easily contaminated by SO 2 [7] and suffer from operational problems, such as sulfuric acid corrosion [8].…”

Strategy and Technical Progress of Recycling of Spent Vanadium–Titanium-Based Selective Catalytic Reduction Catalysts

“…This method has high deoxygenation efficiency (up to 80–90%) and high technology maturity. As the core of the technology, the SCR catalyst constitutes approximately 30–50% of the total de-NO x system investment. , Due to the complex flue gas environment, the SCR catalyst will be poisoned during long-term use, which results in a reduction in specific catalytic activity and affects its denitration efficiency. − Generally, the service life of denitration catalysts is three to five years, depending on the composition of the flue gas and the type of combustion system . The use of SCR technology is increasing, and the catalysts abandoned by denitration units have gradually become problematic.…”

Performance of an SCR Catalyst from Sintering Dust by the Hydrothermal Method and Its Water/Sulfur Resistance

“…Water vapor and sulfur dioxide (SO 2 ) are common contaminants in industrial flue gas, and their presence can lead to the formation of acidic compounds that can corrode and clog the catalyst surface, leading to a decline in its activity. Furthermore, the presence of water can interfere with the adsorption and reaction of ammonia (NH 3 ) on the catalyst surface, which is essential for the reduction of NO x . The challenge of using SCR catalysts is their susceptibility to poisoning by water and sulfur compounds, which can significantly reduce their efficiency and lifespan. , Therefore, the development of SCR catalysts from sintering dust with good water and sulfur resistance is critical for the successful implementation of this technology.…”