This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Catalyst Sulfur Poisoning and Recovery Behaviors: Key for Designing Advanced Emission Control Systems
Technical Paper
2017-26-0133
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Advanced emission control systems for diesel engines usually include a combination of Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF), Selective Catalytic Reduction (SCR), and Ammonia Slip Catalyst (ASC). The performance of these catalysts individually, and of the aftertreatment system overall, is negatively affected by the presence of oxides of sulfur, originating from fuel and lubricant. In this paper, we illustrated some key aspects of sulfur interactions with the most commonly used types of catalysts in advanced aftertreatment systems. In particular, DOC can oxidize SO2 to SO3, collectively referred to as SOx, and store these sulfur containing species. The key functions of a DOC, such as the ability to oxidize NO and HC, are degraded upon SOx poisoning. The impact of sulfur poisoning on the catalytic functions of a DPF is qualitatively similar to DOC. Additionally, the amount and composition of SOx species has an impact on the total particulate matter amount at the tailpipe location of the system. The SO3-related particulates can’t be directly controlled by a DPF.
For Cu- or Fe- containing zeolite-based SCR catalysts, sulfur poisoning decreases their ability to convert NOx and NH3, especially at low temperatures. As shown in this paper, the deactivation depends on SOx concentration, SO3/SOx ratio, and temperature. The impact of upstream DOC on SCR performance is multifaceted, as on the one hand it generates SO3 which aggravates the SCR poisoning as compared to SO2 alone; but on the other hand DOC can bring NO2/NOx ratio in the feed gas to SCR closer to the optimum value, thus improving its efficiency even in a poisoned state. Finally, the impact of sulfur on the last catalyst element, ASC, represents a complex product of poisoning of its two major components - a Ptcontaining under-layer, and SCR-containing over-layer. In particular, oxidation of SO2 to SO3 on the Pt-layer degrades SCR-layer performance more severely, increasing selectivity towards undesired byproducts of NH3 oxidation such as NOx and N2O. Ultimately, all these individual features superimpose to produce the overall effect of sulfur species on an advanced SCR system.
Recommended Content
Authors
- Ashok Kumar - Cummins Inc
- Junhui Li - Cummins Inc
- Jinyong Luo - Cummins Inc
- Saurabh Joshi - Cummins Inc
- Aleksey Yezerets - Cummins Inc
- Krishna Kamasamudram - Cummins Inc
- Niklas Schmidt - Cummins Emission Solutions
- Khyati Pandya - Cummins India Ltd
- Prachetas Kale - Cummins India Ltd
- Thangaraj Mathuraiveeran - Cummins India Ltd
Citation
Kumar, A., Li, J., Luo, J., Joshi, S. et al., "Catalyst Sulfur Poisoning and Recovery Behaviors: Key for Designing Advanced Emission Control Systems," SAE Technical Paper 2017-26-0133, 2017, https://doi.org/10.4271/2017-26-0133.Also In
References
- Li, J., Kumar, A., Chen, X., Currier, N. et al., "Impact of Different Forms of Sulfur Poisoning on Diesel Oxidation Catalyst Performance," SAE Technical Paper 2013-01-0514, 2013, doi:10.4271/2013-01-0514.
- Hamzehlouyan T., Sampara C.S., Li J., Kumar A., Epling W.S., Kinetic study of adsorption and desorption of SO2 over γ-Al2O3 and Pt/γ-Al2O3, Applied Catalysis B: Environmental 181, 2016, 587-598
- Eastwood P., “Critical Topics in Exhaust Gas Aftertreatment”, Research Studies Press, 2000, Baldock, Hertfordshire, England
- Kumar A., Smith M.A., Kamasamudram K., Currier N.W., Yezerets A., “Chemical deSOx: An effective way to recover Cuzeolite SCR catalysts from sulfur poisoning”, Catalysis Today 267, 2016, 10-16
- Jangjou Y., Wang D., Kumar K., Li J., Epling W.S., "SO2 poisoning of the NH3-SCR reaction over Cu-SAPO-34: Impact of ammonium sulfate versus other S-containing species", ACS Catalysis, ACS Catalysis 6, 2016, 6612-6622
- Olsson L., Wijayanti K., Leistner K., Kumar A., et al., “A kinetic model for sulfur poisoning and regeneration of Cu/SSZ-13 used for NH3-SCR”, Applied Catalysis B: Environmental, 183, 2016, 394-406
- Smith, M., Kamasamudram, K., Szailer, T., Kumar, A. et al., "Impact of Sulfur-Oxides on the Ammonia Slip Catalyst Performance," SAE Technical Paper 2014-01-1545, 2014, doi:10.4271/2014-01-1545.
- Kumar A., Smith M.A., Kamasamudram K., Currier N.W., An H., Yezerets A., “Impact of different forms of feed sulfur on small-pore Cu-zeolite SCR catalyst”, Catalysis Today, 231, 2014, 75-82
- Matori K.A., Wah L.C., Hashim M., Ismail I., Zaid M.H.M., Phase Transformations of α-Alumina Made from Waste Aluminum via a Precipitation Technique, Int. J. Mol. Sci. 13, 2012, 16812-16821
- Kumar, A., Kamasamudram, K., Currier, N., and Yezerets, A., “Effect of Transition Metal Ion on the Catalytic Functions of Zeolite-Based SCR Catalysts and SOx Sorage / Removal”, SAE Technical Paper 2017, Offer Number 17PFL-1178.