Performance Degradation and Poison Build-Up of an Oxidation Catalyst in Two-Stroke Natural Gas Engine Exhaust

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Marc E. Baumgardner ◽  
Daniel B. Olsen
Keyword(s):  
Natural Gas ◽  
Photoelectron Spectroscopy ◽  
Catalyst Deactivation ◽  
Catalyst Surface ◽  
Oxidation Catalyst ◽  
Lean Burn ◽  
Gas Field ◽  
X Ray ◽  
Engine Testing ◽  
Carry Over

Due to current and future exhaust emissions regulations, oxidation catalysts are increasingly being added to the exhaust streams of large-bore, two-stroke, natural gas engines. Such catalysts have a limited operational lifetime, primarily due to chemical (i.e., catalyst poisoning) and mechanical fouling resulting from the carry-over of lubrication oil from the cylinders. It is critical for users and catalyst developers to understand the nature and rate of catalyst deactivation under these circumstances. This study examines the degradation of an exhaust oxidation catalyst on a large-bore, two-stroke, lean-burn, natural gas field engine over the course of 2 years. Specifically, this work examines the process by which the catalyst was aged and tested and presents a timeline of catalyst degradation under commercially relevant circumstances. The catalyst was aged in the field for 2-month intervals in the exhaust slipstream of a GMVH-12 engine and intermittently brought back to Colorado State University for both engine testing and catalyst surface analysis. Engine testing consisted of measuring catalyst reduction efficiency as a function of temperature as well as the determination of the light-off temperature for several exhaust components. The catalyst surface was analyzed via scanning electron microscope (SEM)/energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) techniques to examine the location and rate of poison deposition. After 2 years online, the catalyst light-off temperature had increased ∼55 °F (31 °C) and ∼34 wt % poisons (S, P, Zn) were built up on the catalyst surface, both of which represent significant catalyst deactivation.

Poison Build-up and Performance Degradation of an Oxidation Catalyst in 2-Stroke Natural Gas Engine Exhaust

2017 ◽  
Author(s):  
Marc E. Baumgardner ◽  
Daniel B. Olsen
Keyword(s):  
Natural Gas ◽  
Catalyst Deactivation ◽  
Catalyst Surface ◽  
Oxidation Catalyst ◽  
Lean Burn ◽  
Gas Field ◽  
Natural Gas Engines ◽  
Engine Testing ◽  
And Performance ◽  
Carry Over

Due to current and future exhaust emissions regulations, oxidation catalysts are increasingly being added to the exhaust streams of large-bore, 2-stroke, natural gas engines. Such catalysts have been found to have a limited operational lifetime, primarily due to chemical (i.e. catalyst poisoning) and mechanical fouling resulting from the carry-over of lubrication oil from the cylinders. It is critical for users and catalyst developers to understand the nature and rate of catalyst deactivation under these circumstances. This study examines the degradation of an exhaust oxidation catalyst on a large-bore, 2-stroke, lean-burn, natural gas field engine over the course of 2 years. Specifically this work examines the process by which the catalyst was aged and tested and presents a timeline of catalyst degradation under commercially relevant circumstances. The catalyst was aged in the field for 2 month intervals in the exhaust slipstream of a GMVH-12 engine and intermittently brought back to the Colorado State Engines and Energy Conversion Laboratory for both engine testing and catalyst surface analysis. Engine testing consisted of measuring catalyst reduction efficiency as a function of temperature as well as the determination of the light-off temperature for several exhaust components. The catalyst surface was analyzed via SEM/EDS and XPS techniques to examine the location and rate of poison deposition. After 2 years on-line the catalyst light-off temperature had increased ∼55°F (31°C) and ∼34 wt% poisons (S, P, Zn) were built up on the catalyst surface, both of which represent significant catalyst deactivation.

scholarly journals Microstructural Characteristics of Vehicle-Aged Heavy-Duty Diesel Oxidation Catalyst and Natural Gas Three-Way Catalyst

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 137 ◽  
Author(s):  
Tomi Kanerva ◽  
Mari Honkanen ◽  
Tanja Kolli ◽  
Olli Heikkinen ◽  
Kauko Kallinen ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Natural Gas ◽  
Photoelectron Spectroscopy ◽  
Real Life ◽  
Diesel Oxidation Catalyst ◽  
Oxidation Catalyst ◽  
Heavy Duty ◽  
X Ray ◽  
Ageing Effects ◽  
Diesel Oxidation

Techniques to control vehicle engine emissions have been under increasing need for development during the last few years in the more and more strictly regulated society. In this study, vehicle-aged heavy-duty catalysts from diesel and natural gas engines were analyzed using a cross-sectional electron microscopy method with both a scanning electron microscope and a transmission electron microscope. Also, additional supporting characterization methods including X-ray diffractometry, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy and catalytic performance analyses were used to reveal the ageing effects. Structural and elemental investigations were performed on these samples, and the effect of real-life ageing of the catalyst was studied in comparison with fresh catalyst samples. In the real-life use of two different catalysts, the poison penetration varied greatly depending on the engine and fuel at hand: the diesel oxidation catalyst appeared to suffer more thorough changes than the natural gas catalyst, which was affected only in the inlet part of the catalyst. The most common poison, sulphur, in the diesel oxidation catalyst was connected to cerium-rich areas. On the other hand, the severities of the ageing effects were more pronounced in the natural gas catalyst, with heavy structural changes in the washcoat and high concentrations of poisons, mainly zinc, phosphorus and silicon, on the surface of the inlet part.

scholarly journals Hydrothermal Aging of Pd/LTA Monolithic Catalyst for Complete CH4 Oxidation

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 517 ◽  
Author(s):  
Ida Friberg ◽  
Aiyong Wang ◽  
Louise Olsson
Keyword(s):  
Water Vapor ◽  
Catalyst Deactivation ◽  
Oxidation Catalyst ◽  
X Ray Diffraction ◽  
Ch4 Oxidation ◽  
Hydrothermal Aging ◽  
Oxidation Activity ◽  
X Ray ◽  
Lta Zeolite ◽  
Surface Hydroxyls

Palladium-based catalysts are known to provide high CH4 oxidation activity. One drawback for these materials is that they often lose activity in the presence of water vapor due to the formation of surface hydroxyls. It is however possible to improve the water vapor tolerance by using zeolites as support material. In this study, we have investigated Pd supported on thermally stable LTA zeolite with high framework Si/Al ratio (Si/Al = ~44) for CH4 oxidation and the effect of hydrothermal aging at temperatures up to 900 °C. High and stable CH4 oxidation activity in the presence of water vapor was observed for Pd/LTA after hydrothermal aging at temperatures ≤ 700 °C. However, aging at temperatures of 800–900 °C resulted in catalyst deactivation. This deactivation was not a result of structural collapse of the LTA zeolite as the LTA zeolite only showed minor changes in surface area, pore volume, and X-ray diffraction pattern after 900 °C aging. We suggest that the deactivation was caused by extensive formation of ion-exchanged Pd2+ together with Pd sintering. These two types of Pd species appear to have lower CH4 oxidation activity and to be more sensitive to water deactivation compared to the well dispersed Pd particles observed on the LTA support prior to the hydrothermal aging. By contrast, Pd/Al2O3 was generally sensitive to water vapor no matter of the aging temperature. Although the aging caused extensive Pd sintering in Pd/Al2O3, only minor deterioration of the CH4 oxidation activity was seen. The results herein presented show that Pd/LTA is a promising CH4 oxidation catalyst, however Pd rearrangement at high temperatures (≥800 °C) is one remaining challenge.

The role of oxidation catalyst in dual-catalyst bed for after-treatment of lean burn natural gas exhaust

2012 ◽  
Vol 197 (1) ◽  
pp. 127-136 ◽  
Author(s):  
Preshit Gawade ◽  
Anne-Marie C. Alexander ◽  
Ryan Clark ◽  
Umit S. Ozkan
Keyword(s):  
Natural Gas ◽  
Oxidation Catalyst ◽  
Lean Burn

Laser Spark Ignition: Laser Development and Engine Testing

2004 ◽  
Author(s):  
Michael H. McMillian ◽  
Steven D. Woodruff ◽  
Steven W. Richardson ◽  
Dustin L. McIntyre
Keyword(s):  
Natural Gas ◽  
Laser System ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Lean Burn ◽  
Engine Operation ◽  
Natural Gas Engines ◽  
Laser Spark ◽  
Engine Testing ◽  
Laser Spark Ignition

Evermore demanding market and legislative pressures require stationary lean-burn natural gas engines to operate at higher efficiencies and reduced levels of emissions. Higher in-cylinder pressures and leaner air/fuel ratios are required in order to meet these demands. Contemporary ignition systems, more specifically spark plug performance and durability, suffer as a result of the increase in spark energy required to maintain suitable engine operation under these conditions. This paper presents a discussion of the need for an improved ignition source for advanced stationary natural gas engines and introduces laser spark ignition as a potential solution to that need. Recent laser spark ignition engine testing with natural gas fuel including NOx mapping is discussed. A prototype laser system in constructed and tested and the results are discussed and solutions provided for improving the laser system output pulse energy and pulse characteristics.

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