Ultra-low emissions of a heavy-duty engine powered with oxymethylene ethers (OME) under stationary and transient driving conditions

2021 ◽  
pp. 146808742110479
Author(s):  
Alexander D Gelner ◽  
Harald A Beck ◽  
Christian Pastoetter ◽  
Martin Härtl ◽  
Georg Wachtmeister
Keyword(s):  
Catalytic Reduction ◽  
Energy Transition ◽  
Water Electrolysis ◽  
Formaldehyde Emission ◽  
Detailed Calculation ◽  
Air Pollution Control ◽  
Heavy Duty ◽  
Partial Load ◽  
The Difference ◽  
Scr System

Polyoxymethylene dimethyl ethers (OME) are promising candidates as substitutes for fossil diesel fuel. A regenerative electricity-based production, using captured airborne carbon dioxide (CO2) and hydrogen (H2) from water electrolysis as reactants, provides a valuable contribution to the energy transition in mobile applications. Besides the possibility of carbon-neutral production, OME offer the advantage of a sootless combustion, which resolves the trade-off between soot and nitrogen oxides (NOx) emissions, and supports the efforts of air pollution control. While the emission behaviour of OME-powered diesel engines in raw exhaust has been studied extensively, interactions between this exhaust and components of the after-treatment system are mainly unknown. This study contains investigations conducted using a urea dosing variation (alpha titration) on a heavy-duty engine in combination with a system for selective catalytic reduction (SCR). These investigations showed a lower NOx reduction efficiency in OME operation in partial load operation compared with the one in fossil diesel operation. This can be attributed, among other reasons, to lower exhaust temperatures in OME operation. However, the high tolerance of OME to exhaust gas recirculation (EGR) compensates for this disadvantage because of the reduction of the raw NOx emission level. The difference in SCR efficiency disappeared at a high load operation point. Additionally, the alpha titration revealed, that urea dosing decreases formaldehyde emission in the SCR system. A pre-conditioned WHSC and WHTC cycle demonstrated the potential of an OME engine with after-treatment in the form of a twin-dosing SCR system for ultra-low emissions. For the specific evaluation of the emissions during these test cycles, this study contains the detailed calculation of the required factors – so-called ‘ u-values’– for OME exhaust according to the technical standard UN/ECE R49.

scholarly journals Investigation of Urea Uniformity with Different Types of Urea Injectors in an SCR System

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1269
Author(s):  
Muhammad Khristamto Aditya Wardana ◽  
Kwangchul Oh ◽  
Ocktaeck Lim
Keyword(s):  
Diesel Engine ◽  
Catalytic Reduction ◽  
Nox Reduction ◽  
Heavy Duty ◽  
Ammonia Gas ◽  
Experimental Parameters ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel ◽  
Scr System

Heavy-duty diesel engines in highway use account for more than 40% of total particulate and nitrogen oxide (NOx) emissions around the world. Selective catalytic reduction (SCR) is a method with effective results to reduce this problem. This research deals with problems in the urea evaporation process and ammonia gas distribution in an SCR system. The studied system used two types of urea injectors to elucidate the quality of ammonia uniformity in the SCR system, and a 12,000-cc heavy-duty diesel engine was used for experimentation to reduce NOx in the system. The uniformity of the generated quantities of ammonia was sampled at the catalyst inlet using a gas sensor. The ammonia samples from the two types of urea injectors were compared in experimental and simulation results, where the simulation conditions were based on experimental parameters and were performed using the commercial CFD (computational fluid dynamics) code of STAR-CCM+. This study produces temperatures of 371 to 374 °C to assist the vaporization phenomena of two injectors, the gas pattern informs the distributions of ammonia in the system, and the high ammonia quantity from the I-type urea injector and high quality of ammonia uniformity from the L-type urea injector can produce different results for NOx reduction efficiency quality after the catalyst process. The investigations showed the performance of two types of injectors and catalysts in the SCR system in a heavy-duty diesel engine.

A Case Study of the Selective Catalytic Reduction (SCR) System at the Algonquin Power Energy-From-Waste Facility

2008 ◽  
Author(s):  
Janice Hatton ◽  
Peter Bulionis
Keyword(s):  
Selective Catalytic Reduction ◽  
Heat Recovery ◽  
Catalytic Reduction ◽  
Heat Recovery Boiler ◽  
Valuable Insight ◽  
Air Pollution Control ◽  
The North ◽  
The Cost ◽  
Scr System ◽  
Energy From Waste

The Algonquin Power Energy-From-Waste (APEFW) facility is located in the suburban Toronto, Ontario city of Brampton. It receives approximately 140,000 metric tonnes (154,000 tons) of MSW per year from the Region of Peel (Region) and approximately 10,000 metric tonnes (11,000 tons) per year of international airport waste from the area’s two international airports. The APEFW facility commenced initial operations in 1992 and included four, 91 tonne (100 ton) per day Consumat two stage incinerators with heat recovery boilers and a dual-train air pollution control (APC) system consisting of evaporative cooling towers, venturi reactors and fabric filter baghouses. The APEFW facility expanded its capacity in 2001 with the addition of a fifth 91 tonne (100 ton) per day modular incinerator and heat recovery boiler. One of the stipulations in the permitting process was that the entire expanded facility meet more stringent emission standards that included a significantly lower nitrogen oxides (NOx) emission rate. After a review of several available NOx control technologies, the APEFW facility chose to install a Selective Catalytic Reduction (SCR) system. While SCR systems are fairly common on EFW facilities in Europe, the APEFW facility is the only EFW facility in North America that currently operates with an SCR system and as such has gained valuable insight into the application and performance of this technology that is very relevant to the North American EFW industry. This paper discusses the operation and maintenance of the SCR system, compares pre- and post-SCR NOx emissions and presents capital and operating costs for the SCR including the cost per tonne of waste processed and the cost per tonne of NOx removed.

Simultaneous Optimization of Configuration and Control for a Passive SCR System

2018 ◽  
Author(s):  
Pingen Chen ◽  
Qinghua Lin
Keyword(s):  
Catalytic Reduction ◽  
Simultaneous Optimization ◽  
Computationally Efficient ◽  
System Architectures ◽  
Aftertreatment System ◽  
In Series ◽  
System Configurations ◽  
Scr System ◽  
And Control ◽  
Passive Scr

The configuration and control of aftertreatment systems have a significant impact on their functionalities and emission control performance. The traditional aftertreatment system configurations, i.e., connections from one aftertreatment subsystem to another subsystem in series, are simple but generally do not yield the optimal aftertreatment system performance. New aftertreatment configurations, in conjunction with new engine and aftertreatment control, can significantly improve engine efficiency and emission reduction performance. However, new configuration design requires human intuition and in-depth knowledge of engine and aftertreatment system design and control. The purpose of this study is to develop a general systematic and computationally-efficient method which enables automated and simultaneous optimization of passive selective catalytic reduction (SCR) system architectures and the associated non-uniform cylinder-to-cylinder combustion (NUCCC) controls based on a newly proposed highly reconfigurable passive SCR model structure and integer partition theory. The proposed method is general enough to account for passive SCR systems with two or more TWC stages. We demonstrate through this case study that the optimized passive SCR configuration, in conjunction with the optimized NUCCC control, can reduce the NH3 specific fuel consumption by up to 21.90%.

Performance Optimization of High-pressure SCR System in a Marine Diesel. Part II: Catalytic Reduction and Process

2018 ◽  
Vol 62 (1-4) ◽  
pp. 40-48 ◽  
Author(s):  
Yuanqing Zhu ◽  
Rongpei Zhang ◽  
Song Zhou ◽  
Chunan Huang ◽  
Yongming Feng ◽  
...  
Keyword(s):  
High Pressure ◽  
Performance Optimization ◽  
Catalytic Reduction ◽  
Marine Diesel ◽  
Scr System

scholarly journals Folk Psychology and Its Ontology

2020 ◽  
pp. 29-52
Author(s):  
Peter Langland-Hassan
Keyword(s):  
Folk Psychology ◽  
Mental Representations ◽  
Ontological Status ◽  
Heavy Duty ◽  
Important Conclusion ◽  
Psychological States ◽  
Light Duty ◽  
The Difference

The question of whether imagination can be reduced to other folk psychological states will turn, in part, on what we take those other states to be—on how we view their ontological status. There are very different views in philosophy and psychology concerning the nature of folk psychological states, ranging from eliminativism, to dispositionalism, to representationalsim. This chapter explains how those different ontological viewpoints bear on the project of explaining imagination. An important conclusion is that the explanations pursued in this book do not assume or require the existence of mental representations of any sort and thus should be of interest to theorists with quite different commitments concerning folk psychological ontology. However, in some cases, when assessing competing arguments, it will be essential to grasp the difference between “heavy-duty” (representationalist) views of folk psychological states and “light-duty” (dispositionalist) views.

An Experimental Study for NOx - Emission Reduction with Urea-SCR Technology in Vehicular Diesel Engines

2011 ◽  
Vol 71-78 ◽  
pp. 2089-2093 ◽  
Author(s):  
Qian Wang ◽  
Ming Xing Zhou ◽  
Bao Yi Wang
Keyword(s):  
Fuel Consumption ◽  
Control Strategy ◽  
Catalytic Reduction ◽  
Water Solution ◽  
Open Loop ◽  
Loop Control ◽  
Consumption Ratio ◽  
Future Emission ◽  
System Configurations ◽  
Scr System

In order to fulfill future emission standards for middle and heavy-duty vehicles like state Ⅳ and Ⅴ, advanced measures on exhaust gas and engine functionality are required. Selective Catalytic Reduction (SCR) technology is the unique technology currently which can improve the emission and reduce fuel consumption simultaneously. Firstly the reductants and its chemical reactions, SCR system configurations and its working principle and urea dosing control strategy are introduced. Then tests are conducted on a diesel engine with SCR system at bench. The results of ESC cycle show that NOx emission is decreased by more than 67% with the open-loop control strategy. Additionally, the urea and fuel consumption and ammonia leakage have been compared and analyzed respectively, the experiment data indicates that the urea water solution consumption ratio is only 5.7% of fuel for this SCR system, while its average ammonia slip is below 5 ppm.

Perspective on SCR NOx control for diesel vehicles

2019 ◽  
Vol 4 (6) ◽  
pp. 969-974 ◽  
Author(s):  
Christine K. Lambert
Keyword(s):  
Steady State ◽  
Selective Catalytic Reduction ◽  
Research Design ◽  
Catalytic Reduction ◽  
System Research ◽  
Reduction Of No ◽  
Diesel Vehicles ◽  
Aqueous Urea ◽  
Nox Control ◽  
Scr System

The selective catalytic reduction of NOx with aqueous urea (“urea SCR”) is originally a steady-state technology that has been successfully applied to diesel vehicles worldwide. This Perspective summarizes 20+ years of SCR system research, design, and future improvements.

Sign in / Sign up

Export Citation Format

Share Document