The Selective Non-Catalytic Removal (SNCR) of Nitric Oxides From Engine Exhaust Streams: Comparison of Three Processes

2004 ◽  
Vol 126 (2) ◽  
pp. 234-240 ◽  
Author(s):  
Jerald A. Caton ◽  
Zhiyong Xia
Keyword(s):  
Nitric Oxide ◽  
Oxygen Concentration ◽  
Cyanuric Acid ◽  
Operating Conditions ◽  
High Oxygen ◽  
Chemical Agent ◽  
Nitric Oxides ◽  
Engine Exhaust ◽  
Exhaust Gases ◽  
Catalytic Removal

Three processes for the selective non-catalytic removal (SNCR) of nitric oxides from engine exhaust gases are compared. The three processes are similar but each uses a different chemical agent: ammonia, urea, or cyanuric acid. A number of operating conditions have been studied. In particular, results for the removal of nitric oxide are significantly different for the three processes as the oxygen concentration varies. Ammonia, urea, and cyanuric acid were found to be most effective at low, intermediate, and high oxygen concentrations, respectively. The implications of these results for a range of engines and engine applications are discussed.

scholarly journals Determination of the optimal working fluid for the turbine recovering combustion engine exhaust gases heat

2019 ◽  
Vol 91 ◽  
pp. 01001 ◽  
Author(s):  
Yury Matveev ◽  
Marina Cherkasova ◽  
Viktor Rassokhin ◽  
Kirill Lapshin ◽  
Nikolay Kortikov ◽  
...  
Keyword(s):  
Combustion Engine ◽  
Developed Countries ◽  
Operating Conditions ◽  
Working Fluid ◽  
Thermodynamic Efficiency ◽  
Engine Exhaust ◽  
Economic Point ◽  
Flow Passage ◽  
Exhaust Gases ◽  
Turbine Installation

Microsteam turbine implementation for combustion engine exhaust gases heat recovery and subsequent acquisition of additional power is being investigated in many developed countries of the world. The results of such studies have already found application in some trucks. But this type of turbines is very weak in the Russian market. Turbine installation behind the combustion engine works under conditions of low volumetric flow of work fluid. This leads to a decrease in the height of the blade and vane wheels flow passage and an increase of the relative values of the gaps in the seals which are the reasons for the growth of the working fluid leakages. High degree of pressure reduction when selecting single-stage turbine leads to a supersonic velocity in the flow passage and an increase of the losses due to powerful shock waves. The efficiency of the turbine installation under these operating conditions is low and requires additional investigations. In this work, the working fluids which can give the greatest efficiency of the turbine installation were investigated. It was shown that not only thermodynamic but also hazardous and economic parameters must be taken into consideration. Working fluid with the high thermodynamic efficiency was compared with the one that profitable from economic point of view. The most appropriate substance was chosen and implemented in the microsteam turbine. The turbine stage which allows increasing economy and ecological compatibility of the combustion engine was developed and optimized by analytical methods.

scholarly journals Effect of Operating Conditions on Pollutants Concentration Emitted from a Spark Ignition Engine Fueled with Gasoline Bioethanol Blends

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Haroun A. K. Shahad ◽  
Saad K. Wabdan
Keyword(s):  
Nitric Oxide ◽  
Carbon Dioxide ◽  
Experimental Investigation ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Variable Speed ◽  
Exhaust Gases ◽  
Speed Increase ◽  
Energy Replacement

This study is an experimental investigation of the effect of bioethanol gasoline blending on exhaust emissions in terms of carbon dioxide CO2, carbon monoxide CO, unburnt hydrocarbons UHC, and nitric oxide NOxof a spark ignition engine. Tests are conducted at controlled throttle and variable speed condition over the range of 1200 to 2000 rpm with intervals 400 rpm. Different compression ratios are tested for each speed, namely (7,8,10, and 11). Pure gasoline and bioethanol gasoline blends are used. The bioethanol used is produced from Iraqi date crop (Zehdi). Blending is done on energy replacement bases. Ethanol energy ratio (EER) used is 5%, 10%, and 15%. At each of the three designated engine speeds, the torque is set as 0, 3, 7, 10, and 14 N·m. It is found that ethanol blending reduces CO and UHC concentration in the exhaust gases by about 45% and 40.15%, respectively, and increases NOxand CO2concentrations in the exhaust gases by about 16.18% and 7.5%, respectively. It is found also that load and speed increase causes an increase in CO2and NOxconcentrations and reduces CO and UHC concentrations. It is also found that increasing the compression ratio causes the emissions of CO2and NOxto decrease and those of CO and UHC to increase.

scholarly journals Marine Diesel Engine Exhaust Emissions Measured in Ship’s Dynamic Operating Conditions

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6589
Author(s):  
Artur Bogdanowicz ◽  
Tomasz Kniaziewicz
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Systems Engineering ◽  
Operating Conditions ◽  
Marine Diesel Engine ◽  
Engine Exhaust ◽  
Exhaust Gases ◽  
Marine Diesel ◽  
Recorded Data ◽  
Dynamic States

The paper presents the results of research on measuring the emissions from marine diesel engines in dynamic states. The problem is as follows: How to measure emissions of the composition of exhaust gases on board a ship, without direct measurement of fuel consumption and an air flow to marine diesel engine, during maneuvering the ship in the port area. The authors proposed a measurement methodology using an exhaust gas analyzer with simultaneous recording of the load indicator, engine speed, inclinometer, and Global Positioning System (GPS) data. Fuel consumption was calculated based on mean indicated pressure (MIP) tests. Recorded data were processed in the LabView systems engineering software. A simple neural network algorithm was used to model the concentrations of ingredients contained in engine exhaust gases during dynamic states. Using the recorded data, it is possible to calculate the emissions of the composition of exhaust gases from the marine diesel engine and calculate the route emissions of the tested vessel.

The Use of a Three-Zone Combustion Model to Determine Nitric Oxide Emissions From a Homogeneous-Charge, Spark-Ignited Engine

2003 ◽  
Author(s):  
Jerald A. Caton
Keyword(s):  
Nitric Oxide ◽  
Engine Speed ◽  
Combustion Process ◽  
Core Region ◽  
Operating Conditions ◽  
Combustion Model ◽  
Nitric Oxides ◽  
Cycle Simulation ◽  
Nitric Oxide Emissions ◽  
Homogeneous Charge

Nitric oxide emissions were estimated for a homogeneous-charge, spark-ignited automotive engine using a cycle simulation which employed three zones for the combustion process: (1) unburned gas, (2) adiabatic core region, and (3) boundary-layer gas. The use of the adiabatic core region has been shown to be especially necessary to capture the production of nitric oxides which are highly temperature dependent. The effects of major engine parameters such as equivalence ratio, spark timing, inlet manifold pressure, and engine speed on nitric oxide emissions are examined. In particular, the detail reasons for the effects of these engine parameters on the nitric oxide emissions are presented. Comparisons are completed between the computed values and a set of published measurements for the nitric oxide concentrations. Although not all engine parameters were known, reasonable agreement is demonstrated for most cases. In particular, the variations of nitric oxide concentrations as engine speed increased were duplicated. As an example, four operating conditions are examined in detail to help explain the measured results. Nitric oxide emissions are shown to be mainly the net result of gas temperatures, oxygen concentrations, and residence times.

scholarly journals Assessment of Environmental Risks of Particulate Matter Emissions from Road Transport Based on the Emission Inventory

2021 ◽  
Vol 11 (13) ◽  
pp. 6123
Author(s):  
Katarzyna Bebkiewicz ◽  
Zdzisław Chłopek ◽  
Hubert Sar ◽  
Krystian Szczepański ◽  
Magdalena Zimakowska-Laskowska
Keyword(s):  
Particulate Matter ◽  
Legal Status ◽  
Monitoring And Evaluation ◽  
Road Transport ◽  
Solid Particles ◽  
Pollutant Emissions ◽  
European Economic Area ◽  
Engine Exhaust ◽  
Exhaust Gases ◽  
Particulate Matter Emissions

The aim of this study is to investigate the environmental hazards posed by solid particles resulting from road transport. To achieve this, a methodology used to inventory pollutant emissions was used in accordance with the recommendations of the EMEP/EEA (European Monitoring and Evaluation Programme/European Economic Area). This paper classifies particulates derived from road transport with reference to their properties and sources of origin. The legal status of environmental protection against particulate matter is presented. The emissions of particulate matter with different properties from different road transport sources is examined based on the results of Poland’s inventory of pollutant emissions in the year 2018. This study was performed using areas with characteristic traffic conditions: inside and outside cities, as well as on highways and expressways. The effects of vehicles were classified according to Euro emissions standards into the categories relating to the emissions of different particulate matter types. The results obtained showed that technological progress in the automobile sector has largely contributed to a reduction in particulate matter emissions associated with engine exhaust gases, and that this has had slight effect on particulate matter emissions associated with the tribological processes of vehicles. The conclusion formed is that it is advisable to undertake work towards the control and reduction of road transport particulate matter emissions associated with the sources other than engine exhaust gases.

scholarly journals Effects of thermal treatments on characteristics and morphological variations in the deposits of urea-SCR systems

2021 ◽  
Author(s):  
Sadashiva Prabhu S ◽  
Kapilan Natesan ◽  
Nagaraj Shivappa Nayak
Keyword(s):  
Cyanuric Acid ◽  
Catalytic Reduction ◽  
Morphological Changes ◽  
Water Solution ◽  
Slight Variation ◽  
Gravimetric Analysis ◽  
Oxides Of Nitrogen ◽  
Deposit Formation ◽  
X Ray ◽  
Exhaust Gases

AbstractSelective catalytic reduction (SCR) systems are employed by automobile manufacturers for the abatement of environmental pollutants like oxides of nitrogen (NOx) emitted from exhaust gases of diesel engines. In SCR, the urea-water solution (UWS) is injected to exhaust gases in the form of a spray to generate the reducing agent NH3. Deposit formation at lower temperatures is a major concern with this technology. The deposits not only create backpressure but also leak NH3 to the environment as they deplete. It is very important to know the depletion characteristics of deposits formed at lower temperatures in order to assess the NH3 leakage to the environment when the engine exhaust gases attain higher temperatures. In the present work, deposits formed at a low-temperature range of 150–200°C for continuous run along with UWS injection were investigated. Additionally, they were aged at 300°C in the absence of UWS to check the variation in characteristics with the rise of temperature. By gravimetric analysis, it is inferred that the deposits formed at higher pre-age temperatures are less prone to depletion as the temperature increases. The elemental analysis using energy-dispersive X-ray spectroscopy (EDX) indicates slight variation in carbon, nitrogen and oxygen compositions for all the pre-age conditions. As an extended study, the byproducts at pre-age and post-age conditions were investigated through X-ray diffraction (XRD). The compounds like cyanuric acid (CYA) and biuret were not observed when pre-age samples were aged at 300°C. Instead, the compounds like ammelide, ammeline, triuret and melamine were observed. Scanning electron microscope (SEM) study revealed morphological changes in both pre-age and post-age samples. Further, the crystallinity variations were also observed for the changes in the heating cycles during deposit formation. The gravimetric analysis of deposits in pre-age and post-age conditions helps in predicting the amount of deposits for transient load cycles.

Combustion Characteristics of Small Size Gas Turbine Combustor Fueled by Biomass Gas Employing Flameless Combustion

2007 ◽  
Author(s):  
Masato Hiramatsu ◽  
Yoshifumi Nakashima ◽  
Sadamasa Adachi ◽  
Yudai Yamasaki ◽  
Shigehiko Kaneko
Keyword(s):  
Gas Turbine ◽  
Combustion Efficiency ◽  
Combustion Characteristics ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Flameless Combustion ◽  
Engine Exhaust ◽  
Micro Gas Turbine

One approach to achieving 99% combustion efficiency (C.E.) and 10 ppmV or lower NOx (at 15%O2) in a micro gas turbine (MGT) combustor fueled by biomass gas at a variety of operating conditions is with the use of flameless combustion (FLC). This paper compares experimentally obtained results and CHEMKIN analysis conducted for the developed combustor. As a result, increase the number of stage of FLC combustion enlarges the MGT operation range with low-NOx emissions and high-C.E. The composition of fuel has a small effect on the characteristics of ignition in FLC. In addition, NOx in the engine exhaust is reduced by higher levels of CO2 in the fuel.

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