NOx Research Papers - Academia.edu (original) (raw)

An effort has been taken to study the performance and emission characteristics of a Variable Compression Ratio (VCR) diesel engine fuelled with biodiesel (Rapeseed Oil Methyl Ester-ROME) using EGR. Experiments are conducted on a single... more

An effort has been taken to study the performance and emission characteristics of a Variable Compression Ratio (VCR) diesel engine fuelled with biodiesel (Rapeseed Oil Methyl Ester-ROME) using EGR. Experiments are conducted on a single cylinder, four-stroke diesel engine powered by Variable Compression ratio with 0%, 5%, 10 % and 15% EGR keeping the load constant i.e. 12kg. Various engine performance parameters such as Brake thermal efficiency; Specific Fuel Consumption, Mechanical efficiency etc. were calculated from acquired data. The engine performance and efficiency obtained with biodiesel was less as compared to diesel which can be attributed to lower calorific value of biodiesel. At CR-18, the performance and emission parameters for ROME are better when compared to other compression ratio. This indicates the feasibility of using ROME as an alternative fuel for diesel. With application of EGR the NO emissions were considerably reduced. However using EGR at high levels result in certain penalties. It increases CO and HC emissions and also affects the performance. The purpose of this Paper is to determine the possibility of using biodiesel as an alternative fuel for petro diesel and effect of EGR on emission Characteristics of Engine.

Software Defined Networking (SDN) is a challenging chapter in today's networking era. It is a network design approach that engages the framework to be controlled or 'altered' adroitly and halfway using programming... more

Software Defined Networking (SDN) is a challenging chapter in today's networking era. It is a network design approach that engages the framework to be controlled or 'altered' adroitly and halfway using programming applications. SDN is a serious advancement that assures to provide a better strategy than displaying the Quality of Service (QoS) approach in the present correspondence frameworks. SDN etymologically changes the lead and convenience of system instruments using the single high state program. It separates the system control and sending functions, empowering the network control to end up specifically. It provides more functionality and more flexibility than the traditional networks. A network administrator can easily shape the traffic without touching any individual switches and services which are needed in a network. The main technology for implementing SDN is a separation of data plane and control plane, network virtualization through programmability. The total ...

The aim of this work is to study the effect of properties of Karanja (Pongamia pinnata) methyl ester on combustion, and NOx (oxides of nitrogen) emissions of a diesel engine. The properties of the karanja methyl ester such as viscosity,... more

The aim of this work is to study the effect of properties of Karanja (Pongamia pinnata) methyl ester on
combustion, and NOx (oxides of nitrogen) emissions of a diesel engine. The properties of the karanja
methyl ester such as viscosity, density, bulk modulus, calorific value, iodine value, cetane number,
saturation% and oxygen% are considered for this study. Experiments were conducted in a naturally
aspirated, single cylinder, four-stroke, stationary, water cooled, constant rpm, in-line (fuel pumppressure
tube-fuel injector) direct injection diesel engine. The engine tests were conducted with karanja
methyl ester (with and without preheating), and baseline fossil diesel. The peak pressures and peak
heat release rates for methyl ester was slightly higher than diesel fuel. The crank angles for peak
pressure of the karanja methyl ester are very close to top dead center. This is probably due to dynamic
injection advance caused by their higher bulk modulus. However, the peak cylinder pressures for
preheated methyl ester decreases, due to late injection and faster evaporation of the fuel. It was
observed that, at full load the oxides of nitrogen emissions of karanja methyl ester are increased by 6%.
A significant reduction in oxides of nitrogen emission is observed with preheated methyl ester

Software Defined Networking (SDN) is a challenging chapter in today's networking era. It is a network design approach that engages the framework to be controlled or 'altered' adroitly and halfway using programming applications. SDN is a... more

Software Defined Networking (SDN) is a challenging chapter in today's networking era. It is a network design approach that engages the framework to be controlled or 'altered' adroitly and halfway using programming applications. SDN is a serious advancement that assures to provide a better strategy than displaying the Quality of Service (QoS) approach in the present correspondence frameworks. SDN etymologically changes the lead and convenience of system instruments using the single high state program. It separates the system control and sending functions, empowering the network control to end up specifically. It provides more functionality and more flexibility than the traditional networks. A network administrator can easily shape the traffic without touching any individual switches and services which are needed in a network. The main technology for implementing SDN is a separation of data plane and control plane, network virtualization through programmability. The total amount of time in which user can respond is called response time. Throughput is known as how fast a network can send data. In this paper, we have design a network through which we have measured the Response Time and Throughput comparing with the Real-time Online Interactive Applications (ROIA), Multiple Packet Scheduler, and NOX.

Homogeneous Charge Compression Ignition (HCCI) combustion is a combustion concept which offers simultaneous reductions in both NOx and soot emissions from internal combustion engines. In light of increasingly stringent diesel emissions... more

Homogeneous Charge Compression Ignition (HCCI) combustion is a combustion concept which offers simultaneous reductions in both NOx and soot emissions from internal combustion engines. In light of increasingly stringent diesel emissions limits, research efforts have been invested into HCCI combustion as an alternative to conventional diesel combustion. This paper reviews the implementation of HCCI combustion in direct injection diesel engines using early, multiple and late injection strategies. Governing factors in HCCI operations such as injector characteristics, injection pressure, piston bowl geometry, compression ratio, intake charge temperature, exhaust gas recirculation (EGR) and supercharging or turbocharging are discussed in this review. The effects of design and operating parameters on HCCI diesel emissions, particularly NOx and soot, are also investigated. For each of these parameters, the theories are discussed in conjunction with comparative evaluation of studies reported in the specialised literature.

NADPH oxidase (nicotinamide adenine dinucleotide phosphate-oxidase), with its generically termed NOX isoforms, is the major source of ROS (reactive oxigen species) in biological systems. ROS are small oxygen-derived molecules with an... more

NADPH oxidase (nicotinamide adenine dinucleotide phosphate-oxidase), with its generically termed NOX isoforms, is the major source of ROS (reactive oxigen species) in biological systems. ROS are small oxygen-derived molecules with an important role in various biological processes (physiological or pathological). If under physiological cond i-tions some processes are beneficial and necessary for life, under pathophysiological conditions they are noxious, harmful. NADPH oxidases are present in phagocytes and in a wide variety of nonphagocytic cells. The enzyme generates superoxide by transferring electrons from NADPH inside the cell across the membrane and coupling them to molecular oxygen to produce superoxide anion, a reactive free-radical. Structurally, NADPH oxidase is a multi-component enzyme which includes two integral membrane proteins, glycoprotein gp91 phox and adaptor protein p22 phox , which together form the heterodimeric flavocytochrome b558 that constitutes the core of the enzyme. During the resting state, the multidomain regulatory subunits p40 phox , p47 phox , p67 phox are located in the cytosol organized as a complex. The act i-vation of phagocytic NADPH oxidase occurs through a complex series of protein intera c-tions.

Homogeneous Charge Compression Ignition (HCCI) combustion is a combustion concept which offers simultaneous reductions in both NO x and soot emissions from internal combustion engines. In light of increasingly stringent diesel emissions... more

Homogeneous Charge Compression Ignition (HCCI) combustion is a combustion concept which offers simultaneous reductions in both NO x and soot emissions from internal combustion engines. In light of increasingly stringent diesel emissions limits, research efforts have ...

An experimental investigation was carried out to study the NOx formation and reduction by primary measures for five types of biomass (straw, peat, sewage sludge, forest residues/Grot, and wood pellets) and their mixtures. To minimize the... more

An experimental investigation was carried out to study the NOx formation and reduction by primary measures for five types of biomass (straw, peat, sewage sludge, forest residues/Grot, and wood pellets) and their mixtures. To minimize the NOx level in biomass-fired boilers, combustion experiments were performed in a laboratory scale multifuel fixed grate reactor using staged air combustion. Flue gas was extracted to measure final levels of CO, CO2, CxHy, O2, NO, NO2, N2O, and other species. The fuel gas compositions between the first and second stage were also monitored. The experiments showed good combustion quality with very low concentrations of unburnt species in the flue gas. Under optimum conditions, a NOx reduction of 50–80% was achieved, where the highest reduction represents the case with the highest fuel-N content. The NOx emission levels were very sensitive to the primary excess air ratio and an optimum value for primary excess air ratio was seen at about 0.9. Conversion of fuel nitrogen to NOx showed great dependency on the initial fuel-N content, where the blend with the highest nitrogen content had lowest conversion rate. Between 1–25% of the fuel-N content is converted to NOx depending on the fuel blend and excess air ratio. Sewage sludge is suggested as a favorable fuel to be blended with straw. It resulted in a higher NOx reduction and low fuel-N conversion to NOx. Tops and branches did not show desirable NOx reduction and made the combustion also more unstable. N2O emissions were very low, typically below 5 ppm at 11% O2 in the dry flue gas, except for mixtures with high nitrogen content, where values up to 20 ppm were observed. The presented results are part of a larger study on problematic fuels, also considering ash content and corrosive compounds which have been discussed elsewhere.

This study is to determine the effect of the Ethanol as cetane number improves on combustion characteristics and pollutants of diesel engine fuelled by preheated biodiesel-diesel blend. A bench test is to be carried out on a four cylinder... more

This study is to determine the effect of the Ethanol as cetane number improves on combustion characteristics and pollutants of diesel engine fuelled by preheated biodiesel-diesel blend. A bench test is to be carried out on a four cylinder direct injection diesel engine aiming to study the variation of thermal efficiency, exhaust temperature and pollutant at different engine operating conditions.There are three blends chosen to be tested in the engine. It includes preheated B10 (900 ml diesel+100 ml Biodiesel), preheated B20 (800 ml diesel+200 ml biodiesel) and preheated B20E10 (700 ml diesel+200 ml biodiesel+100 ml ethanol). Hydrocarbon, CO2, NOx, emission characteristics are also studied in this paper with different blends of fuel.

Due to its impact on human health and the nature surrounding us, diesel engine emissions have been significantly reduced over the last two decades. This reduction has been enforced by the legislating organizations around the world that... more

Due to its impact on human health and the nature surrounding us, diesel engine emissions have been significantly reduced over the last two decades. This reduction has been enforced by the legislating organizations around the world that gradually have made the manufacturers transform their engines to today's complex high‐tech products. One of the most challenging area to meet the legislations is the emissions of the diesel engines which are the products of the combustion of diesel fuel. More restrictions have been imposed by some governments to reduce these emissions to a level such that will not cause any harmful impacts for the environment after releasing them to the atmosphere. This paper examines the effects of combusting a mixture of diesel fuel, water, and surfactant which forms emulsion on the nitrogen oxides NOx, carbon monoxide CO, carbon dioxide CO2, sulfur oxides SOx emissions and particulate matter (PM) from a compression ignition (CI) or diesel engine. Previous research has attributed the observed reduction of these emissions to a suppression of the flame temperature due to quenching effects from the water, thereby reducing thermal NOx formation and other pollutants. The focus of this review paper will be on experiments were previously conducted using a diesel engine with pure diesel fuel and compare it to the emulsion of water-diesel. Furthermore, results from the testing diesel fuel that mixed with varied ratios of water balanced with a surfactant to stabilize the emulsion will be presented and discussed. Three different samples of water-diesel emulsion were used with 10 % water and 90 % diesel, 20 % water and 80% diesel, and 30 % water and 70 % diesel (by volume) respectively to conduct the experiments in the lab. The purpose was to see the impact of adding the water from 10 % up to 30 % (by volume) to the diesel fuel making the emulsified fuel to investigate the impacts on the emissions and the performance of the engine. The data shows a significant NOx emission reduction when using the emulsion water diesel fuel in the range from 20% to 30 % water (by volume) in diesel. These results are correlated with a thermodynamic first law analysis to estimate the adiabatic flame temperature of the standard fuel and fuel-water emulsion cases. Results indicate that thermal NOx is indeed reduced by quenching and flame temperature suppression confirming reports in the literature. Recommendations are given for further studies, including improving the fuel—water emulsion and considerations for long-term testing.

Nitrogen Oxides (NOx) are major air pollutants from diesel engines. Engines that operate on more than one fuel source (as in Diesel-CNG engines) are gaining popularity because they provide a relatively easy and inexpensive alternative... more

Nitrogen Oxides (NOx) are major air pollutants from diesel engines. Engines that operate on more than one fuel source (as in Diesel-CNG engines) are gaining popularity because they provide a relatively easy and inexpensive alternative which reduce NOx emissions by reduced use of diesel fuel. However, such Diesel-CNG based Dual-FuelTM engines still produce significant NOx exhausts under certain driving conditions. A proven technology for reducing NOx from diesel engine exhausts is the Selective Catalytic Reduction (SCR) process. This paper describes the design and development of an embedded system based control strategy for Diesel-CNG Dual-Fuel™ systems using SCR technology. The developed strategy is designed to work in tandem with the existing Diesel-Specific NOx control strategy to meet the emission targets. It is implemented in an Electronic Control Unit (ECU) that controls the SCR system for NOx reduction. Based on the information available from different sources (via CAN, analog sensors and internally calculated parameters), a closed loop control strategy is developed with a simplified model of the system dynamics (including SCR chemical reaction dynamics). The strategy determines the amount of AdBlue® needed for dosing by the dosing valve of the SCR system. The system is also designed with the flexibility to switch to an open-loop control strategy, or user control inputs. The developed strategy was integrated to work in tandem with the company proprietary Diesel-only Mono-Fuel NOx reducing strategy. This enables both the strategies to work in a single Denoxtronic® ECU environment which can be used either for Mono-Fuel or Dual-Fuel™ engines. The developed strategy for Diesel-CNG engines was benchmarked, under diesel-only operation, against the existing diesel Mono-Fuel strategy. In spite of the simplified model dynamics, the developed strategy was able to perform like a Mono-Fuel strategy by capturing the coarse control dynamics and the results obtained converges to the Mono-Fuel strategy.

The modification of land use is known to be a major climate change driver to the local warming and air quality in cities. Despite the reduction of NOx over the years, the Selangor state has captured a higher level of O3 in year 2011. The... more

The modification of land use is known to be a major climate change driver to the local warming and air quality in cities. Despite the reduction of NOx over the years, the Selangor state has captured a higher level of O3 in year 2011. The measurement result has shown that the surge in O3 level was attributed to the reduction of NOx/NMHC ratio. This paper hence attempted to identify the role of land use change from 1999 to 2011 on the ground ozone air quality in the tropical urban conurbation, Greater Kuala Lumpur (GKL), Selangor, Malaysia. With the state-of-the-art chemical weather prediction tool, WRF-Chem, the external synoptic factors and emission inventory were controlled when comparing the chronological land use changes. The results showed that the urban-induced temperature and wind bias in the tropical region has induced stronger wind to disperse the NOx and carries the TVOC from the suburban to the downwind urban region. The reduction of NOx/TVOC has gradually shifted towards the optimum O3 formation regime in 2011. The formation of highly concentrated ozone becomes more sensitive to the increment of TVOC as the NOx level reduces in the urban. This highlights the essential involvement of TVOC in the ozone formation in lieu of the NOx reduction in the tropical city, a region with growing emitter of reactive biogenic ozone precursors.