Effects of Blending MTBE With Unleaded Gasoline on Exhaust Emissions of SI Engine

2000 ◽  
Vol 122 (4) ◽  
pp. 239-247 ◽  
Author(s):  
Abdulghani A. Al-Farayedhi ◽  
A. M. Al-Dawood ◽  
P. Gandhidasan
Keyword(s):  
Exhaust Emissions ◽  
Operating Conditions ◽  
Current Paper ◽  
Nox Emissions ◽  
Si Engine ◽  
Unleaded Gasoline ◽  
Hc Emissions

The current paper examines the effects of using MTBE as a replacement of lead additives in gasoline on exhaust emissions of a typical SI engine. The MTBE was blended with a base unleaded fuel in three ratios (10, 15, and 20 vol. percent). The emissions of CO, HC, and NOx were measured at a variety of engine operating conditions using an engine dynamometer setup. The results of the MTBE blends were compared to those of the base fuel and of a leaded fuel prepared by adding TEL to the base. With respect to the base fuel, the addition of MTBE decreased the CO emissions, decreased the HC emissions at most operating conditions, but generally increased the NOx emissions. The emissions results for the leaded fuel were comparable to those of the base fuel. [S0195-0738(00)00103-5]

Estimation of aircraft turbofan engine exhaust emissions with environmental and economic aspects at a small-scale airport

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Halil Yalcin Akdeniz
Keyword(s):  
Cost Estimation ◽  
Air Pollutants ◽  
Exhaust Emissions ◽  
Civil Aviation ◽  
Small Scale ◽  
Nox Emissions ◽  
Economic Aspects ◽  
Content Type ◽  
Hc Emissions

Purpose The purpose of this study is to estimate the nitrogen oxide (NOx), carbon monoxide (CO) and hydrocarbon (HC) emissions and their environmental and economic aspects during the actual landing and take-off operations (LTO) of domestic and international flights at a small-scale airport. In this regard, the aircraft-induced NOx, CO and HC emissions analyses, the global warming potential (GWP) estimations of exhaust emissions and the life cycle assessment (LCA)-based environmental impact (EI) estimations of exhaust emissions, and the eco-cost estimation of exhaust emissions are measured. Design/methodology/approach Estimations and calculations are performed in parallel with the International Civil Aviation Organisation’s Engine Emission Databank and Intergovernmental Panel on Climate Change approaches. Also, to assess the environmental effect of the pollutants, the GWP and the EI analyses which is based on the LCA approaches are used. Finally, the eco-cost approach has been used to discuss the economic aspects of these emissions. Findings The total emissions of air pollutants from aircraft are estimated as 601.067 kg/y for HC, 6,074.905 kg/y for CO and 4,156.391 kg/y for NOx at the airport. Also, emissions from international flights account for 79% of emissions from all flights. The Airbus A321 type of aircraft has accounted for more than half of the total HC, CO and NOx emissions. The total amount of emissions from the B738 type of aircraft is estimated as 24%. It is noticed that the taxi phase constitutes 52% of the total HC, CO and NOx emissions. Because of this, it is selected the five different alternative taxi times to observe the effects of pollution role of taxiing time in detail and re-estimated accordingly. According to the re-estimated results with variations in taxiing time, when the taxiing time at the airport is 24 min instead of the original value, this case contributes to a decrease in total LTO emissions of approximately 4%. Also, when the taxiing time is decreased by 2 min, HC, CO and NOx emission amounts decrease by approximately 3.9%, 5.9% and 1.2%, respectively. At this point, the polluting role of taxiing time will be helpful to reduce the aircraft-induced HC, CO and NOx emissions for other larger-scale airports. On the other hand, it is estimated that the GWP of the A321 is 1,066.29 t CO2e whilst the GWP of B738 is 719.50 t CO2e. The eco-cost values of the A321, B738, A320 and CL60-type of aircraft are estimated as almost 61,049.42, 41,086.02, 18,417.43 and 6,163.59 Euros, respectively. Practical implications With the detailed results of this study, the polluting role of taxiing time on total HC, CO and NOx emissions in a small-scale airport will be helpful to reduce aircraft-induced emissions for other larger-scale airports. Also, in the future, this study and its results will be helpful to create an emission inventory at the airport examined. Originality/value In this study, different from some previous studies, air pollutants from aircrafts are evaluated with different aspects such as the EI and eco-cost and GWP. Also, this study will be making a helpful contribution to the literature as it covers the more diversity of the different types of aircrafts in the analyses.

Optimization of Design and Operational Parameters Using Genetic Algorithm for a Spark Ignition Engine With CNG/H2 Mixtures

2005 ◽  
Author(s):  
G. Anand ◽  
R. Balamurugan
Keyword(s):  
Genetic Algorithm ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Nox Emissions ◽  
Engine Fuel ◽  
Operational Parameters ◽  
Si Engine ◽  
Engine Efficiency ◽  
Wide Range

The present contribution describes the potential of using gaseous fuels like Hythane (CNG/H2 mixtures) as a spark ignition (SI) engine fuel. Genetic Algorithm (GA) is used to optimize the design and operational parameters of a CNG/H2 fueled spark ignition engine for maximizing the engine efficiency subjected to NOx emission constraint. This research deals with quasi-dimensional, two-zone thermodynamic simulation of four-stroke SI engine fueled with CNG/H2 blended fuel for the prediction of the combustion and emission characteristics. The validity of the model has been carried out by comparing the computed results with experimental data obtained under same engine setup and operating conditions. A wide range of engine parameters were optimized using a simple GA regarding both engine efficiency and NOx emissions. The five parameters chosen were compression ratio, engine speed, equivalence ratio, H2 fraction in the fuel, and spark plug position in cylinder head. The amount of NOx emissions was being kept under the constrained value of 750 ppm (< 5 g/kWh), which is less than permissible limit for heavy-duty engines.

scholarly journals A review on the effects of ethanol/gasoline fuel blends on NOX emissions in spark-ignition engines

2021 ◽  
Vol 8 (4) ◽  
pp. 1465-1480
Author(s):  
Paolo Iodice ◽  
Amedeo Amoresano ◽  
Giuseppe Langella
Keyword(s):  
Fossil Fuels ◽  
Combustion Products ◽  
Exhaust Emissions ◽  
Spark Ignition ◽  
Combustion Efficiency ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Transportation Fuel ◽  
Nox Formation ◽  
Si Engines

Ethanol can be used as an alternative fuel for spark-ignition (SI) engines to increase the octane number and oxygen content of ethanol/gasoline blends, thereby reducing dependence on fossil fuels and the exhaust emissions of incomplete combustion products. Although it is widely agreed that ethanol can reduce CO and HC exhaust emissions, the literature on ethanol and NOX emissions is far from conclusive; hence there is a need for an in-depth, updated review of ethanol/gasoline blends in SI engines and the relative production of NOX emissions. In light of that, the present work aims to provide a comprehensive literature review on the current state of ethanol combustion in SI engines to shed definitive light on the potential changes in NOX emissions under various operating conditions. The first part of this paper discusses the feasibility of ethanol as an alternative transportation fuel, including world production and ethanol production processes. The physicochemical properties of ethanol and gasoline are then compared to analyze their effects on combustion efficiency and exhaust emissions. Then, the pathways of NOX formation inside the cylinder of SI engines are discussed in depth. Finally, we review and critically discuss the effects of ethanol concentration in blends and different engine parameters on NOX formation.

scholarly journals Impact of Compressed Natural Gas (CNG) Fuel Systems in Small Engine Wood Chippers on Exhaust Emissions and Fuel Consumption

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6709
Author(s):  
Łukasz Warguła ◽  
Mateusz Kukla ◽  
Piotr Lijewski ◽  
Michał Dobrzyński ◽  
Filip Markiewicz
Keyword(s):  
Natural Gas ◽  
Fuel Consumption ◽  
Average Power ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Maximum Diameter ◽  
Nox Emissions ◽  
Compressed Natural Gas ◽  
Hc Emissions

The projected increase in the availability of gaseous fuels by growing popularity of household natural gas (NG) filling stations and the increase in the production of gaseous biogas-derived fuels is conducive to an increase in the use of NG fuel. Currently, natural gas in various forms (compressed natural gas (CNG), liquefied natural gas (LNG)) is popular in maritime, rail and road transport. A new direction of natural gas application may be non-road mobile machines powered by a small spark-ignition engine (SI). The use of these engines in the wood chippers can cause the reduction of machine costs and emissions of harmful exhaust gases. In addition, plant material chippers intended for composting in bio-gas plants can be driven by the gas they are used to produce. The biogas can be purified to bio-methane to meet natural gas quality standards. The article presents the design of the natural gas supply system, which is an upgrade of the Lifan GX 390 combustion engine spark ignition engine (Four-stroke, OHV (over head valve) with a maximum power of 9.56 kW), which is a common representative of small gasoline engines. The engine is mounted in a cylindrical chipper designed for shredding branches with a maximum diameter of up to 100 mm, which is a typical machine used for cleaning work in urban areas. The engine powered by CNG and traditionally gasoline has been tested in real working conditions, when shredding cherry plum (Prunus cerasifera Ehrh. Beitr. Naturk. 4:17. 1789 (Gartenkalender4:189–204. 1784)). Their diameter was ca. 80 mm, 3-metere-long, and humidity content ca. 25%. The systems were tested under the same actual operating conditions, the average power generated by the drives during shredding is about 0.69 kW. Based on the recorded results, it was found that the CNG-fuelled engine was characterized by nitrogen oxides (NOx) emissions higher by 45%. The other effects of CNG were a reduction in carbon dioxide (CO2), carbon monoxide (CO) and hydrocarbon (HC) emissions of about 81%, 26% and 57%, respectively. Additionally, the use of CNG reduced fuel consumption by 31% and hourly estimated machine operating costs resulting from fuel costs by 53% (for average fuel price in Poland: gasoline: 0.99 EUR/L and CNG: 0.71 EUR/m3 on 08 November 2020). The modernization performed by the authors ensured the work of the drive unit during shredding, closer to the value of stoichiometric mixtures. The average (AVG) value of the air fuel ratio (AFR) for CNG was enriched by 1.2% (AVG AFR was 17), while for the gasoline engine the mixture was more enriched by 4.8% (AVG AFR was 14). The operation of spark-ignition (SI) combustion engines is most advantageous when burning stoichiometric mixtures due to the cooperation with exhaust aftertreatment systems (e.g., three-function catalytic converter). A system powered by CNG may be beneficial in systems adapting to operating conditions, used in low-power shredding machines, whose problem is increased HC emissions, and CNG combustion may reduce them. The developed system does not exceed the emission standards applicable in the European Union. For CO emissions expressed in g/kWh, it was about 95% lower than the permissible value, and HC + NOx emissions were 85% lower. This suggests that the use of the fuel in question may contribute to tightening up the permissible emission regulations for non-road machinery.

scholarly journals Ethanol/Gasoline Blends as Alternative Fuel in Last Generation Spark-Ignition Engines: A Review on CO and HC Engine Out Emissions

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4034
Author(s):  
Paolo Iodice ◽  
Massimo Cardone
Keyword(s):  
Physicochemical Properties ◽  
Alternative Fuels ◽  
Experimental Studies ◽  
Alternative Fuel ◽  
Exhaust Emissions ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Spark Ignition Engines ◽  
The Impact

Among the alternative fuels existing for spark-ignition engines, ethanol is considered worldwide as an important renewable fuel when mixed with pure gasoline because of its favorable physicochemical properties. An in-depth and updated investigation on the issue of CO and HC engine out emissions related to use of ethanol/gasoline fuels in spark-ignition engines is therefore necessary. Starting from our experimental studies on engine out emissions of a last generation spark-ignition engine fueled with ethanol/gasoline fuels, the aim of this new investigation is to offer a complete literature review on the present state of ethanol combustion in last generation spark-ignition engines under real working conditions to clarify the possible change in CO and HC emissions. In the first section of this paper, a comparison between physicochemical properties of ethanol and gasoline is examined to assess the practicability of using ethanol as an alternative fuel for spark-ignition engines and to investigate the effect on engine out emissions and combustion efficiency. In the next section, this article focuses on the impact of ethanol/gasoline fuels on CO and HC formation. Many studies related to combustion characteristics and exhaust emissions in spark-ignition engines fueled with ethanol/gasoline fuels are thus discussed in detail. Most of these experimental investigations conclude that the addition of ethanol with gasoline fuel mixtures can really decrease the CO and HC exhaust emissions of last generation spark-ignition engines in several operating conditions.

scholarly journals Investigation on Physicochemical Properties of Wastewater Grown Microalgae Methyl Ester and its Effects on CI Engine

2020 ◽  
Vol 24 (1) ◽  
pp. 72-87 ◽  
Author(s):  
Sara Tayari ◽  
Reza Abedi ◽  
Ali Abedi
Keyword(s):  
Methyl Ester ◽  
Engine Performance ◽  
Exhaust Emissions ◽  
Biodiesel Production ◽  
Emissions Reduction ◽  
Test Results ◽  
Main Fatty Acid ◽  
Ci Engine ◽  
Hc Emissions ◽  
A Minor

AbstractMicroalgae have been mentioned as a promising feedstock for biodiesel production. In this study, microalgae Chlorella vulgaris (MCV) was cultivated in a bioreactor with wastewater. After biodiesel production from MCV oil via transesterification reaction, chemical and physical properties of MCV methyl ester were evaluated with regular diesel and ASTM standard. Besides, engine performance and exhaust emissions of CI engine fuelled with the blends of diesel-biodiesel were measured. The GC-MS analysis showed that oleic and linoleic acids were the main fatty acid compounds in the MCV methyl ester. Engine test results revealed that the use of biodiesel had led to a major decrease in CO and HC emissions and a modest reduction in CO2 emissions, whereas there was a minor increase in NOx emissions. Furthermore, there was a slight decrease in the engine power and torque while a modest increase in brake specific fuel consumption which are acceptable due to exhaust emissions reduction. The experimental results illustrate considerable capabilities of applied MVC biodiesel as an alternative fuel in diesel engines to diminish the emissions.

Two-Stroke Marine Diesel Engine Variable Injection Timing System Performance Evaluation and Optimum Setting for Minimum Fuel Consumption at Acceptable NOx Levels

2014 ◽  
Author(s):  
Dimitrios T. Hountalas ◽  
Spiridon Raptotasios ◽  
Antonis Antonopoulos ◽  
Stavros Daniolos ◽  
Iosif Dolaptzis ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Engine Performance ◽  
Operating Conditions ◽  
Specific Fuel Consumption ◽  
Injection Timing ◽  
Nox Emissions ◽  
Pressure Measurements ◽  
Cylinder Pressure ◽  
Start Of Injection

Currently the most promising solution for marine propulsion is the two-stroke low-speed diesel engine. Start of Injection (SOI) is of significant importance for these engines due to its effect on firing pressure and specific fuel consumption. Therefore these engines are usually equipped with Variable Injection Timing (VIT) systems for variation of SOI with load. Proper operation of these systems is essential for both safe engine operation and performance since they are also used to control peak firing pressure. However, it is rather difficult to evaluate the operation of VIT system and determine the required rack settings for a specific SOI angle without using experimental techniques, which are extremely expensive and time consuming. For this reason in the present work it is examined the use of on-board monitoring and diagnosis techniques to overcome this difficulty. The application is conducted on a commercial vessel equipped with a two-stroke engine from which cylinder pressure measurements were acquired. From the processing of measurements acquired at various operating conditions it is determined the relation between VIT rack position and start of injection angle. This is used to evaluate the VIT system condition and determine the required settings to achieve the desired SOI angle. After VIT system tuning, new measurements were acquired from the processing of which results were derived for various operating parameters, i.e. brake power, specific fuel consumption, heat release rate, start of combustion etc. From the comparative evaluation of results before and after VIT adjustment it is revealed an improvement of specific fuel consumption while firing pressure remains within limits. It is thus revealed that the proposed method has the potential to overcome the disadvantages of purely experimental trial and error methods and that its use can result to fuel saving with minimum effort and time. To evaluate the corresponding effect on NOx emissions, as required by Marpol Annex-VI regulation a theoretical investigation is conducted using a multi-zone combustion model. Shop-test and NOx-file data are used to evaluate its ability to predict engine performance and NOx emissions before conducting the investigation. Moreover, the results derived from the on-board cylinder pressure measurements, after VIT system tuning, are used to evaluate the model’s ability to predict the effect of SOI variation on engine performance. Then the simulation model is applied to estimate the impact of SOI advance on NOx emissions. As revealed NOx emissions remain within limits despite the SOI variation (increase).

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