Evaluating NOx and CO emissions of bio-SPK fuel using a simplified engine combustion model: A preliminary study towards sustainable environment

2016 ◽  
Vol 231 (5) ◽  
pp. 859-865 ◽  
Author(s):  
Nurul Musfirah Mazlan ◽  
Mark Savill ◽  
Timos Kipouros
Keyword(s):  
Alternative Fuels ◽  
Fluid Dynamic ◽  
Flame Temperature ◽  
Chemical Properties ◽  
Initial Step ◽  
Aviation Fuel ◽  
Combustion Model ◽  
Emission Model ◽  
Gaseous Emissions ◽  
Gas Emission

Awareness of environmental and economic issues associated with fossil fuel has led to the exploration of alternative fuels for aviation. Analysis and measurements of alternative fuel using real aircraft engines are complex and costly. Thus, evaluation only through computation is an option at present. This paper presents an analysis of aircraft engine emissions, particularly NOx and CO, from the blend of bio-synthetic paraffinic kerosene (bio-SPK) fuel with kerosene using a simplified gas emission model. Three different fuels, namely, a conventional aviation fuel Jet-A, Jatropha bio-SPK and Camelina bio-SPK were tested as pure and as blends with Jet-A. Chemical properties of the tested fuels were introduced into HEPHAESTUS, an in-house gas emission software developed in Cranfield University. HEPHAESTUS was developed based on the physics-based approach by incorporating a number of stirred reactors to predict NOx, CO, UHC and soot. Gaseous emissions generated from kerosene were observed to follow the trends provided by the ICAO databank. The capability of HEPHAESTUS in predicting the NOx and CO level from biofuel is yet to be explored. The level of NOx and CO predicted in this study followed the trends shown in the literature, although they quantitatively differed. Compared to Jet-A, NOx decreased and CO increased as the percentage of Jatropha bio-SPK and Camelina bio-SPK in the mixture increased. NOx reduction was consistent with the reduction in flame temperature because NOx generation considered in the model was dominantly based on thermal NOx. In contrast, increases in CO were due to low flame temperature that led to incomplete combustion. The consistency of the results obtained showed that the computational work performed in this study as an initial step toward the prediction of emission level of biofuels was successful. However, further studies on the experimental work or computational fluid dynamic simulation is essential.

scholarly journals Towards greener aviation : a comparative study on the substitution of standard jet fuel with algal based second generation biofuels

2021 ◽  
Author(s):  
Mona Abdul Majid Haddad
Keyword(s):  
Alternative Fuels ◽  
Second Generation ◽  
Jet Fuel ◽  
Environmental Benefits ◽  
Aviation Fuel ◽  
Transport Sector ◽  
Aviation Industry ◽  
Gaseous Emissions ◽  
Realistic Potential ◽  
Second Generation Biofuels

The negative environmental impact of the aviation industry, related mainly to the gaseous emissions from turbine exhausts, is increasing with the increased demand on travel. In addition to the adverse environmental effects, the currently used aviation fuel is posing economic burdens on the air transport sector, with the increase in crude oil prices. Therefore, the aviation industry is investigating the potential of substituting the currently used aviation fuel with alternative fuels- mainly with those derived from second generation biofuels. Of all available sources of second generation biofuels, numerous studies indicate that those derived from algae seem to be the most promising, in terms of providing a viable and sustainable alternative to fossil fuels. This study explores the feasibility of microalgal jet fuel, taking into consideration technological, environmental and economic aspects. The results indicate that the viability and sustainability of microalgal jet fuel greatly depend on the technologies and inputs used during the different production stages of microalgal fuels. Provided certain conditions and characteristics are present, microalgal jet fuel has a realistic potential to provide the economic and environmental benefits needed to substitute conventional fuels.

scholarly journals Towards greener aviation : a comparative study on the substitution of standard jet fuel with algal based second generation biofuels

2021 ◽  
Author(s):  
Mona Abdul Majid Haddad
Keyword(s):  
Alternative Fuels ◽  
Second Generation ◽  
Jet Fuel ◽  
Environmental Benefits ◽  
Aviation Fuel ◽  
Transport Sector ◽  
Aviation Industry ◽  
Gaseous Emissions ◽  
Realistic Potential ◽  
Second Generation Biofuels

The negative environmental impact of the aviation industry, related mainly to the gaseous emissions from turbine exhausts, is increasing with the increased demand on travel. In addition to the adverse environmental effects, the currently used aviation fuel is posing economic burdens on the air transport sector, with the increase in crude oil prices. Therefore, the aviation industry is investigating the potential of substituting the currently used aviation fuel with alternative fuels- mainly with those derived from second generation biofuels. Of all available sources of second generation biofuels, numerous studies indicate that those derived from algae seem to be the most promising, in terms of providing a viable and sustainable alternative to fossil fuels. This study explores the feasibility of microalgal jet fuel, taking into consideration technological, environmental and economic aspects. The results indicate that the viability and sustainability of microalgal jet fuel greatly depend on the technologies and inputs used during the different production stages of microalgal fuels. Provided certain conditions and characteristics are present, microalgal jet fuel has a realistic potential to provide the economic and environmental benefits needed to substitute conventional fuels.

scholarly journals A Comparative Study of Biofuels and Fischer–Tropsch Diesel Blends on the Engine Combustion Performance for Reducing Exhaust Gaseous and Particulate Emissions

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1538
Author(s):  
Felipe Andrade Torres ◽  
Omid Doustdar ◽  
Jose Martin Herreros ◽  
Runzhao Li ◽  
Robert Poku ◽  
...  
Keyword(s):  
Diesel Fuel ◽  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Road Transport ◽  
Oxidation Catalyst ◽  
Transport Sector ◽  
Particulate Emissions ◽  
Gaseous Emissions ◽  
Fischer Tropsch ◽  
Engine Combustion

The worldwide consumption of fossil hydrocarbons in the road transport sector in 2020 corresponded to roughly half of the overall consumption. However, biofuels have been discreetly contributing to mitigate gaseous emissions and participating in sustainable development, and thus leading to the extending of the commercial utilization of internal combustion engines. In this scenario, the present work aims at exploring the effects of alternative fuels containing a blend of 15% ethanol and 35% biodiesel with a 50% fossil diesel (E15D50B35) or 50% Fischer–Tropsch (F-T) diesel (E15FTD50B35) on the engine combustion, exhaust emissions (CO, HC, and NOx), particulate emissions characteristics as well as the performance of an aftertreatment system of a common rail diesel engine. It was found that one of the blends (E15FTD50B35) showed more than 30% reduction in PM concentration number, more than 25% reduction in mean particle size, and more than 85% reduction in total PM mass with respect to conventional diesel fuel. Additionally, it was found that the E15FTD50B35 blend reduces gaseous emissions of total hydrocarbons (THC) by more than 25% and NO by 3.8%. The oxidation catalyst was effective in carbonaceous emissions reduction, despite the catalyst light-off being slightly delayed in comparison to diesel fuel blends.

Design and Calibration of Chambers for the Measurement of Housed Dairy Cow Gaseous Emissions

2017 ◽  
Vol 60 (4) ◽  
pp. 1291-1300 ◽  
Author(s):  
Jessica L. Drewry ◽  
J. Mark Powell ◽  
Christopher Y. Choi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Dairy Cows ◽  
Management Practices ◽  
Emission Rates ◽  
Gaseous Emissions ◽  
Gas Emission ◽  
Gas Emissions ◽  
Gas Leakage ◽  
Air Mixing

Abstract. The increased global demand for milk and other dairy products over the past decade has heightened concerns about the potential for increased environmental impacts. Accurate measurement of gas emissions from dairy cows is essential to assess the effects of cow diets and other management practices on both the composition and rate of gas emissions. In this article, methodologies are described to instrument, calibrate, and assess the uncertainty of gas emissions by cows housed in chambers that simulate production settings. The supply and exhaust ducts of each chamber were equipped with pitot tubes, temperature and relative humidity probes, and gas samplers to monitor airflow rates, gas composition, and gas emission rates. A Fourier transform infrared spectroscopy (FTIR) instrument was used to quantify gaseous concentrations in the gas samples on a semi-continuous basis. The measurement uncertainty of the rate of gaseous emission from the chambers was quantified, and gas concentration and differential pressure, as measured by the pitot tubes, were identified as the primary parameters contributing to gas emission uncertainties. Mass recovery tests determined that the recovery of methane from each chamber was within 10% of the released mass. Fan operating curves were experimentally determined to identify optimum differential chamber pressures to minimize gas leakage from the chambers. A computational fluid dynamics model was developed to assess air mixing patterns and define steady-state conditions. The model was validated with experimental data of air velocity within each chamber. These procedures will facilitate accurate measurement of gas emissions from housed dairy cows and provide a laboratory to test various gas mitigation treatments. Keywords: Computational fluid dynamics, Dairy, Emission chamber.

Experimental and Analytical Characterization of Alternative Aviation Fuel Sprays Under Realistic Operating Conditions

2018 ◽  
Author(s):  
Andrew Corber ◽  
Nader Rizk ◽  
Wajid Ali Chishty
Keyword(s):  
Experimental Data ◽  
Alternative Fuels ◽  
Laser Sheet ◽  
National Research Council ◽  
Diagnostic System ◽  
Operating Conditions ◽  
Aviation Fuel ◽  
Injection System ◽  
Test Time

The National Jet Fuel Combustion Program (NJFCP) is an initiative, currently being led by the Office of Environment & Energy at the FAA, to streamline the ASTM jet fuels certification process for alternative aviation fuels. In order to accomplish this objective, the program has identified specific applied research tasks in several areas. The National Research Council of Canada (NRC) is contributing to the NJFCP in the areas of sprays and atomization and high altitude engine performance. This paper describes work pertaining to atomization tests using a reference injection system. The work involves characterization of the injection nozzle, comparison of sprays and atomization quality of various conventional and alternative fuels, as well as use of the experimental data to validate spray correlations. The paper also briefly explores the application viability of a new spray diagnostic system that has potential to reduce test time in characterizing sprays. Measurements were made from ambient up to 10 bar pressures in NRC’s High Pressure Spray Facility using optical diagnostics including laser diffraction, phase Doppler anemometry (PDA), LIF/Mie Imaging and laser sheet imaging to assess differences in the atomization characteristics of the test fuels. A total of nine test fluids including six NJFCP fuels and three calibration fluids were used. The experimental data was then used to validate semi-empirical models, developed through years of experience by engine OEMs and modified under NJFCP, for predicting droplet size and distribution. The work offers effective tools for developing advanced fuel injectors, and generating data that can be used to significantly enhance multi-dimensional combustor simulation capabilities.

Numerical Analysis of Equivalence Ratio Fluctuations in a Partially Premixed Gas Turbine Combustor Using Large Eddy Simulations

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Ping Wang ◽  
Qian Yu ◽  
Prashant Shrotriya ◽  
Mingmin Chen
Keyword(s):  
Reaction Mechanism ◽  
Equivalence Ratio ◽  
Flame Temperature ◽  
Premixed Flames ◽  
Large Eddy Simulations ◽  
Combustion Model ◽  
Inlet Channel ◽  
Large Eddy ◽  
Partially Premixed Flames ◽  
Partially Premixed

In the present work, the fluctuations of equivalence ratio in the PRECCINSTA combustor are investigated via large eddy simulations (LES). Four isothermal flow cases with different combinations of global equivalence ratios (0.7 or 0.83) and grids (1.2 or 1.8 million cells) are simulated to study the mixing process of air with methane, which is injected into the inlet channel through small holes. It is shown that the fluctuations of equivalence ratio are very large, and their ranges are [0.4, 1.3] and [0.3, 1.2] for cases 0.83 and 0.7, respectively. For simulating turbulent partially premixed flames in this burner with the well-known dynamically thickened flame (DTF) combustion model, a suitable multistep reaction mechanism should be chosen aforehand. To do that, laminar premixed flames of 15 different equivalence ratios are calculated using three different methane/air reaction mechanisms: 2S_CH4_BFER, 2sCM2 reduced mechanisms and GRI-Mech 3.0 detailed reaction mechanism. The variations of flame temperature, flame speed and thickness of the laminar flames with the equivalence ratios are compared in detail. It is demonstrated that the applicative equivalence ratio range for the 2S_CH4_BFER mechanism is [0.5, 1.3], which is larger than that of the 2sCM2 mechanism [0.5, 1.2]. Therefore, it is recommended to use the 2S_CH4_BFER scheme to simulate the partially premixed flames in the PRECCINSTA combustion chamber.

scholarly journals Ignition Process and Flame Lift-Off Characteristics of dimethyl ether (DME) Reacting Spray

2021 ◽  
Vol 7 ◽  
Author(s):  
Khanh Duc Cung ◽  
Ahmed Abdul Moiz ◽  
Xiucheng Zhu ◽  
Seong-Young Lee
Keyword(s):  
Dimethyl Ether ◽  
Alternative Fuels ◽  
Chemical Properties ◽  
Injection Pressure ◽  
High Reactivity ◽  
Combustion Characteristic ◽  
Spray Combustion ◽  
Ignition Process ◽  
Compression Ignition ◽  
Lift Off

Advanced combustion systems that utilize different combustion modes and alternative fuels have significantly improved combustion performance and emissions compared to conventional diesel or spark-ignited combustions. As an alternative fuel, dimethyl ether (DME) has been receiving much attention as it runs effectively under low-temperature combustion (LTC) modes such as homogeneous charge compression ignition (HCCI) and reactivity control combustion ignition (RCCI). Under compression-ignition (CI), DME can be injected as liquid fuel into a hot chamber, resulting in a diesel-like spray/combustion characteristic. With its high fuel reactivity and unique chemical formula, DME ignites easily but produces almost smokeless combustion. In the current study, DME spray combustion under several different conditions of ambient temperature (Tamb = 750–1100 K), ambient density (ρamb = 14.8–30 kg/m3), oxygen concentration (O2 = 15–21%), and injection pressure (Pinj = 75–150 MPa) were studied. The results from both experiments (constant-volume combustion vessel) and numerical simulations were used to develop empirical correlations for ignition and lift-off length. Compared to diesel, the established correlation of DME shows a similar Arrhenius-type expression. Sensitivity studies show that Tamb and Pinj have a stronger effect on DME's ignition and combustion than other parameters. Finally, this study provides a simplified conceptual mechanism of DME reacting spray under high reactivity ambient (high Tamb, high O2) and LTC conditions. Finally, this paper discusses engine operating strategies using a non-conventional fuel such as DME with different reactivity and chemical properties.

scholarly journals Alternative solid fuels combustion in small heat source

2018 ◽  
Vol 168 ◽  
pp. 08002 ◽  
Author(s):  
Michal Holubčík ◽  
Nikola Kantová ◽  
Jozef Jandačka ◽  
Zuzana Kolková
Keyword(s):  
Heat Source ◽  
Alternative Fuels ◽  
Beech Wood ◽  
Major Influence ◽  
Heat Output ◽  
Heat Sources ◽  
Gaseous Emissions ◽  
Output Efficiency ◽  
Negative Factors

Air quality is related to the using of solid fuel based heat sources in which the human factor has a major influence on the quality of combustion, which can lead to higher emissions into the air. One of the negative factors is the use of alternative fuels in heat sources. The article deals with the combustion of various alternative fuels, on a waste basis, in small heat sources. There were tested 4 types of fuels: beech wood pieces, 2 types of solid alternative fuel on the base of municipal waste and wood waste. In the experiment, it was tested the influence of used fuel in the fireplace on the heat output, efficiency, production of gaseous emissions and particulate matter. The results confirmed that combustion of fuels not recommended by the heat source manufacturer reduces the efficiency of combustion and significantly increases all monitored emissions.

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