Particulate emissions from tailpipe during idling of public transit buses fueled with alternative fuels

2012 ◽  
Vol 32 (4) ◽  
pp. 1134-1142 ◽  
Author(s):  
Kaushik Shandilya ◽  
Ashok Kumar
Keyword(s):  
Alternative Fuels ◽  
Public Transit ◽  
Particulate Emissions ◽  
Transit Buses

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.

Ethers and esters as alternative fuels for internal combustion engine: A review

2021 ◽  
pp. 146808742110464
Author(s):  
Yang Hua
Keyword(s):  
Alternative Fuels ◽  
Combustion Engine ◽  
Combustion Process ◽  
Pressure Rise ◽  
Engine Performance ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Future Research ◽  
Particulate Emissions ◽  
Ic Engine

Ether and ester fuels can work in the existing internal combustion (IC) engine with some important advantages. This work comprehensively reviews and summarizes the literatures on ether fuels represented by DME, DEE, DBE, DGM, and DMM, and ester fuels represented by DMC and biodiesel from three aspects of properties, production and engine application, so as to prove their feasibility and prospects as alternative fuels for compression ignition (CI) and spark ignition (SI) engines. These studies cover the effects of ether and ester fuels applied in the form of single fuel, mixed fuel, dual-fuel, and multi-fuel on engine performance, combustion and emission characteristics. The evaluation indexes mainly include torque, power, BTE, BSFC, ignition delay, heat release rate, pressure rise rate, combustion duration, exhaust gas temperature, CO, HC, NOx, PM, and smoke. The results show that ethers and esters have varying degrees of impact on engine performance, combustion and emissions. They can basically improve the thermal efficiency of the engine and reduce particulate emissions, but their effects on power, fuel consumption, combustion process, and CO, HC, and NOx emissions are uncertain, which is due to the coupling of operating conditions, fuel molecular structure, in-cylinder environment and application methods. By changing the injection strategy, adjusting the EGR rate, adopting a new combustion mode, adding improvers or synergizing multiple fuels, adverse effects can be avoided and the benefits of oxygenated fuel can be maximized. Finally, some challenges faced by alternative fuels and future research directions are analyzed.

scholarly journals Reductions in aircraft particulate emissions due to the use of Fischer–Tropsch fuels

2013 ◽  
Vol 13 (6) ◽  
pp. 15105-15139 ◽  
Author(s):  
A. J. Beyersdorf ◽  
M. T. Timko ◽  
L. D. Ziemba ◽  
D. Bulzan ◽  
E. Corporan ◽  
...  
Keyword(s):  
Gas Phase ◽  
Alternative Fuels ◽  
Particle Number ◽  
Particulate Emissions ◽  
Synthetic Fuels ◽  
Particle Volume ◽  
Aromatic Content ◽  
Soot Emissions ◽  
Conversion Efficiencies ◽  
Blended Fuels

Abstract. The use of alternative fuels for aviation is likely to increase due to concerns over fuel security, price stability and the sustainability of fuel sources. Concurrent reductions in particulate emissions from these alternative fuels are expected because of changes in fuel composition including reduced sulfur and aromatic content. The NASA Alternative Aviation Fuel Experiment (AAFEX) was conducted in January–February 2009 to investigate the effects of synthetic fuels on gas-phase and particulate emissions. Standard petroleum JP-8 fuel, pure synthetic fuels produced from natural gas and coal feedstocks using the Fischer–Tropsch (FT) process, and 50% blends of both fuels were tested in the CFM-56 engines on a DC-8 aircraft. To examine plume chemistry and particle evolution with time, samples were drawn from inlet probes positioned 1, 30, and 145 m downstream of the aircraft engines. No significant alteration to engine performance was measured when burning the alternative fuels. However, leaks in the aircraft fuel system were detected when operated with the pure FT fuels as a result of the absence of aromatic compounds in the fuel. Dramatic reductions in soot emissions were measured for both the pure FT fuels (reductions of 84% averaged over all powers) and blended fuels (64%) relative to the JP-8 baseline with the largest reductions at idle conditions. The alternative fuels also produced smaller soot (e.g. at 85% power, volume mean diameters were reduced from 78 nm for JP-8 to 51 nm for the FT fuel), which may reduce their ability to act as cloud condensation nuclei (CCN). The reductions in particulate emissions are expected for all alternative fuels with similar reductions in fuel sulfur and aromatic content regardless of the feedstock. As the plume cools downwind of the engine, nucleation-mode aerosols form. For the pure FT fuels, reductions (94% averaged over all powers) in downwind particle number emissions were similar to those measured at the exhaust plane (84%). However, the blended fuels had less of a reduction (reductions of 30–44%) than initially measured (64%). The likely explanation is that the reduced soot emissions in the blended fuel exhaust plume results in promotion of new particle formation microphysics, rather than coating on pre-existing soot particles, which is dominant in the JP-8 exhaust plume. Downwind particle volume emissions were reduced for both the pure (79 and 86% reductions) and blended FT fuels (36 and 46%) due to the large reductions in soot emissions. In addition, the alternative fuels had reduced particulate sulfate production (near-zero for FT fuels) due to decreased fuel sulfur content. To study the formation of volatile aerosols (defined as any aerosol formed as the plume ages) in more detail, tests were performed at varying ambient temperatures (−4 to 20 °C). At idle, particle number and volume emissions were reduced linearly with increasing ambient temperature, with best fit slopes corresponding to −1.2 × 106 # (kg fuel)−1 °C−1 for particle number emissions and −9.7 mm3 (kg fuel)−1 °C−1 for particle volume emissions. The temperature dependence of aerosol formation can have large effects on local air quality surrounding airports in cold regions. Aircraft produced aerosols in these regions will be much larger than levels expected based solely on measurements made directly at the engine exit plane. The majority (90% at idle) of the volatile aerosol mass formed as nucleation-mode aerosols with a smaller fraction as a soot coating. Conversion efficiencies of up to 3.8% were measured for the partitioning of gas-phase precursors (unburned hydrocarbons and SO2) to form volatile aerosols. Highest conversion efficiencies were measured at 45% power.

scholarly journals Reductions in aircraft particulate emissions due to the use of Fischer–Tropsch fuels

2014 ◽  
Vol 14 (1) ◽  
pp. 11-23 ◽  
Author(s):  
A. J. Beyersdorf ◽  
M. T. Timko ◽  
L. D. Ziemba ◽  
D. Bulzan ◽  
E. Corporan ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Phase ◽  
Alternative Fuels ◽  
Particle Number ◽  
Particulate Emissions ◽  
Synthetic Fuels ◽  
Particle Volume ◽  
Soot Emissions ◽  
Conversion Efficiencies ◽  
Blended Fuels

Abstract. The use of alternative fuels for aviation is likely to increase due to concerns over fuel security, price stability, and the sustainability of fuel sources. Concurrent reductions in particulate emissions from these alternative fuels are expected because of changes in fuel composition including reduced sulfur and aromatic content. The NASA Alternative Aviation Fuel Experiment (AAFEX) was conducted in January–February 2009 to investigate the effects of synthetic fuels on gas-phase and particulate emissions. Standard petroleum JP-8 fuel, pure synthetic fuels produced from natural gas and coal feedstocks using the Fischer–Tropsch (FT) process, and 50% blends of both fuels were tested in the CFM-56 engines on a DC-8 aircraft. To examine plume chemistry and particle evolution with time, samples were drawn from inlet probes positioned 1, 30, and 145 m downstream of the aircraft engines. No significant alteration to engine performance was measured when burning the alternative fuels. However, leaks in the aircraft fuel system were detected when operated with the pure FT fuels as a result of the absence of aromatic compounds in the fuel. Dramatic reductions in soot emissions were measured for both the pure FT fuels (reductions in mass of 86% averaged over all powers) and blended fuels (66%) relative to the JP-8 baseline with the largest reductions at idle conditions. At 7% power, this corresponds to a reduction from 7.6 mg kg−1 for JP-8 to 1.2 mg kg−1 for the natural gas FT fuel. At full power, soot emissions were reduced from 103 to 24 mg kg−1 (JP-8 and natural gas FT, respectively). The alternative fuels also produced smaller soot (e.g., at 85% power, volume mean diameters were reduced from 78 nm for JP-8 to 51 nm for the natural gas FT fuel), which may reduce their ability to act as cloud condensation nuclei (CCN). The reductions in particulate emissions are expected for all alternative fuels with similar reductions in fuel sulfur and aromatic content regardless of the feedstock. As the plume cools downwind of the engine, nucleation-mode aerosols form. For the pure FT fuels, reductions (94% averaged over all powers) in downwind particle number emissions were similar to those measured at the exhaust plane (84%). However, the blended fuels had less of a reduction (reductions of 30–44%) than initially measured (64%). The likely explanation is that the reduced soot emissions in the blended fuel exhaust plume results in promotion of new particle formation microphysics, rather than coating on pre-existing soot particles, which is dominant in the JP-8 exhaust plume. Downwind particle volume emissions were reduced for both the pure (79 and 86% reductions) and blended FT fuels (36 and 46%) due to the large reductions in soot emissions. In addition, the alternative fuels had reduced particulate sulfate production (near zero for FT fuels) due to decreased fuel sulfur content. To study the formation of volatile aerosols (defined as any aerosol formed as the plume ages) in more detail, tests were performed at varying ambient temperatures (−4 to 20 °C). At idle, particle number and volume emissions were reduced linearly with increasing ambient temperature, with best fit slopes corresponding to −8 × 1014 particles (kg fuel)−1 °C−1 for particle number emissions and −10 mm3 (kg fuel)−1 °C−1 for particle volume emissions. The temperature dependency of aerosol formation can have large effects on local air quality surrounding airports in cold regions. Aircraft-produced aerosols in these regions will be much larger than levels expected based solely on measurements made directly at the engine exit plane. The majority (90% at idle) of the volatile aerosol mass formed as nucleation-mode aerosols, with a smaller fraction as a soot coating. Conversion efficiencies of up to 2.8% were measured for the partitioning of gas-phase precursors (unburned hydrocarbons and SO2) to form volatile aerosols. Highest conversion efficiencies were measured at 45% power.

Design of a Low Cost, Partial Flow Dilution Tunnel With Tapered Element Oscillating Microbalance Particulate Measurement

2011 ◽  
Author(s):  
Victor Christensen ◽  
Dan Cordon ◽  
Steve Beyerlein ◽  
Judi Steciak ◽  
Ralph Budwig
Keyword(s):  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Low Cost ◽  
Particulate Emissions ◽  
Atmospheric Gases ◽  
Real Time Measurement ◽  
Tunnel Design ◽  
Conditioning Equipment ◽  
The University ◽  
Tapered Element Oscillating Microbalance

Accurate, repeatable measurement of tailpipe emissions is an important factor in the development of internal combustion engines and testing of alternative fuels. A dilution tunnel simulates the action of exhaust mixing with atmospheric gases and prevents condensation prior to gas and particulate measurements. In this work, a micro dilution tunnel was designed for the University of Idaho Small Engine Laboratory (SEL), and experiments were conducted to establish the controllability and accuracy of the tunnel. The tunnel design implements partial flow, Constant Volume Sampling (CVS) using an ejector diluter. Real-time measurement of CO2, CO, O2, NOx, hydrocarbons, and particulate emissions are collected using the combination of a NDIR/electrochemical 5-gas analyzer and a Tapered Element Oscillating Microbalance (TEOM). Data from these instruments and the flow conditioning equipment are collected and logged by a National Instruments data acquisition system. For the desired 11:1 dilution ratio, the system should be operated at 700°F suction temperature and 35 psia motive pressure. This results in an uncertainty of 3% at the 80% confidence level. A procedure has been developed for obtaining and verifying dilution ratios between 11:1 and 15:1. The characterization and use of an ejector diluter have made it possible to create an inexpensive dilution tunnel that will be useful in studying effects of freezing chemical reactions, and analyzing emissions of diesel and two-stroke engines that typically produce elevated levels of hydrocarbons and particulates beyond the saturation range of many emissions analyzers.

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