Operational Experience of Compressed Natural Gas in Heavy Duty Transit Buses

1993 ◽  
Author(s):  
Daniel Quigg ◽  
Vince Pellegrin ◽  
Rudolfo Rey
2005 ◽  
Vol 39 (19) ◽  
pp. 7638-7649 ◽  
Author(s):  
Norman Y. Kado ◽  
Robert A. Okamoto ◽  
Paul A. Kuzmicky ◽  
Reiko Kobayashi ◽  
Alberto Ayala ◽  
...  

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3993
Author(s):  
Elia Distaso ◽  
Riccardo Amirante ◽  
Giuseppe Calò ◽  
Pietro De Palma ◽  
Paolo Tamburrano

An experimental study has been conducted to provide a characterization of the transformations that particle size distributions and the number density of soot particles can encounter along the exhaust line of a modern EURO VI compliant heavy-duty engine, fueled with compressed natural gas. Being aware of the particles history in the exhausts can be of utmost importance to understand soot formation and oxidation dynamics, so that, new strategies for further reducing these emissions can be formulated and present and future regulations met. To this purpose, particle samples were collected from several points along the exhaust pipe, namely upstream and downstream of each device the exhaust gases interact with. The engine was turbocharged and equipped with a two-stage after-treatment system. The measurements were carried out in steady conditions while the engine operated in stoichiometric conditions. Particle emissions were measured using a fast-response particle size spectrometer (DMS500) so that size information was analyzed in the range between 5 and 1000 nm. Particle mass information was derived from size distribution data using a correlation available in the literature. The reported results provide more insight on the particle emission process related to natural gas engines and, in particular, point out the effects that the turbine and the after-treatment devices produce on soot particles. Furthermore, the reported observations suggest that soot particles might not derive only from the fuel, namely, external sources, such as lubricant oil, might have a relevant role in soot formation.


1992 ◽  
Vol 114 (3) ◽  
pp. 561-567 ◽  
Author(s):  
S. G. Fritz ◽  
R. I. Egbuonu

Emissions are reported for four heavy-duty trucks, which were converted to operate on compressed natural gas fuel. Two 1988 model year Ford F700 Series trucks equipped with 7.0 L gasoline engines and two 1986 model year GMC trucks equipped with DDC 8.2 L diesel engines were tested on a heavy-duty chassis dynamometer in a baseline condition and again after conversion to natural gas. The vehicles were tested over the EPA Urban Dynamometer Driving Schedule for Heavy-Duty Vehicles and at no-load curb idle. Regulated emissions of NOx, CO, HC, and diesel particulate, along with nonmethane hydrocarbons, are reported in grams/mile. Fuel economy is reported in energy-equivalent miles per gallon of gasoline or diesel fuel.


2021 ◽  
Vol 266 ◽  
pp. 04011
Author(s):  
F. Zhang ◽  
W.B. Nader ◽  
A. Zoughaib ◽  
X. Luo

Compressed natural gas as an alternative fuel obviously has a great potential to reduce the greenhouse gas emissions. Although several studies on the life cycle are quite comprehensive for passenger vehicles, it is problematic to apply these results to heavy-duty electric hybrid trucks. This paper describes the Well-to-Wheel methodology for environmental impact from the gas production to its final application. The CO2 equivalent emissions and the methane leakage point will be identified at the end. The results indicate that compressed natural gas-based trucks have 18.7% less CO2 equivalent emissions than diesel-based ones. However, this benefit may be affected by methane leakage, particularly, in the recovery phase. Reducing methane emissions upstream could be an opportunity to optimize the pollution performance of heavy hybrid electric trucks.


2020 ◽  
pp. 1-41
Author(s):  
Wahiba Yaïci ◽  
Hajo Ribberink

Abstract Concerns about environmental degradation and finite natural resources necessitate cleaner sources of energy for use in the transportation sector. In Canada, natural gas (NG) is currently being appraised as a potential alternative fuel for use in vehicles for both medium and heavy-duty use due to its relatively lower costs compared to that of conventional fuels. The idea of compressed natural gas vehicles (CNGVs) is being mooted as inexpensive for fleet owners and especially because it will potentially significantly reduce harmful emissions into the environment. A short feasibility study was conducted to ascertain the potential for reduced emissions and savings opportunities presented by CNGVs and renewable NGVs (RNGVs) in both medium and heavy-duty vehicles. The study which is discussed in the present paper was carried out on long-haul trucking and refuse trucks respectively. Emphasis was laid on individual vehicle operating economics and emissions reduction, and the identification of practical considerations for both the individual application and CNGVs/RNGVs as a whole. A financial analysis of the annual cost savings that is achievable when an individual diesel vehicle is replaced with a CNG vehicle was also presented. This paper drew substantial references from published case studies for relevant data on maintenance costs, fuel economy, range, and annual distance traveled. It relied on a summary report from Argonne National Laboratory's GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) [18] for its discussion on relative fuel efficiency penalties for heavy-duty CNGVs. The fuel cost figures were mostly drawn from motor fuel data of the Ontario Ministry of Transportation, since the Ministry is one of the few available sources of compressed natural gas fuel prices. Finally, the GHGenius life-cycle analysis tool [19] was employed to determine fuel-cycle emissions in Canada for comparison purposes. The study produced remarkable findings. Results showed that compared to diesel-fuelled vehicles, emissions in CNG heavy-and-medium-duty vehicles reduced by up to 8.7% (for well-to-wheels) and 11.5% (for pump-to-wheels) respectively. Overall, the most beneficial application appeared to be long-haul trucking based on the long distances covered and higher fuel economy achieved (derived from economies of scale), while refuse trucks appeared to have relatively marginal annual savings. However, these annual savings are actually a conservative estimate, which will ultimately be determined by a number of factors that are likely to be predisposed in favour of NG vehicles. Significantly, the prospect of using RNG as fuel was found to be a factor for improving the value proposition of refuse trucks in particular, certainly from an emissions standpoint with a reduction of up to 100%, but speculatively from operational savings as well.


Author(s):  
Hemanth Kappanna ◽  
Marc C. Besch ◽  
Daniel K. Carder ◽  
Mridul Gautam ◽  
Adewale Oshinuga ◽  
...  

Increasing urban pollution levels have led to the imposition of evermore stringent emissions regulations on heavy-duty engines used in transit buses. This has made compressed natural gas (CNG) a promising fuel for reducing emissions, particularly particulate matter (PM) from heavy-duty transit buses. Indeed, research studies performed at West Virginia University (WVU) and elsewhere have shown that pre-2010 compliant natural gas engines emit an order of magnitude lower PM emissions, on a mass basis, when compared to diesel engines without any exhaust aftertreatment devices. However, on a number basis, particle emissions in the nanoparticulate range were an order of magnitude higher for natural gas fueled buses than their diesel counterparts. There exists a significant number of pre-2007 CNG powered buses in transit agencies in the US and elsewhere in the world. Therefore, an exhaust aftertreatment device was designed and developed by WVU, in association with Lubrizol, to retrofit urban transit buses powered by MY2000 Cummins Westport C8.3G+ heavy-duty CNG engines, and effectively reduce Toxic Air Contaminants (TAC) and PM (mass and number count) exhaust emissions. The speciation results showed that the new exhaust aftertreatment device reduced emissions of metallic elements such as iron, zinc, nonmetallic minerals such as calcium, phosphorus and sulfur derived from lube oil additives to non-detectable levels, which otherwise could contribute to an increase in number count of nanoparticles. The carbonyl compounds were reduced effectively by the oxidation catalyst to levels below what were found in the dilution air. Also, hydrocarbons identified as TAC’s by California Air Resource Board (CARB) [1] were reduced to non-detectable levels. This ultimately reduced the number of nanoparticles to levels equal to that found in the dilution air.


Author(s):  
Gurdas S. Sandhu ◽  
H. Christopher Frey ◽  
Shannon Bartelt-Hunt ◽  
Elizabeth Jones

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