Natural Gas and Biogas Use in Transit Bus Fleets - A Technical, Operational and Environmental Approach

2014 ◽  
Author(s):  
Fábio Coelho Barbosa
Keyword(s):  
Natural Gas ◽  
In Transit ◽  
Transit Bus

Development of an Advanced Retrofit Aftertreatment System Targeting Toxic Air Contaminants and Particulate Matter Emissions From HD-CNG Engines

2010 ◽  
Author(s):  
Hemanth Kappanna ◽  
Marc C. Besch ◽  
Daniel K. Carder ◽  
Mridul Gautam ◽  
Adewale Oshinuga ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Natural Gas ◽  
Exhaust Aftertreatment ◽  
Heavy Duty ◽  
Air Contaminants ◽  
Number Count ◽  
Transit Buses ◽  
Order Of Magnitude ◽  
Toxic Air Contaminants ◽  
In Transit

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.

scholarly journals Analysis of Changes in Natural Gas Physical Flows for Europe via Ukraine in 2020

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5175
Author(s):  
Filip Božić ◽  
Daria Karasalihović Sedlar ◽  
Ivan Smajla ◽  
Ivana Ivančić
Keyword(s):  
Natural Gas ◽  
Eastern European ◽  
Short Term ◽  
High Increase ◽  
Transit System ◽  
Research Findings ◽  
Gas Fuel ◽  
Nord Stream ◽  
In Transit ◽  
Energy Strategies

The main objective of the paper was comparative analyses of natural gas quantities delivered through the existing pipeline capacities in the last decade and new pipeline capacities for the prediction of possible future flows of gas import to Europe. Changes in physical flows have been influenced by European energy strategies that became green oriented resulting with a high amount of non-utilized transmission capacities. The research findings have shown that there is a significant decrease observed in transit of Russian gas through Ukraine in 2020 than previously. Concerning the high increase of LNG import to Europe in the same year, the start of operation of TurkStream, planned start of operation of Nord stream 2, authors project the gradual decrease of transit of Russian gas through Ukraine until the year 2025 with the total stop of transit of Russian gas until the year 2030. The change of supply routes will be also under the economic influence of low gas prices and coal and gas fuel switch until 2030 in the West EU, and after 2030 in the South Eastern European region. In the short-term period transit system for natural gas from Russia via Ukraine will be necessary for supplementing coal with natural gas in the energy mix.

Influence of Different Natural Gas Compositions on the Regulated Emissions, Aldehydes, and Particle Emissions from a Transit Bus

2013 ◽  
Author(s):  
George Karavalakis ◽  
Nicholas Gysel ◽  
Maryam Hajbabaei ◽  
Thomas Durbin ◽  
Kent Johnson ◽  
...  
Keyword(s):  
Natural Gas ◽  
Particle Emissions ◽  
Transit Bus
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