Total Fuel-Cycle Analysis of Heavy-Duty Vehicles Using Biofuels and Natural Gas-Based Alternative Fuels

Abstract

Heavy-duty vehicles (HDVs) present a growing energy and environmental concern worldwide. These vehicles rely almost entirely on diesel fuel for propulsion and create problems associated with local pollution, climate change, and energy security. Given these problems and the expected global expansion of HDVs in transportation sectors, industry and governments are pursuing biofuels and natural gas as potential alternative fuels for HDVs. Using recent lifecycle datasets, this paper evaluates the energy and emissions impacts of these fuels in the HDV sector by conducting a total fuel-cycle (TFC) analysis for Class 8 HDVs for six fuel pathways: (1) petroleum to ultra low sulfur diesel; (2) petroleum and soyoil to biodiesel (methyl soy ester); (3) petroleum, ethanol, and oxygenate to e-diesel; (4) petroleum and natural gas to Fischer-Tropsch diesel; (5) natural gas to compressed natural gas; and (6) natural gas to liquefied natural gas. TFC emissions are evaluated for three greenhouse gases (GHGs) (carbon dioxide, nitrous oxide, and methane) and five other pollutants (volatile organic compounds, carbon monoxide, nitrogen oxides, particulate matter, and sulfur oxides), along with estimates of total energy and petroleum consumption associated with each of the six fuel pathways. Results show definite advantages with biodiesel and compressed natural gas for most pollutants, negligible benefits for e-diesel, and increased GHG emissions for liquefied natural gas and Fischer-Tropsch diesel (from natural gas).

Energy supplies and future engines for land, sea, and air

“…This requires a multipollutant/multieffect air quality management strategy (Chow et al, 2010;Chow and Watson, 2011;Hidy et al, 2011;Hidy and Pennell, 2010). Transportation biofuels may reduce CO 2 emissions over their life cycles (Agusdinata et al, 2011;Hossain and Davies, 2010;Hsu et al, 2010;Meyer et al, 2011;Ou et al, 2010;Yan et al, 2010;Yu and Tao, 2009;Zhai et al, 2009), but they may result in increased gaseous and particulate pollutant emissions (Betha and Balasubramanian, 2011;Bugarski et al, 2010;Di et al, 2009; Guarieiro et al, 2009;Liu et al, 2009;Yanowitz and McCormick, 2009). Some of these emission rates may be small when engines are certified, but emission controls deteriorate over time; the more complex the after treatment, the greater is the potential for deterioration.…”

Life cycle sustainability assessment of autonomous heavy‐duty trucks

“…Graham, Rideout, Rosenblatt, and Hendren () compared GHG emissions from trucks fueled with diesel, biodiesel, CNG, hythane (20% hydrogen, 80% CNG), and LNG, and concluded that GHG emissions varied depending on the choice of fuel, revealing that the use of natural gas only moderately improved the tailpipe emissions compared to conventional truck. Meyer, Green, Corbett, Mas, and Winebrake () conducted a comparative total fuel cycle analysis of diesel and alternative fuel (i.e., diesel and its variations, biodiesel, CNG, and LNG) HDTs, carrying 20 metric‐tons of cargo, based on the GREET model. The researchers found tailpipe emissions to be the main contributor to total GHG emissions, concluding that fuel economy and truck payload are two key variables that affect operational emissions.…”

Goods Movement Life Cycle Assessment for Greenhouse Gas Reduction Goals

“…The life cycle assessment (LCA) of transportation services should include vehicle manufacturing/maintenance, infrastructure construction/rehabilitation/operation, and energy production, including supply chains (Chester and Horvath 2009). In the analysis of freight transportation, there have been only a handful of efforts to develop LCAs (Piecyk 2010;Kim and van Wee 2009), and the few studies that do exist (Strogen and Horvath 2013;Facanha 2006;Facanha and Horvath 2007;Meyer et al 2011) tend to normalize results to a comparative measure of a particular weight moved over a particular distance (e.g., tonne-kilometer [km] or ton-mile [mi]) without analyzing the effects of uni-and multimodal trips or how trips that span long distances should be addressed in environmental policy. It is important to understand trip impacts because (1) with interest in reducing freight emissions, it is not always possible (owing to market or infrastructure conditions) to shift goods from one mode to another and (2) many trips are multimodal.…”