Assessing alternative fuels for heavy-duty trucks in the U.S. based on improved life cycle assessment

The United States is the largest emitter of greenhouse gases in the global transportation field. In response to the growing challenges of climate change and the rising emissions from the freight sector, the U.S. is actively exploring alternative fuel pathways. This study develops an improved life cycle assessment integrating the Aspen Plus process simulation, life cycle assessment, and system dynamics model. Seven different fuel types for heavy-duty trucks are assessed from resource, environmental, and economic perspectives. Considering technological advances and other influencing factors, the study predicts the deployment trends of alternative fuels in the United States. The results show that liquefied natural gas and biomass-based methanol consume the most energy and water. Hydrogen fuel cell and electricity-based methanol achieve the lowest life cycle carbon emissions and global warming potential. From an economic perspective, liquefied natural gas currently offers the lowest total cost of ownership, whereas electricity-based methanol has the lowest environmental costs. Moreover, as e-fuel technology advances, hydrogen fuel cell and electricity-based methanol costs are expected to fall. Therefore, the U.S. is suggested to accelerate infrastructure improvements and strengthen the promotion of low-carbon alternative fuel heavy-duty trucks to achieve carbon reduction targets in the transportation sector.