Renewable Fuel for Asphalt Concrete Production to Reduce Carbon Emissions

Abstract

A recent analysis of Oregon Department of Transportation (ODOT) activities found that the largest source of greenhouse gas emissions comes from asphalt concrete pavement (ACP) production. An average of 65,200 MT CO2e is released into the atmosphere each year from the production of ACP used by ODOT. One of the key recommendations from the aforementioned research study was to substitute renewable fuels for fossil fuels at industry plants.

In September 2022, ODOT partnered with the Asphalt Pavement Association of Oregon (APAO) and an Oregon-based asphalt contractor to test the viability of using renewable propane at a mobile asphalt plant. The project provided an ideal comparison between fossil and renewable propane since the contractor used conventional propane before and after the test section, the weather was consistent, and the paving type and tonnage were identical among the shifts. The contractor reported no noticeable differences between conventional and renewable propane except for the price.

The major objective of this study was to perform a life cycle assessment (LCA) for renewable propane to determine its environmental impact on asphalt production. The outputs from the renewable propane LCA were incorporated into another asphalt LCA tool (Emerald ECO-Label) to quantify the impact of using renewable propane on the CO₂ emissions of a typical asphalt plant in Oregon. The outputs allowed for an apples-to-apples comparison between fossil propane and renewable propane. These outcomes will enable asphalt plant operators and asphalt customers to make more informed decisions on where, or how, to focus sustainability efforts.