Carbon emissions analysis of producing modified asphalt with natural asphalt

Abstract The modification mechanism of modified asphalt with natural asphalt was analyzed through Fourier transform infrared spectrum. The results show that the modification mechanism of both the natural asphalt and petroleum asphalt is mainly a physical blending process. The polar functional groups contained in natural asphalt make modified asphalt with natural asphalt have characteristic good scaling resistance and water stability. Subsequently, the carbon emissions of each link of asphalt production stage were quantified, and the influence of mining, transportation, and processing on the total carbon emissions were all analyzed by establishing the carbon emission calculation model of asphalt production. The calculation results of GREET model showed that the equivalent carbon dioxide emission (CO2e) of rock asphalt mining was only 9.4% of that of crude oil production. At the same time, the CO2e of modified asphalt with natural asphalt processing was 44.7% lower than that of petroleum asphalt, and the carbon emission of rock asphalt transportation accounted for only 1/3 of that of petroleum asphalt transportation. Furthermore, the increased energy consumption caused by petroleum asphalt transportation and modified asphalt with natural asphalt processing will partially offset the contribution of natural asphalt to reducing carbon emissions. Meanwhile, the CO2e of modified asphalt with natural asphalt was lower than that of petroleum asphalt when the content of natural asphalt exceeded 18%. Thereafter, the analytic hierarchy process calculation results showed that petroleum asphalt processing and transportation had the largest weight of carbon emissions in the production stage of modified asphalt with natural asphalt. Ultimately, it is significant to further reduce carbon emissions by increasing the content of natural asphalt, which will then inevitably lead to the reduction in the production and transportation energy consumption of petroleum asphalt.