Research of effect and mechanism of FCC slurry on the aging resistance of asphalt

Key words:  FCC slurry  asphalt  true boiling point distillation  anti-aging property  infrared spectroscopy

Abstract:

AH-70 asphalts were obtained using FCC slurry with heavy crude oil from South America as the feedstock through true boiling point distillation instrument. The thin film oven test (TFOT) and pressure aging vessel (PAV) were applied to simulate the short-term and long-term aging of asphalt respectively, through which the effect and mechanism of FCC slurry on the two anti-aging processes were investigated. It is found that AH-70 asphalts can be produced from the blending of heavy oil and FCC slurry (0％, 3％, 6％, 9％, and 12％ by weight of heavy oil, respectively) at the final boiling point of 425,0, 430,0, and 435 ℃ accordingly. With the increase of the blending ratio for FCC slurry, the retained penetration and ductility at 15 ℃ of the TFOT aged asphalts are reduced. Meanwhile, the growth rate of softening point is increased. After PAV aging, the retained penetration is declined and the growth rate of softening point is also improved. And there is no significant oxidation reaction of functional groups during the TFOT aging process. As the increase of FCC slurry, the volatilization of light components and the condensation of aromatics/resins are the main reasons of deteriorating the TFOT aging performance of asphalt. After PAV aging, the sulfoxide and carboxyl groups are formed in the asphalt. Also, it is found that the aromatics in FCC slurry can inhibit the free radical reaction in the aging process of asphalt. However, the condensation of aromatics and resins still damages the PAV anti-aging property.