In this paper, numerical simulation of asphalt water slurry gasification process as a heavy fuel oil in a single stage gasifier, using the commercial Ansys fluent software, in a two-dimensional geometry And based on the Eulerian-Lagrangian approach has been done. In this simulation, the distribution of velocity, temperature distribution and molar fraction distribution of synthesis gas species have been calculated. The effect of different devolatalization models, the discrete phase particle size on gasification, and also for the first time, the effect of the use of discrete phase non-spherical particles on gasification parameters has been investigated. The results of this study showed that the water mixture of asphalt can be considered as a suitable feed for gasification. In the study of non-spherical particles it was also found that if the particles with a shape factor of 0.1, which have the greatest difference with spherical particles, are used, the temperature of the chamber slightly increases and the maximum temperature is more distant than the feed intake.