ABSTRACT A three-dimensional numerical model consistent with physical simulations (water/oil/thymol) has been developed to explore the mass transfer behaviour of sulphur. Euler-Lagrangian and Euler-Euler, were applied to simulate the multiphase flow; compared with experimental data, the Euler-Euler method was more accurate. The small eddy model was used for mass transfer calculations. As a new type of bottom stirring scheme, the effect of central-eccentric parallel injection on mass transfer was investigated. Moving the eccentric nozzle towards the sidewall or increasing the number of eccentric nozzles decreases the mass transfer rate at a constant total gas flow rate. The mass transfer rate increases with increasing central gas flow rate under the differential flow bottom stirring scheme. The single-nozzle central injection is still considered the most superior bottom-blowing scheme. The bubble diameter has an insignificant effect on the liquid–liquid mass transfer. The mass transfer rate of thymol is weakly accelerated with increasing bubble diameter.