The partial oxidation (PDX) of natural gas is the main approach to produce acetylene. This process involves fuel-rich turbulent combustion, millisecond mixing and rapid quenching cooling, which are difficult to study by experiments and empirical macrokinetics. This work reported numerical simulations of the PDX reactor by computational fluid dynamics (CFD) coupled with detailed chemistry. The GRI 3.0 and San Diego mechanisms were used. A modification was made to GRI 3.0 based on sensitive analysis and comparison with experimental data. With the modified GRI 3.0, the CFD simulation results agreed well with the industrial data. The influence of the reactant preheating temperature and equivalence ratio, which are most important operating parameters, was studied. The results showed that an optimum equivalence ratio exists for maximum acetylene yield. The increase of preheating temperature enhanced the acetylene yield and decreased the corresponding optimum equivalence ratio. The effect of adding C2H6 was also studied to explore the feasibility of using wet shale gas as feedstock of PDX. (C) 2015 Elsevier Ltd. All rights reserved.