Gasification plays an important role in the development of clean coal technology. To seek appropriate operations for synthesis gas (syngas) formation, the present study develops a numerical method to predict coal gasification phenomena in an entrained-flow gasifier. Particular emphasis is placed on the influence of injection pattern upon syngas production. The parameter of steam/coal ratio is also taken into account to evaluate its impact on hydrogen generation. The simulations suggest that the developed numerical method is able to provide an accurate prediction on syngas formation. With oxygen injected from the center inlet and coal from the middle ring inlet of the reactor, the operating pattern gives the best performance of coal gasification where the carbon conversion (CC) and coal gas efficiency (CGE) are 89% and 72%, respectively. Increasing steam into the reactor reduces CC and less CO is generated. Nevertheless, more H-2 is produced stemming from water gas shift reaction. This results in slight variation in CGE with altering steam/coal ratio. The obtained results have provided a useful insight into the operation of fuel and oxidant injection for coal gasification. (C) 2012 Elsevier Ltd. All rights reserved.