Recently, the natural gas is expected to be an environmentally friendlier energy and alternative to the nuclear energy. In the social situation, many oil and gas and engineering companies had studied FEEDs of the FLNG expected to be a new production system for offshore natural gas development in the near future. The FLNG system is no proven technology and there is no operation, which can make it difficult for us to design the FLNG. Furthermore, it is noted that the FLNG designers can't get enough information for the design and need the design standard.Gas explosion is the technical problems for the topside facilities of FLNG. Though it is so difficult for us to understand the gas explosion phenomenon, the FLNG designers have to evaluate the peak over pressure of gas explosion for the design of topside layout to prevent gas explosion from damaging the facilities. The objective of this paper is to study the gas explosion by the numerical simulation. We have conducted the gas explosion analysis for FLNG model by the numerical simulation program AutoReaGas which was developed by TNO and the Century Dynamics. The results show that the physical factors such as ignition location can make significant effects on the peak over pressure of gas explosion.
