Hydrogen Explosion at a Refinery (969)
The accident occurred at a distillate dewaxing Unit (MDDW) of the refinery, during the operation of regeneration of the catalyst. To perform this operation, both temperature and pressure have to be increased. After approximately six hours after having reached the correct regeneration conditions, the 10 inches pipe at the bottom to one of the two reactor experienced a guillotine break, and hot gas was released from both ends. The gas released consisted of 81% of hydrogen, 9.5% of methane and some light hydrocarbons. It rapidly ignited (0.7 sec), causing an explosion.