Pollution
Humain
Environnement
Economique

In a power plant undergoing preparation for generating electricity from recycled non-hazardous waste and ligneous biomass (wood chips) by means of gasification, an explosion occurred at 6:15 pm within the auger feeding biomass into a gas injection system. The operations team immediately closed the hatch separating the gas injector from the auger, whose enclosure was partially destroyed. The gasification process was interrupted when the air intake was cut and nitrogen injected. This accident happened during supply testing. Subsequent to a block in the supply chain, the auger wound up with no biomass, at which point it filled with pressurised gas stemming from the gas injector.

Following analysis, the plant operator planned on adding a pressure sensor in the auger and automating the separation hatch closure in case pressure in the auger was found to be less than that in the gas injector. A new enclosure was installed closer to the auger in order to reduce the internal space and place a pressure surge vent. The filling sensor was also modified: it would no longer be solely used to control the auger feed rate, but also to detect periods when the auger was empty for more than a minute so as to automatically shut down gasification and close the hatch between auger and gas injector. The facility restarted 3 weeks after the explosion.