Studies on extinguishing ethanol tank fires refines foam methods

By Susanne Retka Schill | October 20, 2016

Researchers working on the Etankfire project have completed a number of tests aimed at developing firefighting tactics for large ethanol tank fires.  The research has been led by Henry Persson from the SP Technical Research Institute of Sweden with the participation of a number of industry partners.

In the latest round of tests, reported in the most recent SP Fire Research Brandposten, researchers evaluated the effectiveness of several foams and application techniques, including AFFF-AR 3x3 foam, a fluorine free formulation and alternative extinguishing media such as cellular glass, liquid nitrogen and aqueous vermiculite dispersion media.

Foam extinguishing performance was inadequate in certain tank fire situations that had an increased depth of fuel, prolonged preborn time and a higher impact position of the foam itself. “In several tests, the fire could not be controlled at all or it could not be controlled until the fuel was significantly diluted by the foam solution,” the report said.

Experiments to improve foam performance found a combination of higher foam concentration and CAF, instead of aspirated low expansion foam, provided the best results. “These changes even made it possible to significantly reduce the application rate and still achieve improved performance. The importance of gentle application is well known when extinguishing water-miscible fuels, but these tests also show that an improved quality of the finished foam can compensate for a more forceful application and is far more important than the application rate.”  Combining the cellular glass alternative with foam resulted in good extinguishing performance, the researchers added.

Earlier this year, the research team reported the results of tests done on various levels of ethanol blends on 200-liter and 20,000-liter experiments. The research was initiated five years ago by project leader Henry Persson with SP Fire Technology and the Swedish Petroleum Institute along with other partners.  

A public report will be available this fall and a seminar is being plant for the spring. Further information is available at the Etankfire website.