ETANKFIRE Ethanol Tank Fire FightingAt the initiative of SP Fire Research and the Swedish Petroleum Institute (SPI), a research project on ethanol storage tank fires has been developed – ETANKFIRE. The ultimate goal of the ETANKFIRE project is to develop and validate a methodology for suppression of tank fires containing ethanol fuels and to determine the large scale burning behavior of ethanol fuels to ensure proper investment in the fire protection of ethanol storage facilities.
The project was launched in 2012 and Phase 1 of the project was completed in 2016. The project has involved two large scale free-burning tests and in total 43 tank fire extinguishing tests in reduced scale. We are now planning for Phase 2 of the project, which will involve large scale tank fire extinguishing tests to verify the smaller-scale results of Phase 1.
Large scale ethanol fire hotter than gasoline
The first part of the ETANKFIRE project was to conduct some free-burning tests with two ethanol fuels to study the influence of the scale of fire. The two large scale tests (18 m in diameter) showed that the heat flux was 2-3 times higher than that of a similar gasoline fire. The risk for fire escalation is therefore significantly higher for large ethanol fires compared with gasoline and the heat exposure to firefighting personnel is increased as well, making firefighting operations more difficult.
Many new lessons from reduced scale tank fire extinguishing tests
As part of the goal to develop and validate a methodology for suppression of tank fires containing ethanol fuels, two series of tank fire extinguishing tests were conducted in reduced scale. The aim was to simulate tank fire conditions, i.e. involving larger amount of fuel and longer preburn times than those specified in various foam approval standard tests. The first “small scale” series involved 29 extinguishing tests and used a 0.41 m2 fire tray while the second “laboratory scale” series involved 14 tests and used a 3.14 m2 fire tray. The results show that simulated tank fire conditions had a serious negative influence on foam extinguishing performance. In several tests the fire could not be controlled at all, even when the application rate was doubled. Instead, enhanced foam characteristics obtained by increasing the foam concentration seem to be the key factor.
Phase 2 aims to validate the tank fire extinguishing results in larger scale
The reduced scale extinguishing test results partly explain why extinguishment of real ethanol storage fires has been unsuccessful. Alcohol resistant (AR) foam concentrates don’t provide the enhanced foam characteristics needed for extinguishment of ethanol tank fires partly because the present approval standards for these foams do not adequately simulate tank fire conditions. There are also virtually no fire protection recommendations for water miscible fuels in foam system standards such as NFPA 11 and EN 13565-2. The ETANKFIRE project could provide important knowledge to improve these standards and generate recommendations for foam use. There is a significant demand to improve both approval standards (e.g. UL 162, EN 1568-3) and existing foam system standards. However, the size of the fire tests matters. The laboratory scale tests used in Phase 1 may not provide results that are applicable to real tank fires; it is therefore important to verify the most promising results at a larger scale before they can be used in guidance documents or to support revisions to foam standards.
A suitable test location is sought
The planning for Phase 2 of the ETANKFIRE project is still in an early stage and primary activities are now focused on finding a suitable large scale test location in Europe, the US or elsewhere. We are aiming for a test tank diameter of 10-15 m, allowing a significant fuel depth and an extended preburn time. We estimate that a minimum of four tests would be sufficient to confirm the findings of Phase 1. Aside from the tank size, important considerations for the test facility include logistics for supply of ethanol and handling of the waste fuel after the tests. Please contact the project group if you have any suggestions.
New project partners are important
Phase 2 will provide unique data, making it possible to provide a link between guidelines, approval standards and real scale experience, thereby fulfilling the project’s ultimate goal: to ensure proper investments in the fire protection of ethanol storage facilities. To reach this goal, stakeholders on an international basis are invited to participate in this project. A wide participation is needed, both to obtain the necessary funding to launch Phase 2 and also to aid a wide understanding of the problem and implementation of the results in standards and guidelines. As a partner you will become a member of the project steering committee and contribute with valuable input to the detailed planning of the upcoming tests, participate in the testing, have first-hand access to the test results and provide input to the test report.
The RISE institutes SP, Swedish ICT and Innventia are merging in order to create a unified institute sector and become a stronger innovation partner. At the beginning 2017 we changed our name to RISE.