A unique ethanol fire project
Published: 23 June, 2011
Henry Persson of the SP Technical Research Institute of Sweden provides an update on ETANKFIRE – a unique project focusing on taming ethanol tank fires.
The use of ethanol has increased dramatically in recent years. As a consequence new risks have emerged associated with the mass transport and storage of large volumes of ethanol. At the initiative of SP Fire Technology and the Swedish Petroleum Institute (SPI), a proposal for a research project on ethanol tank firefighting has been developed – Etankfire Ethanol Tank Fire Fighting. The goal of the project is to develop and validate a methodology for fire fighting of tank fires containing ethanol fuels and to determine the large scale burning behavior of ethanol fuels. As part of this, a workshop will be held in London on the 28th June and a similar workshop is planned for the US stakeholders in mid-september.
As described in the article: ‘Are we prepared for the challenges associated with the broad introduction of ethanol?’ in Industrial Fire Journal (Issue 80 2010), the use of ethanol has increased dramatically in recent years as a mean to fulfill climate goals by replacing fossil fuels with renewable fuels. In Europe, 5% of ethanol has been used in gasoline for a number of years; but from 2011, the acceptable proportion of ethanol in low blended fuels will increase to 10%. Similarly, the use of ethanol fuels in US has increased dramatically during the last decade. Presently the ethanol content in the gasoline is nominally 10% but there are ongoing discussions to increase the ethanol content to 15-20%. This will create new risks and challenges from a fire protection point of view. As the volume of bulk ethanol transported, handled and stored increases, the diameter/volume of the storage tanks will likely also increase. Although oil companies and fire brigades in general have extensive experience of fire fighting in petroleum based products, there is a significant lack of experience concerning fire fighting of water miscible fuels, such as ethanol, especially regarding tank fires.
Etankfire: goal and structure
Although tank fires in general are rare, and the number of ethanol tank fires to date is very low, extensive fire protection measures will be required based on by various national laws and regulations. Typically this translates into significant investments, both in preventative measures and risk mitigation measures including extinguishment in case of a full scale fire. However, as practical experience is very limited, and the standards for fire protection often lack specific information concerning ethanol and similar fuels, there is a great risk that such investments will not provide the fire protection level expected.
The main goal with the Etankfire project is to provide a platform of knowledge ensuring proper investment in the fire protection of ethanol storage plants. This will involve gaining information both regarding the large scale burning behavior and to develop and validate a methodology for fire fighting of tank fires containing ethanol fuels. In order to achieve this goal, it will be important to provide an understanding of the differences between conventional fire fighting of spill fires versus tank fire situations containing water miscible products. The main differences that are foreseen from a fire and fire fighting perspective are:
• tank fires means increased depth of fuel and less dilution effects during extinguishment
• longer pre-burn time increasing the fuel temperature and the foam destruction
• difficulty in achieving gentle application of the foam using the most common fire fighting techniques (mobile foam monitors). This might require both different equipment, tactics and perhaps even the use of other types of extinguishing media.
The suggested structure of the ETANKFIRE project involves six work packages. as shown in Figure 1.
In order to optimize the test design in the project, the intention is to start with test series on a laboratory scale to investigate the relative influence of the three factors mentioned above. Based on the results of laboratory tests, the most promising extinguishing methods/media will then be selected for further evaluation and verification in a larger scale or scales.
In total, four work packages related to extinguishment of ethanol fires are proposed. WP1-2 involve testing in laboratory scale while WP3 (‘medium’ scale) and WP4 (‘full’ scale) need to be conducted outdoors. The burning behavior and heat radiation from an ethanol fire in large scale conditions, will be handled in a separate work package (WP5). This WP will involve large scale ethanol pool fire tests to provide accurate data concerning the burning behavior. Furthermore, WP1-4 will to some extent provide further input to WP5 based on the results from the pre-burn periods in the small and medium scale fires. The test program will be focused on ethanol-based fuels but will provide important information that will also be applicable to other water miscible products.
The project will hold Workshops in the UK (28th June) and US (mid-September) aimed at stakeholders from the oil and ethanol industry, fire protection suppliers, first responders, regulators, etc. The project proposal, including the technical content of the project as presently defined, will be presented. Further information concerning the suggested project structure and rules for participation as a funding member will also be given, as well as an opportunity to provide input to the final planning.
An initial Steering Committee will be formed by stakeholders committed to participating through direct or in-kind funding of the ETANKFIRE project. The Steering Committee will conduct the final detailed planning, including the specific test planning throughout and choice of venue for the large scale tests.
Further information about the ETANKFIRE project, the date and locations, etc. for the workshops, and more background literature can be found here.
About the author
Henry Persson is a mechanical engineer working at the fire laboratory at SP Technical Research Institute of Sweden. Henry has over 30 years of experience, mainly with testing and research in the field of fire extinguishing media, extinguishing systems and industrial fire fighting. He participates in International and European standardisation work in this field as the principal Swedish Expert. As project leader at SP for the EC foam research project FOAMSPEX, he was responsible for the experimental work conducted at SP providing the basis for theoretical modelling of foam spread on burning fuel surfaces.
Henry has participated in numerous other national and international research projects in the field of active fire suppression during his carrier. His contributions to the field were recognised in 2008 when he was given the BIV (the Swedish Chapter of SFPE) Annual Award for outstanding contributions to fire research. In recent years, much of his work has been focused on fire related problems with renewable fuels such as ethanol based fuels but also solid fuels, eg large-scale storage of wood pellets and fire fighting of silo fires.
This article has been printed in the latest issue of Industrial Fire Journal – you can read the whole issue here.