Standards Development

Scope

This document provides information on basket heating tests for characterisation of self-heating properties of solid recovered fuels (SRF).

This document includes:

— A compilation of basket heating test methods.

— Guidance on the applicability and use of basket heating tests for solid recovered fuels.

— Information on the application of basket heating test data for calculations of critical conditions in storages.

Data on spontaneous heat generation determined using this document is only associated with the specific quality and age of the sample material.

NOTE The information derived using this document is for use in quality control and in hazard and risk assessments related to the procedures given in ISO/DIS 21912:2020. 

Purpose

There is a continuous global growth in trading and use of solid recovered fuels. This results in increased probability for fires and increased consequences there of when handling, transporting and storage of SRF.

SRF can generate heat spontaneously by exothermic biological, chemical and physical processes. The heat build-up can be significant in large storage volumes if the heat conduction in the material is low. During some conditions the heat generation can lead to pyrolysis and spontaneous ignition. The potential for self-heating varies considerably for different types and qualities of SRF and it is important to be able to identify SRF fractions with high heat generation potential to avoid fires in stored materials. The increasing number of incidents is a clear indicator that safety needs to be prioritized, first of all for human safety and environmental concerns but also because interruptions in energy supply will have significant consequences. SRF fires throughout the supply chain will, in addition to safety and environmental issues and direct economic losses, also have a negative impact on the confidence in the SRF as a reliable energy source. It can also lead to difficulty to obtain insurance coverage. It is today difficult both for SRF producers, logistics providers, SRF users, equipment suppliers/manufacturers, consultants, authorities and insurance providers to determine reasonable safety measures and an appropriate level of protection due to lack of standards and recommendations. Self-ignition often undergoes a two-step reaction at different temperature regimes. Low temperature reactions are covered by isothermal calorimetry operating normally in the range of 5 °C to 90 °C. In order to assess the risk of self-ignition, the reaction behavior at higher temperatures must also be determined. So-called basket tests serve this purpose, various methods are described. This TS is intended to be part 2 to series with general number ISO 21911. Current ISO 21911 number will be changed to ISO 21911-1 by a resolution by correspondence, when/if this WI is approved. Also the number of this WI will be changed to ISO 21911-2 (the system gives it a random automatic number for now).