What is ISO/TS 21596 about?
ISO/TS 21596 describes a method for the determination of grindability of graded thermally treated and densified biomass fuels for the purpose of preparing fuels with a defined particle size distribution for effective combustion in pulverized fuel boilers.
The grindability characteristics determined by the test method provide guidance as to the pulverizing mill performance when utilizing such fuels.
Note: The results created with this method are not relevant for large wood chips, since limitations apply for large pulverizing coal mills, which are typically not used for grinding materials such as chips.
Who is ISO/TS 21596 for?
ISO/TS 21596 on the determination of grindability is beneficial for:
- Biofuel engineers
- Chemical engineers
- Mineral processors
Why should you use ISO/TS 21596?
Grindability characteristics are of fundamental importance during solid biofuel preparation for energy conversion processes, requiring a predictable particle size distribution. Particles that are too large or too wide in their distribution may result in feeding problems as well as unburnt fuel passing through the conversion process. Also, in the case of processing of biomass for pre-treatment, consistency in particle size determines the yield of such pre-treatment as well as the quality of the final solid biofuel. The effectiveness of combustion in a pulverized fuel furnace depends strongly on the reactivity and particle size distribution of the pulverized fuel among other factors.
ISO/TS 21596 was developed to characterize the relative grindability of a particular quality of coal relative to a pre-determined standard quality of coal (ASTM D409). The Hardgrove Grindability Index (HGI) test is an empirical batch method that simulates the continuous grinding and crushing operation of a ball, table, or tube type of industrial coal pulverizer, herein also called coal mill. The HGI value is an indication of the degree of grinding required to reach a particular particle size necessary for effective combustion. ISO/TS 21596 may also be applied to thermally pre-treated compressed biomass materials, such as pellets, for pulverization in coal mills. With increasing interest in the use of such pre-treated biomass fuels for direct co-firing applications in conventional pulverized coal boilers, ISO/TS 21596 herein describes a laboratory procedure for the determination of the grindability of pre-treated biofuels for powder fuel preparation. Three relevant adaptations are applied to ISO/TS 21596 (HGI) method in order to extend its applicability to thermally pre-treated biomass fuels. The adaptations and their justification are as follows:
- Amount of sample used for the test determination
- Particle size used as the basis for defining grindability
- Reference materials for establishing the calibration curve
Overall, ISO/TS 21596 is helpful as it provides a complete description of the Hardgrove type method for thermally treated biomass fuels which can help you out in your business. Pre-treatment methods for biomass fuels such as torrefaction, steam treatment, or hydrothermal carbonization (HTC) upgrade the properties of biomass making it more effective as a fuel.
