Table 3 Methods and Units for Fuel Characterization

Methods and Units for Fuel Characterization

Biomass Coal Bulk density, lb./cf, kg/m3; E 873 Fuel size E 323 Calorific Value, BTU/lb., MJ/kg D 2015 E 711 D 2015 Proximate composition D 3172 Moisture E 871 D 2013, D 3173 Ash D 1102, E830 D 3174 Volatiles E 872/E 897 D 3175 Fixed Carbon By difference By difference Ultimate Analysis: D 3176 C,H E 777 D 3178 N E 778 D 3179 S E 775 D 4239, D 3177 Cl E 776 D2361, AOAC969.10 Water soluble alkali (K, Na, Ca): Soak overnight in H2O @ 90 C. Analyze by AA.
Special precautions must be taken to prepare ash fuel samples for elemental analysis so that some of the constituents will not be volatilized. Microwave digestion or wet ashing methods are preferred. ASTM D 4278, AOAC 14.7, US Bureau of Mines (Appendix B).

Ash preparation (600 C)					D 1102
Ash Elemental (Si, Al, Ti, Fe, Ca, Mg, Na, K, P)		D 3682, D2795
Optional: Ash sinter test
Heat sample in muffle furnace at 100 C intervals from 550 C to 950 C or higher and inspect for sintering.

Ash fusion temperatures						D 1857
Dirty fuels such as bark, urban wood waste, stump grindings, etc., should be screened to determine ash and alkali content of the fines: screen sample with Tyler #8 sieve, record percent of total, analyze both <8mm and >8mm.

Note: ASTM methods underlined are preferred. Refer to Appendix B for descriptions of standards and method.