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.
RESIDUAL OR ASH COMPOSITION
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.