Assessing the credibility of the calorific value of municipal solid waste

Technical Report · Wed Feb 01 04:00:00 EST 1984

OSTI ID:5835930

Churney, K L; Domalski, E S; Ledford, A E; Colbert, J C; Bruce, S S; Buckley, T J; Paule, R C; Reilly, M L

A study has been made at the National Bureau of Standards to establish the limits of reliability of the calorific value of municipal solid waste (MSW) determined by the bomb calorimetric procedure currently used in commercial test laboratories. This procedure involves using gram-size samples derived from MSW that has been processed down to a particle size of 2 mm or less. Critics of the procedure argue that gram-size samples are too small to be representative of such a large quantity of so heterogeneous a material, and that processing MSW may also alter its composition. To test the bomb calorimetric procedure, a 2.5 kg capacity combustion flow calorimeter was designed and constructed for the determination of the enthalpies of combustion of kilogram-size samples of MSW in flowing oxygen near atmospheric pressure. Calorimetric data on processed MSW were obtained using both the kilogram-size flow and a gram-size bomb calorimeter. Intercomparison of results shows that the calorific value (on a dry basis) of gram-size test samples agrees, within the uncertainty of our experiments, with the corresponding values for their kilogram-size parent samples provided that the sample division technique used to obtain the gram-size samples is that described in this work. The average difference of the parent minus gram-size sample values (on a dry basis) is -0.1% with an imprecision (95% confidence interval) of +-1.1% of the mean calorific value. The effects of processing on sample composition were determined by intercomparison of flow calorimetric results on kilogram-size samples of processed and minimally processed MSW (150 mm or less particle size) that are nominally identical. The average difference of the unprocessed minus processed values (on a dry basis) is -0.5% with an imprecision (95% confidence interval) of +-2.9% of the mean calorific value. 7 references, 4 figures, 10 tables.

• Research Organization: National Bureau of Standards, Washington, DC (USA)
• DOE Contract Number: AT01-77CS20459
• OSTI ID: 5835930
• Report Number(s): NBSIR-84-2825(DOE); ON: DE85009325
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
090400* -- Solid Waste & Wood Fuels-- (-1989)
ACCURACY
CALIBRATION STANDARDS
CALORIFIC VALUE
CALORIMETRY
COMBUSTION PROPERTIES
ENTHALPY
MUNICIPAL WASTES
PHYSICAL PROPERTIES
STANDARDS
THERMODYNAMIC PROPERTIES
WASTES