An Oxygen Flow Calorimeter for Determining the Heating Value of Kilogram-Size Samples of Municipal Solid Waste

Abstract

A new calorimeter is being developed at the National Bureau of Standards to determine the enthalpies of combustion of kilogram-size samples of minimally processed municipal solid waste (MSW) in flowing oxygen near atmospheric pressure. The organic fraction of 25 gram pellets of highly processed MSW has been burned in pure oxygen to CO₂ and H₂O in a small prototype calorimeter. The carbon content of the ash and the uncertainty in the amount of CO in the combustion products contribute calorimetric errors of 0.1 percent or less to the enthalpy of combustion. Large pellets of relatively unprocessed MSW have been successfully burned in a prototype kilogram-size combustor at a rate of 15 minutes per kilogram with CO/CO₂ ratios not greater than 0.1 percent. The design and construction of the kilogram-size calorimeter has been completed. Preliminary trial combustions are being performed.