Monika Kuźnia

Thermogravimetric and mass spectrometric analysis of powdered pine bark

ABSTRACT Using thermal analysis and mass spectrometry, this study examined samples of powdered pine bark by subjecting them to: (a) complete combustion, (b) partial combustion, and (c) pyrolysis. For each of the examined samples, which heated at the rate of 30°C min−1, temperature regions corresponded to moisture loss and the degassing process. Global and local maximum values of ionic currents representing H2O, CO2, CO, and additionally for hydrocarbons such as CH4, C2H4, and C2H5 for pyrolysis were identified. Based on the recorded values of ionic currents of hydrocarbons in the helium atmosphere, C2H5 dominance was determined at T ≤ 415°C, and CH4 dominance was determined at T > 415°C. Assuming first-order kinetics, thermogravimetric data were analyzed by the Arrhenius type model, and kinetic parameters were determined.

Comparison of hazelnut and peanut shells combustion in bubbling fluidized-bed combustor

ABSTRACT The combustion of peanut and hazelnut shells was studied in an atmospheric bubbling fluidized bed. The impact of the enrichment of air with oxygen and the flow rate of fluidizing gas on CO2 and CO concentrations was analyzed. It was stated that in air enriched with oxygen up to 25% the mole ratios of CO2 to CO were improved by 15–30%, depending on the flow rate used. For the peanut shell the combustion of volatiles with a hematite as an oxygen carrier was also studied. The effects were observed above ~ 450°C.