Concentration of elements in woody and herbaceous biomass as a function of the dry ashing temperature

The main purposes of the study presented in this paper are to select the optimal temperature of dry ashing and to carry out posterior analyses of elements in the ash formed. The concentration of elements from biomass was compared with the concentration of elements in ash obtained at 400, 500, 550, 600 and 800 °C, utilising four woody and herbaceous biomasses: pine chips, poplar chips, thistle and wheat straw. ashing temperature in the 500–550 °C range was found to produce ashes low in organic carbon (less than 1 wt%) and to recover the greatest amount of the element contents present in the original biomass. A slight loss of potassium and sodium is determined in the ashes produced at temperatures as low as 400 °C for herbaceous biomass compared with the potassium and sodium analysed in biomass.