Fly ash characterization

The entrained fines and fly ash collected in the cyclones and in the hot filter of the pilot-plant gasifier have been analysed by means of a CHN-S elemental analyser, a drying oven and an ash furnace in order to get the ultimate, moisture and ash content analyses. HHV has been also measured using an isoperibolic calorimeter, and LHV has been calculated using Eq. 2.13, where M and H are the moisture and hydrogen content of the sample, respectively, and hstthe latent heat of steam, 2260 MJ/kg (Basu, 2010). Ash is obtained from the samples and digested in H2O2, HNO3, H2SO4 and HF prior to analysis by atomic absorption spectroscopy (AAS) or inductively coupled plasma optical emission spectroscopy (ICP-OES) in order to determine inorganic elemental composition.

LHV = HHV − hst

9 H 100 + M

100



(2.13) The metal mobility in these samples has been tested by means of a leaching test. 5 g of dry fines are combined with deionised water, in a liquid to solid ratio (L/S) of 10. The mixture is continuously rotated for 24 h and then filtered as it is indicated in the DIN 38414-S4 standard for leaching test. Finally, the liquid samples are analysed by AAS or ICP-OES.

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THREE

Fuel particle behaviour and agglomeration