Char Formed during Biomass Combustion and Gasification

The present work aimed at characterizing the char, emitted during biomass utilization in a drop tube furnace (DTF). For that purpose, large sized char particulates (> 10 microns) were collected from the flue gases during biomass combustion and gasification at atmospheric pressure and 1000 oC. The morphology, size, structure and chemical composition of the char particles were studied using scanning electron microscope (SEM), combined with energy dispersive X-ray spectroscopy (EDS). The char derived from softwood combustion and gasification showed different morphology, size and structure. The SEM images of the combustion generated char showed the existence of small sized particulates (micron and sub-micron size), but the large sized (> 10 microns) were the dominant portion. The SEM/EDS and the XRF analyses confirmed that regardless of the biomass choice and its conversion process, the char particles contained mainly carbon and oxygen. Expectedly, the elements Ca, Mg and K were dominating the mineral composition of all char samples. The biochar obtained as by-product of thermochemical conversion of agro-forest biomass residue has promising potential as renewable and environmentally friendly energy resource.