Feedstock Characterization for Pyrolysis and Gasification

Gasification and pyrolysis are promising thermochemical processing technologies for the conversion of complex feedstocks like coal, lignocellulosic biomass and refuse-derived fuels (RDF) into energy and fuels. The quality of the products such as syngas and liquid oil and the process efficiencies depend greatly on the operating parameters of the process, which in turn depend on feedstock characteristics. Hence, it is imperative to map the salient properties of the feedstock to the process characteristics. This review highlights the techniques adopted for characterizing different varieties of coal, biomass and RDF. The various physicochemical and thermal properties discussed in this chapter include density, porosity, specific surface area, thermal conductivity, specific heat, calorific value, thermal stability, pyrolysate composition, proximate and elemental composition, and ash composition. A compendium of proximate analysis (moisture, volatile matter, fixed carbon, ash), ultimate analysis (elemental C, H, N, S, O) and higher heating value data for a large number of solid fuels is provided. The implications of these on the process and product characteristics are addressed. As ash is known to act as a catalyst in the pyrolysis process and cause issues like corrosion and deposition in gasifier systems, the effect of its composition on relevant process parameters is discussed. Finally, the existing challenges and requirements in fuel characterization are discussed.