**3.2 Ultimate analysis**

The ultimate analysis provides the composition of biomass, including major elements (C, H, O, S, N and Cl), moisture and ash on a gravimetric basis. The ultimate analysis of common LCB are listed in **Table 3**. The ultimate analysis is generally reported on a dry and ash-free basis. These are useful in understanding biomass processes and performing mass balances on biomass conversion processes. Elemental chemical composition, moisture, ash and volatiles are essential for thermal/ thermochemical conversions of biomass. Additional information on the polymeric composition of biomass is important for conversions like torrefaction, pyrolysis and gasification. A typical ultimate analysis of the biomass in terms of its basic elements, moisture (M) and inorganic constituents (ASH) can be written as: *C H O ASH* + + + ++ + = N S M 100% . The hydrogen or oxygen content in the ultimate analysis includes only the hydrogen and oxygen present in the organic components of the biomass it does not include the hydrogen and oxygen in the moisture. The moisture in the biomass is expressed separately as M. The ultimate analysis is useful in calculating the quantity of combustion air required to sustain the combustion reactions. Generally, sulfur and nitrogen content of biomass is very low. As a result, biomass produces minimal SOX and NOX pollutants. Particulate emissions of unburned carbon in the flue gases can present pollution problems [49, 51].


### **Table 3.**

*Ultimate analysis (wt%) of common LCB [35].*
