A detailed kinetic model for the hydrothermal decomposition (HTD) of sewage sludge was developed
based on an explicit reaction scheme considering exact intermediates including protein, saccharide,
NH4 + -N and acetic acid. The parameters were estimated by a series of kinetic data at a temperature range
of 180–300 C. This modeling framework is capable of revealing stoichiometric relationships between different
components by determining the conversion coefficients and identifying the reaction behaviors by
determining rate constants and activation energies. The modeling work shows that protein and saccharide
are the primary intermediates in the initial stage of HTD resulting from the fast reduction of biomass.
The oxidation processes of macromolecular products to acetic acid are highly dependent on reaction temperature
and dramatically restrained when temperature is below 220 C. Overall, this detailed model is
meaningful for process simulation and kinetic analysis