Thermo-oxidative characterisation of the residues from persimmon harvest for its use in energy recovery processes

• The thermo-oxidative behaviour of persimmon residues was studied.
• A simplified kinetic triplet and the mechanism of reaction were obtained.
• The evolution of the emitted gases during the reactions were defined and discussed.

The residues from the harvest of persimmon fruit will be thermally valorised by means of high temperature reactions within a spouted bed reactor. With the aim to obtain valuable information for the design of the device, the thermo-chemical processes were simulated by multi-rate linear non-isothermal Thermogravimetric Analysis (TGA) using O2 as carrier gas. In addition, a set of analyses were carried out using Ar as carrier gas in order to evaluate the influence of the atmosphere (oxidative or inert conditions) on the decomposition of the samples evaluating the reactions of pyrolysis. The release of gases was monitored by Evolved Gas Analysis (EGA) with in-line Fourier Transformed Infrared (FT-IR) analysis. The thermo-chemical reaction was mathematically described through the definition of the main kinetic parameters: activation energy (Ea), pre-exponential factor (ln A) and model and order of reaction (n). The so-called kinetic triplet was calculated through the application of a methodology based on complementary iso-conversional methods. These results will be the initial parameters that will help design the Spouted Bed Reactor and it is envisaged that they will be used in computer simulation software to achieve a better understanding of the process to obtain the optimum operational parameters.