Conversion of Lavandula distilled straws into high-quality solid fuel: effect of hydrothermal carbonization conditions on fuel characteristics

Abstract

Lavandin hydrochars obtained by hydrothermal carbonization (HTC) of Lavandula distilled straw (LDS) have been studied as an eco-friendly and economical valorization route of residual biomass from cosmetic industry into solid fuels. The critical parameters of the HTC process (temperature and retention time) were normalized to severity factor (SF). Proximate and ultimate analysis, microscopy and thermal analysis were used to characterize hydrochars surface, combustion behavior and kinetics as a function of SF, and to compare them with those of the raw lavandin sample. Results showed that preparation of lavandin hydrochars in temperature and retention time conditions providing SF close to 6 seemed to be the best compromise since under these conditions, the combustion performance of the hydrochar was close to the bituminous coal and lignite.