REVIEW OF HYDROTHERMAL CONVERSION FOR HYDROCHAR PRODUCTION

Abstract

Introduction:
Hydrothermal carbonization (HTC) is a thermochemical technique that converts wet biomass, such as spent poultry litter, into energy and chemicals without pretreatment. The resulting hydrochar is a valuable carbonaceous material used for soil amendments, energy storage, and as an additive in chemical reactions, highlighting its potential for waste recovery.
Objective:
To identify the process conditions of hydrothermal carbonization (HTC) for obtaining hydrochar from spent poultry litter, based on the similarities with lignocellulosic residues, sludge, and manure.
Materials and Methods:
The research methods used in this study include historical-logical, deduction-induction, critical analysis, systemic analysis and documentary review of dissertations, articles and books. The results and discussion of this study provide a better understanding of the formation process of hydrochar with characteristics similar to those of spent poultry litter.
Results and Discussion:
The physicochemical characteristics of the carbonization process of different residues were analyzed, which can assume two distinct pathways: the dissolution of intermediate products through polymerization and decomposition, both influenced by hydrothermal severity and temperature.
The adsorption capacity and reactivity were conferred by the presence of oxygenated
functional groups in the surface structure of the hydrocarbons.
Conclusions:
The study identifies gaps in the knowledge of hydrochar formation from poultry litter digestion and highlights the potential of the HTC process for valorizing difficult to treat wastes.