Vol. 7, Issue 4 (2018)

Author(s):
Neethu TM and PK Dubey

Abstract:
Hydrothermal carbonization is a thermo chemical process for converting moist biomass feedstock to a homogeneous carbon-rich solid, a high-strength process liquid, and a gaseous product mainly consisting of CO₂. Hydrolysis, dehydration, decarboxylation, aromatization, and condensation-polymerization are the main HTC reactions. The fibrous components degrade into liquid intermediates, followed by liquid biocrude and solid hydrochar by means of liquid-liquid, solidliquid and/or solid-solid reactions. The primary HTC process variables are reaction temperature, reaction time, and pressure as well as the feedstock itself. Many studies have suggested that hydrothermal carbonization (HTC) has been considered as an alternative method of processing biomass for value-added products. The HTC is known to have several advantages such as lower energy consumption and less emission over pyrolysis. Hydrochar and its derivatives are promising materials that has huge potential to be used in a range of applications. Most of the efforts of this review are on reviewing the potential applications of hydrochar in various fields including agriculture, environment, energy, adsorbent and medical applications. Hydrochar has gained global attention as soil amendments to potentially improve soil quality because they contain a variety of organic structures. The HTC process is a promising one for the ecofriendly waste management.