Chapter 8 - Hydrothermal carbonization of nonlignocellulosic wastes using enzyme pretreatment

Abstract

Climate change is one of the existential crises that is looming on humanity. Global food waste is estimated to be about 1.3 billion tons, which is roughly one-third of all food produced and is often disposed of in landfills or is incinerated—contributing to climate change. Therefore, we need technologies that can utilize these wastes in its entirety. Hydrothermal carbonization, a thermochemical process, is one such technology that can treat wet waste streams completely to produce solid hydrochar and biocrude liquor. Hence, it is an obvious choice for wet wastes such as biomass. Several studies have shown the suitability of hydrothermal carbonization for lignocellulosic agricultural wastes. However, it is suitability for unconventional nonlignocellulosic wastes such as seafood wastes were poorly assessed. Here, we discuss how enzyme pretreatment extends the utility of hydrothermal carbonization to completely utilize seafood wastes, thereby increasing the repertoire of waste streams for hydrothermal carbonization including nonlignocellulosic wastes.