14 - Environmental sustainability-based comparison for production, properties, and applications of biochar and hydrochar

Abstract

Biomass can be thermochemically transformed into carbon-rich materials including biochar and hydrochar through pyrolysis and hydrothermal carbonization (HTC) processes, respectively. In addition to the different char yields, the chars from pyrolysis and HTC possess different physicochemical properties such as microporosity, functional groups, and surface area because of the different processing conditions applied (especially operation temperature). In this chapter, the production conditions, physiochemical properties, existing and potential applications, and future prospects of biochar and hydrochar are compared and summarized particularly from an environmentally sustainable perspective. Still, scientific and technological challenges remain due to the current research gaps. Promising research directions for biochar and hydrochar are also addressed in this chapter.