Production of carbon-based adsorbents from lignocellulosic biomass

Several carbon materials technology issues are presented in this chapter and discussed related to its origins, preparation, characterization, and adsorption process applications. Activated carbon, biochar, and hydrochar are materials from precursor sources rich in carbon but made through different carbonization and manufacturing processes. Biochars and hydrochars are made with organic precursors, which the carbon source is from vegetables and animals (biomass), while activated carbon can be made from mineral carbon sources besides biomass carbon-source. The carbon materials’ properties are severely dependent on the type of precursor and the way of its preparation. The different preparation methods (conventional and microwave pyrolysis and hydrothermal carbonization) create carbon materials with different physicochemical properties. As initially prepared by carbonization, the carbon materials porosities and specific surface areas are not sufficiently developed for being successfully applied in the adsorption process. Thus, some improvement steps (chemical or physical activations) are needed; this is performed to further develop porosity by creating new pores and or widening existing ones and creating and boosting carbon surface functionalities. These characteristics are crucial to be successfully employed in the adsorption process.