Investigation of porosity development in biochar from the feedstock of dissimilar lignin content

Abstract

Biochar is a carbonaceous product, that is applied to soils to improve its fertility, reduce contamination and mitigate climate change by carbon sequestration. Application of biochar is determined by its properties, e.g. porosity and mineral composition of biochar. The aim of this work was to determine morphological differences of pores in biochars produced from different types of feedstock and to give recommendations based on carried research towards application of these biochars. 4 biochars were produced by slow pyrolysis from birch, pine, lignin and woodchips of mixed types of wood. The morphological structure and elemental chemical composition of selected biochar units were analyzed. Results showed well-organized pore distribution in biochars from pine and birch, in contrast to biochars from lignin and woodchips. Biochar from pine and lignin had more homogeneous morphology. The following study could be used for design of biochar for specific purposes (e.g. soil amendment or adsorption of contaminants).