Converting sawdust to biochar and its mineral content: A preliminary analysis

Abstract

AbstractIn Indonesia, soil degradation is occurring. A strategy to improve soil conditions is by applying biochar as a soil amendment. On the other hand, Indonesia is an agricultural country with many types of biomass that can be converted into biochar. Sawdust of mahogany, teak, and sappan wood from the furniture industry is easy to find and has great potential as raw materials for biochar. This study used X-ray fluorescence spectrometry to determine the mineral content of sawdust biochar from mahogany, teak, and sappan wood sawdust, especially the ash fraction. Biochar was created by burning sawdust woods in a furnace at temperatures ranging from 250°C to 350°C. In general, the main mineral (ash fraction) content of wood sawdust biochar was calcium (CaO) at concentrations ranging from 51 to 72%, with sappan sawdust biochar having the highest concentration at 70–72%. The potassium (K2O) concentration ranged from 9–23%, with mahogany sawdust biochar having the highest concentration (23%). The phosphorus (P2O5) content ranged from 2 to 10%, with teak sawdust biochar having the highest concentration at 7–10%. Moreover, teak sawdust contained 15-20% silica, and sappan sawdust biochar contained 6-8% Fe. The mineral content in biochar ash included alkaline cations; if the biochar is applied to the soil, then a mineralization process may occur and the cations could improve pH conditions through a liming mechanism. This result is only general information; further research is required to produce more comprehensive data.