Optimisation of Microporous Biochar Synthesis from Guariuba Sawdust

Authors: Omoruwou, F. And Uzomba, T.P.

DOI Info: http://doi.org/10.5281/zenodo.14565707

ABSTRACT

This study was carried out to optimise microporous biochar from sawdust. Biochar was prepared by conducting fast pyrolysis of Guariuba wood sawdust derived from saw timber. The pyrolysis process was carried out at a temperature range of 300–700oC and a time of 10–60 minutes. Chemical activation of Guariuba wood biochar was carried out using potassium hydroxide (KOH) as the activating agent for adsorption studies. The influence of pyrolysis temperature on the biochar pore was investigated by using Brunauer-Emmett-Teller (BET) surface analysis and scanning electron microscopy energy dispersive x-ray spectroscopy (SEM-EDX). It was found that the maximum BET surface area and pore volume were 112.664 m2/g and 0.130 cc/g respectively for biochar pyrolysis at 350 oC. The effects of two variables, including temperature and time, were investigated for maximal porosity by utilising response surface methodology (RSM) with central composite design (CCD). Through the variance of ANOVA, the linear model was established by experimental data with a high R2 value (R2 = 0.9280), small F-value, and p-value indicating that the proposed model is statistically significant. The estimated optimal conditions were validated by confirmation experiments. It was revealed that the porosity reached 86.0016% at the following optimal conditions; temperature = 640.924 oC and time = 50.171 minutes. These results show that Guariuba wood can be used as an effective adsorbent for wastewater treatment and also highlighted the effect of pyrolysis temperature on biochar pores that are associated with soil fertility and nutrient retention in soil, which could be beneficial to the agricultural industries.

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