Biocarvão supermicroporoso de biomassa residual agroflorestal: produção, caracterização e remoção de resorcinol

Abstract

This research aims to use the bark of the baru tree (Dypteryx alata Vogel) as a raw material for biocarvão production. The skin of the baru fruit represents the majority of the fruit's volume, and its reuse is crucial to avoid environmental problems and additional disposal costs. Converting the biomass into biocarvão involves slow pyrolysis in a conventional oven under a partial oxygen atmosphere. The biocarvão produced was characterized using analytical techniques and used as an adsorbent for the adsorption of resorcinol from aqueous media, followed by characterization and adsorption tests. The results show that baru bark is a suitable raw material for producing biocarvão, standing out for its high porosity and surface area, which are fundamental for the material's effectiveness in adsorbing organic and inorganic compounds. The results show that the biocarvão produced had a yield of 42%. It has a high surface area (324.86 m2 g-1) and pores distributed throughout its surface, which are predominantly supermicropores, ranging in size from 0.7 to 2.0 nm. The biocarvão has a slightly acidic surface and a zero charge point of 6.5. FT-IR and RAMAN spectroscopy shows the presence of various functional groups in the biocarvão, including alcohols, phenols, carbonyls, and carboxylic acids. The Pseudo-first order and Pseudo-second order kinetic models were used to study the adsorption kinetics and the equilibrium condition was reached after 30 minutes. The Langmuir, Freundlich and Sips non-linear equilibrium models were used to adjust the experimental data and study the equilibrium condition. The maximum adsorption capacity (Qmax; mg.g-1) of the biocarvão obtained by the Sips model was 39.4 mg.g-1.