Effects of Pyrolysis Conditions on Physicochemical Properties of Oat Hull Derived Biochar

Effects of Pyrolysis Conditions on Physicochemical Properties of Oat Hull Derived Biochar

María Eugenia González, Luis Romero-Hermoso, Aixa González, Pamela Hidalgo, Sebastian Meier, Rodrigo Navia, Mara Cea

The effects of the pyrolysis conditions in terms of temperature (400 to 600 °C), residence time (0.5 to 3.5 h), nitrogen flux (0 to 1 L/min), and temperature increase rate (1.5 to 3 °C/min) on the physicochemical properties of biochar were studied. The physicochemical properties evaluated in the biochar were specific surface area, pore volume, average pore size, total carbon content, pH, total acidity, elemental composition, and polycyclic aromatic hydrocarbons (PAHs) content. A higher specific surface area of 108.28 m2/g and a mean pore size diameter of about 2.24 nm were found when the pyrolysis was conducted at 600 °C. In general, the pH and total acidity increased with the increased pyrolysis temperature. The total PAH concentration in all of the combinations studied varied from 0.16 to 8.73 μg/kg, and only phenanthrene, pyrene, and chrysene were detected. The increased temperature seemed to decrease the PAH concentration in the biochar. Nevertheless, there was no correlation found between the PAH content and the combined evaluated parameters.

2017

Pyrolysis conditions; Biochar; Physicochemical properties; Polycyclic aromatic hydrocarbons

10.15376/biores.12.1.2040-2057

BioResources

North Carolina State University

Biotechnology