Investigation of the material properties of acid-activated biochar produced via low-temperature pyrolysis

Radhika Panickar; Roderquita Moore; Derrick Dean

doi:10.2737/FPL-RN-434

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Investigation of the material properties of acid-activated biochar produced via low-temperature pyrolysis

Informally Refereed

Authors:

Radhika Panickar, Roderquita Moore, Derrick Dean

Year:

2026

Type:

Research Note

Station:

Forest Products Laboratory

DOI:

https://doi.org/10.2737/FPL-RN-434

Source:

Res. Note FPL-RN-434. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory.

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Abstract

This study aims to improve the physical properties of biochar (BC) produced through pyrolysis at 300 °C by employing acid activation. Four acids—nitric acid (HNO₃), hydrochloric acid (HCl), phosphoric acid (H₃PO₄), and sulfuric acid (H₂SO₄)—were used to activate the BC. The acid-activated BC was then characterized to assess the effects of the treatments. Brunauer–Emmett–Teller (BET) analysis indicated a 34 percent increase in surface area for BC activated with H₃PO₄. Fourier transform infrared (FTIR) spectroscopy analysis revealed shifts in peak positions and changes in the functional groups present on the BC for different acids post-treatment. Raman spectroscopy showed a low defect ratio of 0.82, and thermogravimetric analysis (TGA) demonstrated enhanced thermal stability for the H₃PO4-activated sample. Of the acids tested, H₃PO₄ activation resulted in the most significant improvement in the properties of the biochar.

Keywords

biochar, pyrolysis, acid activation, thermomechanical properties, polymer extrusion

Citation

Panickar, Radhika; Moore, Roderquita K.; Dean, Derrick. 2026. Investigation of the material properties of acid-activated biochar produced via low-temperature pyrolysis. Res. Note FPL-RN-434. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 10 p. https://doi.org/10.2737/FPL-RN-434.