ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Characterization of Erythrina indica biomass and its pyrolytic biochar: influence of temperature and time

Ashish Ranjan and Nanda Kishore

School of Agro and Rural Technology, Indian Institute of Technology Guwahati, Guwahati, India

E-mail: nkishore@iitg.ac.in

Received: 11 December 2025  Accepted: 19 May 2026

Abstract:

Thermal degradation of lignocellulosic biomass waste, under oxygen-deprived conditions, produce biochar which is a carbon-rich solid product suitable for several applications. Its quantity and quality depend on several parameters; a few important ones are the type of biomass, reaction temperature, and time. In this study, effects of temperature and reaction time on pyrolysis of Erythrina indica (EI) biomass were examined in a tubular reactor at temperatures of 400–700 °C and reaction times of 60–120 min. The resulting pyrolytic products, especially biochar, underwent a comprehensive characterization employing advanced analytical techniques. The results revealed a clear dependence of product yield and quality on pyrolysis temperature and reaction duration. The surface morphology of fibrous lignocellulosic biomass transformed from compact to a porous biochar structure during pyrolysis. The experimental BET analysis showed that maximum surface area (250.76 m²/g) biochar obtained at 500 °C for 60 min, while XRD indicated partial graphitization at higher pyrolysis temperatures. The bio-oil exhibited acidic characteristics (pH = 3.2–4.4) and a maximum HHV is obtained at 500 °C for 90 min. The regression model was used to explore the combined effects of process variables, and pyrolysis conditions corresponding to maximum response within the experimental domain were identified. These were 506 °C and 60 min. producing 48.35 wt% yield biochar with 55.64 wt% of fixed carbon, 151.62 m²/g of surface area, pH of 9.35, H/C of 0.050, and O/C of 0.377.

Graphical abstract

Keywords: Erythrina indica; Pyrolysis; Reaction time; Temperature; Biochar; Tubular reactor

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-05089-6

Chemical Papers 80 (10) 11751–11771 (2026)