Pyrolysis of hornbeam shell (Carpinus betulus L.) in a fixed bed reactor: Characterization of bio-oil and bio-char

• Hornbeam shell residues were pyrolyzed at different pyrolysis conditions.
• Bio-oil and bio-char were characterized with the various techniques.
• Bio-oil can be used as fuel directly or in a mixture with other conventional fuels.
• Bio-char could be used as precursor for activated carbon production.

In this study, pyrolysis of hornbeam (Carpinus betulus L.) shell residues was investigated to determine the optimum pyrolysis conditions and the physical and chemical characteristics of bio-oil and bio-char. Experiments were performed at the pyrolysis temperatures of 400, 450, 500, 550 and 600 °C, heating rates of 7, 15, 30 and 50 °C min−1 and nitrogen flow rates of 50, 100 and 150 cm3 min−1. The highest bio-oil and bio-char yields were 24.67% and 40.30%, respectively. The thermal degradation of raw material was studied in inert atmosphere by thermogravimetric (TG) and derivative thermogravimetric (DTG) analyses. The elemental composition, higher heating value, density and viscosity of the bio-oil was determined, and then the characterization of the bio-oil was performed using various chromatographic and spectroscopic techniques. Higher heating value, fixed carbon, ash and carbon contents of bio-char were determined. Moreover, the scanning electron microscopy (SEM) images, Fourier Transform Infrared Spectroscopy (FTIR) and Brunauer–Emmett–Teller (BET) analysis of the bio-char were further analyzed. The experimental results showed that the obtained bio-oil can be used as liquid fuels and the bio-char could be used for the production of activated carbon.