Obtaining bio-oil and activated carbon from waste pomegranate peels by pyrolysis

This study aims to produce beneficial products with pomegranate peel waste through pyrolysis. For this purpose, the usability of the liquid product as a biofuel and the solid product as an adsorbent for dye removal was investigated. To characterize the bio-oil and biochar produced under the best pyrolysis conditions, Fourier transforms infrared spectroscopy (FT-IR), Gas chromatography-mass spectrometry (GC-MS), calorific value, Brunauer-Emmett-Teller (BET), and Scanning electron microscopy (SEM) analyses were conducted. When we examine the FT-IR spectrum of the bio-oil, the presence of phenol, alcohol, ketone, and aldehyde groups is seen in the structure. The GC-MS analysis demonstrated that phenol content was 27.9%, aldehyde content was 19%, acid compound content was 18.28%, ketone content was 8.7%, and aromatic compound content was 8.4%. The lower calorific value of bio-oil was determined as 27.33 MJ/kg. It was observed that activated carbon produced from biochar at a 3:1 KOH/biochar impregnation ratio and a carbonization temperature of 800 °C exhibited the highest surface area (1307 m²/g). In adsorption analysis, it was observed that the adsorption efficiency was higher at pH 9 and 35 °C and with 150 ppm initial concentration. Langmuir and Freundlich adsorption isotherms were determined, and the high R² (0.99) was consistent with the Langmuir methylene blue (MB) adsorption model.