Valorization of candlenut shell waste into bio-char and liquid smoke (bio-oil)
Year: 2025
Type: conference-paper
Abstract: This study explores the valorization of candlenut shells as raw material for the production of liquid smoke (bio-oil) and bio-char pellets, while also comparing their performance to bamboo-based pellets. Pyrolysis was carried out on 5 kg of candlenut shells at a temperature range of 400-500 °C for three hours, yielding an average of 1775 g of grade 3 bio-oil and 1441 g of grade 2 bio-oil. GC-MS analysis identified 43 compounds in the bio-oil, with mequinol (34.71%) and phenol derivatives as dominant components, contributing antioxidant and antimicrobial properties. These findings suggest that candlenut shell-derived bio-oil has strong potential as a safe and natural preservative. Bio-char pellets were produced from pyrolysis residue by adding tapioca adhesive at concentrations of 10%, 15%, and 20%. Pellets with 10% adhesive showed the most optimal performance, as indicated by a moisture content of 0.20%, bulk density of 1.03 g/cm 3 , calorific value of 5692 cal/g and compressive strength of 1846.85 kgf/cm 2 . However, the ash content (9.25%) did not meet the ISO 17225-3:2020 class A2 standard. Increasing adhesive concentration tended to reduce yield and mechanical strength. In comparison, yellow bamboo and buluh bamboo pellets exhibited lower moisture and energy content but produced less ash. Overall, candlenut shells demonstrated superior performance compared to bamboo as a raw material for energy pellets, particularly in terms of high calorific value, low moisture content, and high energy density.
Authors: Muhammad Arif, Arif Nuryawan, Vivi Purwandari, Naudi Hayati Siregar
Language: English
Subfield: Fuel Technology
Field: Energy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4417464489