DOI: https://doi.org/10.55373/mjchem.v24i2.293

Keywords: Biochar; cardamom husks; cardamom seed residue; liquid smoke; pyrolysis

Abstract

Most cardamom by-products have not been utilized yet, and by conducting pyrolysis, they can have added value. Pyrolysis is a heating process of biomass without oxygen that produces liquid smoke and biochar. The liquid smoke can be applied as a preservative, and the biochar can be used as an energy source. Cardamom seed residue after oil distillation and the husks were pyrolyzed at 350 – 550 °C with a heating rate of 0.36 - 0.45 °C/s for 1 hour using an N2 carrier gas. The higher yield of liquid smoke (63.91%) was produced after pyrolysis of the husks at 550 °C. At the same time, 51.69% of liquid smoke was produced from pyrolysis of the seed residue at 450 °C. The liquid smoke consisted of chemicals grouped into alcohols, aldehydes, ketones, carboxylic acids, furans, and phenols, with methanol, acetic acid, 1-hydroxy-2-propanone, and furfuryl alcohol as the main compounds. Moreover, 44.86% and 41.86% of biochar were produced from pyrolysis of the husks and the seed residue at 350 °C. The yield of biochar decreased by increasing pyrolysis temperature. After being converted into biochar, the calorific value of the husks and the seed residue increased from 12.95 and 16.24 MJ/kg to 16.79 and 23.07 MJ/kg, respectively.