Characterization of activated micro biochar form rice husk pyrolysis with hydrochloric acid solution activation

Abstract

Rice husk is the result of rice grain milling which is obtained around 20-30% of the initial weight. This high percentage of husk waste has the potential to be processed into activated biochar because it is rich in organic materials, especially carbon. Activated biochar is a porous material with a large surface area, so it can be utilized for various applications. This study aims to analyze the influence between 2 factors, namely variations in HCl activator concentration (1M, 1.5M, 2M) and soaking time (12 hours, 18 hours, 24 hours) on rice husk biochar. After that, characterization was carried out which included testing water content, ash content, volatile matter content, fixed carbon content, iodine number, yield, and BET surface area. The best treatment was also subjected to FTIR test and determined using the zeleny method. The results showed that rice husk biochar has a moisture content between 1.12%-2.24%, ash content between 48.45%-50.01%, volatile substance content between 11.65%-16.23%, fixed carbon content between 34.20%-40.66%, iodine number between 325.18mg/g-470.98mg/g, yield between 81.34%-87.42%, and BET surface area between 358.61m²/g-519.40m²/g. Biochar with the best characteristics was obtained in the treatment of 2M HCl Concentration and 24 hours of soaking time.The treatment has characteristics of moisture content of 1.20%, ash content of 48.62%, volatile matter content of 11.65%, bound carbon content of 40.66%, iodine number of 470.98mg/g. This study highlights the physico-chemical properties of biochar with potential for further applications in agricultural technology, waste treatment, and as an eco-friendly material.