The Isolation and Characterization of Lignin by Alkali Pretreatment Black Liquor of Rice Husk (Oryza sativa) Using Klason Method
Piping Nur Aripin(a), Deana Wahyuningrum(a*), and Rani Kurnia(b).

a)Department of Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung
*e-mail: deana[at]itb.ac.id
b)Department of Petroleum Engineering, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung

Abstract

Rice (Oryza sativa) is one of the agricultural commodities in Indonesia, especially in West Java, such as Majalengka. In 2021, the Central Bureau of Indonesia^s statistics released a production date that West Jawa produces 9.12 million tons of rice. There are potential biopolymers of biomass (such as husk, straw, and brand) that have lignin contents. It^s husk (19,2%), straw (15,6%) and brand (11,5%). In this study, lignin has been isolated with variation alkaline pretreatment black liquor of rice husk by precipitation with sulphuric acid as alternative raw lignin materials. The chemical properties of the isolated lignins were analyzed with their chemical properties, such as lignin content, FT-IR spectra, and LC-MS. The results showed that lignin isolated sodium hydroxide 15% has a lignin content of 22.88%, highest than other concentration variations of 5% alkaline (16.84%) and 10% alkaline (19.82%). The FTIR^s spectrum showed wave number OH phenolic (3481.5 cm-1), -C=C- vibration of aromatic (1635,6 cm-1), C-O streching of syringyl and guauasyl (1224.8 cm-1) groups. Meanwhile, analysis of LC-MS showed that m/z 107 (p-cresol), m/z 151 (guanine and vanillin), m/z 163 (eugenol), m/z 177 (conyferyl aldehyde), and m/z 225 (syringyl aldehyde). Based on the characterization of lignin isolated with typical characteristics of commercial lignin, it can be developed as raw materials for surfactant and bioenergy.

Keywords: Lignin- Rice Husk- Alkaline Concentration- Klason Method.

Topic: CHEMISTRY AND MATERIAL SCIENCES