Acid-based organosolv lignin extraction from acai berry bagasse

Abstract

Lignin is the second most prevalent natural material on the planet with applications as dispersants, wound dressings, animal feed, chemicals and fuel. A promising source for lignin extraction is from acai, a palm tree from the Amazonian floodplain. In this study, lignins were extracted, for the first time from acai berry bagasse using an acetic acid-based organosolv approach, and the effects of reaction time and acid concentration on the delignification yield were assessed through a statistical relationship. The lignins were then characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). According to the results, the higher the acid concentration, the shorter the extraction time to obtain the maximum delignification yield. The best condition to isolate pure lignin from the bagasse was 92.5 % (v/v) acetic acid concentration and 10 h of reaction time.