Properties of microcrystalline cellulose prepared from oil palm empty fruit bunch at different sulfuric acid concentration and hydrolysis temperature

Abstract

Microcrystalline cellulose (MCC) is a biodegradable crystalline powder that normally isolated through acid hydrolysis process of cellulose. However, the implication of high concentration of acid, such as more than 5M sulfuric acid (H2SO4) in MCC production is concerned. Therefore, this work studies the effect of low acid concentration (1.5, 2.5 and 3.5 M) and hydrolysis temperature (40, 60 and 80 °C) for the MCC isolation from oil palm empty fruit bunch (EFB) assisted with steam explosion process cellulose fibers. Yield, crystallinity and chemical properties of the isolated EFB-MCC were discussed and compared with the commercial MCC. The crystallinity result shows the range of 72-77% for the isolated EFB-MCC. The highest crystallinity (77%) achieved at 3.5M H2SO4 at 80°C, similar to the crystallinity of the commercial MCC. As for the yield, the trend is decreasing severely as the increment of temperature, however small reduction of yield detected at different H2SO4 concentration. While for the chemical properties, FTIR spectra illustrated consistent wavenumbers detection for the EFB-MCC, commercial MCC and exploded EFB-Cellulose. It can be concluded that the optimum condition for the acid hydrolysis process is 1.5M H2SO4 at 60 °C with the middle range of crystallinity (74.7 %) and yield (82.4 %).