Study on composition, structural and property changes of oil palm frond biomass under different pretreatments

Abstract

Two pretreatment methods were used to treat oil palm frond (OPF) biomass. The first was a one-step pretreatment by the alkali-autoclave-chemical (AAC) method, whereas the second was a two-step pretreatment, consisting in the combination of the alkali-autoclave-chemical process and the microwave-alkali (Mw-A) pretreatment. After the pretreatments, the chemical composition of the samples (cellulose, hemicellulose and lignin) was analyzed. Field electron scanning electron microscopy (FESEM) and Fourier transform infrared (FTIR) analyses were performed so as to examine the morphology of raw and treated samples. The crystallinity index of cellulose was also measured using X-ray diffraction (XRD). The results revealed a huge degree of reduction in lignin, up to 93% for the treated OPF sample. Both one- and two-step pretreatments were capable of disrupting the OPF structure efficiently and each pretreatment resulted in a significant difference in composition.