Environmentally friendly process based on a combination of ultrasound and peracetic acid treatment to obtain cellulose from orange bagasse

Abstract

AbstractBACKGROUNDBrazil is responsible for 60% of the global production of orange juice, accounting for over three‐quarters of global orange juice exports, resulting in large quantities of orange bagasse (OB). This is an underutilized byproduct of the orange juice industry and corresponds to 50% of the fruit weight. The objectives of this study were to produce cellulose from OB using a combination of ultrasound and peracetic acid (PA) treatment, and to characterize the obtained materials according to their microstructure, crystallinity, thermal stability and water sorption behavior, and their cellulose, hemicellulose and lignin contents.RESULTSUltrasound pretreatment alone was not effective in altering the composition of OB. Samples subjected to both ultrasound and PA presented higher cellulose contents and lower hemicellulose and lignin contents in comparison to their respective samples undergoing PA treatment alone. The sample subjected to ultrasound for 10 min at a 30% amplitude combined with PA treatment for 24 h (USPA.24) resulted in the highest crystallinity index (54%), with 81.49% cellulose, 0.88% hemicellulose and 2.68% lignin. The increase in cellulose content of samples also resulted in lower water‐holding capacity, solubility and water adsorption capacity of samples.CONCLUSIONUltrasonication associated with PA treatment can be considered a promising approach and effective protocol for the extraction of cellulose from lignocellulosic residues, and it has the advantages of simplicity and environmental friendliness when compared to conventional methods, reducing the toxicity and amount of the resulting effluents. © 2020 Society of Chemical Industry (SCI)