Integrated biorefinery for xylooligosaccharides, pectin, and bioenergy production from orange waste

Abstract

AbstractOrange waste is one of the most underutilized biowastes. It accounts for 50% of the fruit weight after juice extraction, presenting an environmental problem due to inappropriate disposal. Industrial waste exploitation is a sustainable way to obtain bioproducts and bioenergy. However, the efficiency of chemical treatments and enzymatic cocktails is still a bottleneck in these processes. One potential route to reduce costs is to design consecutive extraction and hydrolysis stages to yield more products from different fractions of the same feedstock, reducing the use of time and bulk materials. This study assessed the economic performance of an orange processing waste (OPW) biorefinery for xylooligosaccharides (XOS), pectin, and bioenergy, involving three aspects: (1) experimental procedures, (2) a simulation approach, and (3) optimization tools. The optimization of hydrothermal treatment for pectin extraction decreased material costs by more than 60% and preserved the xylan content for xylooligosaccharide production by enzymatic hydrolysis. This study analyzed different biorefinery capacities, and solid waste exploitation for heat and steam generation, improving sustainability. The production cost per kg of high‐purity pectin and xylooligosaccharides is 3.67 $ with an efficient solvent recovery and self‐sufficiency for standard power usage. These results proved the economic feasibility and low environmental impact of the OPW biorefinery.