Co-production of ethanol, xylo-oligosaccharides and magnesium lignosulfonate from wheat straw by a controlled magnesium bisulfite pretreatment (MBSP)

Full utilization of all three major components of biomass (glucan, xylan and lignin) is considered to be the key to commercialization of bio-refinery process of biomass. In this work, based on pretreatment severity (PS), a controlled magnesium bisulfite pretreatment (MBSP) was developed to produce ethanol, xylo-oligosaccharides (XOS) and magnesium lignosulfonate (ML) simultaneously. After MBSP at PS 3.66 (170 °C for 40 min), about 136 g of ethanol, 98 g of XOS and 133 g of ML were achieved from1 kg raw wheat straw. As high values-added chemicals, XOS has many applications in food and pharmaceutical industries while ML can be used as surfactants and dispersing agents. These results suggest that a controlled MBSP offers an effective way to fully utilize its components and coproduce ethanol, XOS and ML from wheat straw.