“…Therefore, soda pulping is primarily used for the fractionation of herbaceous feedstock (e.g., perennial grasses, agricultural residues), which typically possess a more accessible structure, a lower lignin content, and a higher amount of alkali-unstable ester linkages [62,63]. To increase the fractionation efficiency during soda-pulping, anthraquinone is often used, because it can act as a redox shuttle to promote ether bond cleavages (reductive) and stabilize the carbohydrate fraction (oxidative) [61,68]. A major advantage of the soda pulping process is the production of a more valuable sulphur-free lignin, thus avoiding catalyst poisoning or bad odors (often linked to sulphur) during downstream lignin processing [63,69].…”