SULFITE COOKING PROCESS Effect of Pretreatment of Spruce Wood on the Reaction

A Lignin-Carbohydrate Complex in Wood A Review of the Literature

“…This hypothesis is supporced by the fact that, while wood can be sulphonated at quite high pH values, the lignosulphonic acid only becomes water-soluble at a low pH. Since wood which has been premethylated with diazomethane can be sulphonated, but will not yield a water-soluble lignosulphonate (22), an acidic hydroxyl group is apparently involved in the formation of a water-soluble lignosulphonate. Nokihara (109) has also studied the mechanism of sulphite delignification, and concludes that two reactions were involved, a fast reaction involviog a free hydroxyl group, and a slow reaction involving the decomposition of a lignin-carbohydrate complex.…”