Changes from lignin to lignin derivatives during prehydrolysis of lignocellulose

Abstract Lignin derivatives produced in prehydrolysis have hindered the conversion and utilization of carbohydrates. Using Masson pine, poplar, and wheat straw as raw materials, the changes from lignin to lignin derivatives during prehydrolysis were systematically studied under the conditions of hydrolysis temperature (160 °C and 180 °C) and holding time (30 min and 120 min). The results showed that Masson pine lignin was easy to condense, while wheat straw lignin was more prone to degradation. A part of the dissolved lignin was adsorbed on the fiber surface after recondensation, especially at high prehydrolysis temperature. The other part condensed with carbohydrate to form lignin-carbohydrate complex, but it was not stable during long-term hydrolysis. For the specific target products, the two undesirable lignin derivatives can be controlled by designing the prehydrolysis temperature and holding time.