Furfural, a versatile platform compound, is produced from the hydrolysis of pentose (hemicellulose) in lignocellulosic biomass. The manufacturing of furfural results in the production and accumulation of cellulose- and lignin-rich furfural residue, simultaneously. Reasonable and effective utilization of furfural residue would provide both environmental and economic benefits. In this work, alkali cooking technology was applied to extract lignin from industrial furfural residue. The effects of different alkali treatment conditions on the composition and chemical structure of extracted lignin and solid residue were studied. The results showed that extracted lignin contained abundant guaiacyl (G), syringyl (S), and p-hydroxyphenyl (H) structural units, among which the G-type lignin structural unit accounted for the main proportion. The extracted lignin samples were rich in hydroxyl, and the highest content of hydroxyl was 4.02 mM/g under the condition of T3 (135°C−0.35 M). An oxidize resistance test showed that extracted lignin showed a high inhibition effect on DPPH. The increase of lignin content in solid residue was due to the carbonization of cellulose into a lignin-like substance under the condition of a high temperature alkali treatment. This alkali cooking technology is suitable for extracting lignin from furfural residue, which has a promising application as a potential antioxidant in the food and cosmetic industry.

糠醛是一种通用的平台化合物，由木质纤维素生物质中戊糖（半纤维素）的水解产生。糠醛的生产同时导致富含纤维素和木质素的糠醛残留物的产生和积累。糠醛残留物的合理有效利用将带来环境和经济效益。在这项工作中，采用碱蒸煮技术从工业糠醛残留物中提取木质素。研究了不同碱处理条件对提取的木质素和固体残渣的组成和化学结构的影响。结果表明，提取的木质素中含有丰富的愈创木酰基（G），丁香基（S）和p-羟基苯基（H）结构单元，其中G型木质素结构单元占主要比例。提取的木质素样品富含羟基，在T3条件下（135°C-0.35 M），羟基含量最高为4.02 mM / g。耐氧化性测试表明，提取的木质素对DPPH具有很高的抑制作用。固体残渣中木质素含量的增加是由于在高温碱处理条件下纤维素碳化为木质素样物质。这种碱性蒸煮技术适用于从糠醛残留物中提取木质素，在食品和化妆品工业中作为潜在的抗氧化剂具有广阔的应用前景。