Method for recycling lignin from low-boiling alcohol method pulping waste liquor

The invention relates to a method for recycling lignin from low-boiling alcohol method pulping waste liquor, which relates to the technical field of pulping papermaking engineering. The method for recycling the lignin from the low-boiling alcohol method pulping waste liquor is applicable to the waste liquor which is obtained by boiling reagent of plant raw materials with low-boiling alcohols, the waste liquor is processed in steps such as flash evaporation, diluting, cooling, precipitation, filtering, separating, drying and the like to obtain lignin, calcium hydroxide is added in filter liquor, and the precipitate is filtered, separated and dried again to obtain low-molecule lignin. The method has characteristics of high recycling rate, less investment, no pollution and low energy consumption.