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

Abstract

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.

Description

technical field

[0001] The invention relates to a method for recovering lignin from low-boiling alcohol pulping waste liquid, and relates to the technical field of pulping and papermaking engineering. Background technique

[0002] As the economy takes off, China's demand for pulp and paper is increasing rapidly. However, as we all know, many pulp mills in my country still use traditional pulping methods. Waste liquid recycling requires high energy consumption and large investment, which will still cause secondary pollution and bring great pressure to the environment and energy. Therefore, in my country's "11th Five-Year Plan for Pulp and Papermaking", the development of clean pulp production technology has been listed as a key content. In view of this, finding a new pulping method that can effectively recover useful substances such as lignin and better protect the environment has become an urgent problem to be solved in the paper industry.

[0003] The organic solvent pulp...