How to extract lignin
Two method to extract lignin
One is the plant body other than the components are dissolved out of lignin, lignin as an insoluble component separated by filtration; typical example of this approach is the acid hydrolysis of wood, the cellulose is hydrolyzed into glucose, the hydrolysis of lignin residues are separation. Available 65% to 72% sulfuric acid or 42% hydrochloric acid, the former is called the sulfuric acid to obtain lignin, which is called the hydrochloric acid to obtain lignin, lignin cartridge timber or acid hydrolysis lignin. In addition, copper oxide with sulfuric acid and ammonia solution separation method and the use of sodium periodate solution separation method such as several.
Another contrary, lignin as a soluble component, the dissolution of lignin in plants and other ingredients do not dissolve cellulose, for separation. A typical example is the paper pulping process. There are two methods pulping, one is free sulfite containing calcium, magnesium, sodium, ammonium bisulfite solution, heated at 130 ~ 140 ℃ cooking wood chips, this time as the original water-soluble sulfonated lignin of lignin sulfonate, cellulose is precipitated cellulose filter out the rest of the pulp waste, treated with lime to precipitate lignin; second is with concentrated caustic retort Splintertree or cut chopped straw or wheat straw, then dissolved into the alkali lignin original lignin, cellulose is precipitated, filtered cellulose, and the rest is known as black liquor, with an acid treatment, which can early wood precipitation Su.