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Kraft lignin from black liquor, which is produced in much higher amounts, may be processed into sulfonated lignin. The lignin is first precipitated by acidifying the liquor with CO 2 then washed (other methods for isolation exist). Reaction with sodium sulfite or sodium bisulfite and an aldehyde under a basic environment completes sulfonation.
Guaiacol (/ ˈ ɡ w aɪ ə k ɒ l /) is an organic compound with the formula C 6 H 4 (OH)(OCH 3). It is a phenolic compound containing a methoxy functional group. Guaiacol appears as a viscous colorless oil, although aged or impure samples are often yellowish. It occurs widely in nature and is a common product of the pyrolysis of wood. [3]
Lignin was first mentioned in 1813 by the Swiss botanist A. P. de Candolle, who described it as a fibrous, tasteless material, insoluble in water and alcohol but soluble in weak alkaline solutions, and which can be precipitated from solution using acid. [3] He named the substance "lignine", which is derived from the Latin word lignum, [4 ...
The black liquor is an aqueous solution of lignin residues, hemicellulose, and the inorganic chemicals used in the process. The black liquor comprises 15% solids by weight of which two thirds are organic chemicals and the remainder are inorganic. [3] Normally the organics in black liquor are 40-45% soaps, [4] 35-45% lignin and 10-15% other ...
The term "lignin characterization" (or "lignin analysis") refers to a group of activities within lignin research aiming at describing the characteristics of a lignin by determination of its most important properties. [1] Most often, this term is used to describe the characterization of technical lignins by means of chemical or thermo-chemical ...
The major constituents of natural fibers (lignocelluloses) are cellulose, hemicellulose, lignin, pectin and ash. The percentage of each component varies for each different type of fiber, however, generally, are around 60-80% cellulose, 5–20% lignin, and 20% of moisture, besides hemicellulose and a small percent of residual chemical components.
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The results produce fibers that are screened and bleached for paper products. At these conditions, the lignin is dissolved in organic solvent and hemicelluloses are used to produce more organic solvent. Organic solvents are collected by separating water from the cooking liquor and then the lignin is precipitated by adding water, heat, and ...