Lignin Derived Chemicals and Aromatics: A Review

Cellulose makes up roughly 45% of every tree, making it the most widely abundant natural polymer on Earth. Lignin is the second most abundant natural polymer on Earth, making up 18-30% of woody biomass. In general, the two processes that create the most desirable properties for most lignin valorization projects are the Sulfite Process and the Organosolv Process as they lead to the least amount of lignin degradation, although the Kraft Process is the most popular method, with 85% of pulp mills going through with this process. Bio-based polyols are important because these are the precursors to polyurethane. Polyurethane is one of the most versatile plastics in the world, with uses in the automobile, coatings, adhesives, sealants, paints, textile, wood composites, and more. Looking at the applications, adhesives and binding were by far the largest use case for this class of resins and is projected to grow more than other applications with the electrical and electronics industry being the most lucrative market for their usage in photoresists and circuit boards, closely followed by the automotive industry.