Lignin is a complex organic polymer found in the tissues of plants. It plays a number of important roles in plant biology, and it also has an assortment of industrial applications, making it a coveted product among certain manufacturers. In nature, lignin is created by plants, and when plants are processed for various industrial purposes, it is possible to extract the lignin for an assortment of uses.

This chemical compound is found in the cell walls of plants. It binds with cellulose, another plant fiber with many uses, to make sturdy, strong cell walls. The more lignin a plant has, the woodier it becomes; lignin provides the shape and form of stalks, twigs, and tree trunks. In addition to providing support and structure, lignin also helps its parent plant conduct water, and it sequesters carbon in the plant. After a plant dies, the lignin takes more time to break down than the rest of the plant, slowly releasing carbon back into the natural environment.

For humans, wood with a lot of lignin has been recognized as useful for centuries. The more lignin a wood has, the sturdier and stronger it will be, making it suitable for more tasks. Lignin also burns very efficiently, which makes heavily lignified woods like oak popular as fuel, as well. Lignin was named in 1819, after the Latin lignum, which means “wood,” referencing lignin's important role in the structure and development of wood.

When extracted from timber and plant products, lignin can be included in a wide variety of things. It can be used as an emulsifying, sequestering, binding, or dispersal agent, depending on how it is processed and what it is used with, appearing in everything from paints to treatments for roadways. Many paper mills and lumber processing facilities view lignin as a valuable byproduct of their industrial processes, selling extracted lignin to other industries.

Chances are very high that you have a product which contains lignin in your vicinity, aside from the obvious furnishings and construction materials. Lignin appears in a wide variety of chemicals from synthetic flavorings to textile dyes, and it can also be found in a wide variety of industrial materials. You also consume lignin every day, in the cells walls of the fruits and vegetables included in your diet. Most of the lignin used in manufacturing is extracted from timber, most classically in paper mills, where wood is shredded, pulped, and treated to produce paper, extracting the lignin it contains in the process.