NAMUGA is responsible for the hardness of wood due to a polymer substance called lignin. While it is an essential component for the survival of wood, it was of no use in wood processing. The first thing removed when making paper from wood is lignin.
Lignin, which was discarded as industrial waste at a rate of 100 million tons annually, is gaining attention as an eco-friendly new material to replace petrochemical products. Its applications range from fuel to vaccines to hair conditioners.
◇Emerging as an eco-friendly material to replace petrochemical products
Lignin accounts for 30% of wood. It acts as a natural adhesive that enhances the strength of wood by bonding with cellulose, which is fibrous. Unlike cellulose, which is used to make paper and pulp, lignin was considered waste and discarded. According to the University of Delaware, it is estimated that the annual lignin waste reaches about 100 million tons.
Once a headache for wood, lignin is now gaining attention as an alternative material for eco-friendly fuels and petrochemical products. Lignin has a specific molecular structure consisting of six carbon atoms forming a benzene ring, which is used as a raw material for plastics, adhesives, and synthetic fibers. Previously, these chemicals were produced using benzene, toluene, and xylene (BTX) extracted from petroleum. Recently, technology has emerged that breaks down lignin into smaller molecules to obtain substances similar to BTX.
Kim Ho-yong, a senior researcher at the Korea Research Institute of Chemical Technology, noted that “lignin is gaining attention as a natural material that can replace BTX compounds used in existing petrochemicals,” and “As the technology to convert lignin into unit molecules progresses, the applicability of lignin in the traditional petrochemical industry, where BTX was used, is increasing.” This means that petrochemical products can now be made using lignin instead of petroleum.
A prominent area of active lignin research is biofuels. Research team leader Ha Jung-myung from the Clean Energy Research Center at the Korea Institute of Science and Technology (KIST) has developed technology to mass-produce bio-aviation fuel from lignin. Lignin has high viscosity, which made it challenging to use like conventional fuels. The KIST research team solved this problem by employing a ‘hydrogenation depolymerization technology’ that decomposes oil under high temperature and pressure after adding hydrogen.
Ha, the research team leader, stated, “We can obtain benzene rings from lignin, and by blending it with existing sustainable aviation fuel (SAF), we can produce a fuel almost identical to petroleum aviation fuel,” adding that “the benzene ring structure is more advantageous for fuel because it has higher energy and boiling points than linear structures.”
◇Also utilized in vaccine and hair product manufacturing
Professor Kim Jae-yoon from the Department of Chemical Engineering and Polymer Science at Sungkyunkwan University showcased a technology in 2023 that utilizes lignin as a vaccine material. He confirmed that lignin suppresses excessive immune responses and created therapeutic vaccines by binding immunogenic antigen proteins to lignin nanoparticles.
When this vaccine was administered to a multiple sclerosis mouse that experienced paralysis in its hind legs due to an autoimmune reaction attacking spinal nerve cells, the paralysis symptoms were restored. This confirmed the potential of lignin vaccines as a treatment for multiple sclerosis, which currently lacks a clear therapeutic solution. Professor Kim remarked, “We have verified the possibility of utilizing lignin, a natural material, as a high-value immunotherapeutic material.”
Internationally, lignin is also being developed for hair care products. A research team from Stockholm University in Sweden announced last month in the international journal ‘Science Advances’ that they developed a new conditioner by mixing lignin with coconut oil. The conditioner coats the surface of hair washed with shampoo to prevent static electricity and block ultraviolet rays. While it does not restore damaged hair, it helps maintain softness.
Experimental results showed that the lignin conditioner softened hair to a level similar to existing natural conditioners, reducing resistance by 13% during combing. The research team confirmed the same results by observing hair under a microscope.
Kim Ho-yong, the senior researcher at the Institute of Chemical Technology, said, “While corporations are showing interest in utilizing lignin, it seems that it will take time to produce it as a product line,” adding, “As environmental policies are specified, the industrial development of lignin will gain further momentum.”
References
Science Advances(2025), DOI : https://doi.org/10.1126/sciadv.adr8372
ACS Nano(2023), DOI : https://pubs.acs.org/doi/10.1021/acsnano.3c04497
Energy Conversion and Management(2020), DOI : https://doi.org/10.1016/j.enconman.2020.112728