published on 5 October 2020 in energy
Lignin becomes a resource for nylon production
Researchers at the Ames Laboratory of the U.S. Department of Energy have discovered how to bring lignin from the Kraft process, an industrial method of chemical extraction of cellulose from wood, back into the production cycle. This is an industrial method of extracting cellulose pulp from wood, which is then processed into paper. Lignin is an organic polymer used for example to strengthen various plant tissues. Lignin is also one of the main by-products of the paper production process. Generally this biomass is used for combustion with heat recovery, resulting in the release of carbon dioxide into the atmosphere. Ames researchers have found an alternative use for lignin, recovering it to obtain chemical precursors used in nylon production. The first step is the traditional treatment of the polymer with an aqueous solution of sodium hydroxide (i.e. caustic soda). At temperatures of about 200°C, the macro-molecule degrades, returning one of its simplest constituent elements: guaiacol. In turn, this small aromatic compound can be converted into a precursor of nylon in even less energy-intensive conditions, using certain catalysts. It is a solution with low environmental impact, both in terms of solvents and other chemicals used and in terms of the energy required by the process.
The details of the research were published in a study that appeared in the journal Green Chemistry.