Abstract
The technologies for processing solid waste of plant raw materials using the example of amaranth stems into cellulose and nanocellulose and the use of nanocellulose in the production of paper and cardboard are analyzed. It is shown that the use of two-stage thermochemical treatment of plant raw materials allows to obtain cellulose with a low residual lignin content and ash content, which is suitable for further chemical processing, in particular for the extraction of nanocellulose from it. Examples of improving the quality of paper and cardboard through the use of nanocellulose from plant waste are given, which allows to reduce wood consumption and reduce the negative impact on the environment.