Researchers in Perm have improved the process of producing white cellulose.

Cellulose is the primary component in the production of paper and cardboard, but its applications extend far beyond that. It is used to create viscose and silk threads, high-strength fibers, cellophane films, plastics, varnishes, smokeless powder, and much more. Approximately seven percent of the world's cellulose production is utilized for these purposes. The manufacturing process requires meticulous mechanical and chemical processing of wood, employing complex and costly technological equipment. It is crucial for companies to implement the most modern and efficient technologies that can save energy and raw materials while significantly reducing wastewater pollution, particularly from the bleaching of cellulose. Researchers at Perm Polytechnic have developed an improved scheme for this process, enabling the production of bleached and refined cellulose (for chemical processing) of high quality, with a whiteness of at least 90 percent and a reduced environmental footprint.

2025-02-25 10:02:21https://naked-science.ru/article/column/polucheniya-beloj-tsellyu

The article was published in the journal "Chemistry of Plant Raw Materials." The research was conducted as part of the implementation of the academic strategic leadership program "Priority 2030."

Cellulose for chemical processing is often referred to as soluble cellulose, as it is used to produce solutions for a variety of fibers and films during further processing. This enables its use for obtaining a wide range of products in the textile, food, medical, and other industries. However, its production on an industrial scale in Russia has been halted, while the foreign practice of producing such a product is in high demand and the demand for it remains strong.

In Russia, which is rich in forest resources, the revival of wood cellulose production for chemical processing is relevant, as it will help address the issue of import substitution: currently, cotton is used instead of wood, and wood fiber products are often imported. Producing wood cellulose for chemical processing requires improving technology to obtain products that can substitute cotton.

Scientists at Perm Polytechnic University have enhanced their previously developed original technology for producing soluble cellulose. Instead of expensive oxygen, ozone with complex technologies, and environmentally harmful molecular chlorine, the polytechnicians use eco-friendly and more advanced bleaching agents – hydrogen peroxide and sodium chlorite.

“The technology consists of several stages. The cellulose must be treated with hydrogen peroxide in an acidic environment, then with alkali. Next, bleaching is performed: first with sodium chlorite, followed by hot alkaline purification and then another bleaching with sodium chlorite. There are stringent requirements for the viscosity of cellulose for chemical processing depending on its intended use; this indicator is regulated using sodium hypochlorite. At the end of the bleaching process, the cellulose is treated with acid,” comments Olga Noskova, Associate Professor of the Department of Polymer Materials Technology and Gunpowders at PNIPU, PhD in Technical Sciences.

“In our scheme, we optimized the stages of bleaching and refining cellulose to bring the quality indicators of wood cellulose closer to those of cotton cellulose, making the process more environmentally friendly and efficient. For this, a new stage has been added to the scheme – re-bleaching with sodium chlorite. It virtually does not subject the wood fibers to degradation, whereas other methods of this process result in significant fiber loss. The optimized production technology has allowed us to obtain wood cellulose that is not inferior in quality to cotton cellulose,” says Firdaus Hakimova, Professor of the Department of Polymer Materials Technology and Gunpowders at PNIPU, Doctor of Technical Sciences.

The improved cellulose processing technology developed by scientists at Perm Polytechnic University using more eco-friendly reagents opens new prospects for reviving its production in Russia. This will not only help solve the import substitution issue but will also significantly reduce the negative impact on the environment, ensuring high quality of the final product and its compliance with state standards. The advantage of the technology is also that it can be integrated into existing technologies at operational plants with relatively low costs, much less than constructing a new facility.