Important parts of the textile industry, silkworm cocoons provide threads for silk clothing, which are often high-value-added products. A problem with this industrial chain is that, in the process of removing the most valuable threads for the production of the material, waste considered pollutants remains.
In search of ways to reuse waste from this industry, researchers from the Faculty of Chemical Engineering (FEQ) at Unicamp, in partnership with researchers from the State University of Maringá (UEM), developed a technology through which part of the waste material coming from the cocoon from silkworms is used to extract noble and toxic metals.
O invention, whose intellectual property was protected with the support of Inova Unicamp Innovation Agency, seeks to use sericin, one of the components present in the formation of cocoons, for this extraction. From the development of blends, a mixture of molecules, the particle can be used to remove toxic metals or noble metals, such as palladium, gold and silver.
The technology is also a cheaper and environmentally sustainable alternative to activated carbon, a pollutant used by industry to reuse these metals. Another application of sericin is in the removal of metals from secondary sources – equipment and jewelry no longer used, for example. A process that could be called post-consumer reverse logistics.
Post-consumption and circular economy
A concept related to the reuse of products after the end of their useful life, post-consumption has become a legal requirement for several companies following law 12.305/2010, which determines the collection and recycling of products and their waste after consumption. by the end customer. Among the industrial niches that must carry out the process are companies selling electronic products and their components and products sold in plastic, metallic or glass packaging, in accordance with article 33 of the lei.
After this became an important topic, Brazil, in recent years, has witnessed some advances. According to data from the federal government, while in 2019, just over 16 tons of this type of material were collected, in 2020 this number rose to 105 tons. In 2021, more than 1.200 tons of electronic waste were collected and stopped being discarded in the environment
Despite advances, Brazil is still the fifth largest producer of electronic waste in the world, according to report of Electronic Waste Research. One study of the United Nations (UN) also highlights that, in Latin America, there was still a 49% increase in the irregular disposal of electronic waste in the last decade.
This data highlights the potential of sericin blends as a green technology or with positive impacts on the environment, as explained by FEQ professor Melissa Gurgel Adeodato Vieira, one of the project coordinators:
“The adsorbents that we developed with the blends have a high affinity that helps in the extraction of metals from secondary sources, contributing to closing a circular economy cycle: we do not recover disused equipment, but the metals that are inside, which also contributes to the return of these products to the production cycle.”
According to a survey by the National Confederation of Industry (CNI), around 76% of Brazilian companies already carry out some type of circular economy – an inviting scenario for the use of sericin by various sectors of the production chain.
Social technology for family farming
The sericin blend technology also has a social impact: opening up more business opportunities for producers in the sericulture sector.
Sericulture, or silkworm farming, is today an economic activity closely linked to family farming. It is estimated that in Paraná, the largest producer of silkworm cocoons in Brazil, there are more than 1.800 producers, who would be responsible for 84% of national production, according to the Paraná Rural Development Institute (IDR Paraná).
The economic activity is also considered clean production, as it does not use pesticides.
With the demand for sericin present in cocoons, the technology developed by the team of researchers from Unicamp and UEM can contribute to linking family production networks to new ends of the production chain, if there is licensing from an institution or company that operates in the sector to bring technology to society.
“Brazil is one of the countries that produces the most artifacts from sericulture, but the textile industry is very demanding regarding the extraction of threads. There is a correct way to open the cocoons. And producers, after removing what is of interest to the industry, need to discard the waste generated. So, if you can reuse sericin from this waste, it helps to value an entire chain that is strongly familiar in the country”, concludes Meuris Gurgel Carlos da Silva, professor at FEQ and also coordinator of the project.
Currently, the patent is part of a set of inventions that explore the application of blends to various sectors, which go beyond the extraction of noble metals to include the creation of materials with the aim of extracting or incorporating components capable of benefiting the cosmetics and the pharmaceutical industry.
The novelty of the scientific research and the potential application of sericin blends as a green technology that promotes a circular economy led Inova Unicamp to request protection of the invention's intellectual property. The patent was granted by the National Institute of Industrial Property (Inpi). Currently, technology is part of the Unicamp Technology Portfolio and it is available for licensing.
Companies and public or private institutions interested in transferring technology to promote innovation in their products or processes can contact directly Innovates Unicamp for research-market connection form.
In addition to access to cutting-edge technologies, technology transfer reduces risks associated with the development of new products and processes and contributes to socioeconomic development based on scientific knowledge.
Article originally published on the Inova Unicamp website.
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