## 2 Structural Complexity and Composition of Native Lignin
### Lightin in the Textile Industry  
The textile industry is a significant contributor to industrial lignin waste, particularly through the processing of natural fibers such as cotton, flax, hemp, and jute [53]. These lignocellulosic plant materials contain substantial amounts of lignin, often removed and discarded during fiber extraction, retting, and chemical processing [54]. Annually, the global production of lignin-rich textile waste is estimated at approximately 130 million tons, positioning the textile sector as one of the largest untapped sources of industrial lignin [55]. Historically, this lignin-rich waste has been underutilized, commonly disposed of in landfills or incinerated, practices that contribute to environmental degradation and resource inefficiency [56]. However, growing interest in circular economy strategies and sustainable materials has spurred efforts to recover and valorize this resource. Recent developments in alkaline and organosolv pretreatment methods have enabled the selective extraction of lignin from textile residues, with recovery rates ranging from 40% to 60%, depending on the feedstock and process parameters [57]. One promising application is in the development of biodegradable textile coatings. Lignin-based coatings can improve the UV resistance, mechanical strength, and water repellency of natural fiber fabrics, making them suitable for outdoor appear, technical textiles, and geotextiles [58]. Companies like Lignovations ([[https://lignovations.com/](https://lignovations.com/)]([https://lignovations.com/](https://lignovations.com/)) accessed on 10 May 2025) (Austria) are developing lignin-based functional additives and dispersions for textiles, targeting bio-based coatings with antimicrobial and antioxidative performances. Additionally, lignin-derived eco-friendly dyes are gaining attention as sustainable alternatives to synthetic dyes, which are often toxic and non-biodegradable. Lignin-based dyes not only provide a renewable pigment source but also offer inherent antimicrobial and UV-protective properties, enhancing the functional and aesthetic value of textiles. Pilot studies have demonstrated that lignin-derived chromophores can produce color hues ranging from yellow-brown to deep purple, depending on their chemical structure and processing [59]. Textile-derived lignin also shows promise in pyrolysis-based applications, particularly for the production of biochar, a porous, carbon-rich material [60]. Through thermal decomposition in the absence of oxygen, lignin-rich residues can be converted into biochar with high adsorption capaci  
Figure 5: Advantages and uses of lignin-based products in agriculture. ties [60]. This biochar has demonstrated the effective removal of dyes, heavy metals, and organic contaminants from textile wastewater, contributing to closed-loop water treatment systems within the industry [60]. Several pilot projects in India and China have begun implementing lignin-derived biochar in decentralized effluent treatment units, highlighting its practical viability. Beyond coatings and water treatment, lignin from textile waste can serve as a natural binder or reinforcing agent in biocomposites, enhancing the strength and thermal stability of materials used in automotive interiors, building panels, and sustainable packaging [61]. Lignin-based adhesives, which are formaldehyde-free and non-toxic, are increasingly used as sustainable alternatives in wood laminates and fiberboard products for the textile and furniture sectors [62]. Despite its potential, several barriers remain: the lack of standardized and cost-effective extraction methods, variability in lignin composition depending on fiber type and processing, and the need to establish reliable supply chains for consistent lignin quality. Promising advances in enzymatic delignification, deep eutectic solvents (DES), and low-energy pyrolysis technologies are addressing these gaps, while collaborative efforts among academia, startups, and industry are fostering commercial readiness.