## 1 Introduction  
Modern economies worldwide are undergoing a profound transformation as nations recognize the urgent need to shift from fossil-based resources to renewable and sustainable alternatives. This transition is driven by the dual challenges of climate change and resource depletion, which demand innovative solutions to reduce greenhouse gas emissions, protect the environment, and promote circular economic models. The bioeconomy, which integrates biological resources and processes to produce energy, materials, and chemicals, is central to this transition, offering a pathway to reduce dependence on finite petroleum sources and achieve sustainable development goals [1]. With the global bioeconomy projected to reach a value of USD 15 trillion by 2030, its role in mitigating climate change and reducing fossil fuel reliance cannot be overstated. However, the current management of agricultural and industrial waste remains a significant challenge. Annually, 998 million tons of agricultural waste are generated, with over 80% being incinerated or sent to landfills, contributing to 10% of global methane emissions [2; 3]. As the global population is expected to exceed 10 billion by 2050, the need for sustainable agricultural practices and waste management systems becomes increasingly critical. Reducing fossil fuel dependency, minimizing emissions, and converting waste into reusable resources are essential steps toward achieving these goals. In this context, lignocellulosic biomass, derived from agricultural and forestry waste, represents a vast and underutilized resource. With an annual global production of 181.5 billion tons, only 8.2 billion tons are currently utilized [4], highlighting the untapped potential of this renewable feedstock [5]. Lignocellulosic biomass, composed of cellulose, hemicellulose, and lignin, is a cornerstone of the bioeconomy (Figure 1). While cellulose and hemicellulose are widely used in paper production and biofuel generation, lignin, the second most abundant natural polymer on Earth, has historically been undervalued. Traditionally treated as a low-value byproduct in the pulp and paper industry, lignin is often incinerated for energy recovery or discarded as waste [6]. However, recent advancements in research and technology have shifted this perspective, recognizing lignin as a versatile and renewable resource with immense potential for high-value applications. Refs. [7; 8] note its aromatic structure, functional groups, and biodegradability that make it an ideal candidate for producing biofuels, bioplastics, high-value chemicals, and advanced materials [9]. Lignin valorization is a key component of the circular bioeconomy, offering opportunities to reduce environmental impact, minimize resource utilization, and create sustainable alternatives to fossil-based products [10]. Globally, agricultural residues including wheat straw, rice husks, corn stover, and sugarcane bagasse are generated in staggering quantities, reaching an estimated 1 billion tons annually [11]. These residues contain lignin in proportions ranging from 15% to 30% [12], yet a substantial fraction of this  
Figure 1: Composition of lignocellulosic biomass, showing the typical distribution of cellulose (20–40%), lignin (15–30%), and hemicellulose (20–40%) in plant cell walls. These components form the structural basis of biomass and are key to its utilization in bio-based applications. valuable resource remains unexploited, often being burned or discarded, contributing to environmental pollution and resource inefficiency [13]. Despite its potential, the widespread adoption of lignin-based technologies faces several challenges. The structural variability and chemical resilience of lignin make its conversion into valuable products technically complex. Additionally, current industrial applications are limited by the lack of cost-effective and scalable extraction and processing technologies.