Handbook of Lignin

Inhaltsverzeichnis

1. 54. Lignin: Application in Three-Dimensional Printing

   Sarra Tablit, Amina Hachaichi, Mohamed Aymen Kethiri

   Abstract

   Lignin, a natural polymer found in the cell walls of plants, represents an abundant and renewable resource with significant potential for various applications. This chapter examines the novel application of lignin in three-dimensional printing, an area rapidly progressing towards sustainable manufacturing practices. By integrating lignin into three-dimensional printing materials, we can reduce reliance on petroleum-based polymers, enhance mechanical properties, and improve thermal stability of printed objects. Furthermore, lignin contributes to the circular economy by facilitating waste reduction, promoting biodegradability, and enhancing energy efficiency in the production process. However, the integration of lignin into three-dimensional printing materials presents technical challenges, including issues of compatibility and printability that must be addressed to fully realize its potential. This research highlights lignin’s potential to transform three-dimensional printing by encouraging ecofriendly innovation while addressing the challenges of material integration.

2. 55. Lignin in Food Packaging

   Clara Suprani Marques, Tarsila Rodrigues Arruda, Karoline Ferreira Silva, Taíla Veloso de Oliveira

   Abstract

   For a long time, lignin was considered a waste product of the pulp and paper industry. However, as industries shift toward sustainability, materials once treated as waste are now seen as valuable byproducts with potential for creating innovative materials. Thanks to its complex chemical structure and its more hydrophobic nature compared to other bio-based polymers, lignin has become the focus of numerous studies, attracting attention from various market segments, including the food packaging sector. Currently, the food packaging sector is a major contributor to plastic waste, posing a serious environmental challenge. Among the alternatives explored to address this issue, packaging made from bio-based polymers has gained attention. However, despite being more environmentally friendly, these materials face significant performance limitations compared to conventional plastics. In this context, lignin stands out as a promising additive for packaging, thanks to its natural origin, biodegradability, and its potential to enhance the mechanical, thermal, and barrier properties of bio-based polymers. In addition, lignin can increase the hydrophobicity of polymer matrices while imparting antioxidant and antimicrobial properties. This chapter explores the incorporation of lignin into various polymer matrices for the development of food packaging. The results from numerous studies are discussed, along with the limitations, challenges, and future perspectives surrounding this complex molecule. Once discarded by industry, lignin now holds significant scientific importance and added value.

3. 56. Lignin in Water Purification: Enzymatic and Adsorption-Maintained Processes

   Jelena Gržetić, Katarina Banjanac

   Abstract

   The utilization of biocatalytic systems based on lignin in wastewater treatment and bioremediation has emerged as a promising approach to address challenges associated with pollutant removal and water purification. Immobilization of biocatalysts generally offers enhanced stability, reusability, and efficiency compared to free enzymes. Due to that immobilized biocatalysts represent a viable option for various treatment processes. The choice of support material is pivotal. It significantly influences the properties of the resulting biocatalytic system. A wide array of support materials, including inorganic, organic, hybrid, and composite materials, can be utilized to create stable and efficient platforms for biocatalysts. This book chapter provides an overview of the application of enzymes, such as laccases and peroxidases, immobilized on lignin-based matrices in wastewater treatment. It focuses on their role in degrading organic pollutants, such as dyes, phenols, and pharmaceuticals, and explores the design and usage of lignin-based matrices in adsorption-maintained processes for removing heavy metals and organic pollutants from water bodies. Various approaches in the design of lignin materials are discussed, highlighting their impact on enzyme performance and system effectiveness. Furthermore, recent advancements and challenges in the field of development of functional polymers from biorenewable sources, such as lignin and lignocellulosic biomass, are addressed, along with potential future directions for research and application. Overall, the use of biorenewable polymers holds a great promise for advancing wastewater treatment technologies, offering environmentally friendly and sustainable solutions for water remediation.

4. 57. Lignin Recovery from Black Liquor

   Lorranne Marins-Gonçalves, Miria Hespanhol Miranda Reis

   Abstract

   This chapter examines lignin recovery from black liquor, a byproduct of the pulp and paper industry, emphasizing its role in sustainability and the circular economy. Lignin, an abundant biopolymer, offers potential to replace fossil-based materials in applications such as bioplastics, resins, and construction additives. Despite its value, most lignin is currently burned or discarded, representing a significant waste of resources. The chapter discusses the variable composition of black liquor, influenced by feedstock and pulping conditions, and the challenges in lignin recovery, including structural complexity and high ionic strength. Various recovery methods are reviewed: acid precipitation, membrane filtrations processes, solvent extraction, and thermal processes, each with distinct advantages and limitations. A bibliometric analysis highlights growing research interest, with advancements in purification techniques and industrial applications. Membrane filtration, in particular, stands out for its energy efficiency and ability to preserve lignin integrity, though challenges such as fouling and chemical stability remain. In conclusion, lignin recovery from black liquor is crucial for reducing environmental impact and valorizing industrial waste. The chapter underscores the need for integrated research and optimized processes to develop scalable, sustainable solutions aligned with global decarbonization and resource efficiency goals. Future efforts should focus on overcoming technical barriers and fostering industry-academia collaboration to maximize lignin potential.

5. 58. Lignin Fractionation and Concentration from Kraft Black Liquor

   M. Battestini-Vives, O. Wallberg, F. Lipnizki

   Abstract

   Kraft black liquor, a side-stream of the pulp and paper industry, contains lignin, hemicelluloses, and cooking chemicals. This stream is typically evaporated and burned in the recovery boiler to generate power and recover the cooking chemicals used in the pulping process to digest the wood. However, the recovery boiler is often the bottleneck of the chemical-recovery process. By removing lignin from kraft black liquor, the load on the recovery boiler can be reduced, allowing the mill to increase its pulping capacity without having to invest in a new recovery boiler. Moreover, lignin recovery can generate new revenue streams for the mill by replacing fossil materials with lignin. Precipitation by acidification and membrane filtration are the main technologies for lignin fractionation and concentration from kraft black liquor. These methods allow for later valorization of lignin for the production of biofuels and biochemicals. Lignin separation by acid precipitation has been thoroughly investigated, with the most relevant issues being the type of acid used, pH, and temperature conditions for the precipitation. Based on extensive research, several commercial processes have been implemented in different pulp and paper mills worldwide. Membrane filtration has also been thoroughly investigated, with UF being the most popular choice for kraft black liquor fractionation and lignin separation. While membrane processes for lignin recovery have reached the pilot scale stage and are being evaluated economically, more research is needed to reach the commercial stage. Membrane fouling remains the main challenge that membrane filtration faces when it comes to implementation of the processes and understanding how to mitigate fouling and how to improve the cleaning process can be beneficial if membrane processes are to be implemented in pulp and paper mills. Thus, advancing membrane-based lignin recovery and valorization technologies through collaborative efforts is essential to driving the transition to renewable resources, fostering circular economy innovations, and unlocking lignin’s potential in biofuels, sustainable materials, and emerging markets.

6. 59. Deep Eutectic Solvents Lignin: Extraction

   Tingjiao Wang, Yuehan Jiang, Ruqian Shen, Fei Shen, Dong Tian

   Abstract

   Renewable lignin, the richest natural source of aromatics, can be biorefined to produce high-value products to reduce fossil energy consumption. Deep eutectic solvents (DES) have been widely utilized in lignocellulosic biorefineries due to their unique ability to extract lignin in recent years. However, a comprehensive review of the main factors affecting lignin extraction by DES is currently lacking, and their lignin extraction mechanisms have not been systematically summarized. This work reviewed the research progress of the lignin extraction process by DES and the effects of the main parameters, aiming to fill this gap in the literature. The influence of the changes in the composition of DES on the lignin extraction mechanism was highlighted. In addition, this review discussed the coupling effect between various assisted processes and DES for facilitating lignin extraction purpose and the recycling/recovery potential of the spent DES liquid. Finally, the prospects of various challenges and opportunities in the DES lignin extraction field were visualized.

7. 60. Lignin for Thermoelectrics

   Mohammad Ali Nasiri

   Abstract

   This chapter explores how lignin’s complex organic polymer structure can be integrated into thermoelectric materials to enhance their performance. Also, this chapter covers how the unique composition of lignin can be exploited in tuning electrical and thermal conductivity and, in turn, enhance thermoelectric efficiency using methods such as doping, nanostructuring, or composite formation. It also sheds light on lignin’s contributions to improving carrier mobility, thermal stability, and sustainability, developing a clearer understanding of how lignin-based materials could support the advancement of more efficient and eco-friendly thermoelectric technologies. This chapter highlights lignin’s potential in converting low-grade waste heat into usable energy, with attention to environmental and cost considerations. Additionally, it specifically covers recent developments in lignin-derived ionic conducting membranes, hydrogels, solar-driven thermoelectric generation, and the functionalization of carbon nanotubes with lignin biopolymers, as well as a model for ionic conducting membranes.

8. 61. Hydrodeoxygenation of Lignin

   Kamleshwar L. Patle, J. D. Ekhe, K. L. Wasewar

   Abstract

   The exploration of effective methods for valorizing lignin to valuable products attracts the broad interests of a growing scientific community. Hydrodeoxygenation (HDO) of lignin-derived bio-oil is a crucial process for developing biorefineries and one of the promising ways to reduce/eliminate oxygen contents from bio-oil, which generates valuable fuels and chemicals. HDO catalysts have been discussed, including traditional HDO catalysts such as metal sulfide, metal oxide, metal phosphide, nitride, carbide, carbon-based, and zeolite-based catalysts. This chapter provides an overview of the latest progress in lignin HDO catalysts and explains the reaction mechanism that underlies the development of highly effective HDO catalysts.

9. 62. Lignin: Versatile Biomaterial and Building Block for Sustainable Chemistry

   Lina Jadhav, Rahul Patil, Satish V. Patil, Satyendra Mishra, Vikas Patil

   Abstract

   After cellulose, lignin is one of the most prevalent biopolymers naturally occurring on Earth. It is the universe’s primary source of aromatic chemicals. It is a complex macromolecule identified as phenolic material, and its structure varies greatly depending on the type of plant and the method by which it is isolated. The isolation is based on pretreatment as well as acid base methods. The isolation of lignin determines the quality and structural integrity for use. Although lignin has long been produced as a byproduct of the cellulose process in paper pulp, there are very few uses for it that offer an additional value. However, other applications of the lignin have come back into consideration as a result of changes in the paper business. It is valorized by gasification and pyrolysis as well as by combustion. Furthermore, the emergence of biorefinery initiatives aimed at producing biofuels, bio-based goods, and chemicals from carbohydrate polymers ought to yield copious amounts of the lignin with a potential for value addition. These developments have reignited curiosity about lignin and its potential application in polymer materials. Due to the absences of structural homogeneity and oxidative nature of basic phenol in the lignin, put some limitations to the use of lignin. However, the simple chemical modification of the lignin makes up to the useful molecule. It is noted that composite preparation using lignin offers a better way of utilization than the process and singular use of the lignin molecule, which provides structural integrity and strength to the composite material.

10. 63. Exploring the Structural Characterization and Advantages of Lignin as a Biofuel

    Komal Kasana, Shatakshi Srivastava, Tanushri Chatterji, Namrata Khanna, Misook Kang, Sadanand Pandey

    Abstract

    Plant cell walls contain a complex yet important polymer known as lignin. In addition to offering structural support, it acts as a natural barrier against microbial invasion and facilitates the transport of water and nutrients. Despite its abundance and nearly a century of efforts to transform it into valuable products, lignin remains insufficiently utilized in the majority of existing biorefineries. Lignin is primarily used to generate heat and power due to its complicated structure, which hinders its utilization. In the last decade, interest in lignin valorization has increased exponentially to decrease our dependence on nonrenewable energy resources. This chapter highlights the structural properties of lignin which make it a suitable candidate for biofuel. Also, the structural characterization of lignin using different analytical techniques like nuclear magnetic resonance (NMR) spectroscopy, ultraviolet-visible spectroscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR) will be explored in this chapter.

11. 64. Functionalization of Lignin by Sulfomethylation

    Ali Abdulkhani, Shakiba Bagheri, Jaber Hosseinzadeh, Sahab Hedjazi, Fubao Sun

    Abstract

    Lignin, a significant byproduct of the pulp and paper industry, faces limited applications due to its inherent heterogeneity, low reactivity, and poor water solubility. However, sulfomethylation, a chemical modification process, has proven effective in enhancing lignin’s properties, making it more suitable for various industrial uses. This chapter offers a detailed overview of the sulfomethylation process, including the underlying chemical reactions, process conditions, and its impact on lignin’s molecular structure. By introducing sulfonate and methyl groups into lignin, sulfomethylation significantly improves water solubility, reactivity, and anionic charge density. These modifications broaden lignin’s utility, especially in applications requiring dispersants, adhesives, and binders. Additionally, the chapter explores the diverse industrial applications of sulfomethylated lignin, such as in concrete additives, gypsum board production, wood adhesives, and controlled-release fertilizers. The economic viability and environmental benefits of using sulfomethylated lignin are also discussed, emphasizing its potential to support more sustainable and eco-friendly industrial practices.

12. Backmatter