Lignin Depolymerization for Its Valorization

Recent global shift towards sustainable development and biorefinery-based approach for meeting the energy and other needs of the industries and urban population focuses on lignocellulose. The energy trapped within this structure can be exploited for various applications. Other than the commonly explored cellulose, lignin is the second most abundant polymer and an important part of lignocellulose. The review discusses how lignin can be used as a powerhouse of bioenergy along with other biochemicals of industrial application. Since lignin depolymerization is a major hindrance for exploiting them as well as other parts of lignocellulose, the various methods to achieve this are discussed here. The review discusses the composition of lignin in various sources, with focus on the waste materials, and associated complexity for selection of various pre-treatment process for lignin depolymerization. The review explores the various pre-treatment processes such as physical, chemicals, physio chemicals, lignin first, and biological treatment along with new advancements in the pre-treatment technology. In-depth discussion of the limitation of the presently applied valorization techniques along with the suggestions to overcome them has been provided. Also, the future prospects of lignin for generation of various value-added products such as fertilizers, pesticides, plant growth promoter, pharmaceutical, and biofuel production are discussed.

Automated summary

Recent global shift towards sustainable development focuses on lignocellulose as a source of bioenergy and biochemicals. This review discusses the use of lignin, the second most abundant polymer in lignocellulose, as a powerhouse for bioenergy generation and industrial applications. Various methods for lignin depolymerization are discussed, along with the composition of lignin in different sources and the complexity of pre-treatment processes. The review also explores the limitations of current valorization techniques and suggests ways to overcome them, as well as future prospects for lignin in the production of value-added products.