Review on Catalytic Cracking of Lignin for the Production of Fuels and High-Value-Added Chemicals: Advances, Challenges, Opportunities, and Outlook

Nowadays and in the future, environment and energy are important issues that people have to consider. In order to achieve energy sustainability and minimize the increase in environmental pressure, researchers have begun to gradually develop new ways of energy access. Biomass resource is a sustainable and efficient mode of energy supply, which has little impact on the environment. Among them, lignin is a rich organic compound in natural plants and is a promising biomass source. According to different forms of energy, different lignin catalytic cracking reactions can be used. This paper systematically summarizes the research progress of lignin catalytic cracking under different energy effects and focuses on the opportunities of lignin catalytic cracking at this stage. The challenges and future research directions of lignin catalytic cracking and directional conversion composite catalytic system are summarized and discussed. On this basis, a critical perspective based on experiment is proposed. It provides a richer catalytic model for the efficient conversion of lignin into fuel and high-value chemicals in the future. In conclusion, this Review offers insights into future directions for catalytic cracking of lignin through synergistic utilization of multiple energy sources.