With the increasing depletion of fossil resources and the growing severity of environmental pollution, the development and utilization of environmentally friendly renewable resources has drawn widespread attention from researchers, policymakers, and industries alike. Among the various renewable energy technologies, microwave pyrolysis of lignocellulosic biomass has emerged as a promising method due to its numerous advantages, including rapid reaction rates, easier process control, and reduced environmental impact. Unlike conventional pyrolysis, which often requires longer reaction times and can produce a significant amount of pollutants, microwave pyrolysis operates under cleaner conditions and has the potential to produce valuable biofuels and chemicals. Despite these advantages, several challenges need to be addressed to fully realize the potential of biomass energy. One major issue is the uneven distribution of products generated during the pyrolysis process, which can negatively affect the economic viability of biomass utilization. Additionally, the low economic value of some pyrolysis products limits the comprehensive and efficient use of lignocellulosic biomass resources. To tackle these challenges, it is essential to better understand the fundamental aspects of lignocellulosic components and their behavior during pyrolysis.

This review systematically introduces the structural characteristics of lignocellulosic biomass, which primarily consists of cellulose, hemicellulose, and lignin. A thorough understanding of the pyrolysis mechanisms of these components is crucial for optimizing the overall process. By comparing microwave pyrolysis to traditional pyrolysis techniques, this review highlights the differences in reaction mechanisms and product yields, providing insights into how microwave irradiation influences thermal decomposition. Furthermore, the review discusses various factors that affect microwave pyrolysis, such as temperature, heating rate, and residence time, emphasizing how these parameters can be manipulated to enhance product yields and improve product quality. A critical aspect of this review is the examination of product distribution resulting from microwave-catalyzed pyrolysis of lignocellulosic biomass. By analyzing how different catalysts influence the pyrolysis process, this work highlights the potential for optimizing product distribution to favor the formation of high-value chemicals. In particular, the review introduces various catalysts, including carbon-based materials, molecular sieves, and metal oxides, that can promote microwave pyrolysis of biomass. These catalysts enhance the efficiency of lignocellulosic biomass conversion and facilitate the selective production of specific high-value chemicals, thereby promoting both the resource efficiency and value-added utilization of lignocellulosic biomass. Finally, this review presents future research directions and technological developments in lignocellulosic pyrolysis, emphasizing the need for innovative approaches that address current limitations, thereby paving the way for more efficient and sustainable biomass energy solutions in the context of a transitioning energy landscape. The integration of advanced catalytic systems and improved process designs will play a vital role in enhancing the economic feasibility and environmental sustainability of biomass-derived fuels and chemicals.