Exploring the Role of Microwave Pretreatment in Enhancing Biomass Pyrolysis Efficiency and Environmental Performance

This review critically evaluates the scientific progress in this field through a bibliometric analysis that maps research evolution, trends, and collaborative networks. In its second part, the article addresses key research questions regarding the technical advantages of microwave pretreatment, the physicochemical transformations induced in biomass, and the associated environmental benefits. Reported findings demonstrate that microwave irradiation promotes hemicellulose depolymerization, reduces cellulose crystallinity, and partially removes lignin, thereby facilitating higher pyrolysis efficiency, increased yields of bio-oil and syngas, and improved biochar properties. From an environmental perspective, MWP contributes to energy savings, mitigating greenhouse gases, and integrating renewable electricity sources into biomass conversion pathways. By consolidating current evidence, this review highlights both the opportunities and challenges of microwave-assisted strategies, providing a foundation for future research and positioning this technology as a promising enabler for sustainable biomass valorization.