Direct Processing of Biomass Using High-Power Blue Laser

Inventing new approaches to transform abundant plant matter swiftly into valuable products is crucial for sustainable development. Here, the first direct and continuous conversion of lignocellulosic solid mass into synthetic biogas is reported using blue laser irradiation at multi-kW/cm² intensity. It is demonstrated that the on-demand generation of a biogas jet, achieving rapid (in milliseconds) and continuous production of a flame jet 300 times larger than the mm-size laser focus. Remarkably, biogas production occurs exclusively during laser illumination, without triggering bulk combustion, and achieves up to 92% mass conversion. A comprehensive phase diagram of the blue light–wood interaction highlighting three distinct regimes accessed is reported by varying laser parameters and provide mechanistic insight using photothermal simulations. Furthermore, the molecular composition of the synthetic biogas is identified and is shown to result from the photothermal decomposition of lignocellulose molecules. The biogas, collected independently, is shown to produce a sustained flame. Successful bio-gasification of 16 kinds of woods proves that the all-optical approach is solvent-free, non-contact, scalable, and universally applicable.